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  #include <util/overflow.h>
 12  
 13  #include <stdexcept>
 14  
 15  FlatFileSeq::FlatFileSeq(fs::path dir, const char* prefix, size_t chunk_size) :
 16      m_dir(std::move(dir)),
 17      m_prefix(prefix),
 18      m_chunk_size(chunk_size)
 19  {
 20      if (chunk_size == 0) {
 21          throw std::invalid_argument("chunk_size must be positive");
 22      }
 23  }
 24  
 25  std::string FlatFilePos::ToString() const
 26  {
 27      return strprintf("FlatFilePos(nFile=%i, nPos=%i)", nFile, nPos);
 28  }
 29  
 30  fs::path FlatFileSeq::FileName(const FlatFilePos& pos) const
 31  {
 32      return m_dir / fs::u8path(strprintf("%s%05u.dat", m_prefix, pos.nFile));
 33  }
 34  
 35  FILE* FlatFileSeq::Open(const FlatFilePos& pos, bool read_only) const
 36  {
 37      if (pos.IsNull()) {
 38          return nullptr;
 39      }
 40      fs::path path = FileName(pos);
 41      fs::create_directories(path.parent_path());
 42      FILE* file = fsbridge::fopen(path, read_only ? "rb": "rb+");
 43      if (!file && !read_only)
 44          file = fsbridge::fopen(path, "wb+");
 45      if (!file) {
 46          LogError("Unable to open file %s", fs::PathToString(path));
 47          return nullptr;
 48      }
 49      if (pos.nPos && fseek(file, pos.nPos, SEEK_SET)) {
 50          LogError("Unable to seek to position %u of %s", pos.nPos, fs::PathToString(path));
 51          if (fclose(file) != 0) {
 52              LogError("Unable to close file %s", fs::PathToString(path));
 53          }
 54          return nullptr;
 55      }
 56      return file;
 57  }
 58  
 59  size_t FlatFileSeq::Allocate(const FlatFilePos& pos, size_t add_size, bool& out_of_space) const
 60  {
 61      out_of_space = false;
 62  
 63      unsigned int n_old_chunks = CeilDiv(pos.nPos, m_chunk_size);
 64      unsigned int n_new_chunks = CeilDiv(pos.nPos + add_size, m_chunk_size);
 65      if (n_new_chunks > n_old_chunks) {
 66          size_t old_size = pos.nPos;
 67          size_t new_size = n_new_chunks * m_chunk_size;
 68          size_t inc_size = new_size - old_size;
 69  
 70          if (CheckDiskSpace(m_dir, inc_size)) {
 71              FILE *file = Open(pos);
 72              if (file) {
 73                  LogDebug(BCLog::VALIDATION, "Pre-allocating up to position 0x%x in %s%05u.dat\n", new_size, m_prefix, pos.nFile);
 74                  AllocateFileRange(file, pos.nPos, inc_size);
 75                  if (fclose(file) != 0) {
 76                      LogError("Cannot close file %s%05u.dat after extending it with %u bytes", m_prefix, pos.nFile, new_size);
 77                      return 0;
 78                  }
 79                  return inc_size;
 80              }
 81          } else {
 82              out_of_space = true;
 83          }
 84      }
 85      return 0;
 86  }
 87  
 88  bool FlatFileSeq::Flush(const FlatFilePos& pos, bool finalize) const
 89  {
 90      FILE* file = Open(FlatFilePos(pos.nFile, 0)); // Avoid fseek to nPos
 91      if (!file) {
 92          LogError("%s: failed to open file %d\n", __func__, pos.nFile);
 93          return false;
 94      }
 95      if (finalize && !TruncateFile(file, pos.nPos)) {
 96          LogError("%s: failed to truncate file %d\n", __func__, pos.nFile);
 97          if (fclose(file) != 0) {
 98              LogError("Failed to close file %d", pos.nFile);
 99          }
100          return false;
101      }
102      if (!FileCommit(file)) {
103          LogError("%s: failed to commit file %d\n", __func__, pos.nFile);
104          if (fclose(file) != 0) {
105              LogError("Failed to close file %d", pos.nFile);
106          }
107          return false;
108      }
109      DirectoryCommit(m_dir);
110  
111      if (fclose(file) != 0) {
112          LogError("Failed to close file %d after flush", pos.nFile);
113          return false;
114      }
115      return true;
116  }