Function Truncate

src/leveldb/db/fault_injection_test.cc:54–83

A basic file truncation function suitable for this test.

// A basic file truncation function suitable for this test.
Status Truncate(const std::string& filename, uint64_t length) {
  leveldb::Env* env = leveldb::Env::Default();

  SequentialFile* orig_file;
  Status s = env->NewSequentialFile(filename, &orig_file);
  if (!s.ok()) return s;

  char* scratch = new char[length];
  leveldb::Slice result;
  s = orig_file->Read(length, &result, scratch);
  delete orig_file;
  if (s.ok()) {
    std::string tmp_name = GetDirName(filename) + "/truncate.tmp";
    WritableFile* tmp_file;
    s = env->NewWritableFile(tmp_name, &tmp_file);
    if (s.ok()) {
      s = tmp_file->Append(result);
      delete tmp_file;
      if (s.ok()) {
        s = env->RenameFile(tmp_name, filename);
      } else {
        env->DeleteFile(tmp_name);
      }
    }
  }

  delete[] scratch;

  return s;
}

struct FileState {
  std::string filename_;