/*
* op_volatile
*
* Get the provolatile flag for the operator's underlying function.
*/
char
op_volatile(Oid opno)
{
RegProcedure funcid = get_opcode(opno);
if (funcid == (RegProcedure) InvalidOid)
elog(ERROR, "operator %u does not exist", opno);
return func_volatile((Oid) funcid);
}
/*
* ValidateProtocolFunction -- common code for finding readfn, writefn or validatorfn
*/
static Oid
ValidateProtocolFunction(List *fnName, ExtPtcFuncType fntype)
{
Oid fnOid;
bool retset;
bool retstrict;
bool retordered;
Oid *true_oid_array;
Oid actual_rettype;
Oid desired_rettype;
FuncDetailCode fdresult;
AclResult aclresult;
Oid inputTypes[1] = {InvalidOid}; /* dummy */
int nargs = 0; /* true for all 3 function types at the moment */
int nvargs;
if (fntype == EXTPTC_FUNC_VALIDATOR)
desired_rettype = VOIDOID;
else
desired_rettype = INT4OID;
/*
* func_get_detail looks up the function in the catalogs, does
* disambiguation for polymorphic functions, handles inheritance, and
* returns the funcid and type and set or singleton status of the
* function's return value. it also returns the true argument types to
* the function.
*/
fdresult = func_get_detail(fnName, NIL, nargs, inputTypes, false, false,
&fnOid, &actual_rettype, &retset, &retstrict,
&retordered, &nvargs, &true_oid_array, NULL);
/* only valid case is a normal function not returning a set */
if (fdresult != FUNCDETAIL_NORMAL || !OidIsValid(fnOid))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_FUNCTION),
errmsg("function %s does not exist",
func_signature_string(fnName, nargs, inputTypes))));
if (retset)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("Invalid protocol function"),
errdetail("Protocol functions cannot return sets.")));
if (actual_rettype != desired_rettype)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("%s protocol function %s must return %s",
func_type_to_name(fntype),
func_signature_string(fnName, nargs, inputTypes),
(fntype == EXTPTC_FUNC_VALIDATOR ? "void" : "an integer"))));
if (func_volatile(fnOid) == PROVOLATILE_IMMUTABLE)
ereport(ERROR,
(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
errmsg("%s protocol function %s is declared IMMUTABLE",
func_type_to_name(fntype),
func_signature_string(fnName, nargs, inputTypes)),
errhint("PROTOCOL functions must be declared STABLE or VOLATILE")));
/* Check protocol creator has permission to call the function */
aclresult = pg_proc_aclcheck(fnOid, GetUserId(), ACL_EXECUTE);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, ACL_KIND_PROC, get_func_name(fnOid));
return fnOid;
}
/*
* Checks if the results of a function can be cached.
* Only IMMUTABLE functions can be cached.
*
* Returns true if function results can be cached, false otherwise.
*/
static bool
isFuncCacheable(Oid fn_oid)
{
char fn_provolatile = func_volatile(fn_oid);
return (fn_provolatile == PROVOLATILE_IMMUTABLE);
}
