Function PQpipelineSync

src/interfaces/libpq/fe-exec.c:3115–3175

* PQpipelineSync * Send a Sync message as part of a pipeline, and flush to server * * It's legal to start submitting more commands in the pipeline immediately, * without waiting for the results of the current pipeline. There's no need to * end pipeline mode and start it again. * * If a command in a pipeline fails, every subsequent command up to and including * the result to the Sync messa

 * are processed by the client.
 */
int
PQpipelineSync(PGconn *conn)
{
	PGcmdQueueEntry *entry;

	if (!conn)
		return 0;

	if (conn->pipelineStatus == PQ_PIPELINE_OFF)
	{
		appendPQExpBufferStr(&conn->errorMessage,
							 libpq_gettext("cannot send pipeline when not in pipeline mode\n"));
		return 0;
	}

	switch (conn->asyncStatus)
	{
		case PGASYNC_COPY_IN:
		case PGASYNC_COPY_OUT:
		case PGASYNC_COPY_BOTH:
			/* should be unreachable */
			appendPQExpBufferStr(&conn->errorMessage,
								 "internal error: cannot send pipeline while in COPY\n");
			return 0;
		case PGASYNC_READY:
		case PGASYNC_READY_MORE:
		case PGASYNC_BUSY:
		case PGASYNC_IDLE:
			/* OK to send sync */
			break;
	}

	entry = pqAllocCmdQueueEntry(conn);
	if (entry == NULL)
		return 0;				/* error msg already set */

	entry->queryclass = PGQUERY_SYNC;
	entry->query = NULL;

	/* construct the Sync message */
	if (pqPutMsgStart('S', conn) < 0 ||
		pqPutMsgEnd(conn) < 0)
		goto sendFailed;

	/*
	 * Give the data a push.  In nonblock mode, don't complain if we're unable
	 * to send it all; PQgetResult() will do any additional flushing needed.
	 */
	if (PQflush(conn) < 0)
		goto sendFailed;

	/* OK, it's launched! */
	pqAppendCmdQueueEntry(conn, entry);

	return 1;

sendFailed:
	pqRecycleCmdQueueEntry(conn, entry);