bench: Add a benchmark for wallet loading

src/Makefile.bench.include

@@ -74,6 +74,7 @@ endif
 if ENABLE_WALLET
 bench_bench_bitcoin_SOURCES += bench/coin_selection.cpp
 bench_bench_bitcoin_SOURCES += bench/wallet_balance.cpp
+bench_bench_bitcoin_SOURCES += bench/wallet_loading.cpp
 endif
 
 bench_bench_bitcoin_LDADD += $(BDB_LIBS) $(EVENT_PTHREADS_LIBS) $(EVENT_LIBS) $(MINIUPNPC_LIBS) $(NATPMP_LIBS) $(SQLITE_LIBS)

src/bench/wallet_loading.cpp

@@ -0,0 +1,83 @@
+// Copyright (c) 2022 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 <interfaces/chain.h>
+#include <node/context.h>
+#include <test/util/mining.h>
+#include <test/util/setup_common.h>
+#include <test/util/wallet.h>
+#include <util/translation.h>
+#include <validationinterface.h>
+#include <wallet/context.h>
+#include <wallet/receive.h>
+#include <wallet/wallet.h>
+
+#include <optional>
+
+using wallet::CWallet;
+using wallet::DatabaseOptions;
+using wallet::DatabaseStatus;
+using wallet::ISMINE_SPENDABLE;
+using wallet::MakeWalletDatabase;
+using wallet::WALLET_FLAG_DESCRIPTORS;
+using wallet::WalletContext;
+
+static const std::shared_ptr<CWallet> BenchLoadWallet(WalletContext& context, DatabaseOptions& options)
+{
+    DatabaseStatus status;
+    bilingual_str error;
+    std::vector<bilingual_str> warnings;
+    auto database = MakeWalletDatabase("", options, status, error);
+    assert(database);
+    auto wallet = CWallet::Create(context, "", std::move(database), options.create_flags, error, warnings);
+    NotifyWalletLoaded(context, wallet);
+    if (context.chain) {
+        wallet->postInitProcess();
+    }
+    return wallet;
+}
+
+static void BenchUnloadWallet(std::shared_ptr<CWallet>&& wallet)
+{
+    SyncWithValidationInterfaceQueue();
+    wallet->m_chain_notifications_handler.reset();
+    UnloadWallet(std::move(wallet));
+}
+
+static void WalletLoading(benchmark::Bench& bench, bool legacy_wallet)
+{
+    const auto test_setup = MakeNoLogFileContext<TestingSetup>();
+
+    WalletContext context;
+    context.args = &test_setup->m_args;
+    context.chain = test_setup->m_node.chain.get();
+
+    // Setup the wallet
+    // Loading the wallet will also create it
+    DatabaseOptions options;
+    if (!legacy_wallet) options.create_flags = WALLET_FLAG_DESCRIPTORS;
+    auto wallet = BenchLoadWallet(context, options);
+
+    // Generate a bunch of transactions and addresses to put into the wallet
+    for (int i = 0; i < 5000; ++i) {
+        generatetoaddress(test_setup->m_node, getnewaddress(*wallet));
+    }
+
+    // reload the wallet for the actual benchmark
+    BenchUnloadWallet(std::move(wallet));
+
+    bench.minEpochIterations(10).run([&] {
+        wallet = BenchLoadWallet(context, options);
+
+        // Cleanup
+        BenchUnloadWallet(std::move(wallet));
+    });
+}
+
+static void WalletLoadingLegacy(benchmark::Bench& bench) { WalletLoading(bench, /*legacy_wallet=*/true); }
+static void WalletLoadingDescriptors(benchmark::Bench& bench) { WalletLoading(bench, /*legacy_wallet=*/false); }
+
+BENCHMARK(WalletLoadingLegacy);
+BENCHMARK(WalletLoadingDescriptors);