Function PLy_procedure_get

src/pl/plpython/plpy_procedure.c:68–127

* PLy_procedure_get: returns a cached PLyProcedure, or creates, stores and * returns a new PLyProcedure. * * fn_oid is the OID of the function requested * fn_rel is InvalidOid or the relation this function triggers on * is_trigger denotes whether the function is a trigger function * * The reason that both fn_rel and is_trigger need to be passed is that when * trigger functions get validate

 * be used with, so no sensible fn_rel can be passed.
 */
PLyProcedure *
PLy_procedure_get(Oid fn_oid, Oid fn_rel, bool is_trigger)
{
	bool		use_cache = !(is_trigger && fn_rel == InvalidOid);
	HeapTuple	procTup;
	PLyProcedureKey key;
	PLyProcedureEntry *volatile entry = NULL;
	PLyProcedure *volatile proc = NULL;
	bool		found = false;

	procTup = SearchSysCache1(PROCOID, ObjectIdGetDatum(fn_oid));
	if (!HeapTupleIsValid(procTup))
		elog(ERROR, "cache lookup failed for function %u", fn_oid);

	/*
	 * Look for the function in the cache, unless we don't have the necessary
	 * information (e.g. during validation). In that case we just don't cache
	 * anything.
	 */
	if (use_cache)
	{
		key.fn_oid = fn_oid;
		key.fn_rel = fn_rel;
		entry = hash_search(PLy_procedure_cache, &key, HASH_ENTER, &found);
		proc = entry->proc;
	}

	PG_TRY();
	{
		if (!found)
		{
			/* Haven't found it, create a new procedure */
			proc = PLy_procedure_create(procTup, fn_oid, is_trigger);
			if (use_cache)
				entry->proc = proc;
		}
		else if (!PLy_procedure_valid(proc, procTup))
		{
			/* Found it, but it's invalid, free and reuse the cache entry */
			entry->proc = NULL;
			if (proc)
				PLy_procedure_delete(proc);
			proc = PLy_procedure_create(procTup, fn_oid, is_trigger);
			entry->proc = proc;
		}
		/* Found it and it's valid, it's fine to use it */
	}
	PG_CATCH();
	{
		/* Do not leave an uninitialized entry in the cache */
		if (use_cache)
			hash_search(PLy_procedure_cache, &key, HASH_REMOVE, NULL);
		PG_RE_THROW();
	}
	PG_END_TRY();

	ReleaseSysCache(procTup);