1  // Copyright (c) 2009-2010 Satoshi Nakamoto
  2  // Copyright (c) 2009-2022 The Bitcoin Core developers
  3  // Distributed under the MIT software license, see the accompanying
  4  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  5  
  6  #include <stdexcept>
  7  
  8  #include <flatfile.h>
  9  #include <logging.h>
 10  #include <tinyformat.h>
 11  #include <util/fs_helpers.h>
 12  
 13  FlatFileSeq::FlatFileSeq(fs::path dir, const char* prefix, size_t chunk_size) :
 14      m_dir(std::move(dir)),
 15      m_prefix(prefix),
 16      m_chunk_size(chunk_size)
 17  {
 18      if (chunk_size == 0) {
 19          throw std::invalid_argument("chunk_size must be positive");
 20      }
 21  }
 22  
 23  std::string FlatFilePos::ToString() const
 24  {
 25      return strprintf("FlatFilePos(nFile=%i, nPos=%i)", nFile, nPos);
 26  }
 27  
 28  fs::path FlatFileSeq::FileName(const FlatFilePos& pos) const
 29  {
 30      return m_dir / fs::u8path(strprintf("%s%05u.dat", m_prefix, pos.nFile));
 31  }
 32  
 33  FILE* FlatFileSeq::Open(const FlatFilePos& pos, bool read_only) const
 34  {
 35      if (pos.IsNull()) {
 36          return nullptr;
 37      }
 38      fs::path path = FileName(pos);
 39      fs::create_directories(path.parent_path());
 40      FILE* file = fsbridge::fopen(path, read_only ? "rb": "rb+");
 41      if (!file && !read_only)
 42          file = fsbridge::fopen(path, "wb+");
 43      if (!file) {
 44          LogPrintf("Unable to open file %s\n", fs::PathToString(path));
 45          return nullptr;
 46      }
 47      if (pos.nPos && fseek(file, pos.nPos, SEEK_SET)) {
 48          LogPrintf("Unable to seek to position %u of %s\n", pos.nPos, fs::PathToString(path));
 49          fclose(file);
 50          return nullptr;
 51      }
 52      return file;
 53  }
 54  
 55  size_t FlatFileSeq::Allocate(const FlatFilePos& pos, size_t add_size, bool& out_of_space) const
 56  {
 57      out_of_space = false;
 58  
 59      unsigned int n_old_chunks = (pos.nPos + m_chunk_size - 1) / m_chunk_size;
 60      unsigned int n_new_chunks = (pos.nPos + add_size + m_chunk_size - 1) / m_chunk_size;
 61      if (n_new_chunks > n_old_chunks) {
 62          size_t old_size = pos.nPos;
 63          size_t new_size = n_new_chunks * m_chunk_size;
 64          size_t inc_size = new_size - old_size;
 65  
 66          if (CheckDiskSpace(m_dir, inc_size)) {
 67              FILE *file = Open(pos);
 68              if (file) {
 69                  LogDebug(BCLog::VALIDATION, "Pre-allocating up to position 0x%x in %s%05u.dat\n", new_size, m_prefix, pos.nFile);
 70                  AllocateFileRange(file, pos.nPos, inc_size);
 71                  fclose(file);
 72                  return inc_size;
 73              }
 74          } else {
 75              out_of_space = true;
 76          }
 77      }
 78      return 0;
 79  }
 80  
 81  bool FlatFileSeq::Flush(const FlatFilePos& pos, bool finalize) const
 82  {
 83      FILE* file = Open(FlatFilePos(pos.nFile, 0)); // Avoid fseek to nPos
 84      if (!file) {
 85          LogError("%s: failed to open file %d\n", __func__, pos.nFile);
 86          return false;
 87      }
 88      if (finalize && !TruncateFile(file, pos.nPos)) {
 89          fclose(file);
 90          LogError("%s: failed to truncate file %d\n", __func__, pos.nFile);
 91          return false;
 92      }
 93      if (!FileCommit(file)) {
 94          fclose(file);
 95          LogError("%s: failed to commit file %d\n", __func__, pos.nFile);
 96          return false;
 97      }
 98      DirectoryCommit(m_dir);
 99  
100      fclose(file);
101      return true;
102  }