Function pqSaveParameterStatus

src/interfaces/libpq/fe-exec.c:1016–1125

* pqSaveParameterStatus - remember parameter status sent by backend */

 * pqSaveParameterStatus - remember parameter status sent by backend
 */
void
pqSaveParameterStatus(PGconn *conn, const char *name, const char *value)
{
	pgParameterStatus *pstatus;
	pgParameterStatus *prev;

	/*
	 * Forget any old information about the parameter
	 */
	for (pstatus = conn->pstatus, prev = NULL;
		 pstatus != NULL;
		 prev = pstatus, pstatus = pstatus->next)
	{
		if (strcmp(pstatus->name, name) == 0)
		{
			if (prev)
				prev->next = pstatus->next;
			else
				conn->pstatus = pstatus->next;
			free(pstatus);		/* frees name and value strings too */
			break;
		}
	}

	/*
	 * Store new info as a single malloc block
	 */
	pstatus = (pgParameterStatus *) malloc(sizeof(pgParameterStatus) +
										   strlen(name) + strlen(value) + 2);
	if (pstatus)
	{
		char	   *ptr;

		ptr = ((char *) pstatus) + sizeof(pgParameterStatus);
		pstatus->name = ptr;
		strcpy(ptr, name);
		ptr += strlen(name) + 1;
		pstatus->value = ptr;
		strcpy(ptr, value);
		pstatus->next = conn->pstatus;
		conn->pstatus = pstatus;
	}

	/*
	 * Save values of settings that are of interest to libpq in fields of the
	 * PGconn object.  We keep client_encoding and standard_conforming_strings
	 * in static variables as well, so that PQescapeString and PQescapeBytea
	 * can behave somewhat sanely (at least in single-connection-using
	 * programs).
	 */
	if (strcmp(name, "client_encoding") == 0)
	{
		conn->client_encoding = pg_char_to_encoding(value);
		/* if we don't recognize the encoding name, fall back to SQL_ASCII */
		if (conn->client_encoding < 0)
			conn->client_encoding = PG_SQL_ASCII;
		static_client_encoding = conn->client_encoding;
	}