Inside Bitcoin

1// Copyright (c) 2025-present The Bitcoin Core developers
2// Distributed under the MIT software license, see the accompanying
3// file COPYING or http://www.opensource.org/licenses/mit-license.php.
4
5#include <bench/bench.h>
6#include <blockencodings.h>
7#include <consensus/amount.h>
8#include <kernel/cs_main.h>
9#include <net_processing.h>
10#include <primitives/block.h>
11#include <primitives/transaction.h>
12#include <random.h>
13#include <script/script.h>
14#include <sync.h>
15#include <test/util/setup_common.h>
16#include <test/util/txmempool.h>
17#include <txmempool.h>
18#include <uint256.h>
19#include <util/check.h>
20
21#include <algorithm>
22#include <array>
23#include <cstddef>
24#include <memory>
25#include <span>
26#include <utility>
27#include <vector>
28
29
30static void AddTx(const CTransactionRef& tx, const CAmount& fee, CTxMemPool& pool) EXCLUSIVE_LOCKS_REQUIRED(cs_main, pool.cs)
31{
32    LockPoints lp;
33    TryAddToMempool(pool, CTxMemPoolEntry(tx, fee, /*time=*/0, /*entry_height=*/1, /*entry_sequence=*/0, /*spends_coinbase=*/false, /*sigops_cost=*/4, lp));
34}
35
36namespace {
37class BenchCBHAST : public CBlockHeaderAndShortTxIDs
38{
39private:
40    static CBlock DummyBlock()
41    {
42        CBlock block;
43        block.nVersion = 5;
44        block.hashPrevBlock.SetNull();
45        block.hashMerkleRoot.SetNull();
46        block.nTime = 1231006505;
47        block.nBits = 0x1d00ffff;
48        block.nNonce = 2083236893;
49        block.fChecked = false;
50        CMutableTransaction tx;
51        tx.vin.resize(1);
52        tx.vout.resize(1);
53        block.vtx.emplace_back(MakeTransactionRef(tx)); // dummy coinbase
54        return block;
55    }
56
57public:
58    BenchCBHAST(InsecureRandomContext& rng, int txs) : CBlockHeaderAndShortTxIDs(DummyBlock(), rng.rand64())
59    {
60        shorttxids.reserve(txs);
61        while (txs-- > 0) {
62            shorttxids.push_back(rng.randbits<SHORTTXIDS_LENGTH*8>());
63        }
64    }
65};
66} // anon namespace
67
68static void BlockEncodingBench(benchmark::Bench& bench, size_t n_pool, size_t n_extra)
69{
70    const auto testing_setup = MakeNoLogFileContext<const ChainTestingSetup>(ChainType::MAIN);
71    CTxMemPool& pool = *Assert(testing_setup->m_node.mempool);
72    InsecureRandomContext rng(11);
73
74    LOCK2(cs_main, pool.cs);
75
76    std::vector<std::pair<Wtxid, CTransactionRef>> extratxn;
77    extratxn.reserve(n_extra);
78
79    // bump up the size of txs
80    std::array<std::byte,200> sigspam;
81    sigspam.fill(std::byte(42));
82
83    // a reasonably large mempool of 50k txs, ~10MB total
84    std::vector<CTransactionRef> refs;
85    refs.reserve(n_pool + n_extra);
86    for (size_t i = 0; i < n_pool + n_extra; ++i) {
87        CMutableTransaction tx = CMutableTransaction();
88        tx.vin.resize(1);
89        tx.vin[0].scriptSig = CScript() << sigspam;
90        tx.vin[0].scriptWitness.stack.push_back({1});
91        tx.vout = {CTxOut{CAmount(i), CScript() << OP_1 << OP_EQUAL}};
92        refs.push_back(MakeTransactionRef(tx));
93    }
94
95    // ensure mempool ordering is different to memory ordering of transactions,
96    // to simulate a mempool that has changed over time
97    std::shuffle(refs.begin(), refs.end(), rng);
98
99    for (size_t i = 0; i < n_pool; ++i) {
100        AddTx(refs[i], /*fee=*/refs[i]->vout[0].nValue, pool);
101    }
102    for (size_t i = n_pool; i < n_pool + n_extra; ++i) {
103        extratxn.emplace_back(refs[i]->GetWitnessHash(), refs[i]);
104    }
105
106    BenchCBHAST cmpctblock{rng, 3000};
107
108    bench.run([&] {
109        PartiallyDownloadedBlock pdb{&pool};
110        auto res = pdb.InitData(cmpctblock, extratxn);
111
112        // if there were duplicates the benchmark will be invalid
113        // (eg, extra txns will be skipped) and we will receive
114        // READ_STATUS_FAILED
115        assert(res == READ_STATUS_OK);
116    });
117}
118
119static void BlockEncodingNoExtra(benchmark::Bench& bench)
120{
121    BlockEncodingBench(bench, 50000, 0);
122}
123
124static void BlockEncodingStdExtra(benchmark::Bench& bench)
125{
126    static_assert(DEFAULT_BLOCK_RECONSTRUCTION_EXTRA_TXN == 100);
127    BlockEncodingBench(bench, 50000, 100);
128}
129
130static void BlockEncodingLargeExtra(benchmark::Bench& bench)
131{
132    BlockEncodingBench(bench, 50000, 5000);
133}
134
135BENCHMARK(BlockEncodingNoExtra);
136BENCHMARK(BlockEncodingStdExtra);
137BENCHMARK(BlockEncodingLargeExtra);
138