Function transformLocationUris

src/backend/commands/exttablecmds.c:340–488

* Transform the URI string list into a string. While at it we validate the URI * strings. */

 * strings.
 */
static char*
transformLocationUris(List *locs, bool isweb, bool iswritable)
{
	ListCell   *cell;
	StringInfoData buf;
	UriProtocol first_protocol = URI_FILE;		/* initialize to keep gcc
												 * quiet */
	bool		first_uri = true;

#define FDIST_DEF_PORT 8080

	initStringInfo(&buf);

	/* Parser should not let this happen */
	Assert(locs != NIL);

	/*
	 * iterate through the user supplied URI list from LOCATION clause.
	 */
	foreach(cell, locs)
	{
		Uri		   *uri;
		char	   *uri_str_orig;
		char	   *uri_str_final;
		char	   *uri_str_escape;
		Value	   *v = lfirst(cell);

		/* get the current URI string from the command */
		uri_str_orig = v->val.str;

		/* parse it to its components */
		uri = ParseExternalTableUri(uri_str_orig);

		/*
		 * in here edit the uri string if needed
		 */

		/*
		 * no port was specified for gpfdist, gpfdists or hdfs. add the
		 * default
		 */
		if ((uri->protocol == URI_GPFDIST || uri->protocol == URI_GPFDISTS) && uri->port == -1)
		{
			char	   *at_hostname = (char *) uri_str_orig
			+ strlen(uri->protocol == URI_GPFDIST ? "gpfdist://" : "gpfdists://");
			char	   *after_hostname = strchr(at_hostname, '/');
			int			len = after_hostname - at_hostname;
			char	   *hostname = pstrdup(at_hostname);

			hostname[len] = '\0';

			/* add the default port number to the uri string */
			uri_str_final = psprintf("%s%s:%d%s",
					(uri->protocol == URI_GPFDIST ? PROTOCOL_GPFDIST : PROTOCOL_GPFDISTS),
					hostname,
					FDIST_DEF_PORT, after_hostname);

			pfree(hostname);