1 files changed, 128 insertions, 0 deletions
diff --git a/src/bench/disconnected_transactions.cpp b/src/bench/disconnected_transactions.cpp
new file mode 100644
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+++ b/src/bench/disconnected_transactions.cpp
@@ -0,0 +1,128 @@
+// Copyright (c) 2023 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <bench/bench.h>
+#include <test/util/random.h>
+#include <test/util/setup_common.h>
+#include <validation.h>
+
+constexpr size_t BLOCK_VTX_COUNT{4000};
+constexpr size_t BLOCK_VTX_COUNT_10PERCENT{400};
+
+using BlockTxns = decltype(CBlock::vtx);
+
+/** Reorg where 1 block is disconnected and 2 blocks are connected. */
+struct ReorgTxns {
+    /** Disconnected block. */
+    BlockTxns disconnected_txns;
+    /** First connected block. */
+    BlockTxns connected_txns_1;
+    /** Second connected block, new chain tip. Has no overlap with disconnected_txns. */
+    BlockTxns connected_txns_2;
+    /** Transactions shared between disconnected_txns and connected_txns_1. */
+    size_t num_shared;
+};
+
+static BlockTxns CreateRandomTransactions(size_t num_txns)
+{
+    // Ensure every transaction has a different txid by having each one spend the previous one.
+    static uint256 prevout_hash{uint256::ZERO};
+
+    BlockTxns txns;
+    txns.reserve(num_txns);
+    // Simplest spk for every tx
+    CScript spk = CScript() << OP_TRUE;
+    for (uint32_t i = 0; i < num_txns; ++i) {
+        CMutableTransaction tx;
+        tx.vin.emplace_back(CTxIn{COutPoint{prevout_hash, 0}});
+        tx.vout.emplace_back(CTxOut{CENT, spk});
+        auto ptx{MakeTransactionRef(tx)};
+        txns.emplace_back(ptx);
+        prevout_hash = ptx->GetHash();
+    }
+    return txns;
+}
+
+/** Creates blocks for a Reorg, each with BLOCK_VTX_COUNT transactions. Between the disconnected
+ * block and the first connected block, there will be num_not_shared transactions that are
+ * different, and all other transactions the exact same. The second connected block has all unique
+ * transactions. This is to simulate a reorg in which all but num_not_shared transactions are
+ * confirmed in the new chain. */
+static ReorgTxns CreateBlocks(size_t num_not_shared)
+{
+    auto num_shared{BLOCK_VTX_COUNT - num_not_shared};
+    const auto shared_txns{CreateRandomTransactions(/*num_txns=*/num_shared)};
+
+    // Create different sets of transactions...
+    auto disconnected_block_txns{CreateRandomTransactions(/*num_txns=*/num_not_shared)};
+    std::copy(shared_txns.begin(), shared_txns.end(), std::back_inserter(disconnected_block_txns));
+
+    auto connected_block_txns{CreateRandomTransactions(/*num_txns=*/num_not_shared)};
+    std::copy(shared_txns.begin(), shared_txns.end(), std::back_inserter(connected_block_txns));
+
+    assert(disconnected_block_txns.size() == BLOCK_VTX_COUNT);
+    assert(connected_block_txns.size() == BLOCK_VTX_COUNT);
+
+    return ReorgTxns{/*disconnected_txns=*/disconnected_block_txns,
+                     /*connected_txns_1=*/connected_block_txns,
+                     /*connected_txns_2=*/CreateRandomTransactions(BLOCK_VTX_COUNT),
+                     /*num_shared=*/num_shared};
+}
+
+static void Reorg(const ReorgTxns& reorg)
+{
+    DisconnectedBlockTransactions disconnectpool;
+    // Disconnect block
+    disconnectpool.AddTransactionsFromBlock(reorg.disconnected_txns);
+
+    // Connect first block
+    disconnectpool.removeForBlock(reorg.connected_txns_1);
+    // Connect new tip
+    disconnectpool.removeForBlock(reorg.connected_txns_2);
+
+    // Sanity Check
+    assert(disconnectpool.queuedTx.size() == BLOCK_VTX_COUNT - reorg.num_shared);
+
+    disconnectpool.clear();
+}
+
+/** Add transactions from DisconnectedBlockTransactions, remove all but one (the disconnected
+ * block's coinbase transaction) of them, and then pop from the front until empty. This is a reorg
+ * in which all of the non-coinbase transactions in the disconnected chain also exist in the new
+ * chain. */
+static void AddAndRemoveDisconnectedBlockTransactionsAll(benchmark::Bench& bench)
+{
+    const auto chains{CreateBlocks(/*num_not_shared=*/1)};
+    assert(chains.num_shared == BLOCK_VTX_COUNT - 1);
+
+    bench.minEpochIterations(10).run([&]() NO_THREAD_SAFETY_ANALYSIS {
+        Reorg(chains);
+    });
+}
+
+/** Add transactions from DisconnectedBlockTransactions, remove 90% of them, and then pop from the front until empty. */
+static void AddAndRemoveDisconnectedBlockTransactions90(benchmark::Bench& bench)
+{
+    const auto chains{CreateBlocks(/*num_not_shared=*/BLOCK_VTX_COUNT_10PERCENT)};
+    assert(chains.num_shared == BLOCK_VTX_COUNT - BLOCK_VTX_COUNT_10PERCENT);
+
+    bench.minEpochIterations(10).run([&]() NO_THREAD_SAFETY_ANALYSIS {
+        Reorg(chains);
+    });
+}
+
+/** Add transactions from DisconnectedBlockTransactions, remove 10% of them, and then pop from the front until empty. */
+static void AddAndRemoveDisconnectedBlockTransactions10(benchmark::Bench& bench)
+{
+    const auto chains{CreateBlocks(/*num_not_shared=*/BLOCK_VTX_COUNT - BLOCK_VTX_COUNT_10PERCENT)};
+    assert(chains.num_shared == BLOCK_VTX_COUNT_10PERCENT);
+
+    bench.minEpochIterations(10).run([&]() NO_THREAD_SAFETY_ANALYSIS {
+        Reorg(chains);
+    });
+}
+
+BENCHMARK(AddAndRemoveDisconnectedBlockTransactionsAll, benchmark::PriorityLevel::HIGH);
+BENCHMARK(AddAndRemoveDisconnectedBlockTransactions90, benchmark::PriorityLevel::HIGH);
+BENCHMARK(AddAndRemoveDisconnectedBlockTransactions10, benchmark::PriorityLevel::HIGH);