functioncmds.c

PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统

	char	   *languageName;
	Oid			languageOid;
	Oid			languageValidator;
	char	   *funcname;
	Oid			namespaceId;
	AclResult	aclresult;
	oidvector  *parameterTypes;
	ArrayType  *allParameterTypes;
	ArrayType  *parameterModes;
	ArrayType  *parameterNames;
	Oid			requiredResultType;
	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));

	/* default 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))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("language \"%s\" does not exist", languageName),
				 (PLTemplateExists(languageName) ?
				  errhint("Use CREATE LANGUAGE 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.
	 */
	examine_parameter_list(stmt->parameters, languageOid,
						   &parameterTypes,
						   &allParameterTypes,
						   &parameterModes,
						   &parameterNames,
						   &requiredResultType);

	if (stmt->returnType)
	{
		/* explicit RETURNS clause */
		compute_return_type(stmt->returnType, languageOid,
							&prorettype, &returnsSet);
		if (OidIsValid(requiredResultType) && prorettype != requiredResultType)
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
					 errmsg("function result type must be %s because of OUT parameters",
							format_type_be(requiredResultType))));
	}
	else if (OidIsValid(requiredResultType))
	{
		/* default RETURNS clause from OUT parameters */
		prorettype = requiredResultType;
		returnsSet = false;
	}
	else
	{
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
				 errmsg("function result type must be specified")));
		/* Alternative possibility: default to RETURNS VOID */
		prorettype = VOIDOID;
		returnsSet = false;
	}

	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,
					parameterTypes,
					PointerGetDatum(allParameterTypes),
					PointerGetDatum(parameterModes),
					PointerGetDatum(parameterNames));
}


/*
 * 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 = ProcedureRelationId;
	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_open(ProcedureRelationId, 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_open(AggregateRelationId, 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_open(ProcedureRelationId, 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(PROCNAMEARGSNSP,
							 CStringGetDatum(newname),
							 PointerGetDatum(&procForm->proargtypes),
							 ObjectIdGetDatum(namespaceOid),
							 0))
	{
		ereport(ERROR,
				(errcode(ERRCODE_DUPLICATE_FUNCTION),
				 errmsg("function %s already exists in schema \"%s\"",
						funcname_signature_string(newname,
												  procForm->pronargs,
											   procForm->proargtypes.values),
						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);
}

/*
 * Change function owner
 */
void
AlterFunctionOwner(List *name, List *argtypes, Oid newOwnerId)
{
	Oid			procOid;
	HeapTuple	tup;
	Form_pg_proc procForm;
	Relation	rel;
	AclResult	aclresult;

	rel = heap_open(ProcedureRelationId, RowExclusiveLock);

	procOid = LookupFuncNameTypeNames(name, argtypes, false);

	tup = SearchSysCache(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 change owner of aggregate functions.")));

	/*
	 * If the new owner is the same as the existing owner, consider the
	 * command to have succeeded.  This is for dump restoration purposes.
	 */
	if (procForm->proowner != newOwnerId)
	{
		Datum		repl_val[Natts_pg_proc];
		char		repl_null[Natts_pg_proc];
		char		repl_repl[Natts_pg_proc];
		Acl		   *newAcl;
		Datum		aclDatum;
		bool		isNull;
		HeapTuple	newtuple;

		/* Superusers can always do it */
		if (!superuser())
		{
			/* Otherwise, must be owner of the existing object */
			if (!pg_proc_ownercheck(procOid, GetUserId()))
				aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_PROC,
							   NameListToString(name));

			/* Must be able to become new owner */
			check_is_member_of_role(GetUserId(), newOwnerId);

			/* New owner must have CREATE privilege on namespace */
			aclresult = pg_namespace_aclcheck(procForm->pronamespace,
											  newOwnerId,
											  ACL_CREATE);
			if (aclresult != ACLCHECK_OK)
				aclcheck_error(aclresult, ACL_KIND_NAMESPACE,
							   get_namespace_name(procForm->pronamespace));
		}

		memset(repl_null, ' ', sizeof(repl_null));
		memset(repl_repl, ' ', sizeof(repl_repl));

		repl_repl[Anum_pg_proc_proowner - 1] = 'r';
		repl_val[Anum_pg_proc_proowner - 1] = ObjectIdGetDatum(newOwnerId);

		/*
		 * Determine the modified ACL for the new owner.  This is only
		 * necessary when the ACL is non-null.
		 */
		aclDatum = SysCacheGetAttr(PROCOID, tup,
								   Anum_pg_proc_proacl,
								   &isNull);
		if (!isNull)
		{
			newAcl = aclnewowner(DatumGetAclP(aclDatum),
								 procForm->proowner, newOwnerId);
			repl_repl[Anum_pg_proc_proacl - 1] = 'r';
			repl_val[Anum_pg_proc_proacl - 1] = PointerGetDatum(newAcl);
		}

		newtuple = heap_modifytuple(tup, RelationGetDescr(rel), repl_val, repl_null, repl_repl);

		simple_heap_update(rel, &newtuple->t_self, newtuple);
		CatalogUpdateIndexes(rel, newtuple);

		heap_freetuple(newtuple);

		/* Update owner dependency reference */
		changeDependencyOnOwner(ProcedureRelationId, procOid, newOwnerId);
	}

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

/*
 * Implements the ALTER FUNCTION utility command (except for the
 * RENAME and OWNER clauses, which are handled as part of the generic
 * ALTER framework).
 */
void
AlterFunction(AlterFunctionStmt *stmt)
{
	HeapTuple	tup;
	Oid			funcOid;
	Form_pg_proc procForm;
	Relation	rel;
	ListCell   *l;
	DefElem    *volatility_item = NULL;
	DefElem    *strict_item = NULL;
	DefElem    *security_def_item = NULL;

	rel = heap_open(ProcedureRelationId, RowExclusiveLock);

	funcOid = LookupFuncNameTypeNames(stmt->func->funcname,
									  stmt->func->funcargs,
									  false);

	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);

	/* Permission check: must own function */
	if (!pg_proc_ownercheck(funcOid, GetUserId()))
		aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_PROC,
					   NameListToString(stmt->func->funcname));

	if (procForm->proisagg)
		ereport(ERROR,
				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
				 errmsg("\"%s\" is an aggregate function",
						NameListToString(stmt->func->funcname))));

	/* Examine requested actions. */
	foreach(l, stmt->actions)
	{
		DefElem    *defel = (DefElem *) lfirst(l);

		if (compute_common_attribute(defel,
									 &volatility_item,
									 &strict_item,
									 &security_def_item) == false)
			elog(ERROR, "option \"%s\" not recognized", defel->defname);
	}

	if (volatility_item)
		procForm->provolatile = interpret_func_volatility(volatility_item);
	if (strict_item)
		procForm->proisstrict = intVal(strict_item->arg);
	if (security_def_item)
		procForm->prosecdef = intVal(security_def_item->arg);

	/* Do the update */