1  // Copyright (c) 2009-2010 Satoshi Nakamoto
  2  // Copyright (c) 2009-present 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 <flatfile.h>
  7  
  8  #include <tinyformat.h>
  9  #include <util/fs_helpers.h>
 10  #include <util/log.h>
 11  
 12  #include <stdexcept>
 13  
 14  FlatFileSeq::FlatFileSeq(fs::path dir, const char* prefix, size_t chunk_size) :
 15      m_dir(std::move(dir)),
 16      m_prefix(prefix),
 17      m_chunk_size(chunk_size)
 18  {
 19      if (chunk_size == 0) {
 20          throw std::invalid_argument("chunk_size must be positive");
 21      }
 22  }
 23  
 24  std::string FlatFilePos::ToString() const
 25  {
 26      return strprintf("FlatFilePos(nFile=%i, nPos=%i)", nFile, nPos);
 27  }
 28  
 29  fs::path FlatFileSeq::FileName(const FlatFilePos& pos) const
 30  {
 31      return m_dir / fs::u8path(strprintf("%s%05u.dat", m_prefix, pos.nFile));
 32  }
 33  
 34  FILE* FlatFileSeq::Open(const FlatFilePos& pos, bool read_only) const
 35  {
 36      if (pos.IsNull()) {
 37          return nullptr;
 38      }
 39      fs::path path = FileName(pos);
 40      fs::create_directories(path.parent_path());
 41      FILE* file = fsbridge::fopen(path, read_only ? "rb": "rb+");
 42      if (!file && !read_only)
 43          file = fsbridge::fopen(path, "wb+");
 44      if (!file) {
 45          LogError("Unable to open file %s", fs::PathToString(path));
 46          return nullptr;
 47      }
 48      if (pos.nPos && fseek(file, pos.nPos, SEEK_SET)) {
 49          LogError("Unable to seek to position %u of %s", pos.nPos, fs::PathToString(path));
 50          if (fclose(file) != 0) {
 51              LogError("Unable to close file %s", fs::PathToString(path));
 52          }
 53          return nullptr;
 54      }
 55      return file;
 56  }
 57  
 58  size_t FlatFileSeq::Allocate(const FlatFilePos& pos, size_t add_size, bool& out_of_space) const
 59  {
 60      out_of_space = false;
 61  
 62      unsigned int n_old_chunks = (pos.nPos + m_chunk_size - 1) / m_chunk_size;
 63      unsigned int n_new_chunks = (pos.nPos + add_size + m_chunk_size - 1) / m_chunk_size;
 64      if (n_new_chunks > n_old_chunks) {
 65          size_t old_size = pos.nPos;
 66          size_t new_size = n_new_chunks * m_chunk_size;
 67          size_t inc_size = new_size - old_size;
 68  
 69          if (CheckDiskSpace(m_dir, inc_size)) {
 70              FILE *file = Open(pos);
 71              if (file) {
 72                  LogDebug(BCLog::VALIDATION, "Pre-allocating up to position 0x%x in %s%05u.dat\n", new_size, m_prefix, pos.nFile);
 73                  AllocateFileRange(file, pos.nPos, inc_size);
 74                  if (fclose(file) != 0) {
 75                      LogError("Cannot close file %s%05u.dat after extending it with %u bytes", m_prefix, pos.nFile, new_size);
 76                      return 0;
 77                  }
 78                  return inc_size;
 79              }
 80          } else {
 81              out_of_space = true;
 82          }
 83      }
 84      return 0;
 85  }
 86  
 87  bool FlatFileSeq::Flush(const FlatFilePos& pos, bool finalize) const
 88  {
 89      FILE* file = Open(FlatFilePos(pos.nFile, 0)); // Avoid fseek to nPos
 90      if (!file) {
 91          LogError("%s: failed to open file %d\n", __func__, pos.nFile);
 92          return false;
 93      }
 94      if (finalize && !TruncateFile(file, pos.nPos)) {
 95          LogError("%s: failed to truncate file %d\n", __func__, pos.nFile);
 96          if (fclose(file) != 0) {
 97              LogError("Failed to close file %d", pos.nFile);
 98          }
 99          return false;
100      }
101      if (!FileCommit(file)) {
102          LogError("%s: failed to commit file %d\n", __func__, pos.nFile);
103          if (fclose(file) != 0) {
104              LogError("Failed to close file %d", pos.nFile);
105          }
106          return false;
107      }
108      DirectoryCommit(m_dir);
109  
110      if (fclose(file) != 0) {
111          LogError("Failed to close file %d after flush", pos.nFile);
112          return false;
113      }
114      return true;
115  }