void File::InitializeUnsafe()

in src/butil/files/file_posix.cc [171:254]
67 lines of code
26 McCabe index (conditional complexity)

void File::InitializeUnsafe(const FilePath& name, uint32_t flags) {
  butil::ThreadRestrictions::AssertIOAllowed();
  DCHECK(!IsValid());

  int open_flags = 0;
  if (flags & FLAG_CREATE)
    open_flags = O_CREAT | O_EXCL;

  created_ = false;

  if (flags & FLAG_CREATE_ALWAYS) {
    DCHECK(!open_flags);
    DCHECK(flags & FLAG_WRITE);
    open_flags = O_CREAT | O_TRUNC;
  }

  if (flags & FLAG_OPEN_TRUNCATED) {
    DCHECK(!open_flags);
    DCHECK(flags & FLAG_WRITE);
    open_flags = O_TRUNC;
  }

  if (!open_flags && !(flags & FLAG_OPEN) && !(flags & FLAG_OPEN_ALWAYS)) {
    NOTREACHED();
    errno = EOPNOTSUPP;
    error_details_ = FILE_ERROR_FAILED;
    return;
  }

  if (flags & FLAG_WRITE && flags & FLAG_READ) {
    open_flags |= O_RDWR;
  } else if (flags & FLAG_WRITE) {
    open_flags |= O_WRONLY;
  } else if (!(flags & FLAG_READ) &&
             !(flags & FLAG_WRITE_ATTRIBUTES) &&
             !(flags & FLAG_APPEND) &&
             !(flags & FLAG_OPEN_ALWAYS)) {
    NOTREACHED();
  }

  if (flags & FLAG_TERMINAL_DEVICE)
    open_flags |= O_NOCTTY | O_NDELAY;

  if (flags & FLAG_APPEND && flags & FLAG_READ)
    open_flags |= O_APPEND | O_RDWR;
  else if (flags & FLAG_APPEND)
    open_flags |= O_APPEND | O_WRONLY;

  COMPILE_ASSERT(O_RDONLY == 0, O_RDONLY_must_equal_zero);

  int mode = S_IRUSR | S_IWUSR;
#if defined(OS_CHROMEOS)
  mode |= S_IRGRP | S_IROTH;
#endif

  int descriptor = HANDLE_EINTR(open(name.value().c_str(), open_flags, mode));

  if (flags & FLAG_OPEN_ALWAYS) {
    if (descriptor < 0) {
      open_flags |= O_CREAT;
      if (flags & FLAG_EXCLUSIVE_READ || flags & FLAG_EXCLUSIVE_WRITE)
        open_flags |= O_EXCL;   // together with O_CREAT implies O_NOFOLLOW

      descriptor = HANDLE_EINTR(open(name.value().c_str(), open_flags, mode));
      if (descriptor >= 0)
        created_ = true;
    }
  }

  if (descriptor < 0) {
    error_details_ = File::OSErrorToFileError(errno);
    return;
  }

  if (flags & (FLAG_CREATE_ALWAYS | FLAG_CREATE))
    created_ = true;

  if (flags & FLAG_DELETE_ON_CLOSE)
    unlink(name.value().c_str());

  async_ = ((flags & FLAG_ASYNC) == FLAG_ASYNC);
  error_details_ = FILE_OK;
  file_.reset(descriptor);
}