From 4ccb3d6d0d576d32da8a1b9c6e70962cbd0f19fe Mon Sep 17 00:00:00 2001 From: Greg Sanders Date: Tue, 18 Jun 2024 10:13:08 -0400 Subject: fuzz: have package_rbf always make small txns The fuzz target is generating a large amount of transactions, but the core of the logic is ConsumeTxMemPoolEntry making the mempool entries for adding to the mempool. Since ConsumeTxMemPoolEntry generates its own transaction "vsize", we can improve efficiency of the target by explicitly creating very small transactions, reducing the hashing and memory burden. --- src/test/fuzz/rbf.cpp | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/src/test/fuzz/rbf.cpp b/src/test/fuzz/rbf.cpp index 4c7e70e3b0..eb981352ec 100644 --- a/src/test/fuzz/rbf.cpp +++ b/src/test/fuzz/rbf.cpp @@ -91,8 +91,10 @@ FUZZ_TARGET(package_rbf, .init = initialize_package_rbf) FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size()); SetMockTime(ConsumeTime(fuzzed_data_provider)); - std::optional child = ConsumeDeserializable(fuzzed_data_provider, TX_WITH_WITNESS); - if (!child) return; + // "Real" virtual size is not important for this test since ConsumeTxMemPoolEntry generates its own virtual size values + // so we construct small transactions for performance reasons. Child simply needs an input for later to perhaps connect to parent. + CMutableTransaction child; + child.vin.resize(1); bilingual_str error; CTxMemPool pool{MemPoolOptionsForTest(g_setup->m_node), error}; @@ -113,15 +115,13 @@ FUZZ_TARGET(package_rbf, .init = initialize_package_rbf) LIMITED_WHILE(fuzzed_data_provider.ConsumeBool(), NUM_ITERS) { // Make sure txns only have one input, and that a unique input is given to avoid circular references - std::optional parent = ConsumeDeserializable(fuzzed_data_provider, TX_WITH_WITNESS); - if (!parent) { - return; - } + CMutableTransaction parent; assert(iter <= g_outpoints.size()); - parent->vin.resize(1); - parent->vin[0].prevout = g_outpoints[iter++]; + parent.vin.resize(1); + parent.vin[0].prevout = g_outpoints[iter++]; + parent.vout.emplace_back(0, CScript()); - mempool_txs.emplace_back(*parent); + mempool_txs.emplace_back(parent); const auto parent_entry = ConsumeTxMemPoolEntry(fuzzed_data_provider, mempool_txs.back()); running_vsize_total += parent_entry.GetTxSize(); if (running_vsize_total > std::numeric_limits::max()) { @@ -130,10 +130,10 @@ FUZZ_TARGET(package_rbf, .init = initialize_package_rbf) break; } pool.addUnchecked(parent_entry); - if (fuzzed_data_provider.ConsumeBool() && !child->vin.empty()) { - child->vin[0].prevout = COutPoint{mempool_txs.back().GetHash(), 0}; + if (fuzzed_data_provider.ConsumeBool()) { + child.vin[0].prevout = COutPoint{mempool_txs.back().GetHash(), 0}; } - mempool_txs.emplace_back(*child); + mempool_txs.emplace_back(child); const auto child_entry = ConsumeTxMemPoolEntry(fuzzed_data_provider, mempool_txs.back()); running_vsize_total += child_entry.GetTxSize(); if (running_vsize_total > std::numeric_limits::max()) { -- cgit v1.2.3