flatfile.cpp raw

   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  }
 117