Function GetConnection

src/bin/pg_basebackup/streamutil.c:61–270

* Connect to the server. Returns a valid PGconn pointer if connected, * or NULL on non-permanent error. On permanent error, the function will * call exit(1) directly. */

 * call exit(1) directly.
 */
PGconn *
GetConnection(void)
{
	PGconn	   *tmpconn;
	int			argcount = 7;	/* dbname, replication, fallback_app_name,
								 * host, user, port, password */
	int			i;
	const char **keywords;
	const char **values;
	const char *tmpparam;
	bool		need_password;
	PQconninfoOption *conn_opts = NULL;
	PQconninfoOption *conn_opt;
	char	   *err_msg = NULL;

	/* pg_recvlogical uses dbname only; others use connection_string only. */
	Assert(dbname == NULL || connection_string == NULL);

	/*
	 * Merge the connection info inputs given in form of connection string,
	 * options and default values (dbname=replication, replication=true, etc.)
	 * Explicitly discard any dbname value in the connection string;
	 * otherwise, PQconnectdbParams() would interpret that value as being
	 * itself a connection string.
	 */
	i = 0;
	if (connection_string)
	{
		conn_opts = PQconninfoParse(connection_string, &err_msg);
		if (conn_opts == NULL)
		{
			pg_log_error("%s", err_msg);
			exit(1);
		}

		for (conn_opt = conn_opts; conn_opt->keyword != NULL; conn_opt++)
		{
			if (conn_opt->val != NULL && conn_opt->val[0] != '\0' &&
				strcmp(conn_opt->keyword, "dbname") != 0)
				argcount++;
		}

		keywords = pg_malloc0((argcount + 1) * sizeof(*keywords));
		values = pg_malloc0((argcount + 1) * sizeof(*values));

		for (conn_opt = conn_opts; conn_opt->keyword != NULL; conn_opt++)
		{
			if (conn_opt->val != NULL && conn_opt->val[0] != '\0' &&
				strcmp(conn_opt->keyword, "dbname") != 0)
			{
				keywords[i] = conn_opt->keyword;
				values[i] = conn_opt->val;
				i++;
			}
		}
	}
	else
	{