From 0b3ec8c59b2b6d598531cd4e688eb276e597c825 Mon Sep 17 00:00:00 2001
From: Pieter Wuille <pieter@wuille.net>
Date: Mon, 23 Sep 2024 11:32:58 -0400
Subject: [PATCH] clusterlin: remove Cluster type

---
 src/cluster_linearize.h              | 39 +---------------------------
 src/test/cluster_linearize_tests.cpp | 14 +++++-----
 src/test/util/cluster_linearize.h    | 37 --------------------------
 3 files changed, 8 insertions(+), 82 deletions(-)

diff --git a/src/cluster_linearize.h b/src/cluster_linearize.h
index a2450f54908..757c81f1083 100644
--- a/src/cluster_linearize.h
+++ b/src/cluster_linearize.h
@@ -19,14 +19,6 @@
 
 namespace cluster_linearize {
 
-/** Data type to represent cluster input.
- *
- * cluster[i].first is tx_i's fee and size.
- * cluster[i].second[j] is true iff tx_i spends one or more of tx_j's outputs.
- */
-template<typename SetType>
-using Cluster = std::vector<std::pair<FeeFrac, SetType>>;
-
 /** Data type to represent transaction indices in clusters. */
 using ClusterIndex = uint32_t;
 
@@ -54,7 +46,7 @@ class DepGraph
         Entry(const FeeFrac& f, const SetType& a, const SetType& d) noexcept : feerate(f), ancestors(a), descendants(d) {}
     };
 
-    /** Data for each transaction, in the same order as the Cluster it was constructed from. */
+    /** Data for each transaction. */
     std::vector<Entry> entries;
 
     /** Which positions are used. */
@@ -79,35 +71,6 @@ public:
     DepGraph& operator=(const DepGraph&) noexcept = default;
     DepGraph& operator=(DepGraph&&) noexcept = default;
 
-    /** Construct a DepGraph object for ntx transactions, with no dependencies.
-     *
-     * Complexity: O(N) where N=ntx.
-     **/
-    explicit DepGraph(ClusterIndex ntx) noexcept
-    {
-        Assume(ntx <= SetType::Size());
-        entries.resize(ntx);
-        for (ClusterIndex i = 0; i < ntx; ++i) {
-            entries[i].ancestors = SetType::Singleton(i);
-            entries[i].descendants = SetType::Singleton(i);
-        }
-        m_used = SetType::Fill(ntx);
-    }
-
-    /** Construct a DepGraph object given a cluster.
-     *
-     * Complexity: O(N^2) where N=cluster.size().
-     */
-    explicit DepGraph(const Cluster<SetType>& cluster) noexcept : DepGraph(cluster.size())
-    {
-        for (ClusterIndex i = 0; i < cluster.size(); ++i) {
-            // Fill in fee and size.
-            entries[i].feerate = cluster[i].first;
-            // Fill in dependencies.
-            AddDependencies(cluster[i].second, i);
-        }
-    }
-
     /** Construct a DepGraph object given another DepGraph and a mapping from old to new.
      *
      * @param depgraph   The original DepGraph that is being remapped.
diff --git a/src/test/cluster_linearize_tests.cpp b/src/test/cluster_linearize_tests.cpp
index cb87dcbffbe..265ccdc805e 100644
--- a/src/test/cluster_linearize_tests.cpp
+++ b/src/test/cluster_linearize_tests.cpp
@@ -23,18 +23,18 @@ namespace {
 constexpr std::pair<FeeFrac, TestBitSet> HOLE{FeeFrac{0, 0x3FFFFF}, {}};
 
 template<typename SetType>
-void TestDepGraphSerialization(const Cluster<SetType>& cluster, const std::string& hexenc)
+void TestDepGraphSerialization(const std::vector<std::pair<FeeFrac, SetType>>& cluster, const std::string& hexenc)
 {
-    DepGraph depgraph(cluster);
-
-    // Run normal sanity and correspondence checks, which includes a round-trip test.
-    VerifyDepGraphFromCluster(cluster, depgraph);
-
-    // Remove holes (which are expected to be present as HOLE entries in cluster).
+    // Construct DepGraph from cluster argument.
+    DepGraph<SetType> depgraph;
     SetType holes;
     for (ClusterIndex i = 0; i < cluster.size(); ++i) {
+        depgraph.AddTransaction(cluster[i].first);
         if (cluster[i] == HOLE) holes.Set(i);
     }
+    for (ClusterIndex i = 0; i < cluster.size(); ++i) {
+        depgraph.AddDependencies(cluster[i].second, i);
+    }
     depgraph.RemoveTransactions(holes);
 
     // There may be multiple serializations of the same graph, but DepGraphFormatter's serializer
diff --git a/src/test/util/cluster_linearize.h b/src/test/util/cluster_linearize.h
index 44cd6590d38..871aa9d74ed 100644
--- a/src/test/util/cluster_linearize.h
+++ b/src/test/util/cluster_linearize.h
@@ -390,43 +390,6 @@ void SanityCheck(const DepGraph<SetType>& depgraph)
     }
 }
 
-/** Verify that a DepGraph corresponds to the information in a cluster. */
-template<typename SetType>
-void VerifyDepGraphFromCluster(const Cluster<SetType>& cluster, const DepGraph<SetType>& depgraph)
-{
-    // Sanity check the depgraph, which includes a check for correspondence between ancestors and
-    // descendants, so it suffices to check just ancestors below.
-    SanityCheck(depgraph);
-    // Verify transaction count.
-    assert(cluster.size() == depgraph.TxCount());
-    // Verify feerates.
-    for (ClusterIndex i = 0; i < depgraph.TxCount(); ++i) {
-        assert(depgraph.FeeRate(i) == cluster[i].first);
-    }
-    // Verify ancestors.
-    for (ClusterIndex i = 0; i < depgraph.TxCount(); ++i) {
-        // Start with the transaction having itself as ancestor.
-        auto ancestors = SetType::Singleton(i);
-        // Add parents of ancestors to the set of ancestors until it stops changing.
-        while (true) {
-            const auto old_ancestors = ancestors;
-            for (auto ancestor : ancestors) {
-                ancestors |= cluster[ancestor].second;
-            }
-            if (old_ancestors == ancestors) break;
-        }
-        // Compare against depgraph.
-        assert(depgraph.Ancestors(i) == ancestors);
-        // Some additional sanity tests:
-        // - Every transaction has itself as ancestor.
-        assert(ancestors[i]);
-        // - Every transaction has its direct parents as ancestors.
-        for (auto parent : cluster[i].second) {
-            assert(ancestors[parent]);
-        }
-    }
-}
-
 /** Perform a sanity check on a linearization. */
 template<typename SetType>
 void SanityCheck(const DepGraph<SetType>& depgraph, Span<const ClusterIndex> linearization)