Function ReceiveTarFile

src/bin/pg_basebackup/pg_basebackup.c:1066–1321

* Receive a tar format file from the connection to the server, and write * the data from this file directly into a tar file. If compression is * enabled, the data will be compressed while written to the file. * * The file will be named base.tar[.gz] if it's for the main data directory * or .tar[.gz] if it's for another tablespace. * * No attempt to inspect or validate the con

 * No attempt to inspect or validate the contents of the file is done.
 */
static void
ReceiveTarFile(PGconn *conn, PGresult *res, int rownum)
{
	char		zerobuf[TAR_BLOCK_SIZE * 2];
	WriteTarState state;

	memset(&state, 0, sizeof(state));
	state.tablespacenum = rownum;
	state.basetablespace = PQgetisnull(res, rownum, 0);
	state.in_tarhdr = true;

	/* recovery.conf is integrated into postgresql.conf in 12 and newer */
	if (PQserverVersion(conn) >= MINIMUM_VERSION_FOR_RECOVERY_GUC)
		state.is_recovery_guc_supported = true;

	if (state.basetablespace)
	{
		/*
		 * Base tablespaces
		 */
		if (strcmp(basedir, "-") == 0)
		{
#ifdef WIN32
			_setmode(fileno(stdout), _O_BINARY);
#endif

#ifdef HAVE_LIBZ
			if (compresslevel != 0)
			{
				int			fd = dup(fileno(stdout));

				if (fd < 0)
				{
					pg_log_error("could not duplicate stdout: %m");
					exit(1);
				}

				state.ztarfile = gzdopen(fd, "wb");
				if (state.ztarfile == NULL)
				{
					pg_log_error("could not open output file: %m");
					exit(1);
				}

				if (gzsetparams(state.ztarfile, compresslevel,
								Z_DEFAULT_STRATEGY) != Z_OK)
				{
					pg_log_error("could not set compression level %d: %s",
								 compresslevel, get_gz_error(state.ztarfile));
					exit(1);
				}
			}
			else
#endif
				state.tarfile = stdout;
			strcpy(state.filename, "-");
		}
		else