bench: basic block filter index initial sync

Introduce benchmark for the block filter index sync.
And makes synchronous 'Sync()' mechanism accessible.

Author: furszy

src/Makefile.bench.include

@@ -34,6 +34,7 @@ bench_bench_bitcoin_SOURCES = \
   bench/examples.cpp \
   bench/gcs_filter.cpp \
   bench/hashpadding.cpp \
+  bench/index_blockfilter.cpp \
   bench/load_external.cpp \
   bench/lockedpool.cpp \
   bench/logging.cpp \

src/bench/index_blockfilter.cpp

@@ -0,0 +1,43 @@
+// Copyright (c) 2023-present The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or https://www.opensource.org/licenses/mit-license.php.
+
+#include <bench/bench.h>
+
+#include <addresstype.h>
+#include <index/blockfilterindex.h>
+#include <node/chainstate.h>
+#include <node/context.h>
+#include <test/util/setup_common.h>
+#include <util/strencodings.h>
+
+// Very simple block filter index sync benchmark, only using coinbase outputs.
+static void BlockFilterIndexSync(benchmark::Bench& bench)
+{
+    const auto test_setup = MakeNoLogFileContext<TestChain100Setup>();
+
+    // Create more blocks
+    int CHAIN_SIZE = 600;
+    CPubKey pubkey{ParseHex("02ed26169896db86ced4cbb7b3ecef9859b5952825adbeab998fb5b307e54949c9")};
+    CScript script = GetScriptForDestination(WitnessV0KeyHash(pubkey));
+    std::vector<CMutableTransaction> noTxns;
+    for (int i = 0; i < CHAIN_SIZE - 100; i++) {
+        test_setup->CreateAndProcessBlock(noTxns, script);
+        SetMockTime(GetTime() + 1);
+    }
+    assert(WITH_LOCK(::cs_main, return test_setup->m_node.chainman->ActiveHeight() == CHAIN_SIZE));
+
+    bench.minEpochIterations(5).run([&] {
+        BlockFilterIndex filter_index(interfaces::MakeChain(test_setup->m_node), BlockFilterType::BASIC,
+                                      /*n_cache_size=*/0, /*f_memory=*/false, /*f_wipe=*/true);
+        assert(filter_index.Init());
+        assert(!filter_index.BlockUntilSyncedToCurrentChain());
+        filter_index.Sync();
+
+        IndexSummary summary = filter_index.GetSummary();
+        assert(summary.synced);
+        assert(summary.best_block_hash == WITH_LOCK(::cs_main, return test_setup->m_node.chainman->ActiveTip()->GetBlockHash()));
+    });
+}
+
+BENCHMARK(BlockFilterIndexSync, benchmark::PriorityLevel::HIGH);

src/index/base.cpp

@@ -141,7 +141,7 @@ static const CBlockIndex* NextSyncBlock(const CBlockIndex* pindex_prev, CChain&
     return chain.Next(chain.FindFork(pindex_prev));
 }
 
-void BaseIndex::ThreadSync()
+void BaseIndex::Sync()
 {
     const CBlockIndex* pindex = m_best_block_index.load();
     if (!m_synced) {
@@ -394,7 +394,7 @@ bool BaseIndex::StartBackgroundSync()
 {
     if (!m_init) throw std::logic_error("Error: Cannot start a non-initialized index");
 
-    m_thread_sync = std::thread(&util::TraceThread, GetName(), [this] { ThreadSync(); });
+    m_thread_sync = std::thread(&util::TraceThread, GetName(), [this] { Sync(); });
     return true;
 }
 

src/index/base.h

@@ -78,13 +78,6 @@ class BaseIndex : public CValidationInterface
     std::thread m_thread_sync;
     CThreadInterrupt m_interrupt;
 
-    /// Sync the index with the block index starting from the current best block.
-    /// Intended to be run in its own thread, m_thread_sync, and can be
-    /// interrupted with m_interrupt. Once the index gets in sync, the m_synced
-    /// flag is set and the BlockConnected ValidationInterface callback takes
-    /// over and the sync thread exits.
-    void ThreadSync();
-
     /// Write the current index state (eg. chain block locator and subclass-specific items) to disk.
     ///
     /// Recommendations for error handling:
@@ -152,9 +145,16 @@ class BaseIndex : public CValidationInterface
     /// validation interface so that it stays in sync with blockchain updates.
     [[nodiscard]] bool Init();
 
-    /// Starts the initial sync process.
+    /// Starts the initial sync process on a background thread.
     [[nodiscard]] bool StartBackgroundSync();
 
+    /// Sync the index with the block index starting from the current best block.
+    /// Intended to be run in its own thread, m_thread_sync, and can be
+    /// interrupted with m_interrupt. Once the index gets in sync, the m_synced
+    /// flag is set and the BlockConnected ValidationInterface callback takes
+    /// over and the sync thread exits.
+    void Sync();
+
     /// Stops the instance from staying in sync with blockchain updates.
     void Stop();