Function tar_close

src/bin/pg_basebackup/walmethods.c:836–1005

}

static int
tar_close(Walfile f, WalCloseMethod method)
{
	ssize_t		filesize;
	int			padding;
	TarMethodFile *tf = (TarMethodFile *) f;

	Assert(f != NULL);
	tar_clear_error();

	if (method == CLOSE_UNLINK)
	{
		if (tar_data->compression)
		{
			tar_set_error("unlink not supported with compression");
			return -1;
		}

		/*
		 * Unlink the file that we just wrote to the tar. We do this by
		 * truncating it to the start of the header. This is safe as we only
		 * allow writing of the very last file.
		 */
		if (ftruncate(tar_data->fd, tf->ofs_start) != 0)
		{
			tar_data->lasterrno = errno;
			return -1;
		}

		pg_free(tf->pathname);
		pg_free(tf);
		tar_data->currentfile = NULL;

		return 0;
	}

	/*
	 * Pad the file itself with zeroes if necessary. Note that this is
	 * different from the tar format padding -- this is the padding we asked
	 * for when the file was opened.
	 */
	if (tf->pad_to_size)
	{
		if (tar_data->compression)
		{
			/*
			 * A compressed tarfile is padded on close since we cannot know
			 * the size of the compressed output until the end.
			 */
			size_t		sizeleft = tf->pad_to_size - tf->currpos;

			if (sizeleft)
			{
				if (!tar_write_padding_data(tf, sizeleft))
					return -1;
			}
		}
		else