Function lookup_ts_config_cache

src/backend/utils/cache/ts_cache.c:384–547

* Fetch configuration cache entry */

 * Fetch configuration cache entry
 */
TSConfigCacheEntry *
lookup_ts_config_cache(Oid cfgId)
{
	TSConfigCacheEntry *entry;

	if (TSConfigCacheHash == NULL)
	{
		/* First time through: initialize the hash table */
		init_ts_config_cache();
	}

	/* Check single-entry cache */
	if (lastUsedConfig && lastUsedConfig->cfgId == cfgId &&
		lastUsedConfig->isvalid)
		return lastUsedConfig;

	/* Try to look up an existing entry */
	entry = (TSConfigCacheEntry *) hash_search(TSConfigCacheHash,
											   (void *) &cfgId,
											   HASH_FIND, NULL);
	if (entry == NULL || !entry->isvalid)
	{
		/*
		 * If we didn't find one, we want to make one. But first look up the
		 * object to be sure the OID is real.
		 */
		HeapTuple	tp;
		Form_pg_ts_config cfg;
		Relation	maprel;
		Relation	mapidx;
		ScanKeyData mapskey;
		SysScanDesc mapscan;
		HeapTuple	maptup;
		ListDictionary maplists[MAXTOKENTYPE + 1];
		Oid			mapdicts[MAXDICTSPERTT];
		int			maxtokentype;
		int			ndicts;
		int			i;

		tp = SearchSysCache1(TSCONFIGOID, ObjectIdGetDatum(cfgId));
		if (!HeapTupleIsValid(tp))
			elog(ERROR, "cache lookup failed for text search configuration %u",
				 cfgId);
		cfg = (Form_pg_ts_config) GETSTRUCT(tp);

		/*
		 * Sanity checks
		 */
		if (!OidIsValid(cfg->cfgparser))
			elog(ERROR, "text search configuration %u has no parser", cfgId);

		if (entry == NULL)
		{
			bool		found;

			/* Now make the cache entry */
			entry = (TSConfigCacheEntry *)
				hash_search(TSConfigCacheHash,