Inside Bitcoin

1// Copyright (c) 2022-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 <support/allocators/pool.h>
7
8#include <cstddef>
9#include <cstdint>
10#include <functional>
11#include <unordered_map>
12#include <utility>
13
14template <typename Map>
15void BenchFillClearMap(benchmark::Bench& bench, Map& map)
16{
17    size_t batch_size = 5000;
18
19    // make sure each iteration of the benchmark contains exactly 5000 inserts and one clear.
20    // do this at least 10 times so we get reasonable accurate results
21
22    bench.batch(batch_size).minEpochIterations(10).run([&] {
23        auto rng = ankerl::nanobench::Rng(1234);
24        for (size_t i = 0; i < batch_size; ++i) {
25            map[rng()];
26        }
27        map.clear();
28    });
29}
30
31static void PoolAllocator_StdUnorderedMap(benchmark::Bench& bench)
32{
33    auto map = std::unordered_map<uint64_t, uint64_t>();
34    BenchFillClearMap(bench, map);
35}
36
37static void PoolAllocator_StdUnorderedMapWithPoolResource(benchmark::Bench& bench)
38{
39    using Map = std::unordered_map<uint64_t,
40                                   uint64_t,
41                                   std::hash<uint64_t>,
42                                   std::equal_to<uint64_t>,
43                                   PoolAllocator<std::pair<const uint64_t, uint64_t>,
44                                                 sizeof(std::pair<const uint64_t, uint64_t>) + 4 * sizeof(void*)>>;
45
46    // make sure the resource supports large enough pools to hold the node. We do this by adding the size of a few pointers to it.
47    auto pool_resource = Map::allocator_type::ResourceType();
48    auto map = Map{0, std::hash<uint64_t>{}, std::equal_to<uint64_t>{}, &pool_resource};
49    BenchFillClearMap(bench, map);
50}
51
52BENCHMARK(PoolAllocator_StdUnorderedMap);
53BENCHMARK(PoolAllocator_StdUnorderedMapWithPoolResource);
54