LCOV - code coverage report
Current view: top level - src - txgraph.cpp (source / functions) Coverage Total Hit
Test: total_coverage.info Lines: 41.1 % 1573 647
Test Date: 2025-10-19 05:09:57 Functions: 36.1 % 144 52
Branches: 37.2 % 1494 556

             Branch data     Line data    Source code
       1                 :             : // Copyright (c) The Bitcoin Core developers
       2                 :             : // Distributed under the MIT software license, see the accompanying
       3                 :             : // file COPYING or http://www.opensource.org/licenses/mit-license.php.
       4                 :             : 
       5                 :             : #include <txgraph.h>
       6                 :             : 
       7                 :             : #include <cluster_linearize.h>
       8                 :             : #include <random.h>
       9                 :             : #include <util/bitset.h>
      10                 :             : #include <util/check.h>
      11                 :             : #include <util/feefrac.h>
      12                 :             : #include <util/vector.h>
      13                 :             : 
      14                 :             : #include <compare>
      15                 :             : #include <functional>
      16                 :             : #include <memory>
      17                 :             : #include <set>
      18                 :             : #include <span>
      19                 :             : #include <unordered_set>
      20                 :             : #include <utility>
      21                 :             : 
      22                 :             : namespace {
      23                 :             : 
      24                 :             : using namespace cluster_linearize;
      25                 :             : 
      26                 :             : /** The maximum number of levels a TxGraph can have (0 = main, 1 = staging). */
      27                 :             : static constexpr int MAX_LEVELS{2};
      28                 :             : 
      29                 :             : // Forward declare the TxGraph implementation class.
      30                 :             : class TxGraphImpl;
      31                 :             : 
      32                 :             : /** Position of a DepGraphIndex within a Cluster::m_linearization. */
      33                 :             : using LinearizationIndex = uint32_t;
      34                 :             : /** Position of a Cluster within TxGraphImpl::ClusterSet::m_clusters. */
      35                 :             : using ClusterSetIndex = uint32_t;
      36                 :             : 
      37                 :             : /** Quality levels for cached cluster linearizations. */
      38                 :             : enum class QualityLevel
      39                 :             : {
      40                 :             :     /** This is a singleton cluster consisting of a transaction that individually exceeds the
      41                 :             :      *  cluster size limit. It cannot be merged with anything. */
      42                 :             :     OVERSIZED_SINGLETON,
      43                 :             :     /** This cluster may have multiple disconnected components, which are all NEEDS_RELINEARIZE. */
      44                 :             :     NEEDS_SPLIT,
      45                 :             :     /** This cluster may have multiple disconnected components, which are all ACCEPTABLE. */
      46                 :             :     NEEDS_SPLIT_ACCEPTABLE,
      47                 :             :     /** This cluster has undergone changes that warrant re-linearization. */
      48                 :             :     NEEDS_RELINEARIZE,
      49                 :             :     /** The minimal level of linearization has been performed, but it is not known to be optimal. */
      50                 :             :     ACCEPTABLE,
      51                 :             :     /** The linearization is known to be optimal. */
      52                 :             :     OPTIMAL,
      53                 :             :     /** This cluster is not registered in any ClusterSet::m_clusters.
      54                 :             :      *  This must be the last entry in QualityLevel as ClusterSet::m_clusters is sized using it. */
      55                 :             :     NONE,
      56                 :             : };
      57                 :             : 
      58                 :             : /** Information about a transaction inside TxGraphImpl::Trim. */
      59                 :       64217 : struct TrimTxData
      60                 :             : {
      61                 :             :     // Fields populated by Cluster::AppendTrimData(). These are immutable after TrimTxData
      62                 :             :     // construction.
      63                 :             :     /** Chunk feerate for this transaction. */
      64                 :             :     FeePerWeight m_chunk_feerate;
      65                 :             :     /** GraphIndex of the transaction. */
      66                 :             :     TxGraph::GraphIndex m_index;
      67                 :             :     /** Size of the transaction. */
      68                 :             :     uint32_t m_tx_size;
      69                 :             : 
      70                 :             :     // Fields only used internally by TxGraphImpl::Trim():
      71                 :             :     /** Number of unmet dependencies this transaction has. -1 if the transaction is included. */
      72                 :             :     uint32_t m_deps_left;
      73                 :             :     /** Number of dependencies that apply to this transaction as child. */
      74                 :             :     uint32_t m_parent_count;
      75                 :             :     /** Where in deps_by_child those dependencies begin. */
      76                 :             :     uint32_t m_parent_offset;
      77                 :             :     /** Number of dependencies that apply to this transaction as parent. */
      78                 :             :     uint32_t m_children_count;
      79                 :             :     /** Where in deps_by_parent those dependencies begin. */
      80                 :             :     uint32_t m_children_offset;
      81                 :             : 
      82                 :             :     // Fields only used internally by TxGraphImpl::Trim()'s union-find implementation, and only for
      83                 :             :     // transactions that are definitely included or definitely rejected.
      84                 :             :     //
      85                 :             :     // As transactions get processed, they get organized into trees which form partitions
      86                 :             :     // representing the would-be clusters up to that point. The root of each tree is a
      87                 :             :     // representative for that partition. See
      88                 :             :     // https://en.wikipedia.org/wiki/Disjoint-set_data_structure.
      89                 :             :     //
      90                 :             :     /** Pointer to another TrimTxData, towards the root of the tree. If this is a root, m_uf_parent
      91                 :             :      *  is equal to this itself. */
      92                 :             :     TrimTxData* m_uf_parent;
      93                 :             :     /** If this is a root, the total number of transactions in the partition. */
      94                 :             :     uint32_t m_uf_count;
      95                 :             :     /** If this is a root, the total size of transactions in the partition. */
      96                 :             :     uint64_t m_uf_size;
      97                 :             : };
      98                 :             : 
      99                 :             : /** A grouping of connected transactions inside a TxGraphImpl::ClusterSet. */
     100                 :             : class Cluster
     101                 :             : {
     102                 :             :     friend class TxGraphImpl;
     103                 :             :     friend class BlockBuilderImpl;
     104                 :             : 
     105                 :             : protected:
     106                 :             :     using GraphIndex = TxGraph::GraphIndex;
     107                 :             :     using SetType = BitSet<MAX_CLUSTER_COUNT_LIMIT>;
     108                 :             :     /** The quality level of m_linearization. */
     109                 :             :     QualityLevel m_quality{QualityLevel::NONE};
     110                 :             :     /** Which position this Cluster has in TxGraphImpl::ClusterSet::m_clusters[m_quality]. */
     111                 :             :     ClusterSetIndex m_setindex{ClusterSetIndex(-1)};
     112                 :             :     /** Sequence number for this Cluster (for tie-breaking comparison between equal-chunk-feerate
     113                 :             :         transactions in distinct clusters). */
     114                 :             :     uint64_t m_sequence;
     115                 :             : 
     116                 :       64311 :     explicit Cluster(uint64_t sequence) noexcept : m_sequence(sequence) {}
     117                 :             : 
     118                 :             : public:
     119                 :             :     // Provide virtual destructor, for safe polymorphic usage inside std::unique_ptr.
     120                 :           0 :     virtual ~Cluster() = default;
     121                 :             : 
     122                 :             :     // Cannot move or copy (would invalidate Cluster* in Locator and ClusterSet). */
     123                 :             :     Cluster(const Cluster&) = delete;
     124                 :             :     Cluster& operator=(const Cluster&) = delete;
     125                 :             :     Cluster(Cluster&&) = delete;
     126                 :             :     Cluster& operator=(Cluster&&) = delete;
     127                 :             : 
     128                 :             :     // Generic helper functions.
     129                 :             : 
     130                 :             :     /** Whether the linearization of this Cluster can be exposed. */
     131                 :      257122 :     bool IsAcceptable(bool after_split = false) const noexcept
     132                 :             :     {
     133         [ #  # ]:           0 :         return m_quality == QualityLevel::ACCEPTABLE || m_quality == QualityLevel::OPTIMAL ||
     134   [ #  #  #  # ]:           0 :                (after_split && m_quality == QualityLevel::NEEDS_SPLIT_ACCEPTABLE);
     135                 :             :     }
     136                 :             :     /** Whether the linearization of this Cluster is optimal. */
     137                 :      192822 :     bool IsOptimal() const noexcept
     138                 :             :     {
     139                 :      192822 :         return m_quality == QualityLevel::OPTIMAL;
     140                 :             :     }
     141                 :             :     /** Whether this cluster is oversized. Note that no changes that can cause oversizedness are
     142                 :             :      *  ever applied, so the only way a materialized Cluster object can be oversized is by being
     143                 :             :      *  an individually oversized transaction singleton. */
     144                 :      385644 :     bool IsOversized() const noexcept { return m_quality == QualityLevel::OVERSIZED_SINGLETON; }
     145                 :             :     /** Whether this cluster requires splitting. */
     146                 :      192833 :     bool NeedsSplitting() const noexcept
     147                 :             :     {
     148                 :      192833 :         return m_quality == QualityLevel::NEEDS_SPLIT ||
     149                 :             :                m_quality == QualityLevel::NEEDS_SPLIT_ACCEPTABLE;
     150                 :             :     }
     151                 :             : 
     152                 :             :     /** Get the smallest number of transactions this Cluster is intended for. */
     153                 :             :     virtual DepGraphIndex GetMinIntendedTxCount() const noexcept = 0;
     154                 :             :     /** Get the maximum number of transactions this Cluster supports. */
     155                 :             :     virtual DepGraphIndex GetMaxTxCount() const noexcept = 0;
     156                 :             :     /** Total memory usage currently for this Cluster, including all its dynamic memory, plus Cluster
     157                 :             :      *  structure itself, and ClusterSet::m_clusters entry. */
     158                 :             :     virtual size_t TotalMemoryUsage() const noexcept = 0;
     159                 :             :     /** Determine the range of DepGraphIndexes used by this Cluster. */
     160                 :             :     virtual DepGraphIndex GetDepGraphIndexRange() const noexcept = 0;
     161                 :             :     /** Get the number of transactions in this Cluster. */
     162                 :             :     virtual LinearizationIndex GetTxCount() const noexcept = 0;
     163                 :             :     /** Get the total size of the transactions in this Cluster. */
     164                 :             :     virtual uint64_t GetTotalTxSize() const noexcept = 0;
     165                 :             :     /** Given a DepGraphIndex into this Cluster, find the corresponding GraphIndex. */
     166                 :             :     virtual GraphIndex GetClusterEntry(DepGraphIndex index) const noexcept = 0;
     167                 :             :     /** Append a transaction with given GraphIndex at the end of this Cluster and its
     168                 :             :      *  linearization. Return the DepGraphIndex it was placed at. */
     169                 :             :     virtual DepGraphIndex AppendTransaction(GraphIndex graph_idx, FeePerWeight feerate) noexcept = 0;
     170                 :             :     /** Add dependencies to a given child in this cluster. */
     171                 :             :     virtual void AddDependencies(SetType parents, DepGraphIndex child) noexcept = 0;
     172                 :             :     /** Invoke visitor_fn for each transaction in the cluster, in linearization order, then wipe this Cluster. */
     173                 :             :     virtual void ExtractTransactions(const std::function<void (DepGraphIndex, GraphIndex, FeePerWeight, SetType)>& visit_fn) noexcept = 0;
     174                 :             :     /** Figure out what level this Cluster exists at in the graph. In most cases this is known by
     175                 :             :      *  the caller already (see all "int level" arguments below), but not always. */
     176                 :             :     virtual int GetLevel(const TxGraphImpl& graph) const noexcept = 0;
     177                 :             :     /** Only called by TxGraphImpl::SwapIndexes. */
     178                 :             :     virtual void UpdateMapping(DepGraphIndex cluster_idx, GraphIndex graph_idx) noexcept = 0;
     179                 :             :     /** Push changes to Cluster and its linearization to the TxGraphImpl Entry objects. */
     180                 :             :     virtual void Updated(TxGraphImpl& graph, int level) noexcept = 0;
     181                 :             :     /** Create a copy of this Cluster in staging, returning a pointer to it (used by PullIn). */
     182                 :             :     virtual Cluster* CopyToStaging(TxGraphImpl& graph) const noexcept = 0;
     183                 :             :     /** Get the list of Clusters in main that conflict with this one (which is assumed to be in staging). */
     184                 :             :     virtual void GetConflicts(const TxGraphImpl& graph, std::vector<Cluster*>& out) const noexcept = 0;
     185                 :             :     /** Mark all the Entry objects belonging to this staging Cluster as missing. The Cluster must be
     186                 :             :      *  deleted immediately after. */
     187                 :             :     virtual void MakeStagingTransactionsMissing(TxGraphImpl& graph) noexcept = 0;
     188                 :             :     /** Remove all transactions from a (non-empty) Cluster. */
     189                 :             :     virtual void Clear(TxGraphImpl& graph, int level) noexcept = 0;
     190                 :             :     /** Change a Cluster's level from 1 (staging) to 0 (main). */
     191                 :             :     virtual void MoveToMain(TxGraphImpl& graph) noexcept = 0;
     192                 :             :     /** Minimize this Cluster's memory usage. */
     193                 :             :     virtual void Compact() noexcept = 0;
     194                 :             : 
     195                 :             :     // Functions that implement the Cluster-specific side of internal TxGraphImpl mutations.
     196                 :             : 
     197                 :             :     /** Apply all removals from the front of to_remove that apply to this Cluster, popping them
     198                 :             :      *  off. There must be at least one such entry. */
     199                 :             :     virtual void ApplyRemovals(TxGraphImpl& graph, int level, std::span<GraphIndex>& to_remove) noexcept = 0;
     200                 :             :     /** Split this cluster (must have a NEEDS_SPLIT* quality). Returns whether to delete this
     201                 :             :      *  Cluster afterwards. */
     202                 :             :     [[nodiscard]] virtual bool Split(TxGraphImpl& graph, int level) noexcept = 0;
     203                 :             :     /** Move all transactions from cluster to *this (as separate components). */
     204                 :             :     virtual void Merge(TxGraphImpl& graph, int level, Cluster& cluster) noexcept = 0;
     205                 :             :     /** Given a span of (parent, child) pairs that all belong to this Cluster, apply them. */
     206                 :             :     virtual void ApplyDependencies(TxGraphImpl& graph, int level, std::span<std::pair<GraphIndex, GraphIndex>> to_apply) noexcept = 0;
     207                 :             :     /** Improve the linearization of this Cluster. Returns how much work was performed and whether
     208                 :             :      *  the Cluster's QualityLevel improved as a result. */
     209                 :             :     virtual std::pair<uint64_t, bool> Relinearize(TxGraphImpl& graph, int level, uint64_t max_iters) noexcept = 0;
     210                 :             :     /** For every chunk in the cluster, append its FeeFrac to ret. */
     211                 :             :     virtual void AppendChunkFeerates(std::vector<FeeFrac>& ret) const noexcept = 0;
     212                 :             :     /** Add a TrimTxData entry (filling m_chunk_feerate, m_index, m_tx_size) for every
     213                 :             :      *  transaction in the Cluster to ret. Implicit dependencies between consecutive transactions
     214                 :             :      *  in the linearization are added to deps. Return the Cluster's total transaction size. */
     215                 :             :     virtual uint64_t AppendTrimData(std::vector<TrimTxData>& ret, std::vector<std::pair<GraphIndex, GraphIndex>>& deps) const noexcept = 0;
     216                 :             : 
     217                 :             :     // Functions that implement the Cluster-specific side of public TxGraph functions.
     218                 :             : 
     219                 :             :     /** Process elements from the front of args that apply to this cluster, and append Refs for the
     220                 :             :      *  union of their ancestors to output. */
     221                 :             :     virtual void GetAncestorRefs(const TxGraphImpl& graph, std::span<std::pair<Cluster*, DepGraphIndex>>& args, std::vector<TxGraph::Ref*>& output) noexcept = 0;
     222                 :             :     /** Process elements from the front of args that apply to this cluster, and append Refs for the
     223                 :             :      *  union of their descendants to output. */
     224                 :             :     virtual void GetDescendantRefs(const TxGraphImpl& graph, std::span<std::pair<Cluster*, DepGraphIndex>>& args, std::vector<TxGraph::Ref*>& output) noexcept = 0;
     225                 :             :     /** Populate range with refs for the transactions in this Cluster's linearization, from
     226                 :             :      *  position start_pos until start_pos+range.size()-1, inclusive. Returns whether that
     227                 :             :      *  range includes the last transaction in the linearization. */
     228                 :             :     virtual bool GetClusterRefs(TxGraphImpl& graph, std::span<TxGraph::Ref*> range, LinearizationIndex start_pos) noexcept = 0;
     229                 :             :     /** Get the individual transaction feerate of a Cluster element. */
     230                 :             :     virtual FeePerWeight GetIndividualFeerate(DepGraphIndex idx) noexcept = 0;
     231                 :             :     /** Modify the fee of a Cluster element. */
     232                 :             :     virtual void SetFee(TxGraphImpl& graph, int level, DepGraphIndex idx, int64_t fee) noexcept = 0;
     233                 :             : 
     234                 :             :     // Debugging functions.
     235                 :             : 
     236                 :             :     virtual void SanityCheck(const TxGraphImpl& graph, int level) const = 0;
     237                 :             : };
     238                 :             : 
     239                 :             : /** An implementation of Cluster that uses a DepGraph and vectors, to support arbitrary numbers of
     240                 :             :  *  transactions up to MAX_CLUSTER_COUNT_LIMIT. */
     241                 :             : class GenericClusterImpl final : public Cluster
     242                 :             : {
     243                 :             :     friend class TxGraphImpl;
     244                 :             :     /** The DepGraph for this cluster, holding all feerates, and ancestors/descendants. */
     245                 :             :     DepGraph<SetType> m_depgraph;
     246                 :             :     /** m_mapping[i] gives the GraphIndex for the position i transaction in m_depgraph. Values for
     247                 :             :      *  positions i that do not exist in m_depgraph shouldn't ever be accessed and thus don't
     248                 :             :      *  matter. m_mapping.size() equals m_depgraph.PositionRange(). */
     249                 :             :     std::vector<GraphIndex> m_mapping;
     250                 :             :     /** The current linearization of the cluster. m_linearization.size() equals
     251                 :             :      *  m_depgraph.TxCount(). This is always kept topological. */
     252                 :             :     std::vector<DepGraphIndex> m_linearization;
     253                 :             : 
     254                 :             : public:
     255                 :             :     /** The smallest number of transactions this Cluster implementation is intended for. */
     256                 :             :     static constexpr DepGraphIndex MIN_INTENDED_TX_COUNT{2};
     257                 :             :     /** The largest number of transactions this Cluster implementation supports. */
     258                 :             :     static constexpr DepGraphIndex MAX_TX_COUNT{SetType::Size()};
     259                 :             : 
     260                 :             :     GenericClusterImpl() noexcept = delete;
     261                 :             :     /** Construct an empty GenericClusterImpl. */
     262                 :             :     explicit GenericClusterImpl(uint64_t sequence) noexcept;
     263                 :             : 
     264                 :             :     size_t TotalMemoryUsage() const noexcept final;
     265                 :           0 :     constexpr DepGraphIndex GetMinIntendedTxCount() const noexcept final { return MIN_INTENDED_TX_COUNT; }
     266                 :           0 :     constexpr DepGraphIndex GetMaxTxCount() const noexcept final { return MAX_TX_COUNT; }
     267         [ #  # ]:           0 :     DepGraphIndex GetDepGraphIndexRange() const noexcept final { return m_depgraph.PositionRange(); }
     268         [ #  # ]:           0 :     LinearizationIndex GetTxCount() const noexcept final { return m_linearization.size(); }
     269                 :             :     uint64_t GetTotalTxSize() const noexcept final;
     270                 :           0 :     GraphIndex GetClusterEntry(DepGraphIndex index) const noexcept final { return m_mapping[index]; }
     271                 :             :     DepGraphIndex AppendTransaction(GraphIndex graph_idx, FeePerWeight feerate) noexcept final;
     272                 :             :     void AddDependencies(SetType parents, DepGraphIndex child) noexcept final;
     273                 :             :     void ExtractTransactions(const std::function<void (DepGraphIndex, GraphIndex, FeePerWeight, SetType)>& visit_fn) noexcept final;
     274                 :             :     int GetLevel(const TxGraphImpl& graph) const noexcept final;
     275                 :           0 :     void UpdateMapping(DepGraphIndex cluster_idx, GraphIndex graph_idx) noexcept final { m_mapping[cluster_idx] = graph_idx; }
     276                 :             :     void Updated(TxGraphImpl& graph, int level) noexcept final;
     277                 :             :     Cluster* CopyToStaging(TxGraphImpl& graph) const noexcept final;
     278                 :             :     void GetConflicts(const TxGraphImpl& graph, std::vector<Cluster*>& out) const noexcept final;
     279                 :             :     void MakeStagingTransactionsMissing(TxGraphImpl& graph) noexcept final;
     280                 :             :     void Clear(TxGraphImpl& graph, int level) noexcept final;
     281                 :             :     void MoveToMain(TxGraphImpl& graph) noexcept final;
     282                 :             :     void Compact() noexcept final;
     283                 :             :     void ApplyRemovals(TxGraphImpl& graph, int level, std::span<GraphIndex>& to_remove) noexcept final;
     284                 :             :     [[nodiscard]] bool Split(TxGraphImpl& graph, int level) noexcept final;
     285                 :             :     void Merge(TxGraphImpl& graph, int level, Cluster& cluster) noexcept final;
     286                 :             :     void ApplyDependencies(TxGraphImpl& graph, int level, std::span<std::pair<GraphIndex, GraphIndex>> to_apply) noexcept final;
     287                 :             :     std::pair<uint64_t, bool> Relinearize(TxGraphImpl& graph, int level, uint64_t max_iters) noexcept final;
     288                 :             :     void AppendChunkFeerates(std::vector<FeeFrac>& ret) const noexcept final;
     289                 :             :     uint64_t AppendTrimData(std::vector<TrimTxData>& ret, std::vector<std::pair<GraphIndex, GraphIndex>>& deps) const noexcept final;
     290                 :             :     void GetAncestorRefs(const TxGraphImpl& graph, std::span<std::pair<Cluster*, DepGraphIndex>>& args, std::vector<TxGraph::Ref*>& output) noexcept final;
     291                 :             :     void GetDescendantRefs(const TxGraphImpl& graph, std::span<std::pair<Cluster*, DepGraphIndex>>& args, std::vector<TxGraph::Ref*>& output) noexcept final;
     292                 :             :     bool GetClusterRefs(TxGraphImpl& graph, std::span<TxGraph::Ref*> range, LinearizationIndex start_pos) noexcept final;
     293                 :             :     FeePerWeight GetIndividualFeerate(DepGraphIndex idx) noexcept final;
     294                 :             :     void SetFee(TxGraphImpl& graph, int level, DepGraphIndex idx, int64_t fee) noexcept final;
     295                 :             :     void SanityCheck(const TxGraphImpl& graph, int level) const final;
     296                 :             : };
     297                 :             : 
     298                 :             : /** An implementation of Cluster that only supports 1 transaction. */
     299                 :           0 : class SingletonClusterImpl final : public Cluster
     300                 :             : {
     301                 :             :     friend class TxGraphImpl;
     302                 :             : 
     303                 :             :     /** The feerate of the (singular) transaction in this Cluster. */
     304                 :             :     FeePerWeight m_feerate;
     305                 :             :     /** Constant to indicate that this Cluster is empty. */
     306                 :             :     static constexpr auto NO_GRAPH_INDEX = GraphIndex(-1);
     307                 :             :     /** The GraphIndex of the transaction. NO_GRAPH_INDEX if this Cluster is empty. */
     308                 :             :     GraphIndex m_graph_index = NO_GRAPH_INDEX;
     309                 :             : 
     310                 :             : public:
     311                 :             :     /** The smallest number of transactions this Cluster implementation is intended for. */
     312                 :             :     static constexpr DepGraphIndex MIN_INTENDED_TX_COUNT{1};
     313                 :             :     /** The largest number of transactions this Cluster implementation supports. */
     314                 :             :     static constexpr DepGraphIndex MAX_TX_COUNT{1};
     315                 :             : 
     316                 :             :     SingletonClusterImpl() noexcept = delete;
     317                 :             :     /** Construct an empty SingletonClusterImpl. */
     318                 :       64311 :     explicit SingletonClusterImpl(uint64_t sequence) noexcept : Cluster(sequence) {}
     319                 :             : 
     320                 :             :     size_t TotalMemoryUsage() const noexcept final;
     321                 :      192811 :     constexpr DepGraphIndex GetMinIntendedTxCount() const noexcept final { return MIN_INTENDED_TX_COUNT; }
     322                 :      192822 :     constexpr DepGraphIndex GetMaxTxCount() const noexcept final { return MAX_TX_COUNT; }
     323                 :     1927516 :     LinearizationIndex GetTxCount() const noexcept final { return m_graph_index != NO_GRAPH_INDEX; }
     324                 :           0 :     DepGraphIndex GetDepGraphIndexRange() const noexcept final { return GetTxCount(); }
     325         [ +  + ]:      321027 :     uint64_t GetTotalTxSize() const noexcept final { return GetTxCount() ? m_feerate.size : 0; }
     326                 :      192817 :     GraphIndex GetClusterEntry(DepGraphIndex index) const noexcept final { Assume(index == 0); Assume(GetTxCount()); return m_graph_index; }
     327                 :             :     DepGraphIndex AppendTransaction(GraphIndex graph_idx, FeePerWeight feerate) noexcept final;
     328                 :             :     void AddDependencies(SetType parents, DepGraphIndex child) noexcept final;
     329                 :             :     void ExtractTransactions(const std::function<void (DepGraphIndex, GraphIndex, FeePerWeight, SetType)>& visit_fn) noexcept final;
     330                 :             :     int GetLevel(const TxGraphImpl& graph) const noexcept final;
     331                 :           1 :     void UpdateMapping(DepGraphIndex cluster_idx, GraphIndex graph_idx) noexcept final { Assume(cluster_idx == 0); m_graph_index = graph_idx; }
     332                 :             :     void Updated(TxGraphImpl& graph, int level) noexcept final;
     333                 :             :     Cluster* CopyToStaging(TxGraphImpl& graph) const noexcept final;
     334                 :             :     void GetConflicts(const TxGraphImpl& graph, std::vector<Cluster*>& out) const noexcept final;
     335                 :             :     void MakeStagingTransactionsMissing(TxGraphImpl& graph) noexcept final;
     336                 :             :     void Clear(TxGraphImpl& graph, int level) noexcept final;
     337                 :             :     void MoveToMain(TxGraphImpl& graph) noexcept final;
     338                 :             :     void Compact() noexcept final;
     339                 :             :     void ApplyRemovals(TxGraphImpl& graph, int level, std::span<GraphIndex>& to_remove) noexcept final;
     340                 :             :     [[nodiscard]] bool Split(TxGraphImpl& graph, int level) noexcept final;
     341                 :             :     void Merge(TxGraphImpl& graph, int level, Cluster& cluster) noexcept final;
     342                 :             :     void ApplyDependencies(TxGraphImpl& graph, int level, std::span<std::pair<GraphIndex, GraphIndex>> to_apply) noexcept final;
     343                 :             :     std::pair<uint64_t, bool> Relinearize(TxGraphImpl& graph, int level, uint64_t max_iters) noexcept final;
     344                 :             :     void AppendChunkFeerates(std::vector<FeeFrac>& ret) const noexcept final;
     345                 :             :     uint64_t AppendTrimData(std::vector<TrimTxData>& ret, std::vector<std::pair<GraphIndex, GraphIndex>>& deps) const noexcept final;
     346                 :             :     void GetAncestorRefs(const TxGraphImpl& graph, std::span<std::pair<Cluster*, DepGraphIndex>>& args, std::vector<TxGraph::Ref*>& output) noexcept final;
     347                 :             :     void GetDescendantRefs(const TxGraphImpl& graph, std::span<std::pair<Cluster*, DepGraphIndex>>& args, std::vector<TxGraph::Ref*>& output) noexcept final;
     348                 :             :     bool GetClusterRefs(TxGraphImpl& graph, std::span<TxGraph::Ref*> range, LinearizationIndex start_pos) noexcept final;
     349                 :             :     FeePerWeight GetIndividualFeerate(DepGraphIndex idx) noexcept final;
     350                 :             :     void SetFee(TxGraphImpl& graph, int level, DepGraphIndex idx, int64_t fee) noexcept final;
     351                 :             :     void SanityCheck(const TxGraphImpl& graph, int level) const final;
     352                 :             : };
     353                 :             : 
     354                 :             : /** The transaction graph, including staged changes.
     355                 :             :  *
     356                 :             :  * The overall design of the data structure consists of 3 interlinked representations:
     357                 :             :  * - The transactions (held as a vector of TxGraphImpl::Entry inside TxGraphImpl).
     358                 :             :  * - The clusters (Cluster objects in per-quality vectors inside TxGraphImpl::ClusterSet).
     359                 :             :  * - The Refs (TxGraph::Ref objects, held externally by users of the TxGraph class)
     360                 :             :  *
     361                 :             :  * The Clusters are kept in one or two ClusterSet objects, one for the "main" graph, and one for
     362                 :             :  * the proposed changes ("staging"). If a transaction occurs in both, they share the same Entry,
     363                 :             :  * but there will be a separate Cluster per graph.
     364                 :             :  *
     365                 :             :  * Clusters and Refs contain the index of the Entry objects they refer to, and the Entry objects
     366                 :             :  * refer back to the Clusters and Refs the corresponding transaction is contained in.
     367                 :             :  *
     368                 :             :  * While redundant, this permits moving all of them independently, without invalidating things
     369                 :             :  * or costly iteration to fix up everything:
     370                 :             :  * - Entry objects can be moved to fill holes left by removed transactions in the Entry vector
     371                 :             :  *   (see TxGraphImpl::Compact).
     372                 :             :  * - Clusters can be rewritten continuously (removals can cause them to split, new dependencies
     373                 :             :  *   can cause them to be merged).
     374                 :             :  * - Ref objects can be held outside the class, while permitting them to be moved around, and
     375                 :             :  *   inherited from.
     376                 :             :  */
     377                 :             : class TxGraphImpl final : public TxGraph
     378                 :             : {
     379                 :             :     friend class Cluster;
     380                 :             :     friend class SingletonClusterImpl;
     381                 :             :     friend class GenericClusterImpl;
     382                 :             :     friend class BlockBuilderImpl;
     383                 :             : private:
     384                 :             :     /** Internal RNG. */
     385                 :             :     FastRandomContext m_rng;
     386                 :             :     /** This TxGraphImpl's maximum cluster count limit. */
     387                 :             :     const DepGraphIndex m_max_cluster_count;
     388                 :             :     /** This TxGraphImpl's maximum cluster size limit. */
     389                 :             :     const uint64_t m_max_cluster_size;
     390                 :             :     /** The number of linearization improvement steps needed per cluster to be considered
     391                 :             :      *  acceptable. */
     392                 :             :     const uint64_t m_acceptable_iters;
     393                 :             : 
     394                 :             :     /** Information about one group of Clusters to be merged. */
     395                 :             :     struct GroupEntry
     396                 :             :     {
     397                 :             :         /** Where the clusters to be merged start in m_group_clusters. */
     398                 :             :         uint32_t m_cluster_offset;
     399                 :             :         /** How many clusters to merge. */
     400                 :             :         uint32_t m_cluster_count;
     401                 :             :         /** Where the dependencies for this cluster group in m_deps_to_add start. */
     402                 :             :         uint32_t m_deps_offset;
     403                 :             :         /** How many dependencies to add. */
     404                 :             :         uint32_t m_deps_count;
     405                 :             :     };
     406                 :             : 
     407                 :             :     /** Information about all groups of Clusters to be merged. */
     408                 :          14 :     struct GroupData
     409                 :             :     {
     410                 :             :         /** The groups of Clusters to be merged. */
     411                 :             :         std::vector<GroupEntry> m_groups;
     412                 :             :         /** Which clusters are to be merged. GroupEntry::m_cluster_offset indexes into this. */
     413                 :             :         std::vector<Cluster*> m_group_clusters;
     414                 :             :     };
     415                 :             : 
     416                 :             :     /** The collection of all Clusters in main or staged. */
     417                 :             :     struct ClusterSet
     418                 :             :     {
     419                 :             :         /** The vectors of clusters, one vector per quality level. ClusterSetIndex indexes into each. */
     420                 :             :         std::array<std::vector<std::unique_ptr<Cluster>>, int(QualityLevel::NONE)> m_clusters;
     421                 :             :         /** Which removals have yet to be applied. */
     422                 :             :         std::vector<GraphIndex> m_to_remove;
     423                 :             :         /** Which dependencies are to be added ((parent,child) pairs). GroupData::m_deps_offset indexes
     424                 :             :          *  into this. */
     425                 :             :         std::vector<std::pair<GraphIndex, GraphIndex>> m_deps_to_add;
     426                 :             :         /** Information about the merges to be performed, if known. */
     427                 :             :         std::optional<GroupData> m_group_data = GroupData{};
     428                 :             :         /** Which entries were removed in this ClusterSet (so they can be wiped on abort). This
     429                 :             :          *  includes all entries which have an (R) removed locator at this level (staging only),
     430                 :             :          *  plus optionally any transaction in m_unlinked. */
     431                 :             :         std::vector<GraphIndex> m_removed;
     432                 :             :         /** Total number of transactions in this graph (sum of all transaction counts in all
     433                 :             :          *  Clusters, and for staging also those inherited from the main ClusterSet). */
     434                 :             :         GraphIndex m_txcount{0};
     435                 :             :         /** Total number of individually oversized transactions in the graph. */
     436                 :             :         GraphIndex m_txcount_oversized{0};
     437                 :             :         /** Whether this graph is oversized (if known). */
     438                 :             :         std::optional<bool> m_oversized{false};
     439                 :             :         /** The combined TotalMemoryUsage of all clusters in this level (only Clusters that
     440                 :             :          *  are materialized; in staging, implicit Clusters from main are not counted), */
     441                 :             :         size_t m_cluster_usage{0};
     442                 :             : 
     443                 :           4 :         ClusterSet() noexcept = default;
     444                 :             :     };
     445                 :             : 
     446                 :             :     /** The main ClusterSet. */
     447                 :             :     ClusterSet m_main_clusterset;
     448                 :             :     /** The staging ClusterSet, if any. */
     449                 :             :     std::optional<ClusterSet> m_staging_clusterset;
     450                 :             :     /** Next sequence number to assign to created Clusters. */
     451                 :             :     uint64_t m_next_sequence_counter{0};
     452                 :             : 
     453                 :             :     /** Information about a chunk in the main graph. */
     454                 :             :     struct ChunkData
     455                 :             :     {
     456                 :             :         /** The Entry which is the last transaction of the chunk. */
     457                 :             :         mutable GraphIndex m_graph_index;
     458                 :             :         /** How many transactions the chunk contains (-1 = singleton tail of cluster). */
     459                 :             :         LinearizationIndex m_chunk_count;
     460                 :             : 
     461                 :       64305 :         ChunkData(GraphIndex graph_index, LinearizationIndex chunk_count) noexcept :
     462                 :       64305 :             m_graph_index{graph_index}, m_chunk_count{chunk_count} {}
     463                 :             :     };
     464                 :             : 
     465                 :             :     /** Compare two Cluster* by their m_sequence value (while supporting nullptr). */
     466                 :          82 :     static std::strong_ordering CompareClusters(Cluster* a, Cluster* b) noexcept
     467                 :             :     {
     468                 :             :         // The nullptr pointer compares before everything else.
     469         [ -  + ]:          82 :         if (a == nullptr || b == nullptr) {
     470   [ #  #  #  # ]:           0 :             return (a != nullptr) <=> (b != nullptr);
     471                 :             :         }
     472                 :             :         // If neither pointer is nullptr, compare the Clusters' sequence numbers.
     473                 :          82 :         Assume(a == b || a->m_sequence != b->m_sequence);
     474   [ +  -  +  + ]:          82 :         return a->m_sequence <=> b->m_sequence;
     475                 :             :     }
     476                 :             : 
     477                 :             :     /** Compare two entries (which must both exist within the main graph). */
     478                 :     1081681 :     std::strong_ordering CompareMainTransactions(GraphIndex a, GraphIndex b) const noexcept
     479                 :             :     {
     480   [ -  +  +  - ]:     1081681 :         Assume(a < m_entries.size() && b < m_entries.size());
     481         [ +  + ]:     1081681 :         const auto& entry_a = m_entries[a];
     482                 :     1081681 :         const auto& entry_b = m_entries[b];
     483                 :             :         // Compare chunk feerates, and return result if it differs.
     484                 :     1081681 :         auto feerate_cmp = FeeRateCompare(entry_b.m_main_chunk_feerate, entry_a.m_main_chunk_feerate);
     485         [ +  + ]:     1081681 :         if (feerate_cmp < 0) return std::strong_ordering::less;
     486         [ +  + ]:      512314 :         if (feerate_cmp > 0) return std::strong_ordering::greater;
     487                 :             :         // Compare Cluster m_sequence as tie-break for equal chunk feerates.
     488                 :          52 :         const auto& locator_a = entry_a.m_locator[0];
     489                 :          52 :         const auto& locator_b = entry_b.m_locator[0];
     490                 :         104 :         Assume(locator_a.IsPresent() && locator_b.IsPresent());
     491         [ +  - ]:          52 :         if (locator_a.cluster != locator_b.cluster) {
     492                 :          52 :             return CompareClusters(locator_a.cluster, locator_b.cluster);
     493                 :             :         }
     494                 :             :         // As final tie-break, compare position within cluster linearization.
     495   [ #  #  #  # ]:           0 :         return entry_a.m_main_lin_index <=> entry_b.m_main_lin_index;
     496                 :             :     }
     497                 :             : 
     498                 :             :     /** Comparator for ChunkData objects in mining order. */
     499                 :             :     class ChunkOrder
     500                 :             :     {
     501                 :             :         const TxGraphImpl* const m_graph;
     502                 :             :     public:
     503                 :           4 :         explicit ChunkOrder(const TxGraphImpl* graph) : m_graph(graph) {}
     504                 :             : 
     505                 :     1081681 :         bool operator()(const ChunkData& a, const ChunkData& b) const noexcept
     506                 :             :         {
     507                 :     1081681 :             return m_graph->CompareMainTransactions(a.m_graph_index, b.m_graph_index) < 0;
     508                 :             :         }
     509                 :             :     };
     510                 :             : 
     511                 :             :     /** Definition for the mining index type. */
     512                 :             :     using ChunkIndex = std::set<ChunkData, ChunkOrder>;
     513                 :             : 
     514                 :             :     /** Index of ChunkData objects, indexing the last transaction in each chunk in the main
     515                 :             :      *  graph. */
     516                 :             :     ChunkIndex m_main_chunkindex;
     517                 :             :     /** Number of index-observing objects in existence (BlockBuilderImpls). */
     518                 :             :     size_t m_main_chunkindex_observers{0};
     519                 :             :     /** Cache of discarded ChunkIndex node handles to reuse, avoiding additional allocation. */
     520                 :             :     std::vector<ChunkIndex::node_type> m_main_chunkindex_discarded;
     521                 :             : 
     522                 :             :     /** A Locator that describes whether, where, and in which Cluster an Entry appears.
     523                 :             :      *  Every Entry has MAX_LEVELS locators, as it may appear in one Cluster per level.
     524                 :             :      *
     525                 :             :      *  Each level of a Locator is in one of three states:
     526                 :             :      *
     527                 :             :      *  - (P)resent: actually occurs in a Cluster at that level.
     528                 :             :      *
     529                 :             :      *  - (M)issing:
     530                 :             :      *    - In the main graph:    the transaction does not exist in main.
     531                 :             :      *    - In the staging graph: the transaction's existence is the same as in main. If it doesn't
     532                 :             :      *                            exist in main, (M) in staging means it does not exist there
     533                 :             :      *                            either. If it does exist in main, (M) in staging means the
     534                 :             :      *                            cluster it is in has not been modified in staging, and thus the
     535                 :             :      *                            transaction implicitly exists in staging too (without explicit
     536                 :             :      *                            Cluster object; see PullIn() to create it in staging too).
     537                 :             :      *
     538                 :             :      *  - (R)emoved: only possible in staging; it means the transaction exists in main, but is
     539                 :             :      *               removed in staging.
     540                 :             :      *
     541                 :             :      * The following combinations are possible:
     542                 :             :      * - (M,M): the transaction doesn't exist in either graph.
     543                 :             :      * - (P,M): the transaction exists in both, but only exists explicitly in a Cluster object in
     544                 :             :      *          main. Its existence in staging is inherited from main.
     545                 :             :      * - (P,P): the transaction exists in both, and is materialized in both. Thus, the clusters
     546                 :             :      *          and/or their linearizations may be different in main and staging.
     547                 :             :      * - (M,P): the transaction is added in staging, and does not exist in main.
     548                 :             :      * - (P,R): the transaction exists in main, but is removed in staging.
     549                 :             :      *
     550                 :             :      * When staging does not exist, only (M,M) and (P,M) are possible.
     551                 :             :      */
     552                 :             :     struct Locator
     553                 :             :     {
     554                 :             :         /** Which Cluster the Entry appears in (nullptr = missing). */
     555                 :             :         Cluster* cluster{nullptr};
     556                 :             :         /** Where in the Cluster it appears (if cluster == nullptr: 0 = missing, -1 = removed). */
     557                 :             :         DepGraphIndex index{0};
     558                 :             : 
     559                 :             :         /** Mark this Locator as missing (= same as lower level, or non-existing if level 0). */
     560                 :           0 :         void SetMissing() noexcept { cluster = nullptr; index = 0; }
     561                 :             :         /** Mark this Locator as removed (not allowed in level 0). */
     562                 :           0 :         void SetRemoved() noexcept { cluster = nullptr; index = DepGraphIndex(-1); }
     563                 :             :         /** Mark this Locator as present, in the specified Cluster. */
     564                 :       64311 :         void SetPresent(Cluster* c, DepGraphIndex i) noexcept { cluster = c; index = i; }
     565                 :             :         /** Check if this Locator is missing. */
     566   [ -  +  +  - ]:      192841 :         bool IsMissing() const noexcept { return cluster == nullptr && index == 0; }
     567                 :             :         /** Check if this Locator is removed. */
     568   [ +  -  -  -  :      192833 :         bool IsRemoved() const noexcept { return cluster == nullptr && index == DepGraphIndex(-1); }
                   -  - ]
     569                 :             :         /** Check if this Locator is present (in some Cluster). */
     570   [ -  -  +  - ]:          52 :         bool IsPresent() const noexcept { return cluster != nullptr; }
     571                 :             :     };
     572                 :             : 
     573                 :             :     /** Internal information about each transaction in a TxGraphImpl. */
     574                 :       64311 :     struct Entry
     575                 :             :     {
     576                 :             :         /** Pointer to the corresponding Ref object if any, or nullptr if unlinked. */
     577                 :             :         Ref* m_ref{nullptr};
     578                 :             :         /** Iterator to the corresponding ChunkData, if any, and m_main_chunkindex.end() otherwise.
     579                 :             :          *  This is initialized on construction of the Entry, in AddTransaction. */
     580                 :             :         ChunkIndex::iterator m_main_chunkindex_iterator;
     581                 :             :         /** Which Cluster and position therein this Entry appears in. ([0] = main, [1] = staged). */
     582                 :             :         Locator m_locator[MAX_LEVELS];
     583                 :             :         /** The chunk feerate of this transaction in main (if present in m_locator[0]). */
     584                 :             :         FeePerWeight m_main_chunk_feerate;
     585                 :             :         /** The position this transaction has in the main linearization (if present). */
     586                 :             :         LinearizationIndex m_main_lin_index;
     587                 :             :     };
     588                 :             : 
     589                 :             :     /** The set of all transactions (in all levels combined). GraphIndex values index into this. */
     590                 :             :     std::vector<Entry> m_entries;
     591                 :             : 
     592                 :             :     /** Set of Entries which have no linked Ref anymore. */
     593                 :             :     std::vector<GraphIndex> m_unlinked;
     594                 :             : 
     595                 :             : public:
     596                 :             :     /** Construct a new TxGraphImpl with the specified limits. */
     597                 :           4 :     explicit TxGraphImpl(DepGraphIndex max_cluster_count, uint64_t max_cluster_size, uint64_t acceptable_iters) noexcept :
     598                 :           4 :         m_max_cluster_count(max_cluster_count),
     599                 :           4 :         m_max_cluster_size(max_cluster_size),
     600                 :           4 :         m_acceptable_iters(acceptable_iters),
     601                 :           4 :         m_main_chunkindex(ChunkOrder(this))
     602                 :             :     {
     603                 :           4 :         Assume(max_cluster_count >= 1);
     604                 :           4 :         Assume(max_cluster_count <= MAX_CLUSTER_COUNT_LIMIT);
     605                 :           4 :     }
     606                 :             : 
     607                 :             :     /** Destructor. */
     608                 :             :     ~TxGraphImpl() noexcept;
     609                 :             : 
     610                 :             :     // Cannot move or copy (would invalidate TxGraphImpl* in Ref, MiningOrder, EvictionOrder).
     611                 :             :     TxGraphImpl(const TxGraphImpl&) = delete;
     612                 :             :     TxGraphImpl& operator=(const TxGraphImpl&) = delete;
     613                 :             :     TxGraphImpl(TxGraphImpl&&) = delete;
     614                 :             :     TxGraphImpl& operator=(TxGraphImpl&&) = delete;
     615                 :             : 
     616                 :             :     // Simple helper functions.
     617                 :             : 
     618                 :             :     /** Swap the Entry referred to by a and the one referred to by b. */
     619                 :             :     void SwapIndexes(GraphIndex a, GraphIndex b) noexcept;
     620                 :             :     /** If idx exists in the specified level ClusterSet (explicitly, or in the level below and not
     621                 :             :     *   removed), return the Cluster it is in. Otherwise, return nullptr. */
     622                 :      638402 :     Cluster* FindCluster(GraphIndex idx, int level) const noexcept { return FindClusterAndLevel(idx, level).first; }
     623                 :             :     /** Like FindCluster, but also return what level the match was found in (-1 if not found). */
     624                 :             :     std::pair<Cluster*, int> FindClusterAndLevel(GraphIndex idx, int level) const noexcept;
     625                 :             :     /** Extract a Cluster from its ClusterSet, and set its quality to QualityLevel::NONE. */
     626                 :             :     std::unique_ptr<Cluster> ExtractCluster(int level, QualityLevel quality, ClusterSetIndex setindex) noexcept;
     627                 :             :     /** Delete a Cluster. */
     628                 :             :     void DeleteCluster(Cluster& cluster, int level) noexcept;
     629                 :             :     /** Insert a Cluster into its ClusterSet. */
     630                 :             :     ClusterSetIndex InsertCluster(int level, std::unique_ptr<Cluster>&& cluster, QualityLevel quality) noexcept;
     631                 :             :     /** Change the QualityLevel of a Cluster (identified by old_quality and old_index). */
     632                 :             :     void SetClusterQuality(int level, QualityLevel old_quality, ClusterSetIndex old_index, QualityLevel new_quality) noexcept;
     633                 :             :     /** Get the index of the top level ClusterSet (staging if it exists, main otherwise). */
     634         [ -  + ]:      893158 :     int GetTopLevel() const noexcept { return m_staging_clusterset.has_value(); }
     635                 :             :     /** Get the specified level (staging if it exists and level is TOP, main otherwise). */
     636   [ -  -  +  -  :         316 :     int GetSpecifiedLevel(Level level) const noexcept { return level == Level::TOP && m_staging_clusterset.has_value(); }
          +  -  -  -  -  
          -  -  -  -  -  
             -  -  +  - ]
     637                 :             :     /** Get a reference to the ClusterSet at the specified level (which must exist). */
     638                 :             :     ClusterSet& GetClusterSet(int level) noexcept;
     639                 :             :     const ClusterSet& GetClusterSet(int level) const noexcept;
     640                 :             :     /** Make a transaction not exist at a specified level. It must currently exist there.
     641                 :             :      *  oversized_tx indicates whether the transaction is an individually-oversized one
     642                 :             :      *  (OVERSIZED_SINGLETON). */
     643                 :             :     void ClearLocator(int level, GraphIndex index, bool oversized_tx) noexcept;
     644                 :             :     /** Find which Clusters in main conflict with ones in staging. */
     645                 :             :     std::vector<Cluster*> GetConflicts() const noexcept;
     646                 :             :     /** Clear an Entry's ChunkData. */
     647                 :             :     void ClearChunkData(Entry& entry) noexcept;
     648                 :             :     /** Give an Entry a ChunkData object. */
     649                 :             :     void CreateChunkData(GraphIndex idx, LinearizationIndex chunk_count) noexcept;
     650                 :             :     /** Create an empty GenericClusterImpl object. */
     651                 :           0 :     std::unique_ptr<GenericClusterImpl> CreateEmptyGenericCluster() noexcept
     652                 :             :     {
     653                 :           0 :         return std::make_unique<GenericClusterImpl>(m_next_sequence_counter++);
     654                 :             :     }
     655                 :             :     /** Create an empty SingletonClusterImpl object. */
     656                 :       64311 :     std::unique_ptr<SingletonClusterImpl> CreateEmptySingletonCluster() noexcept
     657                 :             :     {
     658                 :       64311 :         return std::make_unique<SingletonClusterImpl>(m_next_sequence_counter++);
     659                 :             :     }
     660                 :             :     /** Create an empty Cluster of the appropriate implementation for the specified (maximum) tx
     661                 :             :      *  count. */
     662                 :       64311 :     std::unique_ptr<Cluster> CreateEmptyCluster(DepGraphIndex tx_count) noexcept
     663                 :             :     {
     664         [ +  - ]:       64311 :         if (tx_count >= SingletonClusterImpl::MIN_INTENDED_TX_COUNT && tx_count <= SingletonClusterImpl::MAX_TX_COUNT) {
     665                 :       64311 :             return CreateEmptySingletonCluster();
     666                 :             :         }
     667         [ #  # ]:           0 :         if (tx_count >= GenericClusterImpl::MIN_INTENDED_TX_COUNT && tx_count <= GenericClusterImpl::MAX_TX_COUNT) {
     668         [ #  # ]:           0 :             return CreateEmptyGenericCluster();
     669                 :             :         }
     670                 :           0 :         assert(false);
     671                 :             :         return {};
     672                 :             :     }
     673                 :             : 
     674                 :             :     // Functions for handling Refs.
     675                 :             : 
     676                 :             :     /** Only called by Ref's move constructor/assignment to update Ref locations. */
     677                 :      129861 :     void UpdateRef(GraphIndex idx, Ref& new_location) noexcept final
     678                 :             :     {
     679                 :      129861 :         auto& entry = m_entries[idx];
     680                 :      129861 :         Assume(entry.m_ref != nullptr);
     681                 :      129861 :         entry.m_ref = &new_location;
     682                 :      129861 :     }
     683                 :             : 
     684                 :             :     /** Only called by Ref::~Ref to unlink Refs, and Ref's move assignment. */
     685                 :         300 :     void UnlinkRef(GraphIndex idx) noexcept final
     686                 :             :     {
     687         [ -  + ]:         300 :         auto& entry = m_entries[idx];
     688                 :         300 :         Assume(entry.m_ref != nullptr);
     689         [ -  + ]:         300 :         Assume(m_main_chunkindex_observers == 0 || !entry.m_locator[0].IsPresent());
     690                 :         300 :         entry.m_ref = nullptr;
     691                 :             :         // Mark the transaction as to be removed in all levels where it explicitly or implicitly
     692                 :             :         // exists.
     693                 :         300 :         bool exists_anywhere{false};
     694                 :         300 :         bool exists{false};
     695         [ +  + ]:         600 :         for (int level = 0; level <= GetTopLevel(); ++level) {
     696         [ +  + ]:         300 :             if (entry.m_locator[level].IsPresent()) {
     697                 :             :                 exists_anywhere = true;
     698                 :             :                 exists = true;
     699         [ +  - ]:           8 :             } else if (entry.m_locator[level].IsRemoved()) {
     700                 :             :                 exists = false;
     701                 :             :             }
     702         [ -  + ]:           8 :             if (exists) {
     703                 :         292 :                 auto& clusterset = GetClusterSet(level);
     704                 :         292 :                 clusterset.m_to_remove.push_back(idx);
     705                 :             :                 // Force recomputation of grouping data.
     706         [ -  + ]:         292 :                 clusterset.m_group_data = std::nullopt;
     707                 :             :                 // Do not wipe the oversized state of main if staging exists. The reason for this
     708                 :             :                 // is that the alternative would mean that cluster merges may need to be applied to
     709                 :             :                 // a formerly-oversized main graph while staging exists (to satisfy chunk feerate
     710                 :             :                 // queries into main, for example), and such merges could conflict with pulls of
     711                 :             :                 // some of their constituents into staging.
     712   [ +  -  +  - ]:         592 :                 if (level == GetTopLevel() && clusterset.m_oversized == true) {
     713                 :           0 :                     clusterset.m_oversized = std::nullopt;
     714                 :             :                 }
     715                 :             :             }
     716                 :             :         }
     717                 :         300 :         m_unlinked.push_back(idx);
     718         [ +  + ]:         300 :         if (!exists_anywhere) Compact();
     719                 :         300 :     }
     720                 :             : 
     721                 :             :     // Functions related to various normalization/application steps.
     722                 :             :     /** Get rid of unlinked Entry objects in m_entries, if possible (this changes the GraphIndex
     723                 :             :      *  values for remaining Entry objects, so this only does something when no to-be-applied
     724                 :             :      *  operations or staged removals referring to GraphIndexes remain). */
     725                 :             :     void Compact() noexcept;
     726                 :             :     /** If cluster is not in staging, copy it there, and return a pointer to it.
     727                 :             :     *   Staging must exist, and this modifies the locators of its
     728                 :             :     *   transactions from inherited (P,M) to explicit (P,P). */
     729                 :             :     Cluster* PullIn(Cluster* cluster, int level) noexcept;
     730                 :             :     /** Apply all removals queued up in m_to_remove to the relevant Clusters (which get a
     731                 :             :      *  NEEDS_SPLIT* QualityLevel) up to the specified level. */
     732                 :             :     void ApplyRemovals(int up_to_level) noexcept;
     733                 :             :     /** Split an individual cluster. */
     734                 :             :     void Split(Cluster& cluster, int level) noexcept;
     735                 :             :     /** Split all clusters that need splitting up to the specified level. */
     736                 :             :     void SplitAll(int up_to_level) noexcept;
     737                 :             :     /** Populate m_group_data based on m_deps_to_add in the specified level. */
     738                 :             :     void GroupClusters(int level) noexcept;
     739                 :             :     /** Merge the specified clusters. */
     740                 :             :     void Merge(std::span<Cluster*> to_merge, int level) noexcept;
     741                 :             :     /** Apply all m_deps_to_add to the relevant Clusters in the specified level. */
     742                 :             :     void ApplyDependencies(int level) noexcept;
     743                 :             :     /** Make a specified Cluster have quality ACCEPTABLE or OPTIMAL. */
     744                 :             :     void MakeAcceptable(Cluster& cluster, int level) noexcept;
     745                 :             :     /** Make all Clusters at the specified level have quality ACCEPTABLE or OPTIMAL. */
     746                 :             :     void MakeAllAcceptable(int level) noexcept;
     747                 :             : 
     748                 :             :     // Implementations for the public TxGraph interface.
     749                 :             : 
     750                 :             :     Ref AddTransaction(const FeePerWeight& feerate) noexcept final;
     751                 :             :     void RemoveTransaction(const Ref& arg) noexcept final;
     752                 :             :     void AddDependency(const Ref& parent, const Ref& child) noexcept final;
     753                 :             :     void SetTransactionFee(const Ref&, int64_t fee) noexcept final;
     754                 :             : 
     755                 :             :     bool DoWork(uint64_t iters) noexcept final;
     756                 :             : 
     757                 :             :     void StartStaging() noexcept final;
     758                 :             :     void CommitStaging() noexcept final;
     759                 :             :     void AbortStaging() noexcept final;
     760                 :           0 :     bool HaveStaging() const noexcept final { return m_staging_clusterset.has_value(); }
     761                 :             : 
     762                 :             :     bool Exists(const Ref& arg, Level level) noexcept final;
     763                 :             :     FeePerWeight GetMainChunkFeerate(const Ref& arg) noexcept final;
     764                 :             :     FeePerWeight GetIndividualFeerate(const Ref& arg) noexcept final;
     765                 :             :     std::vector<Ref*> GetCluster(const Ref& arg, Level level) noexcept final;
     766                 :             :     std::vector<Ref*> GetAncestors(const Ref& arg, Level level) noexcept final;
     767                 :             :     std::vector<Ref*> GetDescendants(const Ref& arg, Level level) noexcept final;
     768                 :             :     std::vector<Ref*> GetAncestorsUnion(std::span<const Ref* const> args, Level level) noexcept final;
     769                 :             :     std::vector<Ref*> GetDescendantsUnion(std::span<const Ref* const> args, Level level) noexcept final;
     770                 :             :     GraphIndex GetTransactionCount(Level level) noexcept final;
     771                 :             :     bool IsOversized(Level level) noexcept final;
     772                 :             :     std::strong_ordering CompareMainOrder(const Ref& a, const Ref& b) noexcept final;
     773                 :             :     GraphIndex CountDistinctClusters(std::span<const Ref* const> refs, Level level) noexcept final;
     774                 :             :     std::pair<std::vector<FeeFrac>, std::vector<FeeFrac>> GetMainStagingDiagrams() noexcept final;
     775                 :             :     std::vector<Ref*> Trim() noexcept final;
     776                 :             : 
     777                 :             :     std::unique_ptr<BlockBuilder> GetBlockBuilder() noexcept final;
     778                 :             :     std::pair<std::vector<Ref*>, FeePerWeight> GetWorstMainChunk() noexcept final;
     779                 :             : 
     780                 :             :     size_t GetMainMemoryUsage() noexcept final;
     781                 :             : 
     782                 :             :     void SanityCheck() const final;
     783                 :             : };
     784                 :             : 
     785                 :      193538 : TxGraphImpl::ClusterSet& TxGraphImpl::GetClusterSet(int level) noexcept
     786                 :             : {
     787         [ +  - ]:      193538 :     if (level == 0) return m_main_clusterset;
     788                 :           0 :     Assume(level == 1);
     789                 :           0 :     Assume(m_staging_clusterset.has_value());
     790                 :           0 :     return *m_staging_clusterset;
     791                 :             : }
     792                 :             : 
     793                 :          11 : const TxGraphImpl::ClusterSet& TxGraphImpl::GetClusterSet(int level) const noexcept
     794                 :             : {
     795         [ +  - ]:          11 :     if (level == 0) return m_main_clusterset;
     796                 :           0 :     Assume(level == 1);
     797                 :           0 :     Assume(m_staging_clusterset.has_value());
     798                 :           0 :     return *m_staging_clusterset;
     799                 :             : }
     800                 :             : 
     801                 :             : /** Implementation of the TxGraph::BlockBuilder interface. */
     802                 :             : class BlockBuilderImpl final : public TxGraph::BlockBuilder
     803                 :             : {
     804                 :             :     /** Which TxGraphImpl this object is doing block building for. It will have its
     805                 :             :      *  m_main_chunkindex_observers incremented as long as this BlockBuilderImpl exists. */
     806                 :             :     TxGraphImpl* const m_graph;
     807                 :             :     /** Cluster sequence numbers which we're not including further transactions from. */
     808                 :             :     std::unordered_set<uint64_t> m_excluded_clusters;
     809                 :             :     /** Iterator to the current chunk in the chunk index. end() if nothing further remains. */
     810                 :             :     TxGraphImpl::ChunkIndex::const_iterator m_cur_iter;
     811                 :             :     /** Which cluster the current chunk belongs to, so we can exclude further transactions from it
     812                 :             :      *  when that chunk is skipped. */
     813                 :             :     Cluster* m_cur_cluster;
     814                 :             :     /** Whether we know that m_cur_iter points to the last chunk of m_cur_cluster. */
     815                 :             :     bool m_known_end_of_cluster;
     816                 :             : 
     817                 :             :     // Move m_cur_iter / m_cur_cluster to the next acceptable chunk.
     818                 :             :     void Next() noexcept;
     819                 :             : 
     820                 :             : public:
     821                 :             :     /** Construct a new BlockBuilderImpl to build blocks for the provided graph. */
     822                 :             :     BlockBuilderImpl(TxGraphImpl& graph) noexcept;
     823                 :             : 
     824                 :             :     // Implement the public interface.
     825                 :             :     ~BlockBuilderImpl() final;
     826                 :             :     std::optional<std::pair<std::vector<TxGraph::Ref*>, FeePerWeight>> GetCurrentChunk() noexcept final;
     827                 :             :     void Include() noexcept final;
     828                 :             :     void Skip() noexcept final;
     829                 :             : };
     830                 :             : 
     831                 :       64330 : void TxGraphImpl::ClearChunkData(Entry& entry) noexcept
     832                 :             : {
     833         [ +  + ]:       64330 :     if (entry.m_main_chunkindex_iterator != m_main_chunkindex.end()) {
     834                 :          13 :         Assume(m_main_chunkindex_observers == 0);
     835                 :             :         // If the Entry has a non-empty m_main_chunkindex_iterator, extract it, and move the handle
     836                 :             :         // to the cache of discarded chunkindex entries.
     837                 :          13 :         m_main_chunkindex_discarded.emplace_back(m_main_chunkindex.extract(entry.m_main_chunkindex_iterator));
     838                 :          13 :         entry.m_main_chunkindex_iterator = m_main_chunkindex.end();
     839                 :             :     }
     840                 :       64330 : }
     841                 :             : 
     842                 :       64305 : void TxGraphImpl::CreateChunkData(GraphIndex idx, LinearizationIndex chunk_count) noexcept
     843                 :             : {
     844         [ -  + ]:       64305 :     auto& entry = m_entries[idx];
     845         [ -  + ]:       64305 :     if (!m_main_chunkindex_discarded.empty()) {
     846                 :             :         // Reuse an discarded node handle.
     847                 :           0 :         auto& node = m_main_chunkindex_discarded.back().value();
     848                 :           0 :         node.m_graph_index = idx;
     849                 :           0 :         node.m_chunk_count = chunk_count;
     850                 :           0 :         auto insert_result = m_main_chunkindex.insert(std::move(m_main_chunkindex_discarded.back()));
     851                 :           0 :         Assume(insert_result.inserted);
     852                 :           0 :         entry.m_main_chunkindex_iterator = insert_result.position;
     853                 :           0 :         m_main_chunkindex_discarded.pop_back();
     854                 :           0 :     } else {
     855                 :             :         // Construct a new entry.
     856                 :       64305 :         auto emplace_result = m_main_chunkindex.emplace(idx, chunk_count);
     857                 :       64305 :         Assume(emplace_result.second);
     858                 :       64305 :         entry.m_main_chunkindex_iterator = emplace_result.first;
     859                 :             :     }
     860                 :       64305 : }
     861                 :             : 
     862                 :           0 : size_t GenericClusterImpl::TotalMemoryUsage() const noexcept
     863                 :             : {
     864                 :           0 :     return // Dynamic memory allocated in this Cluster.
     865   [ #  #  #  # ]:           0 :            memusage::DynamicUsage(m_mapping) + memusage::DynamicUsage(m_linearization) +
     866                 :             :            // Dynamic memory usage inside m_depgraph.
     867         [ #  # ]:           0 :            m_depgraph.DynamicMemoryUsage() +
     868                 :             :            // Memory usage of the allocated Cluster itself.
     869                 :           0 :            memusage::MallocUsage(sizeof(GenericClusterImpl)) +
     870                 :             :            // Memory usage of the ClusterSet::m_clusters entry.
     871                 :           0 :            sizeof(std::unique_ptr<Cluster>);
     872                 :             : }
     873                 :             : 
     874                 :      257133 : size_t SingletonClusterImpl::TotalMemoryUsage() const noexcept
     875                 :             : {
     876                 :      257133 :     return // Memory usage of the allocated SingletonClusterImpl itself.
     877                 :      257133 :            memusage::MallocUsage(sizeof(SingletonClusterImpl)) +
     878                 :             :            // Memory usage of the ClusterSet::m_clusters entry.
     879                 :      257133 :            sizeof(std::unique_ptr<Cluster>);
     880                 :             : }
     881                 :             : 
     882                 :           0 : uint64_t GenericClusterImpl::GetTotalTxSize() const noexcept
     883                 :             : {
     884                 :           0 :     uint64_t ret{0};
     885         [ #  # ]:           0 :     for (auto i : m_linearization) {
     886                 :           0 :         ret += m_depgraph.FeeRate(i).size;
     887                 :             :     }
     888                 :           0 :     return ret;
     889                 :             : }
     890                 :             : 
     891                 :           0 : DepGraphIndex GenericClusterImpl::AppendTransaction(GraphIndex graph_idx, FeePerWeight feerate) noexcept
     892                 :             : {
     893                 :           0 :     Assume(graph_idx != GraphIndex(-1));
     894                 :           0 :     auto ret = m_depgraph.AddTransaction(feerate);
     895                 :           0 :     m_mapping.push_back(graph_idx);
     896                 :           0 :     m_linearization.push_back(ret);
     897                 :           0 :     return ret;
     898                 :             : }
     899                 :             : 
     900                 :       64311 : DepGraphIndex SingletonClusterImpl::AppendTransaction(GraphIndex graph_idx, FeePerWeight feerate) noexcept
     901                 :             : {
     902                 :       64311 :     Assume(!GetTxCount());
     903                 :       64311 :     m_graph_index = graph_idx;
     904                 :       64311 :     m_feerate = feerate;
     905                 :       64311 :     return 0;
     906                 :             : }
     907                 :             : 
     908                 :           0 : void GenericClusterImpl::AddDependencies(SetType parents, DepGraphIndex child) noexcept
     909                 :             : {
     910                 :           0 :     m_depgraph.AddDependencies(parents, child);
     911                 :           0 : }
     912                 :             : 
     913                 :           0 : void SingletonClusterImpl::AddDependencies(SetType parents, DepGraphIndex child) noexcept
     914                 :             : {
     915                 :             :     // Singletons cannot have any dependencies.
     916                 :           0 :     Assume(child == 0);
     917         [ #  # ]:           0 :     Assume(parents == SetType{} || parents == SetType::Fill(0));
     918                 :           0 : }
     919                 :             : 
     920                 :           0 : void GenericClusterImpl::ExtractTransactions(const std::function<void (DepGraphIndex, GraphIndex, FeePerWeight, SetType)>& visit_fn) noexcept
     921                 :             : {
     922         [ #  # ]:           0 :     for (auto pos : m_linearization) {
     923                 :           0 :         visit_fn(pos, m_mapping[pos], FeePerWeight::FromFeeFrac(m_depgraph.FeeRate(pos)), m_depgraph.GetReducedParents(pos));
     924                 :             :     }
     925                 :             :     // Purge this Cluster, now that everything has been moved.
     926                 :           0 :     m_depgraph = DepGraph<SetType>{};
     927         [ #  # ]:           0 :     m_linearization.clear();
     928         [ #  # ]:           0 :     m_mapping.clear();
     929                 :           0 : }
     930                 :             : 
     931                 :           0 : void SingletonClusterImpl::ExtractTransactions(const std::function<void (DepGraphIndex, GraphIndex, FeePerWeight, SetType)>& visit_fn) noexcept
     932                 :             : {
     933         [ #  # ]:           0 :     if (GetTxCount()) {
     934                 :           0 :         visit_fn(0, m_graph_index, m_feerate, SetType{});
     935                 :           0 :         m_graph_index = NO_GRAPH_INDEX;
     936                 :             :     }
     937                 :           0 : }
     938                 :             : 
     939                 :           0 : int GenericClusterImpl::GetLevel(const TxGraphImpl& graph) const noexcept
     940                 :             : {
     941                 :             :     // GetLevel() does not work for empty Clusters.
     942         [ #  # ]:           0 :     if (!Assume(!m_linearization.empty())) return -1;
     943                 :             : 
     944                 :             :     // Pick an arbitrary Entry that occurs in this Cluster.
     945                 :           0 :     const auto& entry = graph.m_entries[m_mapping[m_linearization.front()]];
     946                 :             :     // See if there is a level whose Locator matches this Cluster, if so return that level.
     947         [ #  # ]:           0 :     for (int level = 0; level < MAX_LEVELS; ++level) {
     948         [ #  # ]:           0 :         if (entry.m_locator[level].cluster == this) return level;
     949                 :             :     }
     950                 :             :     // Given that we started with an Entry that occurs in this Cluster, one of its Locators must
     951                 :             :     // point back to it.
     952                 :           0 :     assert(false);
     953                 :             :     return -1;
     954                 :             : }
     955                 :             : 
     956                 :      192811 : int SingletonClusterImpl::GetLevel(const TxGraphImpl& graph) const noexcept
     957                 :             : {
     958                 :             :     // GetLevel() does not work for empty Clusters.
     959         [ +  - ]:      192811 :     if (!Assume(GetTxCount())) return -1;
     960                 :             : 
     961                 :             :     // Get the Entry in this Cluster.
     962                 :      192811 :     const auto& entry = graph.m_entries[m_graph_index];
     963                 :             :     // See if there is a level whose Locator matches this Cluster, if so return that level.
     964         [ +  - ]:      192811 :     for (int level = 0; level < MAX_LEVELS; ++level) {
     965         [ -  + ]:      192811 :         if (entry.m_locator[level].cluster == this) return level;
     966                 :             :     }
     967                 :             :     // Given that we started with an Entry that occurs in this Cluster, one of its Locators must
     968                 :             :     // point back to it.
     969                 :           0 :     assert(false);
     970                 :             :     return -1;
     971                 :             : }
     972                 :             : 
     973                 :          19 : void TxGraphImpl::ClearLocator(int level, GraphIndex idx, bool oversized_tx) noexcept
     974                 :             : {
     975         [ -  + ]:          19 :     auto& entry = m_entries[idx];
     976                 :          19 :     auto& clusterset = GetClusterSet(level);
     977                 :          19 :     Assume(entry.m_locator[level].IsPresent());
     978                 :             :     // Change the locator from Present to Missing or Removed.
     979   [ -  +  -  - ]:          19 :     if (level == 0 || !entry.m_locator[level - 1].IsPresent()) {
     980                 :          19 :         entry.m_locator[level].SetMissing();
     981                 :             :     } else {
     982                 :           0 :         entry.m_locator[level].SetRemoved();
     983                 :           0 :         clusterset.m_removed.push_back(idx);
     984                 :             :     }
     985                 :             :     // Update the transaction count.
     986                 :          19 :     --clusterset.m_txcount;
     987                 :          19 :     clusterset.m_txcount_oversized -= oversized_tx;
     988                 :             :     // If clearing main, adjust the status of Locators of this transaction in staging, if it exists.
     989   [ +  -  -  + ]:          19 :     if (level == 0 && GetTopLevel() == 1) {
     990         [ #  # ]:           0 :         if (entry.m_locator[1].IsRemoved()) {
     991                 :           0 :             entry.m_locator[1].SetMissing();
     992         [ #  # ]:           0 :         } else if (!entry.m_locator[1].IsPresent()) {
     993                 :           0 :             --m_staging_clusterset->m_txcount;
     994                 :           0 :             m_staging_clusterset->m_txcount_oversized -= oversized_tx;
     995                 :             :         }
     996                 :             :     }
     997         [ +  - ]:          19 :     if (level == 0) ClearChunkData(entry);
     998                 :          19 : }
     999                 :             : 
    1000                 :           0 : void GenericClusterImpl::Updated(TxGraphImpl& graph, int level) noexcept
    1001                 :             : {
    1002                 :             :     // Update all the Locators for this Cluster's Entry objects.
    1003         [ #  # ]:           0 :     for (DepGraphIndex idx : m_linearization) {
    1004         [ #  # ]:           0 :         auto& entry = graph.m_entries[m_mapping[idx]];
    1005                 :             :         // Discard any potential ChunkData prior to modifying the Cluster (as that could
    1006                 :             :         // invalidate its ordering).
    1007         [ #  # ]:           0 :         if (level == 0) graph.ClearChunkData(entry);
    1008                 :           0 :         entry.m_locator[level].SetPresent(this, idx);
    1009                 :             :     }
    1010                 :             :     // If this is for the main graph (level = 0), and the Cluster's quality is ACCEPTABLE or
    1011                 :             :     // OPTIMAL, compute its chunking and store its information in the Entry's m_main_lin_index
    1012                 :             :     // and m_main_chunk_feerate. These fields are only accessed after making the entire graph
    1013                 :             :     // ACCEPTABLE, so it is pointless to compute these if we haven't reached that quality level
    1014                 :             :     // yet.
    1015   [ #  #  #  # ]:           0 :     if (level == 0 && IsAcceptable()) {
    1016         [ #  # ]:           0 :         const LinearizationChunking chunking(m_depgraph, m_linearization);
    1017                 :           0 :         LinearizationIndex lin_idx{0};
    1018                 :             :         // Iterate over the chunks.
    1019   [ #  #  #  # ]:           0 :         for (unsigned chunk_idx = 0; chunk_idx < chunking.NumChunksLeft(); ++chunk_idx) {
    1020                 :           0 :             auto chunk = chunking.GetChunk(chunk_idx);
    1021                 :           0 :             auto chunk_count = chunk.transactions.Count();
    1022                 :           0 :             Assume(chunk_count > 0);
    1023                 :             :             // Iterate over the transactions in the linearization, which must match those in chunk.
    1024                 :           0 :             while (true) {
    1025         [ #  # ]:           0 :                 DepGraphIndex idx = m_linearization[lin_idx];
    1026                 :           0 :                 GraphIndex graph_idx = m_mapping[idx];
    1027                 :           0 :                 auto& entry = graph.m_entries[graph_idx];
    1028                 :           0 :                 entry.m_main_lin_index = lin_idx++;
    1029         [ #  # ]:           0 :                 entry.m_main_chunk_feerate = FeePerWeight::FromFeeFrac(chunk.feerate);
    1030                 :           0 :                 Assume(chunk.transactions[idx]);
    1031         [ #  # ]:           0 :                 chunk.transactions.Reset(idx);
    1032         [ #  # ]:           0 :                 if (chunk.transactions.None()) {
    1033                 :             :                     // Last transaction in the chunk.
    1034   [ #  #  #  # ]:           0 :                     if (chunk_count == 1 && chunk_idx + 1 == chunking.NumChunksLeft()) {
    1035                 :             :                         // If this is the final chunk of the cluster, and it contains just a single
    1036                 :             :                         // transaction (which will always be true for the very common singleton
    1037                 :             :                         // clusters), store the special value -1 as chunk count.
    1038                 :             :                         chunk_count = LinearizationIndex(-1);
    1039                 :             :                     }
    1040                 :           0 :                     graph.CreateChunkData(graph_idx, chunk_count);
    1041                 :           0 :                     break;
    1042                 :             :                 }
    1043                 :             :             }
    1044                 :             :         }
    1045                 :           0 :     }
    1046                 :           0 : }
    1047                 :             : 
    1048                 :       64311 : void SingletonClusterImpl::Updated(TxGraphImpl& graph, int level) noexcept
    1049                 :             : {
    1050                 :             :     // Don't do anything if this is empty.
    1051         [ +  - ]:       64311 :     if (GetTxCount() == 0) return;
    1052                 :             : 
    1053         [ +  - ]:       64311 :     auto& entry = graph.m_entries[m_graph_index];
    1054                 :             :     // Discard any potential ChunkData prior to modifying the Cluster (as that could
    1055                 :             :     // invalidate its ordering).
    1056         [ +  - ]:       64311 :     if (level == 0) graph.ClearChunkData(entry);
    1057                 :       64311 :     entry.m_locator[level].SetPresent(this, 0);
    1058                 :             :     // If this is for the main graph (level = 0), compute its chunking and store its information in
    1059                 :             :     // the Entry's m_main_lin_index and m_main_chunk_feerate.
    1060   [ +  -  +  + ]:       64311 :     if (level == 0 && IsAcceptable()) {
    1061                 :       64305 :         entry.m_main_lin_index = 0;
    1062                 :       64305 :         entry.m_main_chunk_feerate = m_feerate;
    1063                 :             :         // Always use the special LinearizationIndex(-1), indicating singleton chunk at end of
    1064                 :             :         // Cluster, here.
    1065                 :       64305 :         graph.CreateChunkData(m_graph_index, LinearizationIndex(-1));
    1066                 :             :     }
    1067                 :             : }
    1068                 :             : 
    1069                 :           0 : void GenericClusterImpl::GetConflicts(const TxGraphImpl& graph, std::vector<Cluster*>& out) const noexcept
    1070                 :             : {
    1071         [ #  # ]:           0 :     for (auto i : m_linearization) {
    1072         [ #  # ]:           0 :         auto& entry = graph.m_entries[m_mapping[i]];
    1073                 :             :         // For every transaction Entry in this Cluster, if it also exists in a lower-level Cluster,
    1074                 :             :         // then that Cluster conflicts.
    1075         [ #  # ]:           0 :         if (entry.m_locator[0].IsPresent()) {
    1076                 :           0 :             out.push_back(entry.m_locator[0].cluster);
    1077                 :             :         }
    1078                 :             :     }
    1079                 :           0 : }
    1080                 :             : 
    1081                 :           0 : void SingletonClusterImpl::GetConflicts(const TxGraphImpl& graph, std::vector<Cluster*>& out) const noexcept
    1082                 :             : {
    1083                 :             :     // Empty clusters have no conflicts.
    1084         [ #  # ]:           0 :     if (GetTxCount() == 0) return;
    1085                 :             : 
    1086         [ #  # ]:           0 :     auto& entry = graph.m_entries[m_graph_index];
    1087                 :             :     // If the transaction in this Cluster also exists in a lower-level Cluster, then that Cluster
    1088                 :             :     // conflicts.
    1089         [ #  # ]:           0 :     if (entry.m_locator[0].IsPresent()) {
    1090                 :           0 :         out.push_back(entry.m_locator[0].cluster);
    1091                 :             :     }
    1092                 :             : }
    1093                 :             : 
    1094                 :           0 : std::vector<Cluster*> TxGraphImpl::GetConflicts() const noexcept
    1095                 :             : {
    1096                 :           0 :     Assume(GetTopLevel() == 1);
    1097                 :           0 :     auto& clusterset = GetClusterSet(1);
    1098                 :           0 :     std::vector<Cluster*> ret;
    1099                 :             :     // All main Clusters containing transactions in m_removed (so (P,R) ones) are conflicts.
    1100         [ #  # ]:           0 :     for (auto i : clusterset.m_removed) {
    1101         [ #  # ]:           0 :         auto& entry = m_entries[i];
    1102         [ #  # ]:           0 :         if (entry.m_locator[0].IsPresent()) {
    1103                 :           0 :             ret.push_back(entry.m_locator[0].cluster);
    1104                 :             :         }
    1105                 :             :     }
    1106                 :             :     // Then go over all Clusters at this level, and find their conflicts (the (P,P) ones).
    1107         [ #  # ]:           0 :     for (int quality = 0; quality < int(QualityLevel::NONE); ++quality) {
    1108                 :           0 :         auto& clusters = clusterset.m_clusters[quality];
    1109         [ #  # ]:           0 :         for (const auto& cluster : clusters) {
    1110                 :           0 :             cluster->GetConflicts(*this, ret);
    1111                 :             :         }
    1112                 :             :     }
    1113                 :             :     // Deduplicate the result (the same Cluster may appear multiple times).
    1114                 :           0 :     std::sort(ret.begin(), ret.end(), [](Cluster* a, Cluster* b) noexcept { return CompareClusters(a, b) < 0; });
    1115                 :           0 :     ret.erase(std::unique(ret.begin(), ret.end()), ret.end());
    1116                 :           0 :     return ret;
    1117                 :             : }
    1118                 :             : 
    1119                 :           0 : Cluster* GenericClusterImpl::CopyToStaging(TxGraphImpl& graph) const noexcept
    1120                 :             : {
    1121                 :             :     // Construct an empty Cluster.
    1122                 :           0 :     auto ret = graph.CreateEmptyGenericCluster();
    1123                 :           0 :     auto ptr = ret.get();
    1124                 :             :     // Copy depgraph, mapping, and linearization.
    1125                 :           0 :     ptr->m_depgraph = m_depgraph;
    1126                 :           0 :     ptr->m_mapping = m_mapping;
    1127                 :           0 :     ptr->m_linearization = m_linearization;
    1128                 :             :     // Insert the new Cluster into the graph.
    1129                 :           0 :     graph.InsertCluster(/*level=*/1, std::move(ret), m_quality);
    1130                 :             :     // Update its Locators.
    1131                 :           0 :     ptr->Updated(graph, /*level=*/1);
    1132                 :             :     // Update memory usage.
    1133                 :           0 :     graph.GetClusterSet(/*level=*/1).m_cluster_usage += ptr->TotalMemoryUsage();
    1134         [ #  # ]:           0 :     return ptr;
    1135                 :           0 : }
    1136                 :             : 
    1137                 :           0 : Cluster* SingletonClusterImpl::CopyToStaging(TxGraphImpl& graph) const noexcept
    1138                 :             : {
    1139                 :             :     // Construct an empty Cluster.
    1140                 :           0 :     auto ret = graph.CreateEmptySingletonCluster();
    1141                 :           0 :     auto ptr = ret.get();
    1142                 :             :     // Copy data.
    1143                 :           0 :     ptr->m_graph_index = m_graph_index;
    1144                 :           0 :     ptr->m_feerate = m_feerate;
    1145                 :             :     // Insert the new Cluster into the graph.
    1146                 :           0 :     graph.InsertCluster(/*level=*/1, std::move(ret), m_quality);
    1147                 :             :     // Update its Locators.
    1148                 :           0 :     ptr->Updated(graph, /*level=*/1);
    1149                 :             :     // Update memory usage.
    1150                 :           0 :     graph.GetClusterSet(/*level=*/1).m_cluster_usage += ptr->TotalMemoryUsage();
    1151                 :           0 :     return ptr;
    1152                 :           0 : }
    1153                 :             : 
    1154                 :           0 : void GenericClusterImpl::ApplyRemovals(TxGraphImpl& graph, int level, std::span<GraphIndex>& to_remove) noexcept
    1155                 :             : {
    1156                 :             :     // Iterate over the prefix of to_remove that applies to this cluster.
    1157                 :           0 :     Assume(!to_remove.empty());
    1158                 :           0 :     SetType todo;
    1159                 :           0 :     graph.GetClusterSet(level).m_cluster_usage -= TotalMemoryUsage();
    1160                 :           0 :     do {
    1161         [ #  # ]:           0 :         GraphIndex idx = to_remove.front();
    1162         [ #  # ]:           0 :         Assume(idx < graph.m_entries.size());
    1163         [ #  # ]:           0 :         auto& entry = graph.m_entries[idx];
    1164                 :           0 :         auto& locator = entry.m_locator[level];
    1165                 :             :         // Stop once we hit an entry that applies to another Cluster.
    1166         [ #  # ]:           0 :         if (locator.cluster != this) break;
    1167                 :             :         // - Remember it in a set of to-remove DepGraphIndexes.
    1168         [ #  # ]:           0 :         todo.Set(locator.index);
    1169                 :             :         // - Remove from m_mapping. This isn't strictly necessary as unused positions in m_mapping
    1170                 :             :         //   are just never accessed, but set it to -1 here to increase the ability to detect a bug
    1171                 :             :         //   that causes it to be accessed regardless.
    1172         [ #  # ]:           0 :         m_mapping[locator.index] = GraphIndex(-1);
    1173                 :             :         // - Remove its linearization index from the Entry (if in main).
    1174         [ #  # ]:           0 :         if (level == 0) {
    1175                 :           0 :             entry.m_main_lin_index = LinearizationIndex(-1);
    1176                 :             :         }
    1177                 :             :         // - Mark it as missing/removed in the Entry's locator.
    1178                 :           0 :         graph.ClearLocator(level, idx, m_quality == QualityLevel::OVERSIZED_SINGLETON);
    1179         [ #  # ]:           0 :         to_remove = to_remove.subspan(1);
    1180         [ #  # ]:           0 :     } while(!to_remove.empty());
    1181                 :             : 
    1182                 :           0 :     auto quality = m_quality;
    1183                 :           0 :     Assume(todo.Any());
    1184                 :             :     // Wipe from the Cluster's DepGraph (this is O(n) regardless of the number of entries
    1185                 :             :     // removed, so we benefit from batching all the removals).
    1186                 :           0 :     m_depgraph.RemoveTransactions(todo);
    1187         [ #  # ]:           0 :     m_mapping.resize(m_depgraph.PositionRange());
    1188                 :             : 
    1189                 :             :     // First remove all removals at the end of the linearization.
    1190   [ #  #  #  # ]:           0 :     while (!m_linearization.empty() && todo[m_linearization.back()]) {
    1191                 :           0 :         todo.Reset(m_linearization.back());
    1192                 :           0 :         m_linearization.pop_back();
    1193                 :             :     }
    1194         [ #  # ]:           0 :     if (todo.None()) {
    1195                 :             :         // If no further removals remain, and thus all removals were at the end, we may be able
    1196                 :             :         // to leave the cluster at a better quality level.
    1197         [ #  # ]:           0 :         if (IsAcceptable(/*after_split=*/true)) {
    1198                 :             :             quality = QualityLevel::NEEDS_SPLIT_ACCEPTABLE;
    1199                 :             :         } else {
    1200                 :             :             quality = QualityLevel::NEEDS_SPLIT;
    1201                 :             :         }
    1202                 :             :     } else {
    1203                 :             :         // If more removals remain, filter those out of m_linearization.
    1204                 :           0 :         m_linearization.erase(std::remove_if(
    1205                 :             :             m_linearization.begin(),
    1206                 :             :             m_linearization.end(),
    1207   [ #  #  #  # ]:           0 :             [&](auto pos) { return todo[pos]; }), m_linearization.end());
    1208                 :           0 :         quality = QualityLevel::NEEDS_SPLIT;
    1209                 :             :     }
    1210                 :           0 :     Compact();
    1211                 :           0 :     graph.GetClusterSet(level).m_cluster_usage += TotalMemoryUsage();
    1212                 :           0 :     graph.SetClusterQuality(level, m_quality, m_setindex, quality);
    1213                 :           0 :     Updated(graph, level);
    1214                 :           0 : }
    1215                 :             : 
    1216                 :          19 : void SingletonClusterImpl::ApplyRemovals(TxGraphImpl& graph, int level, std::span<GraphIndex>& to_remove) noexcept
    1217                 :             : {
    1218                 :             :     // We can only remove the one transaction this Cluster has.
    1219                 :          19 :     Assume(!to_remove.empty());
    1220                 :          19 :     Assume(GetTxCount());
    1221                 :          19 :     Assume(to_remove.front() == m_graph_index);
    1222                 :             :     // Pop all copies of m_graph_index from the front of to_remove (at least one, but there may be
    1223                 :             :     // multiple).
    1224                 :          19 :     do {
    1225         [ +  + ]:          19 :         to_remove = to_remove.subspan(1);
    1226   [ +  +  +  -  :          34 :     } while (!to_remove.empty() && to_remove.front() == m_graph_index);
                   -  + ]
    1227                 :             :     // Clear this cluster.
    1228                 :          19 :     graph.ClearLocator(level, m_graph_index, m_quality == QualityLevel::OVERSIZED_SINGLETON);
    1229                 :          19 :     m_graph_index = NO_GRAPH_INDEX;
    1230                 :          19 :     graph.SetClusterQuality(level, m_quality, m_setindex, QualityLevel::NEEDS_SPLIT);
    1231                 :             :     // No need to account for m_cluster_usage changes here, as SingletonClusterImpl has constant
    1232                 :             :     // memory usage.
    1233                 :          19 : }
    1234                 :             : 
    1235                 :           0 : void GenericClusterImpl::Clear(TxGraphImpl& graph, int level) noexcept
    1236                 :             : {
    1237         [ #  # ]:           0 :     Assume(GetTxCount());
    1238                 :           0 :     graph.GetClusterSet(level).m_cluster_usage -= TotalMemoryUsage();
    1239         [ #  # ]:           0 :     for (auto i : m_linearization) {
    1240                 :           0 :         graph.ClearLocator(level, m_mapping[i], m_quality == QualityLevel::OVERSIZED_SINGLETON);
    1241                 :             :     }
    1242                 :           0 :     m_depgraph = {};
    1243         [ #  # ]:           0 :     m_linearization.clear();
    1244         [ #  # ]:           0 :     m_mapping.clear();
    1245                 :           0 : }
    1246                 :             : 
    1247                 :           0 : void SingletonClusterImpl::Clear(TxGraphImpl& graph, int level) noexcept
    1248                 :             : {
    1249                 :           0 :     Assume(GetTxCount());
    1250                 :           0 :     graph.GetClusterSet(level).m_cluster_usage -= TotalMemoryUsage();
    1251                 :           0 :     graph.ClearLocator(level, m_graph_index, m_quality == QualityLevel::OVERSIZED_SINGLETON);
    1252                 :           0 :     m_graph_index = NO_GRAPH_INDEX;
    1253                 :           0 : }
    1254                 :             : 
    1255                 :           0 : void GenericClusterImpl::MoveToMain(TxGraphImpl& graph) noexcept
    1256                 :             : {
    1257         [ #  # ]:           0 :     for (auto i : m_linearization) {
    1258                 :           0 :         GraphIndex idx = m_mapping[i];
    1259                 :           0 :         auto& entry = graph.m_entries[idx];
    1260                 :           0 :         entry.m_locator[1].SetMissing();
    1261                 :             :     }
    1262                 :           0 :     auto quality = m_quality;
    1263                 :             :     // Subtract memory usage from staging and add it to main.
    1264                 :           0 :     graph.GetClusterSet(/*level=*/1).m_cluster_usage -= TotalMemoryUsage();
    1265                 :           0 :     graph.GetClusterSet(/*level=*/0).m_cluster_usage += TotalMemoryUsage();
    1266                 :             :     // Remove cluster itself from staging and add it to main.
    1267                 :           0 :     auto cluster = graph.ExtractCluster(1, quality, m_setindex);
    1268                 :           0 :     graph.InsertCluster(/*level=*/0, std::move(cluster), quality);
    1269                 :           0 :     Updated(graph, /*level=*/0);
    1270                 :           0 : }
    1271                 :             : 
    1272                 :           0 : void SingletonClusterImpl::MoveToMain(TxGraphImpl& graph) noexcept
    1273                 :             : {
    1274         [ #  # ]:           0 :     if (GetTxCount()) {
    1275                 :           0 :         auto& entry = graph.m_entries[m_graph_index];
    1276                 :           0 :         entry.m_locator[1].SetMissing();
    1277                 :             :     }
    1278                 :           0 :     auto quality = m_quality;
    1279                 :           0 :     graph.GetClusterSet(/*level=*/1).m_cluster_usage -= TotalMemoryUsage();
    1280                 :           0 :     auto cluster = graph.ExtractCluster(/*level=*/1, quality, m_setindex);
    1281                 :           0 :     graph.InsertCluster(/*level=*/0, std::move(cluster), quality);
    1282                 :           0 :     graph.GetClusterSet(/*level=*/0).m_cluster_usage += TotalMemoryUsage();
    1283                 :           0 :     Updated(graph, /*level=*/0);
    1284                 :           0 : }
    1285                 :             : 
    1286                 :           0 : void GenericClusterImpl::Compact() noexcept
    1287                 :             : {
    1288                 :           0 :     m_linearization.shrink_to_fit();
    1289                 :           0 :     m_mapping.shrink_to_fit();
    1290                 :           0 :     m_depgraph.Compact();
    1291                 :           0 : }
    1292                 :             : 
    1293                 :           0 : void SingletonClusterImpl::Compact() noexcept
    1294                 :             : {
    1295                 :             :     // Nothing to compact; SingletonClusterImpl is constant size.
    1296                 :           0 : }
    1297                 :             : 
    1298                 :           0 : void GenericClusterImpl::AppendChunkFeerates(std::vector<FeeFrac>& ret) const noexcept
    1299                 :             : {
    1300         [ #  # ]:           0 :     auto chunk_feerates = ChunkLinearization(m_depgraph, m_linearization);
    1301   [ #  #  #  # ]:           0 :     ret.reserve(ret.size() + chunk_feerates.size());
    1302                 :           0 :     ret.insert(ret.end(), chunk_feerates.begin(), chunk_feerates.end());
    1303                 :           0 : }
    1304                 :             : 
    1305                 :           0 : void SingletonClusterImpl::AppendChunkFeerates(std::vector<FeeFrac>& ret) const noexcept
    1306                 :             : {
    1307         [ #  # ]:           0 :     if (GetTxCount()) {
    1308                 :           0 :         ret.push_back(m_feerate);
    1309                 :             :     }
    1310                 :           0 : }
    1311                 :             : 
    1312                 :           0 : uint64_t GenericClusterImpl::AppendTrimData(std::vector<TrimTxData>& ret, std::vector<std::pair<GraphIndex, GraphIndex>>& deps) const noexcept
    1313                 :             : {
    1314         [ #  # ]:           0 :     const LinearizationChunking linchunking(m_depgraph, m_linearization);
    1315                 :           0 :     LinearizationIndex pos{0};
    1316                 :           0 :     uint64_t size{0};
    1317                 :           0 :     auto prev_index = GraphIndex(-1);
    1318                 :             :     // Iterate over the chunks of this cluster's linearization.
    1319   [ #  #  #  # ]:           0 :     for (unsigned i = 0; i < linchunking.NumChunksLeft(); ++i) {
    1320                 :           0 :         const auto& [chunk, chunk_feerate] = linchunking.GetChunk(i);
    1321                 :             :         // Iterate over the transactions of that chunk, in linearization order.
    1322                 :           0 :         auto chunk_tx_count = chunk.Count();
    1323         [ #  # ]:           0 :         for (unsigned j = 0; j < chunk_tx_count; ++j) {
    1324                 :           0 :             auto cluster_idx = m_linearization[pos];
    1325                 :             :             // The transaction must appear in the chunk.
    1326                 :           0 :             Assume(chunk[cluster_idx]);
    1327                 :             :             // Construct a new element in ret.
    1328                 :           0 :             auto& entry = ret.emplace_back();
    1329         [ #  # ]:           0 :             entry.m_chunk_feerate = FeePerWeight::FromFeeFrac(chunk_feerate);
    1330         [ #  # ]:           0 :             entry.m_index = m_mapping[cluster_idx];
    1331                 :             :             // If this is not the first transaction of the cluster linearization, it has an
    1332                 :             :             // implicit dependency on its predecessor.
    1333         [ #  # ]:           0 :             if (pos != 0) deps.emplace_back(prev_index, entry.m_index);
    1334                 :           0 :             prev_index = entry.m_index;
    1335                 :           0 :             entry.m_tx_size = m_depgraph.FeeRate(cluster_idx).size;
    1336                 :           0 :             size += entry.m_tx_size;
    1337                 :           0 :             ++pos;
    1338                 :             :         }
    1339                 :             :     }
    1340                 :           0 :     return size;
    1341                 :           0 : }
    1342                 :             : 
    1343                 :       64217 : uint64_t SingletonClusterImpl::AppendTrimData(std::vector<TrimTxData>& ret, std::vector<std::pair<GraphIndex, GraphIndex>>& deps) const noexcept
    1344                 :             : {
    1345         [ +  - ]:       64217 :     if (!GetTxCount()) return 0;
    1346                 :       64217 :     auto& entry = ret.emplace_back();
    1347                 :       64217 :     entry.m_chunk_feerate = m_feerate;
    1348                 :       64217 :     entry.m_index = m_graph_index;
    1349                 :       64217 :     entry.m_tx_size = m_feerate.size;
    1350                 :       64217 :     return m_feerate.size;
    1351                 :             : }
    1352                 :             : 
    1353                 :           0 : bool GenericClusterImpl::Split(TxGraphImpl& graph, int level) noexcept
    1354                 :             : {
    1355                 :             :     // This function can only be called when the Cluster needs splitting.
    1356                 :           0 :     Assume(NeedsSplitting());
    1357                 :             :     // Determine the new quality the split-off Clusters will have.
    1358         [ #  # ]:           0 :     QualityLevel new_quality = IsAcceptable(/*after_split=*/true) ? QualityLevel::ACCEPTABLE
    1359                 :             :                                                                   : QualityLevel::NEEDS_RELINEARIZE;
    1360                 :             :     // If we're going to produce ACCEPTABLE clusters (i.e., when in NEEDS_SPLIT_ACCEPTABLE), we
    1361                 :             :     // need to post-linearize to make sure the split-out versions are all connected (as
    1362                 :             :     // connectivity may have changed by removing part of the cluster). This could be done on each
    1363                 :             :     // resulting split-out cluster separately, but it is simpler to do it once up front before
    1364                 :             :     // splitting. This step is not necessary if the resulting clusters are NEEDS_RELINEARIZE, as
    1365                 :             :     // they will be post-linearized anyway in MakeAcceptable().
    1366                 :             :     if (new_quality == QualityLevel::ACCEPTABLE) {
    1367         [ #  # ]:           0 :         PostLinearize(m_depgraph, m_linearization);
    1368                 :             :     }
    1369                 :             :     /** Which positions are still left in this Cluster. */
    1370                 :           0 :     auto todo = m_depgraph.Positions();
    1371                 :             :     /** Mapping from transaction positions in this Cluster to the Cluster where it ends up, and
    1372                 :             :      *  its position therein. */
    1373         [ #  # ]:           0 :     std::vector<std::pair<Cluster*, DepGraphIndex>> remap(m_depgraph.PositionRange());
    1374                 :           0 :     std::vector<Cluster*> new_clusters;
    1375                 :           0 :     bool first{true};
    1376                 :             :     // Iterate over the connected components of this Cluster's m_depgraph.
    1377         [ #  # ]:           0 :     while (todo.Any()) {
    1378                 :           0 :         auto component = m_depgraph.FindConnectedComponent(todo);
    1379         [ #  # ]:           0 :         auto component_size = component.Count();
    1380         [ #  # ]:           0 :         auto split_quality = component_size <= 2 ? QualityLevel::OPTIMAL : new_quality;
    1381   [ #  #  #  #  :           0 :         if (first && component == todo && SetType::Fill(component_size) == component && component_size >= MIN_INTENDED_TX_COUNT) {
             #  #  #  # ]
    1382                 :             :             // The existing Cluster is an entire component, without holes. Leave it be, but update
    1383                 :             :             // its quality. If there are holes, we continue, so that the Cluster is reconstructed
    1384                 :             :             // without holes, reducing memory usage. If the component's size is below the intended
    1385                 :             :             // transaction count for this Cluster implementation, continue so that it can get
    1386                 :             :             // converted.
    1387                 :           0 :             Assume(todo == m_depgraph.Positions());
    1388                 :           0 :             graph.SetClusterQuality(level, m_quality, m_setindex, split_quality);
    1389                 :             :             // If this made the quality ACCEPTABLE or OPTIMAL, we need to compute and cache its
    1390                 :             :             // chunking.
    1391                 :           0 :             Updated(graph, level);
    1392                 :           0 :             return false;
    1393                 :             :         }
    1394                 :           0 :         first = false;
    1395                 :             :         // Construct a new Cluster to hold the found component.
    1396                 :           0 :         auto new_cluster = graph.CreateEmptyCluster(component_size);
    1397                 :           0 :         new_clusters.push_back(new_cluster.get());
    1398                 :             :         // Remember that all the component's transactions go to this new Cluster. The positions
    1399                 :             :         // will be determined below, so use -1 for now.
    1400   [ #  #  #  # ]:           0 :         for (auto i : component) {
    1401         [ #  # ]:           0 :             remap[i] = {new_cluster.get(), DepGraphIndex(-1)};
    1402                 :             :         }
    1403                 :           0 :         graph.InsertCluster(level, std::move(new_cluster), split_quality);
    1404                 :           0 :         todo -= component;
    1405                 :           0 :     }
    1406                 :             :     // We have to split the Cluster up. Remove accounting for the existing one first.
    1407                 :           0 :     graph.GetClusterSet(level).m_cluster_usage -= TotalMemoryUsage();
    1408                 :             :     // Redistribute the transactions.
    1409         [ #  # ]:           0 :     for (auto i : m_linearization) {
    1410                 :             :         /** The cluster which transaction originally in position i is moved to. */
    1411                 :           0 :         Cluster* new_cluster = remap[i].first;
    1412                 :             :         // Copy the transaction to the new cluster's depgraph, and remember the position.
    1413                 :           0 :         remap[i].second = new_cluster->AppendTransaction(m_mapping[i], FeePerWeight::FromFeeFrac(m_depgraph.FeeRate(i)));
    1414                 :             :     }
    1415                 :             :     // Redistribute the dependencies.
    1416         [ #  # ]:           0 :     for (auto i : m_linearization) {
    1417                 :             :         /** The cluster transaction in position i is moved to. */
    1418                 :           0 :         Cluster* new_cluster = remap[i].first;
    1419                 :             :         // Copy its parents, translating positions.
    1420                 :           0 :         SetType new_parents;
    1421   [ #  #  #  #  :           0 :         for (auto par : m_depgraph.GetReducedParents(i)) new_parents.Set(remap[par].second);
                   #  # ]
    1422                 :           0 :         new_cluster->AddDependencies(new_parents, remap[i].second);
    1423                 :             :     }
    1424                 :             :     // Update all the Locators of moved transactions, and memory usage.
    1425         [ #  # ]:           0 :     for (Cluster* new_cluster : new_clusters) {
    1426                 :           0 :         new_cluster->Updated(graph, level);
    1427                 :           0 :         new_cluster->Compact();
    1428                 :           0 :         graph.GetClusterSet(level).m_cluster_usage += new_cluster->TotalMemoryUsage();
    1429                 :             :     }
    1430                 :             :     // Wipe this Cluster, and return that it needs to be deleted.
    1431                 :           0 :     m_depgraph = DepGraph<SetType>{};
    1432         [ #  # ]:           0 :     m_mapping.clear();
    1433         [ #  # ]:           0 :     m_linearization.clear();
    1434                 :             :     return true;
    1435                 :           0 : }
    1436                 :             : 
    1437                 :           0 : bool SingletonClusterImpl::Split(TxGraphImpl& graph, int level) noexcept
    1438                 :             : {
    1439                 :           0 :     Assume(NeedsSplitting());
    1440         [ #  # ]:           0 :     if (GetTxCount() == 0) {
    1441                 :             :         // The cluster is now empty.
    1442                 :           0 :         graph.GetClusterSet(level).m_cluster_usage -= TotalMemoryUsage();
    1443                 :           0 :         return true;
    1444                 :             :     } else {
    1445                 :             :         // Nothing changed.
    1446                 :           0 :         graph.SetClusterQuality(level, m_quality, m_setindex, QualityLevel::OPTIMAL);
    1447                 :           0 :         Updated(graph, level);
    1448                 :           0 :         return false;
    1449                 :             :     }
    1450                 :             : }
    1451                 :             : 
    1452                 :           0 : void GenericClusterImpl::Merge(TxGraphImpl& graph, int level, Cluster& other) noexcept
    1453                 :             : {
    1454                 :             :     /** Vector to store the positions in this Cluster for each position in other. */
    1455                 :           0 :     std::vector<DepGraphIndex> remap(other.GetDepGraphIndexRange());
    1456                 :             :     // Iterate over all transactions in the other Cluster (the one being absorbed).
    1457                 :           0 :     other.ExtractTransactions([&](DepGraphIndex pos, GraphIndex idx, FeePerWeight feerate, SetType other_parents) noexcept {
    1458                 :             :         // Copy the transaction into this Cluster, and remember its position.
    1459                 :           0 :         auto new_pos = m_depgraph.AddTransaction(feerate);
    1460                 :             :         // Since this cluster must have been made hole-free before being merged into, all added
    1461                 :             :         // transactions should appear at the end.
    1462         [ #  # ]:           0 :         Assume(new_pos == m_mapping.size());
    1463                 :           0 :         remap[pos] = new_pos;
    1464                 :           0 :         m_mapping.push_back(idx);
    1465                 :           0 :         m_linearization.push_back(new_pos);
    1466                 :             :         // Copy the transaction's dependencies, translating them using remap. Note that since
    1467                 :             :         // pos iterates in linearization order, which is topological, all parents of pos should
    1468                 :             :         // already be in remap.
    1469                 :           0 :         SetType parents;
    1470   [ #  #  #  # ]:           0 :         for (auto par : other_parents) {
    1471         [ #  # ]:           0 :             parents.Set(remap[par]);
    1472                 :             :         }
    1473                 :           0 :         m_depgraph.AddDependencies(parents, remap[pos]);
    1474                 :             :         // Update the transaction's Locator. There is no need to call Updated() to update chunk
    1475                 :             :         // feerates, as Updated() will be invoked by Cluster::ApplyDependencies on the resulting
    1476                 :             :         // merged Cluster later anyway.
    1477         [ #  # ]:           0 :         auto& entry = graph.m_entries[idx];
    1478                 :             :         // Discard any potential ChunkData prior to modifying the Cluster (as that could
    1479                 :             :         // invalidate its ordering).
    1480         [ #  # ]:           0 :         if (level == 0) graph.ClearChunkData(entry);
    1481                 :           0 :         entry.m_locator[level].SetPresent(this, new_pos);
    1482                 :           0 :     });
    1483                 :           0 : }
    1484                 :             : 
    1485                 :           0 : void SingletonClusterImpl::Merge(TxGraphImpl& graph, int level, Cluster& other_abstract) noexcept
    1486                 :             : {
    1487                 :             :     // Nothing can be merged into a singleton; it should have been converted to GenericClusterImpl
    1488                 :             :     // first.
    1489                 :           0 :     Assume(false);
    1490                 :           0 : }
    1491                 :             : 
    1492                 :           0 : void GenericClusterImpl::ApplyDependencies(TxGraphImpl& graph, int level, std::span<std::pair<GraphIndex, GraphIndex>> to_apply) noexcept
    1493                 :             : {
    1494                 :             :     // This function is invoked by TxGraphImpl::ApplyDependencies after merging groups of Clusters
    1495                 :             :     // between which dependencies are added, which simply concatenates their linearizations. Invoke
    1496                 :             :     // PostLinearize, which has the effect that the linearization becomes a merge-sort of the
    1497                 :             :     // constituent linearizations. Do this here rather than in Cluster::Merge, because this
    1498                 :             :     // function is only invoked once per merged Cluster, rather than once per constituent one.
    1499                 :             :     // This concatenation + post-linearization could be replaced with an explicit merge-sort.
    1500         [ #  # ]:           0 :     PostLinearize(m_depgraph, m_linearization);
    1501                 :             : 
    1502                 :             :     // Sort the list of dependencies to apply by child, so those can be applied in batch.
    1503   [ #  #  #  #  :           0 :     std::sort(to_apply.begin(), to_apply.end(), [](auto& a, auto& b) { return a.second < b.second; });
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
             #  #  #  #  
                      # ]
    1504                 :             :     // Iterate over groups of to-be-added dependencies with the same child.
    1505                 :           0 :     auto it = to_apply.begin();
    1506         [ #  # ]:           0 :     while (it != to_apply.end()) {
    1507                 :           0 :         auto& first_child = graph.m_entries[it->second].m_locator[level];
    1508                 :           0 :         const auto child_idx = first_child.index;
    1509                 :             :         // Iterate over all to-be-added dependencies within that same child, gather the relevant
    1510                 :             :         // parents.
    1511                 :           0 :         SetType parents;
    1512         [ #  # ]:           0 :         while (it != to_apply.end()) {
    1513         [ #  # ]:           0 :             auto& child = graph.m_entries[it->second].m_locator[level];
    1514                 :           0 :             auto& parent = graph.m_entries[it->first].m_locator[level];
    1515                 :           0 :             Assume(child.cluster == this && parent.cluster == this);
    1516         [ #  # ]:           0 :             if (child.index != child_idx) break;
    1517                 :           0 :             parents.Set(parent.index);
    1518                 :           0 :             ++it;
    1519                 :             :         }
    1520                 :             :         // Push all dependencies to the underlying DepGraph. Note that this is O(N) in the size of
    1521                 :             :         // the cluster, regardless of the number of parents being added, so batching them together
    1522                 :             :         // has a performance benefit.
    1523                 :           0 :         m_depgraph.AddDependencies(parents, child_idx);
    1524                 :             :     }
    1525                 :             : 
    1526                 :             :     // Finally fix the linearization, as the new dependencies may have invalidated the
    1527                 :             :     // linearization, and post-linearize it to fix up the worst problems with it.
    1528         [ #  # ]:           0 :     FixLinearization(m_depgraph, m_linearization);
    1529         [ #  # ]:           0 :     PostLinearize(m_depgraph, m_linearization);
    1530                 :           0 :     Assume(!NeedsSplitting());
    1531                 :           0 :     Assume(!IsOversized());
    1532         [ #  # ]:           0 :     if (IsAcceptable()) {
    1533                 :           0 :         graph.SetClusterQuality(level, m_quality, m_setindex, QualityLevel::NEEDS_RELINEARIZE);
    1534                 :             :     }
    1535                 :             : 
    1536                 :             :     // Finally push the changes to graph.m_entries.
    1537                 :           0 :     Updated(graph, level);
    1538                 :           0 : }
    1539                 :             : 
    1540                 :           0 : void SingletonClusterImpl::ApplyDependencies(TxGraphImpl& graph, int level, std::span<std::pair<GraphIndex, GraphIndex>> to_apply) noexcept
    1541                 :             : {
    1542                 :             :     // Nothing can actually be applied.
    1543         [ #  # ]:           0 :     for (auto& [par, chl] : to_apply) {
    1544                 :           0 :         Assume(par == m_graph_index);
    1545                 :           0 :         Assume(chl == m_graph_index);
    1546                 :             :     }
    1547                 :           0 : }
    1548                 :             : 
    1549                 :           8 : TxGraphImpl::~TxGraphImpl() noexcept
    1550                 :             : {
    1551                 :             :     // If Refs outlive the TxGraphImpl they refer to, unlink them, so that their destructor does not
    1552                 :             :     // try to reach into a non-existing TxGraphImpl anymore.
    1553         [ +  + ]:       64314 :     for (auto& entry : m_entries) {
    1554         [ +  + ]:       64310 :         if (entry.m_ref != nullptr) {
    1555                 :       64011 :             GetRefGraph(*entry.m_ref) = nullptr;
    1556                 :             :         }
    1557                 :             :     }
    1558                 :           8 : }
    1559                 :             : 
    1560                 :          19 : std::unique_ptr<Cluster> TxGraphImpl::ExtractCluster(int level, QualityLevel quality, ClusterSetIndex setindex) noexcept
    1561                 :             : {
    1562                 :          19 :     Assume(quality != QualityLevel::NONE);
    1563                 :             : 
    1564                 :          19 :     auto& clusterset = GetClusterSet(level);
    1565         [ -  + ]:          19 :     auto& quality_clusters = clusterset.m_clusters[int(quality)];
    1566         [ -  + ]:          19 :     Assume(setindex < quality_clusters.size());
    1567                 :             : 
    1568                 :             :     // Extract the Cluster-owning unique_ptr.
    1569         [ -  + ]:          19 :     std::unique_ptr<Cluster> ret = std::move(quality_clusters[setindex]);
    1570         [ -  + ]:          19 :     ret->m_quality = QualityLevel::NONE;
    1571                 :          19 :     ret->m_setindex = ClusterSetIndex(-1);
    1572                 :             : 
    1573                 :             :     // Clean up space in quality_cluster.
    1574         [ -  + ]:          19 :     auto max_setindex = quality_clusters.size() - 1;
    1575         [ +  + ]:          19 :     if (setindex != max_setindex) {
    1576                 :             :         // If the cluster was not the last element of quality_clusters, move that to take its place.
    1577                 :          10 :         quality_clusters.back()->m_setindex = setindex;
    1578                 :          10 :         quality_clusters[setindex] = std::move(quality_clusters.back());
    1579                 :             :     }
    1580                 :             :     // The last element of quality_clusters is now unused; drop it.
    1581                 :          19 :     quality_clusters.pop_back();
    1582                 :             : 
    1583                 :          19 :     return ret;
    1584                 :             : }
    1585                 :             : 
    1586                 :       64330 : ClusterSetIndex TxGraphImpl::InsertCluster(int level, std::unique_ptr<Cluster>&& cluster, QualityLevel quality) noexcept
    1587                 :             : {
    1588                 :             :     // Cannot insert with quality level NONE (as that would mean not inserted).
    1589                 :       64330 :     Assume(quality != QualityLevel::NONE);
    1590                 :             :     // The passed-in Cluster must not currently be in the TxGraphImpl.
    1591         [ -  + ]:       64330 :     Assume(cluster->m_quality == QualityLevel::NONE);
    1592                 :             : 
    1593                 :             :     // Append it at the end of the relevant TxGraphImpl::m_cluster.
    1594                 :       64330 :     auto& clusterset = GetClusterSet(level);
    1595         [ -  + ]:       64330 :     auto& quality_clusters = clusterset.m_clusters[int(quality)];
    1596         [ -  + ]:       64330 :     ClusterSetIndex ret = quality_clusters.size();
    1597                 :       64330 :     cluster->m_quality = quality;
    1598                 :       64330 :     cluster->m_setindex = ret;
    1599                 :       64330 :     quality_clusters.push_back(std::move(cluster));
    1600                 :       64330 :     return ret;
    1601                 :             : }
    1602                 :             : 
    1603                 :          19 : void TxGraphImpl::SetClusterQuality(int level, QualityLevel old_quality, ClusterSetIndex old_index, QualityLevel new_quality) noexcept
    1604                 :             : {
    1605                 :          19 :     Assume(new_quality != QualityLevel::NONE);
    1606                 :             : 
    1607                 :             :     // Don't do anything if the quality did not change.
    1608         [ +  - ]:          19 :     if (old_quality == new_quality) return;
    1609                 :             :     // Extract the cluster from where it currently resides.
    1610                 :          19 :     auto cluster_ptr = ExtractCluster(level, old_quality, old_index);
    1611                 :             :     // And re-insert it where it belongs.
    1612                 :          19 :     InsertCluster(level, std::move(cluster_ptr), new_quality);
    1613                 :          19 : }
    1614                 :             : 
    1615                 :           0 : void TxGraphImpl::DeleteCluster(Cluster& cluster, int level) noexcept
    1616                 :             : {
    1617                 :             :     // Extract the cluster from where it currently resides.
    1618                 :           0 :     auto cluster_ptr = ExtractCluster(level, cluster.m_quality, cluster.m_setindex);
    1619                 :             :     // And throw it away.
    1620         [ #  # ]:           0 :     cluster_ptr.reset();
    1621                 :           0 : }
    1622                 :             : 
    1623                 :      892818 : std::pair<Cluster*, int> TxGraphImpl::FindClusterAndLevel(GraphIndex idx, int level) const noexcept
    1624                 :             : {
    1625         [ +  - ]:      892818 :     Assume(level >= 0 && level <= GetTopLevel());
    1626                 :      892818 :     auto& entry = m_entries[idx];
    1627                 :             :     // Search the entry's locators from top to bottom.
    1628         [ +  + ]:      892826 :     for (int l = level; l >= 0; --l) {
    1629                 :             :         // If the locator is missing, dig deeper; it may exist at a lower level and therefore be
    1630                 :             :         // implicitly existing at this level too.
    1631         [ +  + ]:      892826 :         if (entry.m_locator[l].IsMissing()) continue;
    1632                 :             :         // If the locator has the entry marked as explicitly removed, stop.
    1633         [ -  + ]:      892810 :         if (entry.m_locator[l].IsRemoved()) break;
    1634                 :             :         // Otherwise, we have found the topmost ClusterSet that contains this entry.
    1635                 :      892810 :         return {entry.m_locator[l].cluster, l};
    1636                 :             :     }
    1637                 :             :     // If no non-empty locator was found, or an explicitly removed was hit, return nothing.
    1638                 :           8 :     return {nullptr, -1};
    1639                 :             : }
    1640                 :             : 
    1641                 :           0 : Cluster* TxGraphImpl::PullIn(Cluster* cluster, int level) noexcept
    1642                 :             : {
    1643         [ #  # ]:           0 :     int to_level = GetTopLevel();
    1644                 :           0 :     Assume(to_level == 1);
    1645                 :           0 :     Assume(level <= to_level);
    1646                 :             :     // Copy the Cluster from main to staging, if it's not already there.
    1647         [ #  # ]:           0 :     if (level == 0) {
    1648                 :             :         // Make the Cluster Acceptable before copying. This isn't strictly necessary, but doing it
    1649                 :             :         // now avoids doing double work later.
    1650                 :           0 :         MakeAcceptable(*cluster, level);
    1651                 :           0 :         cluster = cluster->CopyToStaging(*this);
    1652                 :             :     }
    1653                 :           0 :     return cluster;
    1654                 :             : }
    1655                 :             : 
    1656                 :         316 : void TxGraphImpl::ApplyRemovals(int up_to_level) noexcept
    1657                 :             : {
    1658         [ +  - ]:         316 :     Assume(up_to_level >= 0 && up_to_level <= GetTopLevel());
    1659         [ +  + ]:         632 :     for (int level = 0; level <= up_to_level; ++level) {
    1660                 :         316 :         auto& clusterset = GetClusterSet(level);
    1661                 :         316 :         auto& to_remove = clusterset.m_to_remove;
    1662                 :             :         // Skip if there is nothing to remove in this level.
    1663         [ +  + ]:         316 :         if (to_remove.empty()) continue;
    1664                 :             :         // Pull in all Clusters that are not in staging.
    1665         [ -  + ]:           4 :         if (level == 1) {
    1666         [ #  # ]:           0 :             for (GraphIndex index : to_remove) {
    1667         [ #  # ]:           0 :                 auto [cluster, cluster_level] = FindClusterAndLevel(index, level);
    1668         [ #  # ]:           0 :                 if (cluster != nullptr) PullIn(cluster, cluster_level);
    1669                 :             :             }
    1670                 :             :         }
    1671                 :             :         // Group the set of to-be-removed entries by Cluster::m_sequence.
    1672                 :           4 :         std::sort(to_remove.begin(), to_remove.end(), [&](GraphIndex a, GraphIndex b) noexcept {
    1673                 :          30 :             Cluster* cluster_a = m_entries[a].m_locator[level].cluster;
    1674                 :          30 :             Cluster* cluster_b = m_entries[b].m_locator[level].cluster;
    1675                 :          30 :             return CompareClusters(cluster_a, cluster_b) < 0;
    1676                 :             :         });
    1677                 :             :         // Process per Cluster.
    1678         [ -  + ]:           4 :         std::span to_remove_span{to_remove};
    1679         [ +  + ]:          23 :         while (!to_remove_span.empty()) {
    1680         [ +  - ]:          19 :             Cluster* cluster = m_entries[to_remove_span.front()].m_locator[level].cluster;
    1681         [ +  - ]:          19 :             if (cluster != nullptr) {
    1682                 :             :                 // If the first to_remove_span entry's Cluster exists, hand to_remove_span to it, so it
    1683                 :             :                 // can pop off whatever applies to it.
    1684                 :          19 :                 cluster->ApplyRemovals(*this, level, to_remove_span);
    1685                 :             :             } else {
    1686                 :             :                 // Otherwise, skip this already-removed entry. This may happen when
    1687                 :             :                 // RemoveTransaction was called twice on the same Ref, for example.
    1688                 :           0 :                 to_remove_span = to_remove_span.subspan(1);
    1689                 :             :             }
    1690                 :             :         }
    1691         [ +  - ]:         320 :         to_remove.clear();
    1692                 :             :     }
    1693                 :         316 :     Compact();
    1694                 :         316 : }
    1695                 :             : 
    1696                 :           1 : void TxGraphImpl::SwapIndexes(GraphIndex a, GraphIndex b) noexcept
    1697                 :             : {
    1698         [ -  + ]:           1 :     Assume(a < m_entries.size());
    1699                 :           1 :     Assume(b < m_entries.size());
    1700                 :             :     // Swap the Entry objects.
    1701                 :           1 :     std::swap(m_entries[a], m_entries[b]);
    1702                 :             :     // Iterate over both objects.
    1703         [ +  + ]:           3 :     for (int i = 0; i < 2; ++i) {
    1704         [ +  + ]:           2 :         GraphIndex idx = i ? b : a;
    1705         [ +  + ]:           2 :         Entry& entry = m_entries[idx];
    1706                 :             :         // Update linked Ref, if any exists.
    1707         [ +  + ]:           2 :         if (entry.m_ref) GetRefIndex(*entry.m_ref) = idx;
    1708                 :             :         // Update linked chunk index entries, if any exist.
    1709         [ +  + ]:           2 :         if (entry.m_main_chunkindex_iterator != m_main_chunkindex.end()) {
    1710                 :           1 :             entry.m_main_chunkindex_iterator->m_graph_index = idx;
    1711                 :             :         }
    1712                 :             :         // Update the locators for both levels. The rest of the Entry information will not change,
    1713                 :             :         // so no need to invoke Cluster::Updated().
    1714         [ +  + ]:           6 :         for (int level = 0; level < MAX_LEVELS; ++level) {
    1715                 :           4 :             Locator& locator = entry.m_locator[level];
    1716         [ +  + ]:           4 :             if (locator.IsPresent()) {
    1717                 :           1 :                 locator.cluster->UpdateMapping(locator.index, idx);
    1718                 :             :             }
    1719                 :             :         }
    1720                 :             :     }
    1721                 :           1 : }
    1722                 :             : 
    1723                 :         329 : void TxGraphImpl::Compact() noexcept
    1724                 :             : {
    1725                 :             :     // We cannot compact while any to-be-applied operations or staged removals remain as we'd need
    1726                 :             :     // to rewrite them. It is easier to delay the compaction until they have been applied.
    1727         [ +  + ]:         329 :     if (!m_main_clusterset.m_deps_to_add.empty()) return;
    1728         [ +  + ]:         109 :     if (!m_main_clusterset.m_to_remove.empty()) return;
    1729                 :         104 :     Assume(m_main_clusterset.m_removed.empty()); // non-staging m_removed is always empty
    1730         [ -  + ]:         104 :     if (m_staging_clusterset.has_value()) {
    1731         [ #  # ]:           0 :         if (!m_staging_clusterset->m_deps_to_add.empty()) return;
    1732         [ #  # ]:           0 :         if (!m_staging_clusterset->m_to_remove.empty()) return;
    1733         [ #  # ]:           0 :         if (!m_staging_clusterset->m_removed.empty()) return;
    1734                 :             :     }
    1735                 :             : 
    1736                 :             :     // Release memory used by discarded ChunkData index entries.
    1737                 :         104 :     ClearShrink(m_main_chunkindex_discarded);
    1738                 :             : 
    1739                 :             :     // Sort the GraphIndexes that need to be cleaned up. They are sorted in reverse, so the last
    1740                 :             :     // ones get processed first. This means earlier-processed GraphIndexes will not cause moving of
    1741                 :             :     // later-processed ones during the "swap with end of m_entries" step below (which might
    1742                 :             :     // invalidate them).
    1743                 :         104 :     std::sort(m_unlinked.begin(), m_unlinked.end(), std::greater{});
    1744                 :             : 
    1745                 :         104 :     auto last = GraphIndex(-1);
    1746         [ +  + ]:         105 :     for (GraphIndex idx : m_unlinked) {
    1747                 :             :         // m_unlinked should never contain the same GraphIndex twice (the code below would fail
    1748                 :             :         // if so, because GraphIndexes get invalidated by removing them).
    1749                 :           1 :         Assume(idx != last);
    1750                 :           1 :         last = idx;
    1751                 :             : 
    1752                 :             :         // Make sure the entry is unlinked.
    1753                 :           1 :         Entry& entry = m_entries[idx];
    1754                 :           1 :         Assume(entry.m_ref == nullptr);
    1755                 :             :         // Make sure the entry does not occur in the graph.
    1756         [ +  + ]:           3 :         for (int level = 0; level < MAX_LEVELS; ++level) {
    1757                 :           2 :             Assume(!entry.m_locator[level].IsPresent());
    1758                 :             :         }
    1759                 :             : 
    1760                 :             :         // Move the entry to the end.
    1761   [ -  +  +  - ]:           1 :         if (idx != m_entries.size() - 1) SwapIndexes(idx, m_entries.size() - 1);
    1762                 :             :         // Drop the entry for idx, now that it is at the end.
    1763                 :           1 :         m_entries.pop_back();
    1764                 :             :     }
    1765         [ +  + ]:         104 :     m_unlinked.clear();
    1766                 :             : }
    1767                 :             : 
    1768                 :           0 : void TxGraphImpl::Split(Cluster& cluster, int level) noexcept
    1769                 :             : {
    1770                 :             :     // To split a Cluster, first make sure all removals are applied (as we might need to split
    1771                 :             :     // again afterwards otherwise).
    1772                 :           0 :     ApplyRemovals(level);
    1773                 :           0 :     bool del = cluster.Split(*this, level);
    1774         [ #  # ]:           0 :     if (del) {
    1775                 :             :         // Cluster::Split reports whether the Cluster is to be deleted.
    1776                 :           0 :         DeleteCluster(cluster, level);
    1777                 :             :     }
    1778                 :           0 : }
    1779                 :             : 
    1780                 :           5 : void TxGraphImpl::SplitAll(int up_to_level) noexcept
    1781                 :             : {
    1782         [ +  - ]:           5 :     Assume(up_to_level >= 0 && up_to_level <= GetTopLevel());
    1783                 :             :     // Before splitting all Cluster, first make sure all removals are applied.
    1784                 :           5 :     ApplyRemovals(up_to_level);
    1785         [ +  + ]:          10 :     for (int level = 0; level <= up_to_level; ++level) {
    1786         [ +  + ]:          15 :         for (auto quality : {QualityLevel::NEEDS_SPLIT, QualityLevel::NEEDS_SPLIT_ACCEPTABLE}) {
    1787                 :          10 :             auto& queue = GetClusterSet(level).m_clusters[int(quality)];
    1788         [ -  + ]:          10 :             while (!queue.empty()) {
    1789                 :           0 :                 Split(*queue.back().get(), level);
    1790                 :             :             }
    1791                 :             :         }
    1792                 :             :     }
    1793                 :           5 : }
    1794                 :             : 
    1795                 :           8 : void TxGraphImpl::GroupClusters(int level) noexcept
    1796                 :             : {
    1797                 :           8 :     auto& clusterset = GetClusterSet(level);
    1798                 :             :     // If the groupings have been computed already, nothing is left to be done.
    1799         [ +  + ]:           8 :     if (clusterset.m_group_data.has_value()) return;
    1800                 :             : 
    1801                 :             :     // Before computing which Clusters need to be merged together, first apply all removals and
    1802                 :             :     // split the Clusters into connected components. If we would group first, we might end up
    1803                 :             :     // with inefficient and/or oversized Clusters which just end up being split again anyway.
    1804                 :           5 :     SplitAll(level);
    1805                 :             : 
    1806                 :             :     /** Annotated clusters: an entry for each Cluster, together with the sequence number for the
    1807                 :             :      *  representative for the partition it is in (initially its own, later that of the
    1808                 :             :      *  to-be-merged group). */
    1809                 :           5 :     std::vector<std::pair<Cluster*, uint64_t>> an_clusters;
    1810                 :             :     /** Annotated dependencies: an entry for each m_deps_to_add entry (excluding ones that apply
    1811                 :             :      *  to removed transactions), together with the sequence number of the representative root of
    1812                 :             :      *  Clusters it applies to (initially that of the child Cluster, later that of the
    1813                 :             :      *  to-be-merged group). */
    1814                 :           5 :     std::vector<std::pair<std::pair<GraphIndex, GraphIndex>, uint64_t>> an_deps;
    1815                 :             : 
    1816                 :             :     // Construct an an_clusters entry for every oversized cluster, including ones from levels below,
    1817                 :             :     // as they may be inherited in this one.
    1818         [ +  + ]:          10 :     for (int level_iter = 0; level_iter <= level; ++level_iter) {
    1819         [ +  + ]:          11 :         for (auto& cluster : GetClusterSet(level_iter).m_clusters[int(QualityLevel::OVERSIZED_SINGLETON)]) {
    1820                 :           6 :             auto graph_idx = cluster->GetClusterEntry(0);
    1821                 :           6 :             auto cur_cluster = FindCluster(graph_idx, level);
    1822         [ -  + ]:           6 :             if (cur_cluster == nullptr) continue;
    1823                 :           6 :             an_clusters.emplace_back(cur_cluster, cur_cluster->m_sequence);
    1824                 :             :         }
    1825                 :             :     }
    1826                 :             : 
    1827                 :             :     // Construct a an_clusters entry for every parent and child in the to-be-applied dependencies,
    1828                 :             :     // and an an_deps entry for each dependency to be applied.
    1829         [ -  + ]:           5 :     an_deps.reserve(clusterset.m_deps_to_add.size());
    1830   [ +  -  +  + ]:      127213 :     for (const auto& [par, chl] : clusterset.m_deps_to_add) {
    1831                 :      127208 :         auto par_cluster = FindCluster(par, level);
    1832                 :      127208 :         auto chl_cluster = FindCluster(chl, level);
    1833                 :             :         // Skip dependencies for which the parent or child transaction is removed.
    1834   [ +  -  -  + ]:      127208 :         if (par_cluster == nullptr || chl_cluster == nullptr) continue;
    1835                 :      127208 :         an_clusters.emplace_back(par_cluster, par_cluster->m_sequence);
    1836                 :             :         // Do not include a duplicate when parent and child are identical, as it'll be removed
    1837                 :             :         // below anyway.
    1838         [ +  - ]:      127208 :         if (chl_cluster != par_cluster) an_clusters.emplace_back(chl_cluster, chl_cluster->m_sequence);
    1839                 :             :         // Add entry to an_deps, using the child sequence number.
    1840                 :      127208 :         an_deps.emplace_back(std::pair{par, chl}, chl_cluster->m_sequence);
    1841                 :             :     }
    1842                 :             :     // Sort and deduplicate an_clusters, so we end up with a sorted list of all involved Clusters
    1843                 :             :     // to which dependencies apply, or which are oversized.
    1844   [ +  +  +  +  :     4849133 :     std::sort(an_clusters.begin(), an_clusters.end(), [](auto& a, auto& b) noexcept { return a.second < b.second; });
          +  +  +  +  +  
          +  +  +  +  +  
          +  +  +  +  +  
             +  -  -  +  
                      + ]
    1845                 :           5 :     an_clusters.erase(std::unique(an_clusters.begin(), an_clusters.end()), an_clusters.end());
    1846                 :             :     // Sort an_deps by applying the same order to the involved child cluster.
    1847   [ -  -  -  -  :     2312193 :     std::sort(an_deps.begin(), an_deps.end(), [&](auto& a, auto& b) noexcept { return a.second < b.second; });
          +  +  +  +  +  
          +  +  +  +  +  
          +  +  +  +  +  
             +  -  -  +  
                      + ]
    1848                 :             : 
    1849                 :             :     // Run the union-find algorithm to to find partitions of the input Clusters which need to be
    1850                 :             :     // grouped together. See https://en.wikipedia.org/wiki/Disjoint-set_data_structure.
    1851                 :           5 :     {
    1852                 :             :         /** Each PartitionData entry contains information about a single input Cluster. */
    1853                 :           5 :         struct PartitionData
    1854                 :             :         {
    1855                 :             :             /** The sequence number of the cluster this holds information for. */
    1856                 :             :             uint64_t sequence;
    1857                 :             :             /** All PartitionData entries belonging to the same partition are organized in a tree.
    1858                 :             :              *  Each element points to its parent, or to itself if it is the root. The root is then
    1859                 :             :              *  a representative for the entire tree, and can be found by walking upwards from any
    1860                 :             :              *  element. */
    1861                 :             :             PartitionData* parent;
    1862                 :             :             /** (only if this is a root, so when parent == this) An upper bound on the height of
    1863                 :             :              *  tree for this partition. */
    1864                 :             :             unsigned rank;
    1865                 :             :         };
    1866                 :             :         /** Information about each input Cluster. Sorted by Cluster::m_sequence. */
    1867                 :           5 :         std::vector<PartitionData> partition_data;
    1868                 :             : 
    1869                 :             :         /** Given a Cluster, find its corresponding PartitionData. */
    1870                 :      253274 :         auto locate_fn = [&](uint64_t sequence) noexcept -> PartitionData* {
    1871                 :      253269 :             auto it = std::lower_bound(partition_data.begin(), partition_data.end(), sequence,
    1872         [ +  + ]:     4043971 :                                        [](auto& a, uint64_t seq) noexcept { return a.sequence < seq; });
    1873                 :      253269 :             Assume(it != partition_data.end());
    1874                 :      253269 :             Assume(it->sequence == sequence);
    1875                 :      253269 :             return &*it;
    1876                 :           5 :         };
    1877                 :             : 
    1878                 :             :         /** Given a PartitionData, find the root of the tree it is in (its representative). */
    1879                 :      255430 :         static constexpr auto find_root_fn = [](PartitionData* data) noexcept -> PartitionData* {
    1880   [ +  +  +  + ]:      447428 :             while (data->parent != data) {
    1881                 :             :                 // Replace pointers to parents with pointers to grandparents.
    1882                 :             :                 // See https://en.wikipedia.org/wiki/Disjoint-set_data_structure#Finding_set_representatives.
    1883                 :      314003 :                 auto par = data->parent;
    1884                 :      314003 :                 data->parent = par->parent;
    1885                 :      314003 :                 data = par;
    1886                 :             :             }
    1887                 :      255425 :             return data;
    1888                 :             :         };
    1889                 :             : 
    1890                 :             :         /** Given two PartitionDatas, union the partitions they are in, and return their
    1891                 :             :          *  representative. */
    1892                 :      127213 :         static constexpr auto union_fn = [](PartitionData* arg1, PartitionData* arg2) noexcept {
    1893                 :             :             // Find the roots of the trees, and bail out if they are already equal (which would
    1894                 :             :             // mean they are in the same partition already).
    1895         [ +  + ]:      376416 :             auto rep1 = find_root_fn(arg1);
    1896                 :      127208 :             auto rep2 = find_root_fn(arg2);
    1897         [ +  - ]:      127208 :             if (rep1 == rep2) return rep1;
    1898                 :             :             // Pick the lower-rank root to become a child of the higher-rank one.
    1899                 :             :             // See https://en.wikipedia.org/wiki/Disjoint-set_data_structure#Union_by_rank.
    1900         [ +  + ]:      127208 :             if (rep1->rank < rep2->rank) std::swap(rep1, rep2);
    1901                 :      127208 :             rep2->parent = rep1;
    1902                 :      127208 :             rep1->rank += (rep1->rank == rep2->rank);
    1903                 :      127208 :             return rep1;
    1904                 :             :         };
    1905                 :             : 
    1906                 :             :         // Start by initializing every Cluster as its own singleton partition.
    1907         [ -  + ]:           5 :         partition_data.resize(an_clusters.size());
    1908   [ -  +  +  + ]:      128222 :         for (size_t i = 0; i < an_clusters.size(); ++i) {
    1909                 :      128217 :             partition_data[i].sequence = an_clusters[i].first->m_sequence;
    1910                 :      128217 :             partition_data[i].parent = &partition_data[i];
    1911                 :      128217 :             partition_data[i].rank = 0;
    1912                 :             :         }
    1913                 :             : 
    1914                 :             :         // Run through all parent/child pairs in an_deps, and union the partitions their Clusters
    1915                 :             :         // are in.
    1916                 :           5 :         Cluster* last_chl_cluster{nullptr};
    1917                 :           5 :         PartitionData* last_partition{nullptr};
    1918   [ -  +  +  + ]:      127213 :         for (const auto& [dep, _] : an_deps) {
    1919         [ -  + ]:      127208 :             auto [par, chl] = dep;
    1920                 :      127208 :             auto par_cluster = FindCluster(par, level);
    1921                 :      127208 :             auto chl_cluster = FindCluster(chl, level);
    1922                 :      127208 :             Assume(chl_cluster != nullptr && par_cluster != nullptr);
    1923                 :             :             // Nothing to do if parent and child are in the same Cluster.
    1924         [ -  + ]:      127208 :             if (par_cluster == chl_cluster) continue;
    1925                 :      127208 :             Assume(par != chl);
    1926         [ +  + ]:      127208 :             if (chl_cluster == last_chl_cluster) {
    1927                 :             :                 // If the child Clusters is the same as the previous iteration, union with the
    1928                 :             :                 // tree they were in, avoiding the need for another lookup. Note that an_deps
    1929                 :             :                 // is sorted by child Cluster, so batches with the same child are expected.
    1930                 :        1147 :                 last_partition = union_fn(locate_fn(par_cluster->m_sequence), last_partition);
    1931                 :             :             } else {
    1932                 :      126061 :                 last_chl_cluster = chl_cluster;
    1933                 :      126061 :                 last_partition = union_fn(locate_fn(par_cluster->m_sequence), locate_fn(chl_cluster->m_sequence));
    1934                 :             :             }
    1935                 :             :         }
    1936                 :             : 
    1937                 :             :         // Update the sequence numbers in an_clusters and an_deps to be those of the partition
    1938                 :             :         // representative.
    1939                 :           5 :         auto deps_it = an_deps.begin();
    1940   [ -  +  +  + ]:      128222 :         for (size_t i = 0; i < partition_data.size(); ++i) {
    1941                 :      128217 :             auto& data = partition_data[i];
    1942                 :             :             // Find the sequence of the representative of the partition Cluster i is in, and store
    1943                 :             :             // it with the Cluster.
    1944                 :      128217 :             auto rep_seq = find_root_fn(&data)->sequence;
    1945                 :      128217 :             an_clusters[i].second = rep_seq;
    1946                 :             :             // Find all dependencies whose child Cluster is Cluster i, and annotate them with rep.
    1947         [ +  + ]:      255425 :             while (deps_it != an_deps.end()) {
    1948         [ +  + ]:      255264 :                 auto [par, chl] = deps_it->first;
    1949                 :      255264 :                 auto chl_cluster = FindCluster(chl, level);
    1950                 :      255264 :                 Assume(chl_cluster != nullptr);
    1951         [ +  + ]:      255264 :                 if (chl_cluster->m_sequence > data.sequence) break;
    1952                 :      127208 :                 deps_it->second = rep_seq;
    1953                 :      127208 :                 ++deps_it;
    1954                 :             :             }
    1955                 :             :         }
    1956                 :           5 :     }
    1957                 :             : 
    1958                 :             :     // Sort both an_clusters and an_deps by sequence number of the representative of the
    1959                 :             :     // partition they are in, grouping all those applying to the same partition together.
    1960   [ -  -  -  -  :     1767204 :     std::sort(an_deps.begin(), an_deps.end(), [](auto& a, auto& b) noexcept { return a.second < b.second; });
          +  +  +  +  +  
          +  +  +  +  +  
          +  +  +  +  +  
             +  -  -  -  
                      + ]
    1961   [ -  -  -  -  :     1763821 :     std::sort(an_clusters.begin(), an_clusters.end(), [](auto& a, auto& b) noexcept { return a.second < b.second; });
          +  +  +  +  +  
          +  +  +  +  +  
          +  +  +  +  -  
             +  -  -  -  
                      + ]
    1962                 :             : 
    1963                 :             :     // Translate the resulting cluster groups to the m_group_data structure, and the dependencies
    1964                 :             :     // back to m_deps_to_add.
    1965                 :           5 :     clusterset.m_group_data = GroupData{};
    1966         [ -  + ]:           5 :     clusterset.m_group_data->m_group_clusters.reserve(an_clusters.size());
    1967         [ +  + ]:           5 :     clusterset.m_deps_to_add.clear();
    1968         [ -  + ]:           5 :     clusterset.m_deps_to_add.reserve(an_deps.size());
    1969                 :           5 :     clusterset.m_oversized = false;
    1970                 :           5 :     auto an_deps_it = an_deps.begin();
    1971                 :           5 :     auto an_clusters_it = an_clusters.begin();
    1972         [ +  + ]:        1014 :     while (an_clusters_it != an_clusters.end()) {
    1973                 :             :         // Process all clusters/dependencies belonging to the partition with representative rep.
    1974                 :        1009 :         auto rep = an_clusters_it->second;
    1975                 :             :         // Create and initialize a new GroupData entry for the partition.
    1976                 :        1009 :         auto& new_entry = clusterset.m_group_data->m_groups.emplace_back();
    1977         [ -  + ]:        1009 :         new_entry.m_cluster_offset = clusterset.m_group_data->m_group_clusters.size();
    1978                 :        1009 :         new_entry.m_cluster_count = 0;
    1979         [ -  + ]:        1009 :         new_entry.m_deps_offset = clusterset.m_deps_to_add.size();
    1980                 :        1009 :         new_entry.m_deps_count = 0;
    1981                 :        1009 :         uint32_t total_count{0};
    1982                 :        1009 :         uint64_t total_size{0};
    1983                 :             :         // Add all its clusters to it (copying those from an_clusters to m_group_clusters).
    1984   [ +  +  +  + ]:      129226 :         while (an_clusters_it != an_clusters.end() && an_clusters_it->second == rep) {
    1985                 :      128217 :             clusterset.m_group_data->m_group_clusters.push_back(an_clusters_it->first);
    1986                 :      128217 :             total_count += an_clusters_it->first->GetTxCount();
    1987                 :      128217 :             total_size += an_clusters_it->first->GetTotalTxSize();
    1988                 :      128217 :             ++an_clusters_it;
    1989                 :      128217 :             ++new_entry.m_cluster_count;
    1990                 :             :         }
    1991                 :             :         // Add all its dependencies to it (copying those back from an_deps to m_deps_to_add).
    1992   [ +  +  +  + ]:      128217 :         while (an_deps_it != an_deps.end() && an_deps_it->second == rep) {
    1993                 :      127208 :             clusterset.m_deps_to_add.push_back(an_deps_it->first);
    1994                 :      127208 :             ++an_deps_it;
    1995                 :      127208 :             ++new_entry.m_deps_count;
    1996                 :             :         }
    1997                 :             :         // Detect oversizedness.
    1998   [ +  +  +  + ]:        1009 :         if (total_count > m_max_cluster_count || total_size > m_max_cluster_size) {
    1999                 :           9 :             clusterset.m_oversized = true;
    2000                 :             :         }
    2001                 :             :     }
    2002                 :           5 :     Assume(an_deps_it == an_deps.end());
    2003                 :           5 :     Assume(an_clusters_it == an_clusters.end());
    2004                 :           5 :     Compact();
    2005                 :           5 : }
    2006                 :             : 
    2007                 :           0 : void TxGraphImpl::Merge(std::span<Cluster*> to_merge, int level) noexcept
    2008                 :             : {
    2009         [ #  # ]:           0 :     Assume(!to_merge.empty());
    2010                 :             :     // Nothing to do if a group consists of just a single Cluster.
    2011         [ #  # ]:           0 :     if (to_merge.size() == 1) return;
    2012                 :             : 
    2013                 :             :     // Move the largest Cluster to the front of to_merge. As all transactions in other to-be-merged
    2014                 :             :     // Clusters will be moved to that one, putting the largest one first minimizes the number of
    2015                 :             :     // moves.
    2016                 :           0 :     size_t max_size_pos{0};
    2017                 :           0 :     DepGraphIndex max_size = to_merge[max_size_pos]->GetTxCount();
    2018                 :           0 :     GetClusterSet(level).m_cluster_usage -= to_merge[max_size_pos]->TotalMemoryUsage();
    2019                 :           0 :     DepGraphIndex total_size = max_size;
    2020         [ #  # ]:           0 :     for (size_t i = 1; i < to_merge.size(); ++i) {
    2021                 :           0 :         GetClusterSet(level).m_cluster_usage -= to_merge[i]->TotalMemoryUsage();
    2022                 :           0 :         DepGraphIndex size = to_merge[i]->GetTxCount();
    2023                 :           0 :         total_size += size;
    2024         [ #  # ]:           0 :         if (size > max_size) {
    2025                 :           0 :             max_size_pos = i;
    2026                 :           0 :             max_size = size;
    2027                 :             :         }
    2028                 :             :     }
    2029         [ #  # ]:           0 :     if (max_size_pos != 0) std::swap(to_merge[0], to_merge[max_size_pos]);
    2030                 :             : 
    2031                 :           0 :     size_t start_idx = 1;
    2032                 :           0 :     Cluster* into_cluster = to_merge[0];
    2033         [ #  # ]:           0 :     if (total_size > into_cluster->GetMaxTxCount()) {
    2034                 :             :         // The into_merge cluster is too small to fit all transactions being merged. Construct a
    2035                 :             :         // a new Cluster using an implementation that matches the total size, and merge everything
    2036                 :             :         // in there.
    2037                 :           0 :         auto new_cluster = CreateEmptyCluster(total_size);
    2038                 :           0 :         into_cluster = new_cluster.get();
    2039                 :           0 :         InsertCluster(level, std::move(new_cluster), QualityLevel::OPTIMAL);
    2040                 :           0 :         start_idx = 0;
    2041                 :           0 :     }
    2042                 :             : 
    2043                 :             :     // Merge all further Clusters in the group into the result (first one, or new one), and delete
    2044                 :             :     // them.
    2045         [ #  # ]:           0 :     for (size_t i = start_idx; i < to_merge.size(); ++i) {
    2046                 :           0 :         into_cluster->Merge(*this, level, *to_merge[i]);
    2047                 :           0 :         DeleteCluster(*to_merge[i], level);
    2048                 :             :     }
    2049                 :           0 :     into_cluster->Compact();
    2050                 :           0 :     GetClusterSet(level).m_cluster_usage += into_cluster->TotalMemoryUsage();
    2051                 :             : }
    2052                 :             : 
    2053                 :           0 : void TxGraphImpl::ApplyDependencies(int level) noexcept
    2054                 :             : {
    2055                 :           0 :     auto& clusterset = GetClusterSet(level);
    2056                 :             :     // Do not bother computing groups if we already know the result will be oversized.
    2057         [ #  # ]:           0 :     if (clusterset.m_oversized == true) return;
    2058                 :             :     // Compute the groups of to-be-merged Clusters (which also applies all removals, and splits).
    2059                 :           0 :     GroupClusters(level);
    2060         [ #  # ]:           0 :     Assume(clusterset.m_group_data.has_value());
    2061                 :             :     // Nothing to do if there are no dependencies to be added.
    2062         [ #  # ]:           0 :     if (clusterset.m_deps_to_add.empty()) return;
    2063                 :             :     // Dependencies cannot be applied if it would result in oversized clusters.
    2064         [ #  # ]:           0 :     if (clusterset.m_oversized == true) return;
    2065                 :             : 
    2066                 :             :     // For each group of to-be-merged Clusters.
    2067         [ #  # ]:           0 :     for (const auto& group_entry : clusterset.m_group_data->m_groups) {
    2068         [ #  # ]:           0 :         auto cluster_span = std::span{clusterset.m_group_data->m_group_clusters}
    2069         [ #  # ]:           0 :                                 .subspan(group_entry.m_cluster_offset, group_entry.m_cluster_count);
    2070                 :             :         // Pull in all the Clusters that contain dependencies.
    2071         [ #  # ]:           0 :         if (level == 1) {
    2072         [ #  # ]:           0 :             for (Cluster*& cluster : cluster_span) {
    2073                 :           0 :                 cluster = PullIn(cluster, cluster->GetLevel(*this));
    2074                 :             :             }
    2075                 :             :         }
    2076                 :             :         // Invoke Merge() to merge them into a single Cluster.
    2077                 :           0 :         Merge(cluster_span, level);
    2078                 :             :         // Actually apply all to-be-added dependencies (all parents and children from this grouping
    2079                 :             :         // belong to the same Cluster at this point because of the merging above).
    2080         [ #  # ]:           0 :         auto deps_span = std::span{clusterset.m_deps_to_add}
    2081                 :           0 :                              .subspan(group_entry.m_deps_offset, group_entry.m_deps_count);
    2082                 :           0 :         Assume(!deps_span.empty());
    2083                 :           0 :         const auto& loc = m_entries[deps_span[0].second].m_locator[level];
    2084                 :           0 :         Assume(loc.IsPresent());
    2085                 :           0 :         loc.cluster->ApplyDependencies(*this, level, deps_span);
    2086                 :             :     }
    2087                 :             : 
    2088                 :             :     // Wipe the list of to-be-added dependencies now that they are applied.
    2089         [ #  # ]:           0 :     clusterset.m_deps_to_add.clear();
    2090                 :           0 :     Compact();
    2091                 :             :     // Also no further Cluster mergings are needed (note that we clear, but don't set to
    2092                 :             :     // std::nullopt, as that would imply the groupings are unknown).
    2093                 :           0 :     clusterset.m_group_data = GroupData{};
    2094                 :             : }
    2095                 :             : 
    2096                 :           0 : std::pair<uint64_t, bool> GenericClusterImpl::Relinearize(TxGraphImpl& graph, int level, uint64_t max_iters) noexcept
    2097                 :             : {
    2098                 :             :     // We can only relinearize Clusters that do not need splitting.
    2099                 :           0 :     Assume(!NeedsSplitting());
    2100                 :             :     // No work is required for Clusters which are already optimally linearized.
    2101         [ #  # ]:           0 :     if (IsOptimal()) return {0, false};
    2102                 :             :     // Invoke the actual linearization algorithm (passing in the existing one).
    2103                 :           0 :     uint64_t rng_seed = graph.m_rng.rand64();
    2104   [ #  #  #  # ]:           0 :     auto [linearization, optimal, cost] = Linearize(m_depgraph, max_iters, rng_seed, m_linearization);
    2105                 :             :     // Postlinearize if the result isn't optimal already. This guarantees (among other things)
    2106                 :             :     // that the chunks of the resulting linearization are all connected.
    2107   [ #  #  #  # ]:           0 :     if (!optimal) PostLinearize(m_depgraph, linearization);
    2108                 :             :     // Update the linearization.
    2109                 :           0 :     m_linearization = std::move(linearization);
    2110                 :             :     // Update the Cluster's quality.
    2111                 :           0 :     bool improved = false;
    2112         [ #  # ]:           0 :     if (optimal) {
    2113                 :           0 :         graph.SetClusterQuality(level, m_quality, m_setindex, QualityLevel::OPTIMAL);
    2114                 :           0 :         improved = true;
    2115   [ #  #  #  # ]:           0 :     } else if (max_iters >= graph.m_acceptable_iters && !IsAcceptable()) {
    2116                 :           0 :         graph.SetClusterQuality(level, m_quality, m_setindex, QualityLevel::ACCEPTABLE);
    2117                 :           0 :         improved = true;
    2118                 :             :     }
    2119                 :             :     // Update the Entry objects.
    2120                 :           0 :     Updated(graph, level);
    2121                 :           0 :     return {cost, improved};
    2122                 :           0 : }
    2123                 :             : 
    2124                 :           0 : std::pair<uint64_t, bool> SingletonClusterImpl::Relinearize(TxGraphImpl& graph, int level, uint64_t max_iters) noexcept
    2125                 :             : {
    2126                 :             :     // All singletons are optimal, oversized, or need splitting. Each of these precludes
    2127                 :             :     // Relinearize from being called.
    2128                 :           0 :     assert(false);
    2129                 :             :     return {0, false};
    2130                 :             : }
    2131                 :             : 
    2132                 :           0 : void TxGraphImpl::MakeAcceptable(Cluster& cluster, int level) noexcept
    2133                 :             : {
    2134                 :             :     // Relinearize the Cluster if needed.
    2135   [ #  #  #  # ]:           0 :     if (!cluster.NeedsSplitting() && !cluster.IsAcceptable() && !cluster.IsOversized()) {
    2136                 :           0 :         cluster.Relinearize(*this, level, m_acceptable_iters);
    2137                 :             :     }
    2138                 :           0 : }
    2139                 :             : 
    2140                 :           0 : void TxGraphImpl::MakeAllAcceptable(int level) noexcept
    2141                 :             : {
    2142                 :           0 :     ApplyDependencies(level);
    2143                 :           0 :     auto& clusterset = GetClusterSet(level);
    2144         [ #  # ]:           0 :     if (clusterset.m_oversized == true) return;
    2145                 :           0 :     auto& queue = clusterset.m_clusters[int(QualityLevel::NEEDS_RELINEARIZE)];
    2146         [ #  # ]:           0 :     while (!queue.empty()) {
    2147                 :           0 :         MakeAcceptable(*queue.back().get(), level);
    2148                 :             :     }
    2149                 :             : }
    2150                 :             : 
    2151                 :           0 : GenericClusterImpl::GenericClusterImpl(uint64_t sequence) noexcept : Cluster{sequence} {}
    2152                 :             : 
    2153                 :       64311 : TxGraph::Ref TxGraphImpl::AddTransaction(const FeePerWeight& feerate) noexcept
    2154                 :             : {
    2155         [ -  + ]:       64311 :     Assume(m_main_chunkindex_observers == 0 || GetTopLevel() != 0);
    2156                 :       64311 :     Assume(feerate.size > 0);
    2157                 :             :     // Construct a new Ref.
    2158                 :       64311 :     Ref ret;
    2159                 :             :     // Construct a new Entry, and link it with the Ref.
    2160         [ -  + ]:       64311 :     auto idx = m_entries.size();
    2161                 :       64311 :     m_entries.emplace_back();
    2162                 :       64311 :     auto& entry = m_entries.back();
    2163                 :       64311 :     entry.m_main_chunkindex_iterator = m_main_chunkindex.end();
    2164                 :       64311 :     entry.m_ref = &ret;
    2165                 :       64311 :     GetRefGraph(ret) = this;
    2166                 :       64311 :     GetRefIndex(ret) = idx;
    2167                 :             :     // Construct a new singleton Cluster (which is necessarily optimally linearized).
    2168                 :       64311 :     bool oversized = uint64_t(feerate.size) > m_max_cluster_size;
    2169                 :       64311 :     auto cluster = CreateEmptyCluster(1);
    2170                 :       64311 :     cluster->AppendTransaction(idx, feerate);
    2171         [ +  + ]:       64311 :     auto cluster_ptr = cluster.get();
    2172         [ +  + ]:       64311 :     int level = GetTopLevel();
    2173                 :       64311 :     auto& clusterset = GetClusterSet(level);
    2174         [ +  + ]:      128616 :     InsertCluster(level, std::move(cluster), oversized ? QualityLevel::OVERSIZED_SINGLETON : QualityLevel::OPTIMAL);
    2175                 :       64311 :     cluster_ptr->Updated(*this, level);
    2176                 :       64311 :     clusterset.m_cluster_usage += cluster_ptr->TotalMemoryUsage();
    2177                 :       64311 :     ++clusterset.m_txcount;
    2178                 :             :     // Deal with individually oversized transactions.
    2179         [ +  + ]:       64311 :     if (oversized) {
    2180                 :           6 :         ++clusterset.m_txcount_oversized;
    2181                 :           6 :         clusterset.m_oversized = true;
    2182         [ +  + ]:           6 :         clusterset.m_group_data = std::nullopt;
    2183                 :             :     }
    2184                 :             :     // Return the Ref.
    2185                 :      128622 :     return ret;
    2186                 :       64311 : }
    2187                 :             : 
    2188                 :           0 : void TxGraphImpl::RemoveTransaction(const Ref& arg) noexcept
    2189                 :             : {
    2190                 :             :     // Don't do anything if the Ref is empty (which may be indicative of the transaction already
    2191                 :             :     // having been removed).
    2192         [ #  # ]:           0 :     if (GetRefGraph(arg) == nullptr) return;
    2193                 :           0 :     Assume(GetRefGraph(arg) == this);
    2194         [ #  # ]:           0 :     Assume(m_main_chunkindex_observers == 0 || GetTopLevel() != 0);
    2195                 :             :     // Find the Cluster the transaction is in, and stop if it isn't in any.
    2196         [ #  # ]:           0 :     int level = GetTopLevel();
    2197         [ #  # ]:           0 :     auto cluster = FindCluster(GetRefIndex(arg), level);
    2198         [ #  # ]:           0 :     if (cluster == nullptr) return;
    2199                 :             :     // Remember that the transaction is to be removed.
    2200                 :           0 :     auto& clusterset = GetClusterSet(level);
    2201                 :           0 :     clusterset.m_to_remove.push_back(GetRefIndex(arg));
    2202                 :             :     // Wipe m_group_data (as it will need to be recomputed).
    2203         [ #  # ]:           0 :     clusterset.m_group_data.reset();
    2204         [ #  # ]:           0 :     if (clusterset.m_oversized == true) clusterset.m_oversized = std::nullopt;
    2205                 :             : }
    2206                 :             : 
    2207                 :       64208 : void TxGraphImpl::AddDependency(const Ref& parent, const Ref& child) noexcept
    2208                 :             : {
    2209                 :             :     // Don't do anything if either Ref is empty (which may be indicative of it having already been
    2210                 :             :     // removed).
    2211   [ +  -  +  - ]:       64208 :     if (GetRefGraph(parent) == nullptr || GetRefGraph(child) == nullptr) return;
    2212                 :       64208 :     Assume(GetRefGraph(parent) == this && GetRefGraph(child) == this);
    2213         [ -  + ]:       64208 :     Assume(m_main_chunkindex_observers == 0 || GetTopLevel() != 0);
    2214                 :             :     // Don't do anything if this is a dependency on self.
    2215         [ +  - ]:       64208 :     if (GetRefIndex(parent) == GetRefIndex(child)) return;
    2216                 :             :     // Find the Cluster the parent and child transaction are in, and stop if either appears to be
    2217                 :             :     // already removed.
    2218         [ +  - ]:       64208 :     int level = GetTopLevel();
    2219                 :       64208 :     auto par_cluster = FindCluster(GetRefIndex(parent), level);
    2220         [ +  - ]:       64208 :     if (par_cluster == nullptr) return;
    2221                 :       64208 :     auto chl_cluster = FindCluster(GetRefIndex(child), level);
    2222         [ +  - ]:       64208 :     if (chl_cluster == nullptr) return;
    2223                 :             :     // Remember that this dependency is to be applied.
    2224                 :       64208 :     auto& clusterset = GetClusterSet(level);
    2225                 :       64208 :     clusterset.m_deps_to_add.emplace_back(GetRefIndex(parent), GetRefIndex(child));
    2226                 :             :     // Wipe m_group_data (as it will need to be recomputed).
    2227         [ +  + ]:       64208 :     clusterset.m_group_data.reset();
    2228         [ +  + ]:       64212 :     if (clusterset.m_oversized == false) clusterset.m_oversized = std::nullopt;
    2229                 :             : }
    2230                 :             : 
    2231                 :         300 : bool TxGraphImpl::Exists(const Ref& arg, Level level_select) noexcept
    2232                 :             : {
    2233         [ +  - ]:         300 :     if (GetRefGraph(arg) == nullptr) return false;
    2234                 :         300 :     Assume(GetRefGraph(arg) == this);
    2235         [ +  - ]:         300 :     size_t level = GetSpecifiedLevel(level_select);
    2236                 :             :     // Make sure the transaction isn't scheduled for removal.
    2237                 :         300 :     ApplyRemovals(level);
    2238                 :         300 :     auto cluster = FindCluster(GetRefIndex(arg), level);
    2239                 :         300 :     return cluster != nullptr;
    2240                 :             : }
    2241                 :             : 
    2242                 :           0 : void GenericClusterImpl::GetAncestorRefs(const TxGraphImpl& graph, std::span<std::pair<Cluster*, DepGraphIndex>>& args, std::vector<TxGraph::Ref*>& output) noexcept
    2243                 :             : {
    2244                 :             :     /** The union of all ancestors to be returned. */
    2245                 :           0 :     SetType ancestors_union;
    2246                 :             :     // Process elements from the front of args, as long as they apply.
    2247         [ #  # ]:           0 :     while (!args.empty()) {
    2248         [ #  # ]:           0 :         if (args.front().first != this) break;
    2249                 :           0 :         ancestors_union |= m_depgraph.Ancestors(args.front().second);
    2250                 :           0 :         args = args.subspan(1);
    2251                 :             :     }
    2252         [ #  # ]:           0 :     Assume(ancestors_union.Any());
    2253                 :             :     // Translate all ancestors (in arbitrary order) to Refs (if they have any), and return them.
    2254   [ #  #  #  #  :           0 :     for (auto idx : ancestors_union) {
                   #  # ]
    2255                 :           0 :         const auto& entry = graph.m_entries[m_mapping[idx]];
    2256                 :           0 :         Assume(entry.m_ref != nullptr);
    2257                 :           0 :         output.push_back(entry.m_ref);
    2258                 :             :     }
    2259                 :           0 : }
    2260                 :             : 
    2261                 :           0 : void SingletonClusterImpl::GetAncestorRefs(const TxGraphImpl& graph, std::span<std::pair<Cluster*, DepGraphIndex>>& args, std::vector<TxGraph::Ref*>& output) noexcept
    2262                 :             : {
    2263                 :           0 :     Assume(GetTxCount());
    2264         [ #  # ]:           0 :     while (!args.empty()) {
    2265         [ #  # ]:           0 :         if (args.front().first != this) break;
    2266                 :           0 :         args = args.subspan(1);
    2267                 :             :     }
    2268                 :           0 :     const auto& entry = graph.m_entries[m_graph_index];
    2269                 :           0 :     Assume(entry.m_ref != nullptr);
    2270                 :           0 :     output.push_back(entry.m_ref);
    2271                 :           0 : }
    2272                 :             : 
    2273                 :           0 : void GenericClusterImpl::GetDescendantRefs(const TxGraphImpl& graph, std::span<std::pair<Cluster*, DepGraphIndex>>& args, std::vector<TxGraph::Ref*>& output) noexcept
    2274                 :             : {
    2275                 :             :     /** The union of all descendants to be returned. */
    2276                 :           0 :     SetType descendants_union;
    2277                 :             :     // Process elements from the front of args, as long as they apply.
    2278         [ #  # ]:           0 :     while (!args.empty()) {
    2279         [ #  # ]:           0 :         if (args.front().first != this) break;
    2280                 :           0 :         descendants_union |= m_depgraph.Descendants(args.front().second);
    2281                 :           0 :         args = args.subspan(1);
    2282                 :             :     }
    2283         [ #  # ]:           0 :     Assume(descendants_union.Any());
    2284                 :             :     // Translate all descendants (in arbitrary order) to Refs (if they have any), and return them.
    2285   [ #  #  #  #  :           0 :     for (auto idx : descendants_union) {
                   #  # ]
    2286                 :           0 :         const auto& entry = graph.m_entries[m_mapping[idx]];
    2287                 :           0 :         Assume(entry.m_ref != nullptr);
    2288                 :           0 :         output.push_back(entry.m_ref);
    2289                 :             :     }
    2290                 :           0 : }
    2291                 :             : 
    2292                 :           0 : void SingletonClusterImpl::GetDescendantRefs(const TxGraphImpl& graph, std::span<std::pair<Cluster*, DepGraphIndex>>& args, std::vector<TxGraph::Ref*>& output) noexcept
    2293                 :             : {
    2294                 :             :     // In a singleton cluster, the ancestors or descendants are always just the entire cluster.
    2295                 :           0 :     GetAncestorRefs(graph, args, output);
    2296                 :           0 : }
    2297                 :             : 
    2298                 :           0 : bool GenericClusterImpl::GetClusterRefs(TxGraphImpl& graph, std::span<TxGraph::Ref*> range, LinearizationIndex start_pos) noexcept
    2299                 :             : {
    2300                 :             :     // Translate the transactions in the Cluster (in linearization order, starting at start_pos in
    2301                 :             :     // the linearization) to Refs, and fill them in range.
    2302         [ #  # ]:           0 :     for (auto& ref : range) {
    2303         [ #  # ]:           0 :         Assume(start_pos < m_linearization.size());
    2304                 :           0 :         const auto& entry = graph.m_entries[m_mapping[m_linearization[start_pos++]]];
    2305                 :           0 :         Assume(entry.m_ref != nullptr);
    2306                 :           0 :         ref = entry.m_ref;
    2307                 :             :     }
    2308                 :             :     // Return whether start_pos has advanced to the end of the Cluster.
    2309         [ #  # ]:           0 :     return start_pos == m_linearization.size();
    2310                 :             : }
    2311                 :             : 
    2312                 :           0 : bool SingletonClusterImpl::GetClusterRefs(TxGraphImpl& graph, std::span<TxGraph::Ref*> range, LinearizationIndex start_pos) noexcept
    2313                 :             : {
    2314                 :           0 :     Assume(!range.empty());
    2315                 :           0 :     Assume(GetTxCount());
    2316                 :           0 :     Assume(start_pos == 0);
    2317                 :           0 :     const auto& entry = graph.m_entries[m_graph_index];
    2318                 :           0 :     Assume(entry.m_ref != nullptr);
    2319                 :           0 :     range[0] = entry.m_ref;
    2320                 :           0 :     return true;
    2321                 :             : }
    2322                 :             : 
    2323                 :           0 : FeePerWeight GenericClusterImpl::GetIndividualFeerate(DepGraphIndex idx) noexcept
    2324                 :             : {
    2325                 :           0 :     return FeePerWeight::FromFeeFrac(m_depgraph.FeeRate(idx));
    2326                 :             : }
    2327                 :             : 
    2328                 :           0 : FeePerWeight SingletonClusterImpl::GetIndividualFeerate(DepGraphIndex idx) noexcept
    2329                 :             : {
    2330                 :           0 :     Assume(GetTxCount());
    2331                 :           0 :     Assume(idx == 0);
    2332                 :           0 :     return m_feerate;
    2333                 :             : }
    2334                 :             : 
    2335                 :           0 : void GenericClusterImpl::MakeStagingTransactionsMissing(TxGraphImpl& graph) noexcept
    2336                 :             : {
    2337                 :             :     // Mark all transactions of a Cluster missing, needed when aborting staging, so that the
    2338                 :             :     // corresponding Locators don't retain references into aborted Clusters.
    2339         [ #  # ]:           0 :     for (auto ci : m_linearization) {
    2340                 :           0 :         GraphIndex idx = m_mapping[ci];
    2341                 :           0 :         auto& entry = graph.m_entries[idx];
    2342                 :           0 :         entry.m_locator[1].SetMissing();
    2343                 :             :     }
    2344                 :           0 : }
    2345                 :             : 
    2346                 :           0 : void SingletonClusterImpl::MakeStagingTransactionsMissing(TxGraphImpl& graph) noexcept
    2347                 :             : {
    2348         [ #  # ]:           0 :     if (GetTxCount()) {
    2349                 :           0 :         auto& entry = graph.m_entries[m_graph_index];
    2350                 :           0 :         entry.m_locator[1].SetMissing();
    2351                 :             :     }
    2352                 :           0 : }
    2353                 :             : 
    2354                 :           0 : std::vector<TxGraph::Ref*> TxGraphImpl::GetAncestors(const Ref& arg, Level level_select) noexcept
    2355                 :             : {
    2356                 :             :     // Return the empty vector if the Ref is empty.
    2357         [ #  # ]:           0 :     if (GetRefGraph(arg) == nullptr) return {};
    2358                 :           0 :     Assume(GetRefGraph(arg) == this);
    2359                 :             :     // Apply all removals and dependencies, as the result might be incorrect otherwise.
    2360         [ #  # ]:           0 :     size_t level = GetSpecifiedLevel(level_select);
    2361                 :           0 :     ApplyDependencies(level);
    2362                 :             :     // Ancestry cannot be known if unapplied dependencies remain.
    2363                 :           0 :     Assume(GetClusterSet(level).m_deps_to_add.empty());
    2364                 :             :     // Find the Cluster the argument is in, and return the empty vector if it isn't in any.
    2365         [ #  # ]:           0 :     auto [cluster, cluster_level] = FindClusterAndLevel(GetRefIndex(arg), level);
    2366         [ #  # ]:           0 :     if (cluster == nullptr) return {};
    2367                 :             :     // Dispatch to the Cluster.
    2368                 :           0 :     std::pair<Cluster*, DepGraphIndex> match = {cluster, m_entries[GetRefIndex(arg)].m_locator[cluster_level].index};
    2369                 :           0 :     auto matches = std::span(&match, 1);
    2370                 :           0 :     std::vector<TxGraph::Ref*> ret;
    2371                 :           0 :     cluster->GetAncestorRefs(*this, matches, ret);
    2372                 :           0 :     return ret;
    2373                 :           0 : }
    2374                 :             : 
    2375                 :           0 : std::vector<TxGraph::Ref*> TxGraphImpl::GetDescendants(const Ref& arg, Level level_select) noexcept
    2376                 :             : {
    2377                 :             :     // Return the empty vector if the Ref is empty.
    2378         [ #  # ]:           0 :     if (GetRefGraph(arg) == nullptr) return {};
    2379                 :           0 :     Assume(GetRefGraph(arg) == this);
    2380                 :             :     // Apply all removals and dependencies, as the result might be incorrect otherwise.
    2381         [ #  # ]:           0 :     size_t level = GetSpecifiedLevel(level_select);
    2382                 :           0 :     ApplyDependencies(level);
    2383                 :             :     // Ancestry cannot be known if unapplied dependencies remain.
    2384                 :           0 :     Assume(GetClusterSet(level).m_deps_to_add.empty());
    2385                 :             :     // Find the Cluster the argument is in, and return the empty vector if it isn't in any.
    2386         [ #  # ]:           0 :     auto [cluster, cluster_level] = FindClusterAndLevel(GetRefIndex(arg), level);
    2387         [ #  # ]:           0 :     if (cluster == nullptr) return {};
    2388                 :             :     // Dispatch to the Cluster.
    2389                 :           0 :     std::pair<Cluster*, DepGraphIndex> match = {cluster, m_entries[GetRefIndex(arg)].m_locator[cluster_level].index};
    2390                 :           0 :     auto matches = std::span(&match, 1);
    2391                 :           0 :     std::vector<TxGraph::Ref*> ret;
    2392                 :           0 :     cluster->GetDescendantRefs(*this, matches, ret);
    2393                 :           0 :     return ret;
    2394                 :           0 : }
    2395                 :             : 
    2396                 :           0 : std::vector<TxGraph::Ref*> TxGraphImpl::GetAncestorsUnion(std::span<const Ref* const> args, Level level_select) noexcept
    2397                 :             : {
    2398                 :             :     // Apply all dependencies, as the result might be incorrect otherwise.
    2399         [ #  # ]:           0 :     size_t level = GetSpecifiedLevel(level_select);
    2400                 :           0 :     ApplyDependencies(level);
    2401                 :             :     // Ancestry cannot be known if unapplied dependencies remain.
    2402                 :           0 :     Assume(GetClusterSet(level).m_deps_to_add.empty());
    2403                 :             : 
    2404                 :             :     // Translate args to matches.
    2405                 :           0 :     std::vector<std::pair<Cluster*, DepGraphIndex>> matches;
    2406                 :           0 :     matches.reserve(args.size());
    2407         [ #  # ]:           0 :     for (auto arg : args) {
    2408                 :           0 :         Assume(arg);
    2409                 :             :         // Skip empty Refs.
    2410         [ #  # ]:           0 :         if (GetRefGraph(*arg) == nullptr) continue;
    2411                 :           0 :         Assume(GetRefGraph(*arg) == this);
    2412                 :             :         // Find the Cluster the argument is in, and skip if none is found.
    2413         [ #  # ]:           0 :         auto [cluster, cluster_level] = FindClusterAndLevel(GetRefIndex(*arg), level);
    2414         [ #  # ]:           0 :         if (cluster == nullptr) continue;
    2415                 :             :         // Append to matches.
    2416                 :           0 :         matches.emplace_back(cluster, m_entries[GetRefIndex(*arg)].m_locator[cluster_level].index);
    2417                 :             :     }
    2418                 :             :     // Group by Cluster.
    2419                 :           0 :     std::sort(matches.begin(), matches.end(), [](auto& a, auto& b) noexcept { return CompareClusters(a.first, b.first) < 0; });
    2420                 :             :     // Dispatch to the Clusters.
    2421         [ #  # ]:           0 :     std::span match_span(matches);
    2422                 :           0 :     std::vector<TxGraph::Ref*> ret;
    2423         [ #  # ]:           0 :     while (!match_span.empty()) {
    2424                 :           0 :         match_span.front().first->GetAncestorRefs(*this, match_span, ret);
    2425                 :             :     }
    2426                 :           0 :     return ret;
    2427                 :           0 : }
    2428                 :             : 
    2429                 :           0 : std::vector<TxGraph::Ref*> TxGraphImpl::GetDescendantsUnion(std::span<const Ref* const> args, Level level_select) noexcept
    2430                 :             : {
    2431                 :             :     // Apply all dependencies, as the result might be incorrect otherwise.
    2432         [ #  # ]:           0 :     size_t level = GetSpecifiedLevel(level_select);
    2433                 :           0 :     ApplyDependencies(level);
    2434                 :             :     // Ancestry cannot be known if unapplied dependencies remain.
    2435                 :           0 :     Assume(GetClusterSet(level).m_deps_to_add.empty());
    2436                 :             : 
    2437                 :             :     // Translate args to matches.
    2438                 :           0 :     std::vector<std::pair<Cluster*, DepGraphIndex>> matches;
    2439                 :           0 :     matches.reserve(args.size());
    2440         [ #  # ]:           0 :     for (auto arg : args) {
    2441                 :           0 :         Assume(arg);
    2442                 :             :         // Skip empty Refs.
    2443         [ #  # ]:           0 :         if (GetRefGraph(*arg) == nullptr) continue;
    2444                 :           0 :         Assume(GetRefGraph(*arg) == this);
    2445                 :             :         // Find the Cluster the argument is in, and skip if none is found.
    2446         [ #  # ]:           0 :         auto [cluster, cluster_level] = FindClusterAndLevel(GetRefIndex(*arg), level);
    2447         [ #  # ]:           0 :         if (cluster == nullptr) continue;
    2448                 :             :         // Append to matches.
    2449                 :           0 :         matches.emplace_back(cluster, m_entries[GetRefIndex(*arg)].m_locator[cluster_level].index);
    2450                 :             :     }
    2451                 :             :     // Group by Cluster.
    2452                 :           0 :     std::sort(matches.begin(), matches.end(), [](auto& a, auto& b) noexcept { return CompareClusters(a.first, b.first) < 0; });
    2453                 :             :     // Dispatch to the Clusters.
    2454         [ #  # ]:           0 :     std::span match_span(matches);
    2455                 :           0 :     std::vector<TxGraph::Ref*> ret;
    2456         [ #  # ]:           0 :     while (!match_span.empty()) {
    2457                 :           0 :         match_span.front().first->GetDescendantRefs(*this, match_span, ret);
    2458                 :             :     }
    2459                 :           0 :     return ret;
    2460                 :           0 : }
    2461                 :             : 
    2462                 :           0 : std::vector<TxGraph::Ref*> TxGraphImpl::GetCluster(const Ref& arg, Level level_select) noexcept
    2463                 :             : {
    2464                 :             :     // Return the empty vector if the Ref is empty (which may be indicative of the transaction
    2465                 :             :     // having been removed already.
    2466         [ #  # ]:           0 :     if (GetRefGraph(arg) == nullptr) return {};
    2467                 :           0 :     Assume(GetRefGraph(arg) == this);
    2468                 :             :     // Apply all removals and dependencies, as the result might be incorrect otherwise.
    2469         [ #  # ]:           0 :     size_t level = GetSpecifiedLevel(level_select);
    2470                 :           0 :     ApplyDependencies(level);
    2471                 :             :     // Cluster linearization cannot be known if unapplied dependencies remain.
    2472                 :           0 :     Assume(GetClusterSet(level).m_deps_to_add.empty());
    2473                 :             :     // Find the Cluster the argument is in, and return the empty vector if it isn't in any.
    2474         [ #  # ]:           0 :     auto [cluster, cluster_level] = FindClusterAndLevel(GetRefIndex(arg), level);
    2475         [ #  # ]:           0 :     if (cluster == nullptr) return {};
    2476                 :             :     // Make sure the Cluster has an acceptable quality level, and then dispatch to it.
    2477                 :           0 :     MakeAcceptable(*cluster, cluster_level);
    2478         [ #  # ]:           0 :     std::vector<TxGraph::Ref*> ret(cluster->GetTxCount());
    2479         [ #  # ]:           0 :     cluster->GetClusterRefs(*this, ret, 0);
    2480                 :           0 :     return ret;
    2481                 :           0 : }
    2482                 :             : 
    2483                 :           7 : TxGraph::GraphIndex TxGraphImpl::GetTransactionCount(Level level_select) noexcept
    2484                 :             : {
    2485         [ +  - ]:           7 :     size_t level = GetSpecifiedLevel(level_select);
    2486                 :           7 :     ApplyRemovals(level);
    2487                 :           7 :     return GetClusterSet(level).m_txcount;
    2488                 :             : }
    2489                 :             : 
    2490                 :           0 : FeePerWeight TxGraphImpl::GetIndividualFeerate(const Ref& arg) noexcept
    2491                 :             : {
    2492                 :             :     // Return the empty FeePerWeight if the passed Ref is empty.
    2493         [ #  # ]:           0 :     if (GetRefGraph(arg) == nullptr) return {};
    2494                 :             :     Assume(GetRefGraph(arg) == this);
    2495                 :             :     // Find the cluster the argument is in (the level does not matter as individual feerates will
    2496                 :             :     // be identical if it occurs in both), and return the empty FeePerWeight if it isn't in any.
    2497                 :           0 :     Cluster* cluster{nullptr};
    2498                 :             :     int level;
    2499         [ #  # ]:           0 :     for (level = 0; level <= GetTopLevel(); ++level) {
    2500                 :             :         // Apply removals, so that we can correctly report FeePerWeight{} for non-existing
    2501                 :             :         // transactions.
    2502                 :           0 :         ApplyRemovals(level);
    2503         [ #  # ]:           0 :         if (m_entries[GetRefIndex(arg)].m_locator[level].IsPresent()) {
    2504                 :             :             cluster = m_entries[GetRefIndex(arg)].m_locator[level].cluster;
    2505                 :             :             break;
    2506                 :             :         }
    2507                 :             :     }
    2508         [ #  # ]:           0 :     if (cluster == nullptr) return {};
    2509                 :             :     // Dispatch to the Cluster.
    2510                 :           0 :     return cluster->GetIndividualFeerate(m_entries[GetRefIndex(arg)].m_locator[level].index);
    2511                 :             : }
    2512                 :             : 
    2513                 :           0 : FeePerWeight TxGraphImpl::GetMainChunkFeerate(const Ref& arg) noexcept
    2514                 :             : {
    2515                 :             :     // Return the empty FeePerWeight if the passed Ref is empty.
    2516         [ #  # ]:           0 :     if (GetRefGraph(arg) == nullptr) return {};
    2517                 :           0 :     Assume(GetRefGraph(arg) == this);
    2518                 :             :     // Apply all removals and dependencies, as the result might be inaccurate otherwise.
    2519                 :           0 :     ApplyDependencies(/*level=*/0);
    2520                 :             :     // Chunk feerates cannot be accurately known if unapplied dependencies remain.
    2521                 :           0 :     Assume(m_main_clusterset.m_deps_to_add.empty());
    2522                 :             :     // Find the cluster the argument is in, and return the empty FeePerWeight if it isn't in any.
    2523         [ #  # ]:           0 :     auto [cluster, cluster_level] = FindClusterAndLevel(GetRefIndex(arg), /*level=*/0);
    2524         [ #  # ]:           0 :     if (cluster == nullptr) return {};
    2525                 :             :     // Make sure the Cluster has an acceptable quality level, and then return the transaction's
    2526                 :             :     // chunk feerate.
    2527                 :           0 :     MakeAcceptable(*cluster, cluster_level);
    2528                 :           0 :     const auto& entry = m_entries[GetRefIndex(arg)];
    2529                 :           0 :     return entry.m_main_chunk_feerate;
    2530                 :             : }
    2531                 :             : 
    2532                 :           9 : bool TxGraphImpl::IsOversized(Level level_select) noexcept
    2533                 :             : {
    2534         [ +  - ]:           9 :     size_t level = GetSpecifiedLevel(level_select);
    2535                 :           9 :     auto& clusterset = GetClusterSet(level);
    2536         [ +  + ]:           9 :     if (clusterset.m_oversized.has_value()) {
    2537                 :             :         // Return cached value if known.
    2538                 :           5 :         return *clusterset.m_oversized;
    2539                 :             :     }
    2540                 :           4 :     ApplyRemovals(level);
    2541         [ -  + ]:           4 :     if (clusterset.m_txcount_oversized > 0) {
    2542                 :           0 :         clusterset.m_oversized = true;
    2543                 :             :     } else {
    2544                 :             :         // Find which Clusters will need to be merged together, as that is where the oversize
    2545                 :             :         // property is assessed.
    2546                 :           4 :         GroupClusters(level);
    2547                 :             :     }
    2548                 :           4 :     Assume(clusterset.m_oversized.has_value());
    2549                 :           4 :     return *clusterset.m_oversized;
    2550                 :             : }
    2551                 :             : 
    2552                 :           0 : void TxGraphImpl::StartStaging() noexcept
    2553                 :             : {
    2554                 :             :     // Staging cannot already exist.
    2555                 :           0 :     Assume(!m_staging_clusterset.has_value());
    2556                 :             :     // Apply all remaining dependencies in main before creating a staging graph. Once staging
    2557                 :             :     // exists, we cannot merge Clusters anymore (because of interference with Clusters being
    2558                 :             :     // pulled into staging), so to make sure all inspectors are available (if not oversized), do
    2559                 :             :     // all merging work now. Call SplitAll() first, so that even if ApplyDependencies does not do
    2560                 :             :     // any thing due to knowing the result is oversized, splitting is still performed.
    2561                 :           0 :     SplitAll(0);
    2562                 :           0 :     ApplyDependencies(0);
    2563                 :             :     // Construct the staging ClusterSet.
    2564                 :           0 :     m_staging_clusterset.emplace();
    2565                 :             :     // Copy statistics, precomputed data, and to-be-applied dependencies (only if oversized) to
    2566                 :             :     // the new graph. To-be-applied removals will always be empty at this point.
    2567                 :           0 :     m_staging_clusterset->m_txcount = m_main_clusterset.m_txcount;
    2568                 :           0 :     m_staging_clusterset->m_txcount_oversized = m_main_clusterset.m_txcount_oversized;
    2569                 :           0 :     m_staging_clusterset->m_deps_to_add = m_main_clusterset.m_deps_to_add;
    2570                 :           0 :     m_staging_clusterset->m_group_data = m_main_clusterset.m_group_data;
    2571                 :           0 :     m_staging_clusterset->m_oversized = m_main_clusterset.m_oversized;
    2572                 :           0 :     Assume(m_staging_clusterset->m_oversized.has_value());
    2573                 :           0 :     m_staging_clusterset->m_cluster_usage = 0;
    2574                 :           0 : }
    2575                 :             : 
    2576                 :           0 : void TxGraphImpl::AbortStaging() noexcept
    2577                 :             : {
    2578                 :             :     // Staging must exist.
    2579                 :           0 :     Assume(m_staging_clusterset.has_value());
    2580                 :             :     // Mark all removed transactions as Missing (so the staging locator for these transactions
    2581                 :             :     // can be reused if another staging is created).
    2582         [ #  # ]:           0 :     for (auto idx : m_staging_clusterset->m_removed) {
    2583                 :           0 :         m_entries[idx].m_locator[1].SetMissing();
    2584                 :             :     }
    2585                 :             :     // Do the same with the non-removed transactions in staging Clusters.
    2586         [ #  # ]:           0 :     for (int quality = 0; quality < int(QualityLevel::NONE); ++quality) {
    2587         [ #  # ]:           0 :         for (auto& cluster : m_staging_clusterset->m_clusters[quality]) {
    2588                 :           0 :             cluster->MakeStagingTransactionsMissing(*this);
    2589                 :             :         }
    2590                 :             :     }
    2591                 :             :     // Destroy the staging ClusterSet.
    2592                 :           0 :     m_staging_clusterset.reset();
    2593                 :           0 :     Compact();
    2594         [ #  # ]:           0 :     if (!m_main_clusterset.m_group_data.has_value()) {
    2595                 :             :         // In case m_oversized in main was kept after a Ref destruction while staging exists, we
    2596                 :             :         // need to re-evaluate m_oversized now.
    2597   [ #  #  #  # ]:           0 :         if (m_main_clusterset.m_to_remove.empty() && m_main_clusterset.m_txcount_oversized > 0) {
    2598                 :             :             // It is possible that a Ref destruction caused a removal in main while staging existed.
    2599                 :             :             // In this case, m_txcount_oversized may be inaccurate.
    2600                 :           0 :             m_main_clusterset.m_oversized = true;
    2601                 :             :         } else {
    2602         [ #  # ]:           0 :             m_main_clusterset.m_oversized = std::nullopt;
    2603                 :             :         }
    2604                 :             :     }
    2605                 :           0 : }
    2606                 :             : 
    2607                 :           0 : void TxGraphImpl::CommitStaging() noexcept
    2608                 :             : {
    2609                 :             :     // Staging must exist.
    2610                 :           0 :     Assume(m_staging_clusterset.has_value());
    2611                 :           0 :     Assume(m_main_chunkindex_observers == 0);
    2612                 :             :     // Delete all conflicting Clusters in main, to make place for moving the staging ones
    2613                 :             :     // there. All of these have been copied to staging in PullIn().
    2614                 :           0 :     auto conflicts = GetConflicts();
    2615         [ #  # ]:           0 :     for (Cluster* conflict : conflicts) {
    2616                 :           0 :         conflict->Clear(*this, /*level=*/0);
    2617                 :           0 :         DeleteCluster(*conflict, /*level=*/0);
    2618                 :             :     }
    2619                 :             :     // Mark the removed transactions as Missing (so the staging locator for these transactions
    2620                 :             :     // can be reused if another staging is created).
    2621         [ #  # ]:           0 :     for (auto idx : m_staging_clusterset->m_removed) {
    2622                 :           0 :         m_entries[idx].m_locator[1].SetMissing();
    2623                 :             :     }
    2624                 :             :     // Then move all Clusters in staging to main.
    2625         [ #  # ]:           0 :     for (int quality = 0; quality < int(QualityLevel::NONE); ++quality) {
    2626                 :           0 :         auto& stage_sets = m_staging_clusterset->m_clusters[quality];
    2627         [ #  # ]:           0 :         while (!stage_sets.empty()) {
    2628                 :           0 :             stage_sets.back()->MoveToMain(*this);
    2629                 :             :         }
    2630                 :             :     }
    2631                 :             :     // Move all statistics, precomputed data, and to-be-applied removals and dependencies.
    2632                 :           0 :     m_main_clusterset.m_deps_to_add = std::move(m_staging_clusterset->m_deps_to_add);
    2633                 :           0 :     m_main_clusterset.m_to_remove = std::move(m_staging_clusterset->m_to_remove);
    2634                 :           0 :     m_main_clusterset.m_group_data = std::move(m_staging_clusterset->m_group_data);
    2635                 :           0 :     m_main_clusterset.m_oversized = std::move(m_staging_clusterset->m_oversized);
    2636                 :           0 :     m_main_clusterset.m_txcount = std::move(m_staging_clusterset->m_txcount);
    2637                 :           0 :     m_main_clusterset.m_txcount_oversized = std::move(m_staging_clusterset->m_txcount_oversized);
    2638                 :             :     // Delete the old staging graph, after all its information was moved to main.
    2639                 :           0 :     m_staging_clusterset.reset();
    2640                 :           0 :     Compact();
    2641                 :           0 : }
    2642                 :             : 
    2643                 :           0 : void GenericClusterImpl::SetFee(TxGraphImpl& graph, int level, DepGraphIndex idx, int64_t fee) noexcept
    2644                 :             : {
    2645                 :             :     // Make sure the specified DepGraphIndex exists in this Cluster.
    2646                 :           0 :     Assume(m_depgraph.Positions()[idx]);
    2647                 :             :     // Bail out if the fee isn't actually being changed.
    2648         [ #  # ]:           0 :     if (m_depgraph.FeeRate(idx).fee == fee) return;
    2649                 :             :     // Update the fee, remember that relinearization will be necessary, and update the Entries
    2650                 :             :     // in the same Cluster.
    2651         [ #  # ]:           0 :     m_depgraph.FeeRate(idx).fee = fee;
    2652         [ #  # ]:           0 :     if (m_quality == QualityLevel::OVERSIZED_SINGLETON) {
    2653                 :             :         // Nothing to do.
    2654         [ #  # ]:           0 :     } else if (!NeedsSplitting()) {
    2655                 :           0 :         graph.SetClusterQuality(level, m_quality, m_setindex, QualityLevel::NEEDS_RELINEARIZE);
    2656                 :             :     } else {
    2657                 :           0 :         graph.SetClusterQuality(level, m_quality, m_setindex, QualityLevel::NEEDS_SPLIT);
    2658                 :             :     }
    2659                 :           0 :     Updated(graph, level);
    2660                 :             : }
    2661                 :             : 
    2662                 :           0 : void SingletonClusterImpl::SetFee(TxGraphImpl& graph, int level, DepGraphIndex idx, int64_t fee) noexcept
    2663                 :             : {
    2664                 :           0 :     Assume(GetTxCount());
    2665                 :           0 :     Assume(idx == 0);
    2666                 :           0 :     m_feerate.fee = fee;
    2667                 :           0 :     Updated(graph, level);
    2668                 :           0 : }
    2669                 :             : 
    2670                 :           0 : void TxGraphImpl::SetTransactionFee(const Ref& ref, int64_t fee) noexcept
    2671                 :             : {
    2672                 :             :     // Don't do anything if the passed Ref is empty.
    2673         [ #  # ]:           0 :     if (GetRefGraph(ref) == nullptr) return;
    2674                 :           0 :     Assume(GetRefGraph(ref) == this);
    2675                 :           0 :     Assume(m_main_chunkindex_observers == 0);
    2676                 :             :     // Find the entry, its locator, and inform its Cluster about the new feerate, if any.
    2677                 :           0 :     auto& entry = m_entries[GetRefIndex(ref)];
    2678         [ #  # ]:           0 :     for (int level = 0; level < MAX_LEVELS; ++level) {
    2679                 :           0 :         auto& locator = entry.m_locator[level];
    2680         [ #  # ]:           0 :         if (locator.IsPresent()) {
    2681                 :           0 :             locator.cluster->SetFee(*this, level, locator.index, fee);
    2682                 :             :         }
    2683                 :             :     }
    2684                 :             : }
    2685                 :             : 
    2686                 :           0 : std::strong_ordering TxGraphImpl::CompareMainOrder(const Ref& a, const Ref& b) noexcept
    2687                 :             : {
    2688                 :             :     // The references must not be empty.
    2689                 :           0 :     Assume(GetRefGraph(a) == this);
    2690                 :           0 :     Assume(GetRefGraph(b) == this);
    2691                 :             :     // Apply dependencies in main.
    2692                 :           0 :     ApplyDependencies(0);
    2693                 :           0 :     Assume(m_main_clusterset.m_deps_to_add.empty());
    2694                 :             :     // Make both involved Clusters acceptable, so chunk feerates are relevant.
    2695                 :           0 :     const auto& entry_a = m_entries[GetRefIndex(a)];
    2696                 :           0 :     const auto& entry_b = m_entries[GetRefIndex(b)];
    2697                 :           0 :     const auto& locator_a = entry_a.m_locator[0];
    2698                 :           0 :     const auto& locator_b = entry_b.m_locator[0];
    2699                 :           0 :     Assume(locator_a.IsPresent());
    2700                 :           0 :     Assume(locator_b.IsPresent());
    2701                 :           0 :     MakeAcceptable(*locator_a.cluster, /*level=*/0);
    2702                 :           0 :     MakeAcceptable(*locator_b.cluster, /*level=*/0);
    2703                 :             :     // Invoke comparison logic.
    2704                 :           0 :     return CompareMainTransactions(GetRefIndex(a), GetRefIndex(b));
    2705                 :             : }
    2706                 :             : 
    2707                 :           0 : TxGraph::GraphIndex TxGraphImpl::CountDistinctClusters(std::span<const Ref* const> refs, Level level_select) noexcept
    2708                 :             : {
    2709         [ #  # ]:           0 :     size_t level = GetSpecifiedLevel(level_select);
    2710                 :           0 :     ApplyDependencies(level);
    2711                 :           0 :     auto& clusterset = GetClusterSet(level);
    2712                 :           0 :     Assume(clusterset.m_deps_to_add.empty());
    2713                 :             :     // Build a vector of Clusters that the specified Refs occur in.
    2714                 :           0 :     std::vector<Cluster*> clusters;
    2715                 :           0 :     clusters.reserve(refs.size());
    2716         [ #  # ]:           0 :     for (const Ref* ref : refs) {
    2717                 :           0 :         Assume(ref);
    2718         [ #  # ]:           0 :         if (GetRefGraph(*ref) == nullptr) continue;
    2719                 :           0 :         Assume(GetRefGraph(*ref) == this);
    2720         [ #  # ]:           0 :         auto cluster = FindCluster(GetRefIndex(*ref), level);
    2721         [ #  # ]:           0 :         if (cluster != nullptr) clusters.push_back(cluster);
    2722                 :             :     }
    2723                 :             :     // Count the number of distinct elements in clusters.
    2724                 :           0 :     std::sort(clusters.begin(), clusters.end(), [](Cluster* a, Cluster* b) noexcept { return CompareClusters(a, b) < 0; });
    2725                 :           0 :     Cluster* last{nullptr};
    2726                 :           0 :     GraphIndex ret{0};
    2727         [ #  # ]:           0 :     for (Cluster* cluster : clusters) {
    2728                 :           0 :         ret += (cluster != last);
    2729                 :           0 :         last = cluster;
    2730                 :             :     }
    2731                 :           0 :     return ret;
    2732                 :           0 : }
    2733                 :             : 
    2734                 :           0 : std::pair<std::vector<FeeFrac>, std::vector<FeeFrac>> TxGraphImpl::GetMainStagingDiagrams() noexcept
    2735                 :             : {
    2736                 :           0 :     Assume(m_staging_clusterset.has_value());
    2737                 :           0 :     MakeAllAcceptable(0);
    2738                 :           0 :     Assume(m_main_clusterset.m_deps_to_add.empty()); // can only fail if main is oversized
    2739                 :           0 :     MakeAllAcceptable(1);
    2740                 :           0 :     Assume(m_staging_clusterset->m_deps_to_add.empty()); // can only fail if staging is oversized
    2741                 :             :     // For all Clusters in main which conflict with Clusters in staging (i.e., all that are removed
    2742                 :             :     // by, or replaced in, staging), gather their chunk feerates.
    2743                 :           0 :     auto main_clusters = GetConflicts();
    2744                 :           0 :     std::vector<FeeFrac> main_feerates, staging_feerates;
    2745         [ #  # ]:           0 :     for (Cluster* cluster : main_clusters) {
    2746                 :           0 :         cluster->AppendChunkFeerates(main_feerates);
    2747                 :             :     }
    2748                 :             :     // Do the same for the Clusters in staging themselves.
    2749         [ #  # ]:           0 :     for (int quality = 0; quality < int(QualityLevel::NONE); ++quality) {
    2750         [ #  # ]:           0 :         for (const auto& cluster : m_staging_clusterset->m_clusters[quality]) {
    2751                 :           0 :             cluster->AppendChunkFeerates(staging_feerates);
    2752                 :             :         }
    2753                 :             :     }
    2754                 :             :     // Sort both by decreasing feerate to obtain diagrams, and return them.
    2755   [ #  #  #  #  :           0 :     std::sort(main_feerates.begin(), main_feerates.end(), [](auto& a, auto& b) { return a > b; });
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
             #  #  #  #  
                      # ]
    2756   [ #  #  #  #  :           0 :     std::sort(staging_feerates.begin(), staging_feerates.end(), [](auto& a, auto& b) { return a > b; });
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
             #  #  #  #  
                      # ]
    2757                 :           0 :     return std::make_pair(std::move(main_feerates), std::move(staging_feerates));
    2758                 :           0 : }
    2759                 :             : 
    2760                 :           0 : void GenericClusterImpl::SanityCheck(const TxGraphImpl& graph, int level) const
    2761                 :             : {
    2762                 :             :     // There must be an m_mapping for each m_depgraph position (including holes).
    2763   [ #  #  #  #  :           0 :     assert(m_depgraph.PositionRange() == m_mapping.size());
                   #  # ]
    2764                 :             :     // The linearization for this Cluster must contain every transaction once.
    2765   [ #  #  #  # ]:           0 :     assert(m_depgraph.TxCount() == m_linearization.size());
    2766                 :             :     // Unless a split is to be applied, the cluster cannot have any holes.
    2767         [ #  # ]:           0 :     if (!NeedsSplitting()) {
    2768   [ #  #  #  # ]:           0 :         assert(m_depgraph.Positions() == SetType::Fill(m_depgraph.TxCount()));
    2769                 :             :     }
    2770                 :             : 
    2771                 :             :     // Compute the chunking of m_linearization.
    2772                 :           0 :     LinearizationChunking linchunking(m_depgraph, m_linearization);
    2773                 :             : 
    2774                 :             :     // Verify m_linearization.
    2775                 :           0 :     SetType m_done;
    2776                 :           0 :     LinearizationIndex linindex{0};
    2777                 :           0 :     DepGraphIndex chunk_pos{0}; //!< position within the current chunk
    2778         [ #  # ]:           0 :     assert(m_depgraph.IsAcyclic());
    2779         [ #  # ]:           0 :     for (auto lin_pos : m_linearization) {
    2780   [ #  #  #  # ]:           0 :         assert(lin_pos < m_mapping.size());
    2781         [ #  # ]:           0 :         const auto& entry = graph.m_entries[m_mapping[lin_pos]];
    2782                 :             :         // Check that the linearization is topological.
    2783         [ #  # ]:           0 :         m_done.Set(lin_pos);
    2784         [ #  # ]:           0 :         assert(m_done.IsSupersetOf(m_depgraph.Ancestors(lin_pos)));
    2785                 :             :         // Check that the Entry has a locator pointing back to this Cluster & position within it.
    2786         [ #  # ]:           0 :         assert(entry.m_locator[level].cluster == this);
    2787         [ #  # ]:           0 :         assert(entry.m_locator[level].index == lin_pos);
    2788                 :             :         // For main-level entries, check linearization position and chunk feerate.
    2789   [ #  #  #  # ]:           0 :         if (level == 0 && IsAcceptable()) {
    2790         [ #  # ]:           0 :             assert(entry.m_main_lin_index == linindex);
    2791                 :           0 :             ++linindex;
    2792   [ #  #  #  # ]:           0 :             if (!linchunking.GetChunk(0).transactions[lin_pos]) {
    2793                 :           0 :                 linchunking.MarkDone(linchunking.GetChunk(0).transactions);
    2794                 :           0 :                 chunk_pos = 0;
    2795                 :             :             }
    2796   [ #  #  #  # ]:           0 :             assert(entry.m_main_chunk_feerate == linchunking.GetChunk(0).feerate);
    2797                 :             :             // Verify that an entry in the chunk index exists for every chunk-ending transaction.
    2798                 :           0 :             ++chunk_pos;
    2799         [ #  # ]:           0 :             bool is_chunk_end = (chunk_pos == linchunking.GetChunk(0).transactions.Count());
    2800         [ #  # ]:           0 :             assert((entry.m_main_chunkindex_iterator != graph.m_main_chunkindex.end()) == is_chunk_end);
    2801         [ #  # ]:           0 :             if (is_chunk_end) {
    2802         [ #  # ]:           0 :                 auto& chunk_data = *entry.m_main_chunkindex_iterator;
    2803   [ #  #  #  # ]:           0 :                 if (m_done == m_depgraph.Positions() && chunk_pos == 1) {
    2804         [ #  # ]:           0 :                     assert(chunk_data.m_chunk_count == LinearizationIndex(-1));
    2805                 :             :                 } else {
    2806         [ #  # ]:           0 :                     assert(chunk_data.m_chunk_count == chunk_pos);
    2807                 :             :                 }
    2808                 :             :             }
    2809                 :             :             // If this Cluster has an acceptable quality level, its chunks must be connected.
    2810         [ #  # ]:           0 :             assert(m_depgraph.IsConnected(linchunking.GetChunk(0).transactions));
    2811                 :             :         }
    2812                 :             :     }
    2813                 :             :     // Verify that each element of m_depgraph occurred in m_linearization.
    2814         [ #  # ]:           0 :     assert(m_done == m_depgraph.Positions());
    2815                 :           0 : }
    2816                 :             : 
    2817                 :      192822 : void SingletonClusterImpl::SanityCheck(const TxGraphImpl& graph, int level) const
    2818                 :             : {
    2819                 :             :     // All singletons are optimal, oversized, or need splitting.
    2820   [ +  +  +  + ]:      192822 :     Assume(IsOptimal() || IsOversized() || NeedsSplitting());
    2821         [ +  + ]:      192822 :     if (GetTxCount()) {
    2822         [ -  + ]:      192811 :         const auto& entry = graph.m_entries[m_graph_index];
    2823                 :             :         // Check that the Entry has a locator pointing back to this Cluster & position within it.
    2824         [ -  + ]:      192811 :         assert(entry.m_locator[level].cluster == this);
    2825         [ -  + ]:      192811 :         assert(entry.m_locator[level].index == 0);
    2826                 :             :         // For main-level entries, check linearization position and chunk feerate.
    2827   [ +  -  +  + ]:      192811 :         if (level == 0 && IsAcceptable()) {
    2828         [ -  + ]:      192799 :             assert(entry.m_main_lin_index == 0);
    2829         [ +  - ]:      192799 :             assert(entry.m_main_chunk_feerate == m_feerate);
    2830         [ -  + ]:      192799 :             assert(entry.m_main_chunkindex_iterator != graph.m_main_chunkindex.end());
    2831         [ -  + ]:      192799 :             auto& chunk_data = *entry.m_main_chunkindex_iterator;
    2832         [ -  + ]:      192799 :             assert(chunk_data.m_chunk_count == LinearizationIndex(-1));
    2833                 :             :         }
    2834                 :             :     }
    2835                 :      192822 : }
    2836                 :             : 
    2837                 :          11 : void TxGraphImpl::SanityCheck() const
    2838                 :             : {
    2839                 :             :     /** Which GraphIndexes ought to occur in m_unlinked, based on m_entries. */
    2840                 :          11 :     std::set<GraphIndex> expected_unlinked;
    2841                 :             :     /** Which Clusters ought to occur in ClusterSet::m_clusters, based on m_entries. */
    2842         [ +  + ]:          55 :     std::set<const Cluster*> expected_clusters[MAX_LEVELS];
    2843                 :             :     /** Which GraphIndexes ought to occur in ClusterSet::m_removed, based on m_entries. */
    2844         [ +  + ]:          55 :     std::set<GraphIndex> expected_removed[MAX_LEVELS];
    2845                 :             :     /** Which Cluster::m_sequence values have been encountered. */
    2846                 :          11 :     std::set<uint64_t> sequences;
    2847                 :             :     /** Which GraphIndexes ought to occur in m_main_chunkindex, based on m_entries. */
    2848                 :          11 :     std::set<GraphIndex> expected_chunkindex;
    2849                 :             :     /** Whether compaction is possible in the current state. */
    2850                 :          11 :     bool compact_possible{true};
    2851                 :             : 
    2852                 :             :     // Go over all Entry objects in m_entries.
    2853   [ -  +  +  + ]:      192833 :     for (GraphIndex idx = 0; idx < m_entries.size(); ++idx) {
    2854         [ -  + ]:      192822 :         const auto& entry = m_entries[idx];
    2855         [ -  + ]:      192822 :         if (entry.m_ref == nullptr) {
    2856                 :             :             // Unlinked Entry must have indexes appear in m_unlinked.
    2857         [ #  # ]:           0 :             expected_unlinked.insert(idx);
    2858                 :             :         } else {
    2859                 :             :             // Every non-unlinked Entry must have a Ref that points back to it.
    2860         [ -  + ]:      192822 :             assert(GetRefGraph(*entry.m_ref) == this);
    2861         [ -  + ]:      192822 :             assert(GetRefIndex(*entry.m_ref) == idx);
    2862                 :             :         }
    2863         [ +  + ]:      192822 :         if (entry.m_main_chunkindex_iterator != m_main_chunkindex.end()) {
    2864                 :             :             // Remember which entries we see a chunkindex entry for.
    2865         [ -  + ]:      192799 :             assert(entry.m_locator[0].IsPresent());
    2866         [ +  - ]:      192799 :             expected_chunkindex.insert(idx);
    2867                 :             :         }
    2868                 :             :         // Verify the Entry m_locators.
    2869                 :             :         bool was_present{false}, was_removed{false};
    2870         [ +  + ]:      578466 :         for (int level = 0; level < MAX_LEVELS; ++level) {
    2871                 :      385644 :             const auto& locator = entry.m_locator[level];
    2872                 :             :             // Every Locator must be in exactly one of these 3 states.
    2873   [ +  +  +  +  :     1156932 :             assert(locator.IsMissing() + locator.IsRemoved() + locator.IsPresent() == 1);
                   -  + ]
    2874         [ +  + ]:      385644 :             if (locator.IsPresent()) {
    2875                 :             :                 // Once removed, a transaction cannot be revived.
    2876         [ -  + ]:      192811 :                 assert(!was_removed);
    2877                 :             :                 // Verify that the Cluster agrees with where the Locator claims the transaction is.
    2878         [ -  + ]:      192811 :                 assert(locator.cluster->GetClusterEntry(locator.index) == idx);
    2879                 :             :                 // Remember that we expect said Cluster to appear in the ClusterSet::m_clusters.
    2880         [ +  - ]:      192811 :                 expected_clusters[level].insert(locator.cluster);
    2881                 :             :                 was_present = true;
    2882         [ -  + ]:      385644 :             } else if (locator.IsRemoved()) {
    2883                 :             :                 // Level 0 (main) cannot have IsRemoved locators (IsMissing there means non-existing).
    2884         [ #  # ]:           0 :                 assert(level > 0);
    2885                 :             :                 // A Locator can only be IsRemoved if it was IsPresent before, and only once.
    2886         [ #  # ]:           0 :                 assert(was_present && !was_removed);
    2887                 :             :                 // Remember that we expect this GraphIndex to occur in the ClusterSet::m_removed.
    2888         [ #  # ]:           0 :                 expected_removed[level].insert(idx);
    2889                 :             :                 was_removed = true;
    2890                 :             :             }
    2891                 :             :         }
    2892                 :             :     }
    2893                 :             : 
    2894                 :             :     // For all levels (0 = main, 1 = staged)...
    2895         [ +  + ]:          22 :     for (int level = 0; level <= GetTopLevel(); ++level) {
    2896                 :          11 :         assert(level < MAX_LEVELS);
    2897                 :          11 :         auto& clusterset = GetClusterSet(level);
    2898                 :          11 :         std::set<const Cluster*> actual_clusters;
    2899                 :          11 :         size_t recomputed_cluster_usage{0};
    2900                 :             : 
    2901                 :             :         // For all quality levels...
    2902         [ +  + ]:          77 :         for (int qual = 0; qual < int(QualityLevel::NONE); ++qual) {
    2903                 :          66 :             QualityLevel quality{qual};
    2904                 :          66 :             const auto& quality_clusters = clusterset.m_clusters[qual];
    2905                 :             :             // ... for all clusters in them ...
    2906   [ -  +  +  + ]:      192888 :             for (ClusterSetIndex setindex = 0; setindex < quality_clusters.size(); ++setindex) {
    2907                 :      192822 :                 const auto& cluster = *quality_clusters[setindex];
    2908                 :             :                 // The number of transactions in a Cluster cannot exceed m_max_cluster_count.
    2909         [ -  + ]:      192822 :                 assert(cluster.GetTxCount() <= m_max_cluster_count);
    2910                 :             :                 // The level must match the Cluster's own idea of what level it is in (but GetLevel
    2911                 :             :                 // can only be called for non-empty Clusters).
    2912   [ +  +  -  + ]:      192822 :                 assert(cluster.GetTxCount() == 0 || level == cluster.GetLevel(*this));
    2913                 :             :                 // The sum of their sizes cannot exceed m_max_cluster_size, unless it is an
    2914                 :             :                 // individually oversized transaction singleton. Note that groups of to-be-merged
    2915                 :             :                 // clusters which would exceed this limit are marked oversized, which means they
    2916                 :             :                 // are never applied.
    2917   [ +  +  -  + ]:      192822 :                 assert(cluster.IsOversized() || cluster.GetTotalTxSize() <= m_max_cluster_size);
    2918                 :             :                 // OVERSIZED clusters are singletons.
    2919   [ +  +  -  + ]:      192822 :                 assert(!cluster.IsOversized() || cluster.GetTxCount() == 1);
    2920                 :             :                 // Transaction counts cannot exceed the Cluster implementation's maximum
    2921                 :             :                 // supported transactions count.
    2922         [ -  + ]:      192822 :                 assert(cluster.GetTxCount() <= cluster.GetMaxTxCount());
    2923                 :             :                 // Unless a Split is yet to be applied, the number of transactions must not be
    2924                 :             :                 // below the Cluster implementation's intended transaction count.
    2925         [ +  + ]:      192822 :                 if (!cluster.NeedsSplitting()) {
    2926         [ -  + ]:      192811 :                     assert(cluster.GetTxCount() >= cluster.GetMinIntendedTxCount());
    2927                 :             :                 }
    2928                 :             : 
    2929                 :             :                 // Check the sequence number.
    2930         [ -  + ]:      192822 :                 assert(cluster.m_sequence < m_next_sequence_counter);
    2931         [ -  + ]:      192822 :                 assert(sequences.count(cluster.m_sequence) == 0);
    2932         [ +  - ]:      192822 :                 sequences.insert(cluster.m_sequence);
    2933                 :             :                 // Remember we saw this Cluster (only if it is non-empty; empty Clusters aren't
    2934                 :             :                 // expected to be referenced by the Entry vector).
    2935         [ +  + ]:      192822 :                 if (cluster.GetTxCount() != 0) {
    2936         [ +  - ]:      192811 :                     actual_clusters.insert(&cluster);
    2937                 :             :                 }
    2938                 :             :                 // Sanity check the cluster, according to the Cluster's internal rules.
    2939         [ +  - ]:      192822 :                 cluster.SanityCheck(*this, level);
    2940                 :             :                 // Check that the cluster's quality and setindex matches its position in the quality list.
    2941         [ -  + ]:      192822 :                 assert(cluster.m_quality == quality);
    2942         [ -  + ]:      192822 :                 assert(cluster.m_setindex == setindex);
    2943                 :             :                 // Count memory usage.
    2944                 :      192822 :                 recomputed_cluster_usage += cluster.TotalMemoryUsage();
    2945                 :             :             }
    2946                 :             :         }
    2947                 :             : 
    2948                 :             :         // Verify memory usage.
    2949         [ -  + ]:          11 :         assert(clusterset.m_cluster_usage == recomputed_cluster_usage);
    2950                 :             : 
    2951                 :             :         // Verify that all to-be-removed transactions have valid identifiers.
    2952         [ +  + ]:          19 :         for (GraphIndex idx : clusterset.m_to_remove) {
    2953   [ -  +  -  + ]:           8 :             assert(idx < m_entries.size());
    2954                 :             :             // We cannot assert that all m_to_remove transactions are still present: ~Ref on a
    2955                 :             :             // (P,M) transaction (present in main, inherited in staging) will cause an m_to_remove
    2956                 :             :             // addition in both main and staging, but a subsequence ApplyRemovals in main will
    2957                 :             :             // cause it to disappear from staging too, leaving the m_to_remove in place.
    2958                 :             :         }
    2959                 :             : 
    2960                 :             :         // Verify that all to-be-added dependencies have valid identifiers.
    2961   [ -  +  +  + ]:      191427 :         for (auto [par_idx, chl_idx] : clusterset.m_deps_to_add) {
    2962         [ -  + ]:      191416 :             assert(par_idx != chl_idx);
    2963   [ -  +  -  + ]:      191416 :             assert(par_idx < m_entries.size());
    2964         [ -  + ]:      191416 :             assert(chl_idx < m_entries.size());
    2965                 :             :         }
    2966                 :             : 
    2967                 :             :         // Verify that the actually encountered clusters match the ones occurring in Entry vector.
    2968         [ -  + ]:          11 :         assert(actual_clusters == expected_clusters[level]);
    2969                 :             : 
    2970                 :             :         // Verify that the contents of m_removed matches what was expected based on the Entry vector.
    2971         [ +  - ]:          11 :         std::set<GraphIndex> actual_removed(clusterset.m_removed.begin(), clusterset.m_removed.end());
    2972         [ -  + ]:          11 :         for (auto i : expected_unlinked) {
    2973                 :             :             // If a transaction exists in both main and staging, and is removed from staging (adding
    2974                 :             :             // it to m_removed there), and consequently destroyed (wiping the locator completely),
    2975                 :             :             // it can remain in m_removed despite not having an IsRemoved() locator. Exclude those
    2976                 :             :             // transactions from the comparison here.
    2977                 :           0 :             actual_removed.erase(i);
    2978                 :           0 :             expected_removed[level].erase(i);
    2979                 :             :         }
    2980                 :             : 
    2981         [ -  + ]:          11 :         assert(actual_removed == expected_removed[level]);
    2982                 :             : 
    2983                 :             :         // If any GraphIndex entries remain in this ClusterSet, compact is not possible.
    2984         [ +  + ]:          11 :         if (!clusterset.m_deps_to_add.empty()) compact_possible = false;
    2985         [ +  + ]:          11 :         if (!clusterset.m_to_remove.empty()) compact_possible = false;
    2986         [ -  + ]:          11 :         if (!clusterset.m_removed.empty()) compact_possible = false;
    2987                 :             : 
    2988                 :             :         // For non-top levels, m_oversized must be known (as it cannot change until the level
    2989                 :             :         // on top is gone).
    2990   [ -  +  -  - ]:          11 :         if (level < GetTopLevel()) assert(clusterset.m_oversized.has_value());
    2991                 :          11 :     }
    2992                 :             : 
    2993                 :             :     // Verify that the contents of m_unlinked matches what was expected based on the Entry vector.
    2994         [ +  - ]:          11 :     std::set<GraphIndex> actual_unlinked(m_unlinked.begin(), m_unlinked.end());
    2995         [ -  + ]:          11 :     assert(actual_unlinked == expected_unlinked);
    2996                 :             : 
    2997                 :             :     // If compaction was possible, it should have been performed already, and m_unlinked must be
    2998                 :             :     // empty (to prevent memory leaks due to an ever-growing m_entries vector).
    2999         [ +  + ]:          11 :     if (compact_possible) {
    3000         [ -  + ]:           3 :         assert(actual_unlinked.empty());
    3001                 :             :     }
    3002                 :             : 
    3003                 :             :     // Finally, check the chunk index.
    3004                 :          11 :     std::set<GraphIndex> actual_chunkindex;
    3005                 :          11 :     FeeFrac last_chunk_feerate;
    3006         [ +  + ]:      192810 :     for (const auto& chunk : m_main_chunkindex) {
    3007                 :      192799 :         GraphIndex idx = chunk.m_graph_index;
    3008         [ +  - ]:      192799 :         actual_chunkindex.insert(idx);
    3009         [ +  + ]:      192799 :         auto chunk_feerate = m_entries[idx].m_main_chunk_feerate;
    3010         [ +  + ]:      192799 :         if (!last_chunk_feerate.IsEmpty()) {
    3011         [ -  + ]:      192788 :             assert(FeeRateCompare(last_chunk_feerate, chunk_feerate) >= 0);
    3012                 :             :         }
    3013                 :      192799 :         last_chunk_feerate = chunk_feerate;
    3014                 :             :     }
    3015         [ -  + ]:          11 :     assert(actual_chunkindex == expected_chunkindex);
    3016   [ +  +  +  +  :          77 : }
             -  -  -  - ]
    3017                 :             : 
    3018                 :           0 : bool TxGraphImpl::DoWork(uint64_t iters) noexcept
    3019                 :             : {
    3020                 :           0 :     uint64_t iters_done{0};
    3021                 :             :     // First linearize everything in NEEDS_RELINEARIZE to an acceptable level. If more budget
    3022                 :             :     // remains after that, try to make everything optimal.
    3023         [ #  # ]:           0 :     for (QualityLevel quality : {QualityLevel::NEEDS_RELINEARIZE, QualityLevel::ACCEPTABLE}) {
    3024                 :             :         // First linearize staging, if it exists, then main.
    3025         [ #  # ]:           0 :         for (int level = GetTopLevel(); level >= 0; --level) {
    3026                 :             :             // Do not modify main if it has any observers.
    3027   [ #  #  #  # ]:           0 :             if (level == 0 && m_main_chunkindex_observers != 0) continue;
    3028                 :           0 :             ApplyDependencies(level);
    3029                 :           0 :             auto& clusterset = GetClusterSet(level);
    3030                 :             :             // Do not modify oversized levels.
    3031         [ #  # ]:           0 :             if (clusterset.m_oversized == true) continue;
    3032                 :           0 :             auto& queue = clusterset.m_clusters[int(quality)];
    3033         [ #  # ]:           0 :             while (!queue.empty()) {
    3034         [ #  # ]:           0 :                 if (iters_done >= iters) return false;
    3035                 :             :                 // Randomize the order in which we process, so that if the first cluster somehow
    3036                 :             :                 // needs more work than what iters allows, we don't keep spending it on the same
    3037                 :             :                 // one.
    3038         [ #  # ]:           0 :                 auto pos = m_rng.randrange<size_t>(queue.size());
    3039                 :           0 :                 auto iters_now = iters - iters_done;
    3040         [ #  # ]:           0 :                 if (quality == QualityLevel::NEEDS_RELINEARIZE) {
    3041                 :             :                     // If we're working with clusters that need relinearization still, only perform
    3042                 :             :                     // up to m_acceptable_iters iterations. If they become ACCEPTABLE, and we still
    3043                 :             :                     // have budget after all other clusters are ACCEPTABLE too, we'll spend the
    3044                 :             :                     // remaining budget on trying to make them OPTIMAL.
    3045         [ #  # ]:           0 :                     iters_now = std::min(iters_now, m_acceptable_iters);
    3046                 :             :                 }
    3047         [ #  # ]:           0 :                 auto [cost, improved] = queue[pos].get()->Relinearize(*this, level, iters_now);
    3048                 :           0 :                 iters_done += cost;
    3049                 :             :                 // If no improvement was made to the Cluster, it means we've essentially run out of
    3050                 :             :                 // budget. Even though it may be the case that iters_done < iters still, the
    3051                 :             :                 // linearizer decided there wasn't enough budget left to attempt anything with.
    3052                 :             :                 // To avoid an infinite loop that keeps trying clusters with minuscule budgets,
    3053                 :             :                 // stop here too.
    3054         [ #  # ]:           0 :                 if (!improved) return false;
    3055                 :             :             }
    3056                 :             :         }
    3057                 :             :     }
    3058                 :             :     // All possible work has been performed, so we can return true. Note that this does *not* mean
    3059                 :             :     // that all clusters are optimally linearized now. It may be that there is nothing to do left
    3060                 :             :     // because all non-optimal clusters are in oversized and/or observer-bearing levels.
    3061                 :             :     return true;
    3062                 :             : }
    3063                 :             : 
    3064                 :           0 : void BlockBuilderImpl::Next() noexcept
    3065                 :             : {
    3066                 :             :     // Don't do anything if we're already done.
    3067         [ #  # ]:           0 :     if (m_cur_iter == m_graph->m_main_chunkindex.end()) return;
    3068                 :           0 :     while (true) {
    3069                 :             :         // Advance the pointer, and stop if we reach the end.
    3070         [ #  # ]:           0 :         ++m_cur_iter;
    3071                 :           0 :         m_cur_cluster = nullptr;
    3072         [ #  # ]:           0 :         if (m_cur_iter == m_graph->m_main_chunkindex.end()) break;
    3073                 :             :         // Find the cluster pointed to by m_cur_iter.
    3074                 :           0 :         const auto& chunk_data = *m_cur_iter;
    3075                 :           0 :         const auto& chunk_end_entry = m_graph->m_entries[chunk_data.m_graph_index];
    3076                 :           0 :         m_cur_cluster = chunk_end_entry.m_locator[0].cluster;
    3077                 :           0 :         m_known_end_of_cluster = false;
    3078                 :             :         // If we previously skipped a chunk from this cluster we cannot include more from it.
    3079         [ #  # ]:           0 :         if (!m_excluded_clusters.contains(m_cur_cluster->m_sequence)) break;
    3080                 :             :     }
    3081                 :             : }
    3082                 :             : 
    3083                 :           0 : std::optional<std::pair<std::vector<TxGraph::Ref*>, FeePerWeight>> BlockBuilderImpl::GetCurrentChunk() noexcept
    3084                 :             : {
    3085                 :           0 :     std::optional<std::pair<std::vector<TxGraph::Ref*>, FeePerWeight>> ret;
    3086                 :             :     // Populate the return value if we are not done.
    3087         [ #  # ]:           0 :     if (m_cur_iter != m_graph->m_main_chunkindex.end()) {
    3088                 :           0 :         ret.emplace();
    3089         [ #  # ]:           0 :         const auto& chunk_data = *m_cur_iter;
    3090         [ #  # ]:           0 :         const auto& chunk_end_entry = m_graph->m_entries[chunk_data.m_graph_index];
    3091         [ #  # ]:           0 :         if (chunk_data.m_chunk_count == LinearizationIndex(-1)) {
    3092                 :             :             // Special case in case just a single transaction remains, avoiding the need to
    3093                 :             :             // dispatch to and dereference Cluster.
    3094                 :           0 :             ret->first.resize(1);
    3095                 :           0 :             Assume(chunk_end_entry.m_ref != nullptr);
    3096                 :           0 :             ret->first[0] = chunk_end_entry.m_ref;
    3097                 :           0 :             m_known_end_of_cluster = true;
    3098                 :             :         } else {
    3099                 :           0 :             Assume(m_cur_cluster);
    3100                 :           0 :             ret->first.resize(chunk_data.m_chunk_count);
    3101                 :           0 :             auto start_pos = chunk_end_entry.m_main_lin_index + 1 - chunk_data.m_chunk_count;
    3102         [ #  # ]:           0 :             m_known_end_of_cluster = m_cur_cluster->GetClusterRefs(*m_graph, ret->first, start_pos);
    3103                 :             :             // If the chunk size was 1 and at end of cluster, then the special case above should
    3104                 :             :             // have been used.
    3105                 :           0 :             Assume(!m_known_end_of_cluster || chunk_data.m_chunk_count > 1);
    3106                 :             :         }
    3107                 :           0 :         ret->second = chunk_end_entry.m_main_chunk_feerate;
    3108                 :             :     }
    3109                 :           0 :     return ret;
    3110                 :             : }
    3111                 :             : 
    3112                 :           0 : BlockBuilderImpl::BlockBuilderImpl(TxGraphImpl& graph) noexcept : m_graph(&graph)
    3113                 :             : {
    3114                 :             :     // Make sure all clusters in main are up to date, and acceptable.
    3115                 :           0 :     m_graph->MakeAllAcceptable(0);
    3116                 :             :     // There cannot remain any inapplicable dependencies (only possible if main is oversized).
    3117         [ #  # ]:           0 :     Assume(m_graph->m_main_clusterset.m_deps_to_add.empty());
    3118                 :             :     // Remember that this object is observing the graph's index, so that we can detect concurrent
    3119                 :             :     // modifications.
    3120                 :           0 :     ++m_graph->m_main_chunkindex_observers;
    3121                 :             :     // Find the first chunk.
    3122         [ #  # ]:           0 :     m_cur_iter = m_graph->m_main_chunkindex.begin();
    3123                 :           0 :     m_cur_cluster = nullptr;
    3124         [ #  # ]:           0 :     if (m_cur_iter != m_graph->m_main_chunkindex.end()) {
    3125                 :             :         // Find the cluster pointed to by m_cur_iter.
    3126                 :           0 :         const auto& chunk_data = *m_cur_iter;
    3127                 :           0 :         const auto& chunk_end_entry = m_graph->m_entries[chunk_data.m_graph_index];
    3128                 :           0 :         m_cur_cluster = chunk_end_entry.m_locator[0].cluster;
    3129                 :             :     }
    3130                 :           0 : }
    3131                 :             : 
    3132                 :           0 : BlockBuilderImpl::~BlockBuilderImpl()
    3133                 :             : {
    3134                 :           0 :     Assume(m_graph->m_main_chunkindex_observers > 0);
    3135                 :             :     // Permit modifications to the main graph again after destroying the BlockBuilderImpl.
    3136                 :           0 :     --m_graph->m_main_chunkindex_observers;
    3137                 :           0 : }
    3138                 :             : 
    3139                 :           0 : void BlockBuilderImpl::Include() noexcept
    3140                 :             : {
    3141                 :             :     // The actual inclusion of the chunk is done by the calling code. All we have to do is switch
    3142                 :             :     // to the next chunk.
    3143                 :           0 :     Next();
    3144                 :           0 : }
    3145                 :             : 
    3146                 :           0 : void BlockBuilderImpl::Skip() noexcept
    3147                 :             : {
    3148                 :             :     // When skipping a chunk we need to not include anything more of the cluster, as that could make
    3149                 :             :     // the result topologically invalid. However, don't do this if the chunk is known to be the last
    3150                 :             :     // chunk of the cluster. This may significantly reduce the size of m_excluded_clusters,
    3151                 :             :     // especially when many singleton clusters are ignored.
    3152   [ #  #  #  # ]:           0 :     if (m_cur_cluster != nullptr && !m_known_end_of_cluster) {
    3153                 :           0 :         m_excluded_clusters.insert(m_cur_cluster->m_sequence);
    3154                 :             :     }
    3155                 :           0 :     Next();
    3156                 :           0 : }
    3157                 :             : 
    3158                 :           0 : std::unique_ptr<TxGraph::BlockBuilder> TxGraphImpl::GetBlockBuilder() noexcept
    3159                 :             : {
    3160         [ #  # ]:           0 :     return std::make_unique<BlockBuilderImpl>(*this);
    3161                 :             : }
    3162                 :             : 
    3163                 :           0 : std::pair<std::vector<TxGraph::Ref*>, FeePerWeight> TxGraphImpl::GetWorstMainChunk() noexcept
    3164                 :             : {
    3165                 :           0 :     std::pair<std::vector<Ref*>, FeePerWeight> ret;
    3166                 :             :     // Make sure all clusters in main are up to date, and acceptable.
    3167                 :           0 :     MakeAllAcceptable(0);
    3168                 :           0 :     Assume(m_main_clusterset.m_deps_to_add.empty());
    3169                 :             :     // If the graph is not empty, populate ret.
    3170         [ #  # ]:           0 :     if (!m_main_chunkindex.empty()) {
    3171         [ #  # ]:           0 :         const auto& chunk_data = *m_main_chunkindex.rbegin();
    3172         [ #  # ]:           0 :         const auto& chunk_end_entry = m_entries[chunk_data.m_graph_index];
    3173                 :           0 :         Cluster* cluster = chunk_end_entry.m_locator[0].cluster;
    3174         [ #  # ]:           0 :         if (chunk_data.m_chunk_count == LinearizationIndex(-1) || chunk_data.m_chunk_count == 1)  {
    3175                 :             :             // Special case for singletons.
    3176                 :           0 :             ret.first.resize(1);
    3177                 :           0 :             Assume(chunk_end_entry.m_ref != nullptr);
    3178                 :           0 :             ret.first[0] = chunk_end_entry.m_ref;
    3179                 :             :         } else {
    3180                 :           0 :             ret.first.resize(chunk_data.m_chunk_count);
    3181                 :           0 :             auto start_pos = chunk_end_entry.m_main_lin_index + 1 - chunk_data.m_chunk_count;
    3182         [ #  # ]:           0 :             cluster->GetClusterRefs(*this, ret.first, start_pos);
    3183                 :           0 :             std::reverse(ret.first.begin(), ret.first.end());
    3184                 :             :         }
    3185                 :           0 :         ret.second = chunk_end_entry.m_main_chunk_feerate;
    3186                 :             :     }
    3187                 :           0 :     return ret;
    3188                 :             : }
    3189                 :             : 
    3190                 :           4 : std::vector<TxGraph::Ref*> TxGraphImpl::Trim() noexcept
    3191                 :             : {
    3192         [ +  - ]:           4 :     int level = GetTopLevel();
    3193                 :           4 :     Assume(m_main_chunkindex_observers == 0 || level != 0);
    3194                 :           4 :     std::vector<TxGraph::Ref*> ret;
    3195                 :             : 
    3196                 :             :     // Compute the groups of to-be-merged Clusters (which also applies all removals, and splits).
    3197                 :           4 :     auto& clusterset = GetClusterSet(level);
    3198         [ +  - ]:           4 :     if (clusterset.m_oversized == false) return ret;
    3199                 :           4 :     GroupClusters(level);
    3200         [ +  - ]:           4 :     Assume(clusterset.m_group_data.has_value());
    3201                 :             :     // Nothing to do if not oversized.
    3202                 :           4 :     Assume(clusterset.m_oversized.has_value());
    3203         [ +  - ]:           4 :     if (clusterset.m_oversized == false) return ret;
    3204                 :             : 
    3205                 :             :     // In this function, would-be clusters (as precomputed in m_group_data by GroupClusters) are
    3206                 :             :     // trimmed by removing transactions in them such that the resulting clusters satisfy the size
    3207                 :             :     // and count limits.
    3208                 :             :     //
    3209                 :             :     // It works by defining for each would-be cluster a rudimentary linearization: at every point
    3210                 :             :     // the highest-chunk-feerate remaining transaction is picked among those with no unmet
    3211                 :             :     // dependencies. "Dependency" here means either a to-be-added dependency (m_deps_to_add), or
    3212                 :             :     // an implicit dependency added between any two consecutive transaction in their current
    3213                 :             :     // cluster linearization. So it can be seen as a "merge sort" of the chunks of the clusters,
    3214                 :             :     // but respecting the dependencies being added.
    3215                 :             :     //
    3216                 :             :     // This rudimentary linearization is computed lazily, by putting all eligible (no unmet
    3217                 :             :     // dependencies) transactions in a heap, and popping the highest-feerate one from it. Along the
    3218                 :             :     // way, the counts and sizes of the would-be clusters up to that point are tracked (by
    3219                 :             :     // partitioning the involved transactions using a union-find structure). Any transaction whose
    3220                 :             :     // addition would cause a violation is removed, along with all their descendants.
    3221                 :             :     //
    3222                 :             :     // A next invocation of GroupClusters (after applying the removals) will compute the new
    3223                 :             :     // resulting clusters, and none of them will violate the limits.
    3224                 :             : 
    3225                 :             :     /** All dependencies (both to be added ones, and implicit ones between consecutive transactions
    3226                 :             :      *  in existing cluster linearizations), sorted by parent. */
    3227                 :           4 :     std::vector<std::pair<GraphIndex, GraphIndex>> deps_by_parent;
    3228                 :             :     /** Same, but sorted by child. */
    3229                 :           4 :     std::vector<std::pair<GraphIndex, GraphIndex>> deps_by_child;
    3230                 :             :     /** Information about all transactions involved in a Cluster group to be trimmed, sorted by
    3231                 :             :      *  GraphIndex. It contains entries both for transactions that have already been included,
    3232                 :             :      *  and ones that have not yet been. */
    3233                 :           4 :     std::vector<TrimTxData> trim_data;
    3234                 :             :     /** Iterators into trim_data, treated as a max heap according to cmp_fn below. Each entry is
    3235                 :             :      *  a transaction that has not yet been included yet, but all its ancestors have. */
    3236                 :           4 :     std::vector<std::vector<TrimTxData>::iterator> trim_heap;
    3237                 :             :     /** The list of representatives of the partitions a given transaction depends on. */
    3238                 :           4 :     std::vector<TrimTxData*> current_deps;
    3239                 :             : 
    3240                 :             :     /** Function to define the ordering of trim_heap. */
    3241                 :     1082781 :     static constexpr auto cmp_fn = [](auto a, auto b) noexcept {
    3242                 :             :         // Sort by increasing chunk feerate, and then by decreasing size.
    3243                 :             :         // We do not need to sort by cluster or within clusters, because due to the implicit
    3244                 :             :         // dependency between consecutive linearization elements, no two transactions from the
    3245                 :             :         // same Cluster will ever simultaneously be in the heap.
    3246                 :     1082777 :         return a->m_chunk_feerate < b->m_chunk_feerate;
    3247                 :             :     };
    3248                 :             : 
    3249                 :             :     /** Given a TrimTxData entry, find the representative of the partition it is in. */
    3250                 :      127308 :     static constexpr auto find_fn = [](TrimTxData* arg) noexcept {
    3251   [ +  +  -  + ]:      189351 :         while (arg != arg->m_uf_parent) {
    3252                 :             :             // Replace pointer to parent with pointer to grandparent (path splitting).
    3253                 :             :             // See https://en.wikipedia.org/wiki/Disjoint-set_data_structure#Finding_set_representatives.
    3254                 :       62047 :             auto par = arg->m_uf_parent;
    3255                 :       62047 :             arg->m_uf_parent = par->m_uf_parent;
    3256                 :       62047 :             arg = par;
    3257                 :             :         }
    3258                 :      127304 :         return arg;
    3259                 :             :     };
    3260                 :             : 
    3261                 :             :     /** Given two TrimTxData entries, union the partitions they are in, and return the
    3262                 :             :      *  representative. */
    3263                 :       63100 :     static constexpr auto union_fn = [](TrimTxData* arg1, TrimTxData* arg2) noexcept {
    3264                 :             :         // Replace arg1 and arg2 by their representatives.
    3265         [ -  + ]:      126192 :         auto rep1 = find_fn(arg1);
    3266                 :       63096 :         auto rep2 = find_fn(arg2);
    3267                 :             :         // Bail out if both representatives are the same, because that means arg1 and arg2 are in
    3268                 :             :         // the same partition already.
    3269         [ +  - ]:       63096 :         if (rep1 == rep2) return rep1;
    3270                 :             :         // Pick the lower-count root to become a child of the higher-count one.
    3271                 :             :         // See https://en.wikipedia.org/wiki/Disjoint-set_data_structure#Union_by_size.
    3272         [ +  + ]:       63096 :         if (rep1->m_uf_count < rep2->m_uf_count) std::swap(rep1, rep2);
    3273                 :       63096 :         rep2->m_uf_parent = rep1;
    3274                 :             :         // Add the statistics of arg2 (which is no longer a representative) to those of arg1 (which
    3275                 :             :         // is now the representative for both).
    3276                 :       63096 :         rep1->m_uf_size += rep2->m_uf_size;
    3277                 :       63096 :         rep1->m_uf_count += rep2->m_uf_count;
    3278                 :       63096 :         return rep1;
    3279                 :             :     };
    3280                 :             : 
    3281                 :             :     /** Get iterator to TrimTxData entry for a given index. */
    3282                 :      128420 :     auto locate_fn = [&](GraphIndex index) noexcept {
    3283                 :      128416 :         auto it = std::lower_bound(trim_data.begin(), trim_data.end(), index, [](TrimTxData& elem, GraphIndex idx) noexcept {
    3284         [ +  + ]:     2048000 :             return elem.m_index < idx;
    3285                 :             :         });
    3286         [ +  - ]:      128416 :         Assume(it != trim_data.end() && it->m_index == index);
    3287                 :      128416 :         return it;
    3288                 :           4 :     };
    3289                 :             : 
    3290                 :             :     // For each group of to-be-merged Clusters.
    3291         [ +  + ]:          13 :     for (const auto& group_data : clusterset.m_group_data->m_groups) {
    3292         [ +  + ]:           9 :         trim_data.clear();
    3293         [ -  + ]:           9 :         trim_heap.clear();
    3294         [ -  + ]:           9 :         deps_by_child.clear();
    3295         [ -  + ]:           9 :         deps_by_parent.clear();
    3296                 :             : 
    3297                 :             :         // Gather trim data and implicit dependency data from all involved Clusters.
    3298         [ -  + ]:           9 :         auto cluster_span = std::span{clusterset.m_group_data->m_group_clusters}
    3299                 :           9 :                                 .subspan(group_data.m_cluster_offset, group_data.m_cluster_count);
    3300                 :           9 :         uint64_t size{0};
    3301         [ +  + ]:       64226 :         for (Cluster* cluster : cluster_span) {
    3302                 :       64217 :             size += cluster->AppendTrimData(trim_data, deps_by_child);
    3303                 :             :         }
    3304                 :             :         // If this group of Clusters does not violate any limits, continue to the next group.
    3305   [ -  +  +  +  :           9 :         if (trim_data.size() <= m_max_cluster_count && size <= m_max_cluster_size) continue;
                   +  - ]
    3306                 :             :         // Sort the trim data by GraphIndex. In what follows, we will treat this sorted vector as
    3307                 :             :         // a map from GraphIndex to TrimTxData via locate_fn, and its ordering will not change
    3308                 :             :         // anymore.
    3309   [ +  +  +  +  :     1315115 :         std::sort(trim_data.begin(), trim_data.end(), [](auto& a, auto& b) noexcept { return a.m_index < b.m_index; });
          +  +  +  +  +  
          +  +  +  +  +  
          +  +  +  +  +  
             +  -  -  +  
                      + ]
    3310                 :             : 
    3311                 :             :         // Add the explicitly added dependencies to deps_by_child.
    3312                 :           9 :         deps_by_child.insert(deps_by_child.end(),
    3313                 :           9 :                              clusterset.m_deps_to_add.begin() + group_data.m_deps_offset,
    3314                 :           9 :                              clusterset.m_deps_to_add.begin() + group_data.m_deps_offset + group_data.m_deps_count);
    3315                 :             : 
    3316                 :             :         // Sort deps_by_child by child transaction GraphIndex. The order will not be changed
    3317                 :             :         // anymore after this.
    3318   [ +  +  +  +  :     1453049 :         std::sort(deps_by_child.begin(), deps_by_child.end(), [](auto& a, auto& b) noexcept { return a.second < b.second; });
          +  +  +  +  +  
          +  +  +  +  +  
          +  +  +  +  +  
             +  -  -  +  
                      + ]
    3319                 :             :         // Fill m_parents_count and m_parents_offset in trim_data, as well as m_deps_left, and
    3320                 :             :         // initially populate trim_heap. Because of the sort above, all dependencies involving the
    3321                 :             :         // same child are grouped together, so a single linear scan suffices.
    3322                 :           9 :         auto deps_it = deps_by_child.begin();
    3323         [ +  + ]:       64226 :         for (auto trim_it = trim_data.begin(); trim_it != trim_data.end(); ++trim_it) {
    3324                 :       64217 :             trim_it->m_parent_offset = deps_it - deps_by_child.begin();
    3325                 :       64217 :             trim_it->m_deps_left = 0;
    3326   [ +  +  +  + ]:      128425 :             while (deps_it != deps_by_child.end() && deps_it->second == trim_it->m_index) {
    3327                 :       64208 :                 ++trim_it->m_deps_left;
    3328                 :       64208 :                 ++deps_it;
    3329                 :             :             }
    3330                 :       64217 :             trim_it->m_parent_count = trim_it->m_deps_left;
    3331                 :             :             // If this transaction has no unmet dependencies, and is not oversized, add it to the
    3332                 :             :             // heap (just append for now, the heapification happens below).
    3333   [ +  +  +  + ]:       64217 :             if (trim_it->m_deps_left == 0 && trim_it->m_tx_size <= m_max_cluster_size) {
    3334                 :        1150 :                 trim_heap.push_back(trim_it);
    3335                 :             :             }
    3336                 :             :         }
    3337                 :           9 :         Assume(deps_it == deps_by_child.end());
    3338                 :             : 
    3339                 :             :         // Construct deps_by_parent, sorted by parent transaction GraphIndex. The order will not be
    3340                 :             :         // changed anymore after this.
    3341                 :           9 :         deps_by_parent = deps_by_child;
    3342   [ +  +  +  +  :     1787289 :         std::sort(deps_by_parent.begin(), deps_by_parent.end(), [](auto& a, auto& b) noexcept { return a.first < b.first; });
          +  +  +  +  +  
          +  +  +  +  +  
          +  +  +  +  +  
             +  -  -  +  
                      + ]
    3343                 :             :         // Fill m_children_offset and m_children_count in trim_data. Because of the sort above, all
    3344                 :             :         // dependencies involving the same parent are grouped together, so a single linear scan
    3345                 :             :         // suffices.
    3346                 :           9 :         deps_it = deps_by_parent.begin();
    3347         [ +  + ]:       64226 :         for (auto& trim_entry : trim_data) {
    3348                 :       64217 :             trim_entry.m_children_count = 0;
    3349                 :       64217 :             trim_entry.m_children_offset = deps_it - deps_by_parent.begin();
    3350   [ +  +  +  + ]:      128425 :             while (deps_it != deps_by_parent.end() && deps_it->first == trim_entry.m_index) {
    3351                 :       64208 :                 ++trim_entry.m_children_count;
    3352                 :       64208 :                 ++deps_it;
    3353                 :             :             }
    3354                 :             :         }
    3355                 :           9 :         Assume(deps_it == deps_by_parent.end());
    3356                 :             : 
    3357                 :             :         // Build a heap of all transactions with 0 unmet dependencies.
    3358                 :           9 :         std::make_heap(trim_heap.begin(), trim_heap.end(), cmp_fn);
    3359                 :             : 
    3360                 :             :         // Iterate over to-be-included transactions, and convert them to included transactions, or
    3361                 :             :         // skip them if adding them would violate resource limits of the would-be cluster.
    3362                 :             :         //
    3363                 :             :         // It is possible that the heap empties without ever hitting either cluster limit, in case
    3364                 :             :         // the implied graph (to be added dependencies plus implicit dependency between each
    3365                 :             :         // original transaction and its predecessor in the linearization it came from) contains
    3366                 :             :         // cycles. Such cycles will be removed entirely, because each of the transactions in the
    3367                 :             :         // cycle permanently have unmet dependencies. However, this cannot occur in real scenarios
    3368                 :             :         // where Trim() is called to deal with reorganizations that would violate cluster limits,
    3369                 :             :         // as all added dependencies are in the same direction (from old mempool transactions to
    3370                 :             :         // new from-block transactions); cycles require dependencies in both directions to be
    3371                 :             :         // added.
    3372         [ +  + ]:       64229 :         while (!trim_heap.empty()) {
    3373                 :             :             // Move the best remaining transaction to the end of trim_heap.
    3374                 :       64211 :             std::pop_heap(trim_heap.begin(), trim_heap.end(), cmp_fn);
    3375                 :             :             // Pop it, and find its TrimTxData.
    3376         [ +  + ]:       64211 :             auto& entry = *trim_heap.back();
    3377         [ +  + ]:       64211 :             trim_heap.pop_back();
    3378                 :             : 
    3379                 :             :             // Initialize it as a singleton partition.
    3380                 :       64211 :             entry.m_uf_parent = &entry;
    3381                 :       64211 :             entry.m_uf_count = 1;
    3382                 :       64211 :             entry.m_uf_size = entry.m_tx_size;
    3383                 :             : 
    3384                 :             :             // Find the distinct transaction partitions this entry depends on.
    3385         [ +  + ]:       64211 :             current_deps.clear();
    3386   [ -  +  +  + ]:      128419 :             for (auto& [par, chl] : std::span{deps_by_child}.subspan(entry.m_parent_offset, entry.m_parent_count)) {
    3387                 :       64208 :                 Assume(chl == entry.m_index);
    3388                 :      128416 :                 current_deps.push_back(find_fn(&*locate_fn(par)));
    3389                 :             :             }
    3390                 :       64211 :             std::sort(current_deps.begin(), current_deps.end());
    3391                 :       64211 :             current_deps.erase(std::unique(current_deps.begin(), current_deps.end()), current_deps.end());
    3392                 :             : 
    3393                 :             :             // Compute resource counts.
    3394                 :       64211 :             uint32_t new_count = 1;
    3395                 :       64211 :             uint64_t new_size = entry.m_tx_size;
    3396         [ +  + ]:      128419 :             for (TrimTxData* ptr : current_deps) {
    3397                 :       64208 :                 new_count += ptr->m_uf_count;
    3398                 :       64208 :                 new_size += ptr->m_uf_size;
    3399                 :             :             }
    3400                 :             :             // Skip the entry if this would violate any limit.
    3401   [ +  +  -  + ]:       64211 :             if (new_count > m_max_cluster_count || new_size > m_max_cluster_size) continue;
    3402                 :             : 
    3403                 :             :             // Union the partitions this transaction and all its dependencies are in together.
    3404                 :       64198 :             auto rep = &entry;
    3405         [ +  + ]:      127294 :             for (TrimTxData* ptr : current_deps) rep = union_fn(ptr, rep);
    3406                 :             :             // Mark the entry as included (so the loop below will not remove the transaction).
    3407                 :       64198 :             entry.m_deps_left = uint32_t(-1);
    3408                 :             :             // Mark each to-be-added dependency involving this transaction as parent satisfied.
    3409   [ -  +  +  + ]:      128406 :             for (auto& [par, chl] : std::span{deps_by_parent}.subspan(entry.m_children_offset, entry.m_children_count)) {
    3410                 :       64208 :                 Assume(par == entry.m_index);
    3411                 :       64208 :                 auto chl_it = locate_fn(chl);
    3412                 :             :                 // Reduce the number of unmet dependencies of chl_it, and if that brings the number
    3413                 :             :                 // to zero, add it to the heap of includable transactions.
    3414                 :       64208 :                 Assume(chl_it->m_deps_left > 0);
    3415         [ +  + ]:       64208 :                 if (--chl_it->m_deps_left == 0) {
    3416                 :       63061 :                     trim_heap.push_back(chl_it);
    3417                 :       63061 :                     std::push_heap(trim_heap.begin(), trim_heap.end(), cmp_fn);
    3418                 :             :                 }
    3419                 :             :             }
    3420                 :             :         }
    3421                 :             : 
    3422                 :             :         // Remove all the transactions that were not processed above. Because nothing gets
    3423                 :             :         // processed until/unless all its dependencies are met, this automatically guarantees
    3424                 :             :         // that if a transaction is removed, all its descendants, or would-be descendants, are
    3425                 :             :         // removed as well.
    3426         [ +  + ]:       64226 :         for (const auto& trim_entry : trim_data) {
    3427         [ +  + ]:       64217 :             if (trim_entry.m_deps_left != uint32_t(-1)) {
    3428                 :          19 :                 ret.push_back(m_entries[trim_entry.m_index].m_ref);
    3429                 :          19 :                 clusterset.m_to_remove.push_back(trim_entry.m_index);
    3430                 :             :             }
    3431                 :             :         }
    3432                 :             :     }
    3433         [ +  - ]:           4 :     clusterset.m_group_data.reset();
    3434                 :           4 :     clusterset.m_oversized = false;
    3435                 :           4 :     Assume(!ret.empty());
    3436                 :           4 :     return ret;
    3437                 :           4 : }
    3438                 :             : 
    3439                 :           0 : size_t TxGraphImpl::GetMainMemoryUsage() noexcept
    3440                 :             : {
    3441                 :             :     // Make sure splits/merges are applied, as memory usage may not be representative otherwise.
    3442                 :           0 :     SplitAll(/*up_to_level=*/0);
    3443                 :           0 :     ApplyDependencies(/*level=*/0);
    3444                 :             :     // Compute memory usage
    3445                 :           0 :     size_t usage = /* From clusters */
    3446                 :           0 :                    m_main_clusterset.m_cluster_usage +
    3447                 :             :                    /* From Entry objects. */
    3448                 :           0 :                    sizeof(Entry) * m_main_clusterset.m_txcount +
    3449                 :             :                    /* From the chunk index. */
    3450                 :           0 :                    memusage::DynamicUsage(m_main_chunkindex);
    3451                 :           0 :     return usage;
    3452                 :             : }
    3453                 :             : 
    3454                 :             : } // namespace
    3455                 :             : 
    3456                 :      194172 : TxGraph::Ref::~Ref()
    3457                 :             : {
    3458         [ +  + ]:      194172 :     if (m_graph) {
    3459                 :             :         // Inform the TxGraph about the Ref being destroyed.
    3460                 :         300 :         m_graph->UnlinkRef(m_index);
    3461                 :         300 :         m_graph = nullptr;
    3462                 :             :     }
    3463                 :      194172 : }
    3464                 :             : 
    3465                 :           0 : TxGraph::Ref& TxGraph::Ref::operator=(Ref&& other) noexcept
    3466                 :             : {
    3467                 :             :     // Unlink the current graph, if any.
    3468         [ #  # ]:           0 :     if (m_graph) m_graph->UnlinkRef(m_index);
    3469                 :             :     // Inform the other's graph about the move, if any.
    3470         [ #  # ]:           0 :     if (other.m_graph) other.m_graph->UpdateRef(other.m_index, *this);
    3471                 :             :     // Actually update the contents.
    3472                 :           0 :     m_graph = other.m_graph;
    3473                 :           0 :     m_index = other.m_index;
    3474                 :           0 :     other.m_graph = nullptr;
    3475                 :           0 :     other.m_index = GraphIndex(-1);
    3476                 :           0 :     return *this;
    3477                 :             : }
    3478                 :             : 
    3479                 :      129861 : TxGraph::Ref::Ref(Ref&& other) noexcept
    3480                 :             : {
    3481                 :             :     // Inform the TxGraph of other that its Ref is being moved.
    3482         [ +  - ]:      129861 :     if (other.m_graph) other.m_graph->UpdateRef(other.m_index, *this);
    3483                 :             :     // Actually move the contents.
    3484                 :      129861 :     std::swap(m_graph, other.m_graph);
    3485                 :      129861 :     std::swap(m_index, other.m_index);
    3486                 :      129861 : }
    3487                 :             : 
    3488                 :           4 : std::unique_ptr<TxGraph> MakeTxGraph(unsigned max_cluster_count, uint64_t max_cluster_size, uint64_t acceptable_iters) noexcept
    3489                 :             : {
    3490         [ -  + ]:           4 :     return std::make_unique<TxGraphImpl>(max_cluster_count, max_cluster_size, acceptable_iters);
    3491                 :             : }
        

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