1  // Copyright (c) 2022-present The Bitcoin Core developers
 2  // Distributed under the MIT software license, see the accompanying
 3  // file COPYING or https://www.opensource.org/licenses/mit-license.php.
 4  
 5  #include <bench/bench.h>
 6  #include <bench/data/block413567.raw.h>
 7  #include <chainparams.h>
 8  #include <flatfile.h>
 9  #include <node/blockstorage.h>
10  #include <span.h>
11  #include <streams.h>
12  #include <test/util/setup_common.h>
13  #include <uint256.h>
14  #include <util/fs.h>
15  #include <validation.h>
16  
17  #include <cstdint>
18  #include <cstdio>
19  #include <map>
20  #include <memory>
21  #include <stdexcept>
22  #include <vector>
23  
24  /**
25   * The LoadExternalBlockFile() function is used during -reindex and -loadblock.
26   *
27   * Create a test file that's similar to a datadir/blocks/blk?????.dat file,
28   * It contains around 134 copies of the same block (typical size of real block files).
29   * For each block in the file, LoadExternalBlockFile() won't find its parent,
30   * and so will skip the block. (In the real system, it will re-read the block
31   * from disk later when it encounters its parent.)
32   *
33   * This benchmark measures the performance of deserializing the block (or just
34   * its header, beginning with PR 16981).
35   */
36  static void LoadExternalBlockFile(benchmark::Bench& bench)
37  {
38      const auto testing_setup{MakeNoLogFileContext<const TestingSetup>(ChainType::MAIN)};
39  
40      // Create a single block as in the blocks files (magic bytes, block size,
41      // block data) as a stream object.
42      const fs::path blkfile{testing_setup.get()->m_path_root / "blk.dat"};
43      DataStream ss{};
44      auto params{testing_setup->m_node.chainman->GetParams()};
45      ss << params.MessageStart();
46      ss << static_cast<uint32_t>(benchmark::data::block413567.size());
47      // Use span-serialization to avoid writing the size first.
48      ss << std::span{benchmark::data::block413567};
49  
50      // Create the test file.
51      {
52          // "wb+" is "binary, O_RDWR | O_CREAT | O_TRUNC".
53          FILE* file{fsbridge::fopen(blkfile, "wb+")};
54          // Make the test block file about 128 MB in length.
55          for (size_t i = 0; i < node::MAX_BLOCKFILE_SIZE / ss.size(); ++i) {
56              if (fwrite(ss.data(), 1, ss.size(), file) != ss.size()) {
57                  throw std::runtime_error("write to test file failed\n");
58              }
59          }
60          fclose(file);
61      }
62  
63      std::multimap<uint256, FlatFilePos> blocks_with_unknown_parent;
64      FlatFilePos pos;
65      bench.run([&] {
66          // "rb" is "binary, O_RDONLY", positioned to the start of the file.
67          // The file will be closed by LoadExternalBlockFile().
68          AutoFile file{fsbridge::fopen(blkfile, "rb")};
69          testing_setup->m_node.chainman->LoadExternalBlockFile(file, &pos, &blocks_with_unknown_parent);
70      });
71      fs::remove(blkfile);
72  }
73  
74  BENCHMARK(LoadExternalBlockFile);