int FileUtil::openForRead()

in util/FileByteSource.cpp [18:58]

• 40 lines of code
• 6 McCabe index (conditional complexity)

int FileUtil::openForRead(ThreadCtx &threadCtx, const std::string &filename,
                          const bool isDirectReads) {
  int openFlags = O_RDONLY;
  if (isDirectReads) {
#ifdef O_DIRECT
    // no need to change any flags if we are using F_NOCACHE
    openFlags |= O_DIRECT;
#endif
  }
  if (threadCtx.getOptions().close_on_exec) {
#ifdef O_CLOEXEC
    openFlags |= O_CLOEXEC;
#endif
  }
  int fd;
  {
    PerfStatCollector statCollector(threadCtx, PerfStatReport::FILE_OPEN);
    fd = ::open(filename.c_str(), openFlags);
  }
  if (fd >= 0) {
    if (isDirectReads) {
#ifndef O_DIRECT
#ifdef F_NOCACHE
      WVLOG(1) << "O_DIRECT not found, using F_NOCACHE instead "
               << "for " << filename;
      int ret = fcntl(fd, F_NOCACHE, 1);
      if (ret) {
        WPLOG(ERROR) << "Not able to set F_NOCACHE";
      }
#else
      WDT_CHECK(false)
          << "Direct read enabled, but both O_DIRECT and F_NOCACHE not defined "
          << filename;
#endif
#endif
    }
  } else {
    WPLOG(ERROR) << "Error opening file " << filename;
  }
  return fd;
}