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  
14  template <typename Map>
15  void 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  
31  static void PoolAllocator_StdUnorderedMap(benchmark::Bench& bench)
32  {
33      auto map = std::unordered_map<uint64_t, uint64_t>();
34      BenchFillClearMap(bench, map);
35  }
36  
37  static 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  
52  BENCHMARK(PoolAllocator_StdUnorderedMap);
53  BENCHMARK(PoolAllocator_StdUnorderedMapWithPoolResource);