Line data    Source code

       1             : // Copyright (c) 2021 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 <node/minisketchwrapper.h>
       6             : 
       7             : #include <logging.h>
       8             : #include <util/time.h>
       9             : 
      10             : #include <minisketch.h>
      11             : 
      12             : #include <algorithm>
      13             : #include <cstddef>
      14             : #include <cstdint>
      15             : #include <optional>
      16             : #include <utility>
      17             : #include <vector>
      18             : 
      19             : namespace node {
      20             : namespace {
      21             : 
      22             : static constexpr uint32_t BITS = 32;
      23             : 
      24           0 : uint32_t FindBestImplementation()
      25             : {
      26           0 :     std::optional<std::pair<SteadyClock::duration, uint32_t>> best;
      27             : 
      28           0 :     uint32_t max_impl = Minisketch::MaxImplementation();
      29           0 :     for (uint32_t impl = 0; impl <= max_impl; ++impl) {
      30           0 :         std::vector<SteadyClock::duration> benches;
      31           0 :         uint64_t offset = 0;
      32             :         /* Run a little benchmark with capacity 32, adding 184 entries, and decoding 11 of them once. */
      33           0 :         for (int b = 0; b < 11; ++b) {
      34           0 :             if (!Minisketch::ImplementationSupported(BITS, impl)) break;
      35           0 :             Minisketch sketch(BITS, impl, 32);
      36           0 :             auto start = SteadyClock::now();
      37           0 :             for (uint64_t e = 0; e < 100; ++e) {
      38           0 :                 sketch.Add(e*1337 + b*13337 + offset);
      39           0 :             }
      40           0 :             for (uint64_t e = 0; e < 84; ++e) {
      41           0 :                 sketch.Add(e*1337 + b*13337 + offset);
      42           0 :             }
      43           0 :             offset += (*sketch.Decode(32))[0];
      44           0 :             auto stop = SteadyClock::now();
      45           0 :             benches.push_back(stop - start);
      46           0 :         }
      47             :         /* Remember which implementation has the best median benchmark time. */
      48           0 :         if (!benches.empty()) {
      49           0 :             std::sort(benches.begin(), benches.end());
      50           0 :             if (!best || best->first > benches[5]) {
      51           0 :                 best = std::make_pair(benches[5], impl);
      52           0 :             }
      53           0 :         }
      54           0 :     }
      55           0 :     assert(best.has_value());
      56           0 :     LogPrintf("Using Minisketch implementation number %i\n", best->second);
      57           0 :     return best->second;
      58           0 : }
      59             : 
      60           0 : uint32_t Minisketch32Implementation()
      61             : {
      62             :     // Fast compute-once idiom.
      63           0 :     static uint32_t best = FindBestImplementation();
      64           0 :     return best;
      65           0 : }
      66             : 
      67             : } // namespace
      68             : 
      69             : 
      70           0 : Minisketch MakeMinisketch32(size_t capacity)
      71             : {
      72           0 :     return Minisketch(BITS, Minisketch32Implementation(), capacity);
      73             : }
      74           2 : 
      75           0 : Minisketch MakeMinisketch32FP(size_t max_elements, uint32_t fpbits)
      76             : {
      77           0 :     return Minisketch::CreateFP(BITS, Minisketch32Implementation(), max_elements, fpbits);
      78             : }
      79             : } // namespace node