functioncmds.c

来自「PostgreSQL7.4.6 for Linux」· C语言 代码 · 共 1,115 行 · 第 1/3 页

		if (lnext(as) != NIL)
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
					 errmsg("only one AS item needed for language \"%s\"",
							languageName)));
	}
}



/*
 * CreateFunction
 *	 Execute a CREATE FUNCTION utility statement.
 */
void
CreateFunction(CreateFunctionStmt *stmt)
{
	char	   *probin_str;
	char	   *prosrc_str;
	Oid			prorettype;
	bool		returnsSet;
	char	   *language;
	char	   *languageName;
	Oid			languageOid;
	Oid			languageValidator;
	char	   *funcname;
	Oid			namespaceId;
	AclResult	aclresult;
	int			parameterCount;
	Oid			parameterTypes[FUNC_MAX_ARGS];
	bool		isStrict,
				security;
	char		volatility;
	HeapTuple	languageTuple;
	Form_pg_language languageStruct;
	List	   *as_clause;

	/* Convert list of names to a name and namespace */
	namespaceId = QualifiedNameGetCreationNamespace(stmt->funcname,
													&funcname);

	/* Check we have creation rights in target namespace */
	aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(), ACL_CREATE);
	if (aclresult != ACLCHECK_OK)
		aclcheck_error(aclresult, ACL_KIND_NAMESPACE,
					   get_namespace_name(namespaceId));

	/* defaults attributes */
	isStrict = false;
	security = false;
	volatility = PROVOLATILE_VOLATILE;

	/* override attributes from explicit list */
	compute_attributes_sql_style(stmt->options,
			   &as_clause, &language, &volatility, &isStrict, &security);

	/* Convert language name to canonical case */
	languageName = case_translate_language_name(language);

	/* Look up the language and validate permissions */
	languageTuple = SearchSysCache(LANGNAME,
								   PointerGetDatum(languageName),
								   0, 0, 0);
	if (!HeapTupleIsValid(languageTuple))
		/* Add any new languages to this list to invoke the hint. */
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("language \"%s\" does not exist", languageName),
				   (strcmp(languageName, "plperl") == 0 ||
					strcmp(languageName, "plperlu") == 0 ||
					strcmp(languageName, "plpgsql") == 0 ||
					strcmp(languageName, "plpythonu") == 0 ||
					strcmp(languageName, "pltcl") == 0 ||
					strcmp(languageName, "pltclu") == 0) ?
				 errhint("You need to use \"createlang\" to load the language into the database.") : 0));
	
	languageOid = HeapTupleGetOid(languageTuple);
	languageStruct = (Form_pg_language) GETSTRUCT(languageTuple);

	if (languageStruct->lanpltrusted)
	{
		/* if trusted language, need USAGE privilege */
		AclResult	aclresult;

		aclresult = pg_language_aclcheck(languageOid, GetUserId(), ACL_USAGE);
		if (aclresult != ACLCHECK_OK)
			aclcheck_error(aclresult, ACL_KIND_LANGUAGE,
						   NameStr(languageStruct->lanname));
	}
	else
	{
		/* if untrusted language, must be superuser */
		if (!superuser())
			aclcheck_error(ACLCHECK_NO_PRIV, ACL_KIND_LANGUAGE,
						   NameStr(languageStruct->lanname));
	}

	languageValidator = languageStruct->lanvalidator;

	ReleaseSysCache(languageTuple);

	/*
	 * Convert remaining parameters of CREATE to form wanted by
	 * ProcedureCreate.
	 */
	compute_return_type(stmt->returnType, languageOid,
						&prorettype, &returnsSet);

	parameterCount = compute_parameter_types(stmt->argTypes, languageOid,
											 parameterTypes);

	compute_attributes_with_style(stmt->withClause, &isStrict, &volatility);

	interpret_AS_clause(languageOid, languageName, as_clause,
						&prosrc_str, &probin_str);

	if (languageOid == INTERNALlanguageId)
	{
		/*
		 * In PostgreSQL versions before 6.5, the SQL name of the created
		 * function could not be different from the internal name, and
		 * "prosrc" wasn't used.  So there is code out there that does
		 * CREATE FUNCTION xyz AS '' LANGUAGE 'internal'. To preserve some
		 * modicum of backwards compatibility, accept an empty "prosrc"
		 * value as meaning the supplied SQL function name.
		 */
		if (strlen(prosrc_str) == 0)
			prosrc_str = funcname;
	}

	if (languageOid == ClanguageId)
	{
		/* If link symbol is specified as "-", substitute procedure name */
		if (strcmp(prosrc_str, "-") == 0)
			prosrc_str = funcname;
	}

	/*
	 * And now that we have all the parameters, and know we're permitted
	 * to do so, go ahead and create the function.
	 */
	ProcedureCreate(funcname,
					namespaceId,
					stmt->replace,
					returnsSet,
					prorettype,
					languageOid,
					languageValidator,
					prosrc_str, /* converted to text later */
					probin_str, /* converted to text later */
					false,		/* not an aggregate */
					security,
					isStrict,
					volatility,
					parameterCount,
					parameterTypes);
}


/*
 * RemoveFunction
 *		Deletes a function.
 */
void
RemoveFunction(RemoveFuncStmt *stmt)
{
	List	   *functionName = stmt->funcname;
	List	   *argTypes = stmt->args;	/* list of TypeName nodes */
	Oid			funcOid;
	HeapTuple	tup;
	ObjectAddress object;

	/*
	 * Find the function, do permissions and validity checks
	 */
	funcOid = LookupFuncNameTypeNames(functionName, argTypes, false);

	tup = SearchSysCache(PROCOID,
						 ObjectIdGetDatum(funcOid),
						 0, 0, 0);
	if (!HeapTupleIsValid(tup)) /* should not happen */
		elog(ERROR, "cache lookup failed for function %u", funcOid);

	/* Permission check: must own func or its namespace */
	if (!pg_proc_ownercheck(funcOid, GetUserId()) &&
		!pg_namespace_ownercheck(((Form_pg_proc) GETSTRUCT(tup))->pronamespace,
								 GetUserId()))
		aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_PROC,
					   NameListToString(functionName));

	if (((Form_pg_proc) GETSTRUCT(tup))->proisagg)
		ereport(ERROR,
				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
				 errmsg("\"%s\" is an aggregate function",
						NameListToString(functionName)),
			errhint("Use DROP AGGREGATE to drop aggregate functions.")));

	if (((Form_pg_proc) GETSTRUCT(tup))->prolang == INTERNALlanguageId)
	{
		/* "Helpful" NOTICE when removing a builtin function ... */
		ereport(NOTICE,
				(errcode(ERRCODE_WARNING),
				 errmsg("removing built-in function \"%s\"",
						NameListToString(functionName))));
	}

	ReleaseSysCache(tup);

	/*
	 * Do the deletion
	 */
	object.classId = RelOid_pg_proc;
	object.objectId = funcOid;
	object.objectSubId = 0;

	performDeletion(&object, stmt->behavior);
}

/*
 * Guts of function deletion.
 *
 * Note: this is also used for aggregate deletion, since the OIDs of
 * both functions and aggregates point to pg_proc.
 */
void
RemoveFunctionById(Oid funcOid)
{
	Relation	relation;
	HeapTuple	tup;
	bool		isagg;

	/*
	 * Delete the pg_proc tuple.
	 */
	relation = heap_openr(ProcedureRelationName, RowExclusiveLock);

	tup = SearchSysCache(PROCOID,
						 ObjectIdGetDatum(funcOid),
						 0, 0, 0);
	if (!HeapTupleIsValid(tup)) /* should not happen */
		elog(ERROR, "cache lookup failed for function %u", funcOid);

	isagg = ((Form_pg_proc) GETSTRUCT(tup))->proisagg;

	simple_heap_delete(relation, &tup->t_self);

	ReleaseSysCache(tup);

	heap_close(relation, RowExclusiveLock);

	/*
	 * If there's a pg_aggregate tuple, delete that too.
	 */
	if (isagg)
	{
		relation = heap_openr(AggregateRelationName, RowExclusiveLock);

		tup = SearchSysCache(AGGFNOID,
							 ObjectIdGetDatum(funcOid),
							 0, 0, 0);
		if (!HeapTupleIsValid(tup))		/* should not happen */
			elog(ERROR, "cache lookup failed for pg_aggregate tuple for function %u", funcOid);

		simple_heap_delete(relation, &tup->t_self);

		ReleaseSysCache(tup);

		heap_close(relation, RowExclusiveLock);
	}
}


/*
 * Rename function
 */
void
RenameFunction(List *name, List *argtypes, const char *newname)
{
	Oid			procOid;
	Oid			namespaceOid;
	HeapTuple	tup;
	Form_pg_proc procForm;
	Relation	rel;
	AclResult	aclresult;

	rel = heap_openr(ProcedureRelationName, RowExclusiveLock);

	procOid = LookupFuncNameTypeNames(name, argtypes, false);

	tup = SearchSysCacheCopy(PROCOID,
							 ObjectIdGetDatum(procOid),
							 0, 0, 0);
	if (!HeapTupleIsValid(tup)) /* should not happen */
		elog(ERROR, "cache lookup failed for function %u", procOid);
	procForm = (Form_pg_proc) GETSTRUCT(tup);

	if (procForm->proisagg)
		ereport(ERROR,
				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
				 errmsg("\"%s\" is an aggregate function",
						NameListToString(name)),
		 errhint("Use ALTER AGGREGATE to rename aggregate functions.")));

	namespaceOid = procForm->pronamespace;

	/* make sure the new name doesn't exist */
	if (SearchSysCacheExists(PROCNAMENSP,
							 CStringGetDatum(newname),
							 Int16GetDatum(procForm->pronargs),
							 PointerGetDatum(procForm->proargtypes),
							 ObjectIdGetDatum(namespaceOid)))
	{
		ereport(ERROR,
				(errcode(ERRCODE_DUPLICATE_FUNCTION),
				 errmsg("function %s already exists in schema \"%s\"",
						funcname_signature_string(newname,
												  procForm->pronargs,
												  procForm->proargtypes),
						get_namespace_name(namespaceOid))));
	}

	/* must be owner */
	if (!pg_proc_ownercheck(procOid, GetUserId()))
		aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_PROC,
					   NameListToString(name));

	/* must have CREATE privilege on namespace */
	aclresult = pg_namespace_aclcheck(namespaceOid, GetUserId(), ACL_CREATE);
	if (aclresult != ACLCHECK_OK)
		aclcheck_error(aclresult, ACL_KIND_NAMESPACE,
					   get_namespace_name(namespaceOid));

	/* rename */
	namestrcpy(&(procForm->proname), newname);
	simple_heap_update(rel, &tup->t_self, tup);
	CatalogUpdateIndexes(rel, tup);

	heap_close(rel, NoLock);
	heap_freetuple(tup);
}


/*
 * SetFunctionReturnType - change declared return type of a function
 *
 * This is presently only used for adjusting legacy functions that return
 * OPAQUE to return whatever we find their correct definition should be.
 * The caller should emit a suitable warning explaining what we did.
 */
void
SetFunctionReturnType(Oid funcOid, Oid newRetType)
{
	Relation	pg_proc_rel;
	HeapTuple	tup;
	Form_pg_proc procForm;

	pg_proc_rel = heap_openr(ProcedureRelationName, RowExclusiveLock);

	tup = SearchSysCacheCopy(PROCOID,
							 ObjectIdGetDatum(funcOid),
							 0, 0, 0);
	if (!HeapTupleIsValid(tup)) /* should not happen */
		elog(ERROR, "cache lookup failed for function %u", funcOid);
	procForm = (Form_pg_proc) GETSTRUCT(tup);

	if (procForm->prorettype != OPAQUEOID)		/* caller messed up */
		elog(ERROR, "function %u doesn't return OPAQUE", funcOid);

	/* okay to overwrite copied tuple */
	procForm->prorettype = newRetType;