/*
* nth_value
* return the value of VE evaluated on the n-th row from the first
* row of the window frame, per spec.
*/
datum_t window_nth_value(PG_FUNC_ARGS)
{
winobj_s* winobj = PG_WINOBJ();
bool const_offset;
datum_t result;
bool isnull;
int32 nth;
nth = D_TO_INT32(winfunc_get_arg_current(winobj, 1, &isnull));
if (isnull)
RET_NULL();
const_offset = get_fn_expr_arg_stable(fcinfo->flinfo, 1);
if (nth <= 0)
ereport(ERROR, (
errcode(E_INVALID_ARGUMENT_FOR_NTH_VALUE),
errmsg("argument of nth_value must be greater than zero")));
result = winfunc_get_arg_in_frame(
winobj,
0,
nth - 1,
WINDOW_SEEK_HEAD,
const_offset,
&isnull,
NULL);
if (isnull)
RET_NULL();
RET_DATUM(result);
}
/*
* nth_value
* return the value of VE evaluated on the n-th row from the first
* row of the window frame, per spec.
*/
Datum
window_nth_value(PG_FUNCTION_ARGS)
{
WindowObject winobj = PG_WINDOW_OBJECT();
bool const_offset;
Datum result;
bool isnull;
int32 nth;
nth = DatumGetInt32(WinGetFuncArgCurrent(winobj, 1, &isnull));
if (isnull)
PG_RETURN_NULL();
const_offset = get_fn_expr_arg_stable(fcinfo->flinfo, 1);
if (nth <= 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_ARGUMENT_FOR_NTH_VALUE),
errmsg("argument of nth_value must be greater than zero")));
result = WinGetFuncArgInFrame(winobj, 0,
nth - 1, WINDOW_SEEK_HEAD, const_offset,
&isnull, NULL);
if (isnull)
PG_RETURN_NULL();
PG_RETURN_DATUM(result);
}
/*
* leadlag_common
* common operation of lead() and lag()
* For lead() forward is true, whereas for lag() it is false.
* withoffset indicates we have an offset second argument.
* withdefault indicates we have a default third argument.
*/
static Datum
leadlag_common(FunctionCallInfo fcinfo,
bool forward, bool withoffset, bool withdefault)
{
WindowObject winobj = PG_WINDOW_OBJECT();
int32 offset;
bool const_offset;
Datum result;
bool isnull;
bool isout;
if (withoffset)
{
offset = DatumGetInt32(WinGetFuncArgCurrent(winobj, 1, &isnull));
if (isnull)
PG_RETURN_NULL();
const_offset = get_fn_expr_arg_stable(fcinfo->flinfo, 1);
}
else
{
offset = 1;
const_offset = true;
}
result = WinGetFuncArgInPartition(winobj, 0,
(forward ? offset : -offset),
WINDOW_SEEK_CURRENT,
const_offset,
&isnull, &isout);
if (isout)
{
/*
* target row is out of the partition; supply default value if
* provided. otherwise it'll stay NULL
*/
if (withdefault)
result = WinGetFuncArgCurrent(winobj, 2, &isnull);
}
if (isnull)
PG_RETURN_NULL();
PG_RETURN_DATUM(result);
}
/*
* leadlag_common
* common operation of lead() and lag()
* For lead() forward is true, whereas for lag() it is false.
* withoffset indicates we have an offset second argument.
* withdefault indicates we have a default third argument.
*/
static datum_t
leadlag_common(struct fc_info * fcinfo, bool forward, bool withoffset, bool withdefault)
{
winobj_s* winobj = PG_WINOBJ();
int32 offset;
bool const_offset;
datum_t result;
bool isnull;
bool isout;
if (withoffset) {
offset = D_TO_INT32(winfunc_get_arg_current(winobj, 1, &isnull));
if (isnull)
RET_NULL();
const_offset = get_fn_expr_arg_stable(fcinfo->flinfo, 1);
} else {
offset = 1;
const_offset = true;
}
result = winfunc_get_arg_in_partition(
winobj,
0,
(forward ? offset : -offset),
WINDOW_SEEK_CURRENT,
const_offset,
&isnull,
&isout);
if (isout) {
/*
* target row is out of the partition; supply default value if
* provided. otherwise it'll stay NULL
*/
if (withdefault)
result = winfunc_get_arg_current(winobj, 2, &isnull);
}
if (isnull)
RET_NULL();
RET_DATUM(result);
}
/*
* SQL function jsonb_build_array(variadic "any")
*/
Datum
jsonb_build_array(PG_FUNCTION_ARGS)
{
int nargs = PG_NARGS();
int i;
Datum arg;
Oid val_type;
JsonbInState result;
memset(&result, 0, sizeof(JsonbInState));
result.res = pushJsonbValue(&result.parseState, WJB_BEGIN_ARRAY, NULL);
for (i = 0; i < nargs; i++)
{
val_type = get_fn_expr_argtype(fcinfo->flinfo, i);
arg = PG_GETARG_DATUM(i + 1);
/* see comments in jsonb_build_object above */
if (val_type == UNKNOWNOID && get_fn_expr_arg_stable(fcinfo->flinfo, i))
{
val_type = TEXTOID;
if (PG_ARGISNULL(i))
arg = (Datum) 0;
else
arg = CStringGetTextDatum(PG_GETARG_POINTER(i));
}
else
{
arg = PG_GETARG_DATUM(i);
}
if (val_type == InvalidOid || val_type == UNKNOWNOID)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("arg %d: could not determine data type", i + 1)));
add_jsonb(arg, PG_ARGISNULL(i), &result, val_type, false);
}
result.res = pushJsonbValue(&result.parseState, WJB_END_ARRAY, NULL);
PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
}
/*
* SQL function jsonb_build_object(variadic "any")
*/
Datum
jsonb_build_object(PG_FUNCTION_ARGS)
{
int nargs = PG_NARGS();
int i;
Datum arg;
Oid val_type;
JsonbInState result;
if (nargs % 2 != 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("invalid number of arguments: object must be matched key value pairs")));
memset(&result, 0, sizeof(JsonbInState));
result.res = pushJsonbValue(&result.parseState, WJB_BEGIN_OBJECT, NULL);
for (i = 0; i < nargs; i += 2)
{
/* process key */
if (PG_ARGISNULL(i))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("argument %d: key must not be null", i + 1)));
val_type = get_fn_expr_argtype(fcinfo->flinfo, i);
/*
* turn a constant (more or less literal) value that's of unknown type
* into text. Unknowns come in as a cstring pointer.
*/
if (val_type == UNKNOWNOID && get_fn_expr_arg_stable(fcinfo->flinfo, i))
{
val_type = TEXTOID;
arg = CStringGetTextDatum(PG_GETARG_POINTER(i));
}
else
{
arg = PG_GETARG_DATUM(i);
}
if (val_type == InvalidOid || val_type == UNKNOWNOID)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("argument %d: could not determine data type", i + 1)));
add_jsonb(arg, false, &result, val_type, true);
/* process value */
val_type = get_fn_expr_argtype(fcinfo->flinfo, i + 1);
/* see comments above */
if (val_type == UNKNOWNOID && get_fn_expr_arg_stable(fcinfo->flinfo, i + 1))
{
val_type = TEXTOID;
if (PG_ARGISNULL(i + 1))
arg = (Datum) 0;
else
arg = CStringGetTextDatum(PG_GETARG_POINTER(i + 1));
}
else
{
arg = PG_GETARG_DATUM(i + 1);
}
if (val_type == InvalidOid || val_type == UNKNOWNOID)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("argument %d: could not determine data type", i + 2)));
add_jsonb(arg, PG_ARGISNULL(i + 1), &result, val_type, false);
}
result.res = pushJsonbValue(&result.parseState, WJB_END_OBJECT, NULL);
PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
}
/*
* extract_variadic_args
*
* Extract a set of argument values, types and NULL markers for a given
* input function which makes use of a VARIADIC input whose argument list
* depends on the caller context. When doing a VARIADIC call, the caller
* has provided one argument made of an array of values, so deconstruct the
* array data before using it for the next processing. If no VARIADIC call
* is used, just fill in the status data based on all the arguments given
* by the caller.
*
* This function returns the number of arguments generated, or -1 in the
* case of "VARIADIC NULL".
*/
int
extract_variadic_args(FunctionCallInfo fcinfo, int variadic_start,
bool convert_unknown, Datum **args, Oid **types,
bool **nulls)
{
bool variadic = get_fn_expr_variadic(fcinfo->flinfo);
Datum *args_res;
bool *nulls_res;
Oid *types_res;
int nargs,
i;
*args = NULL;
*types = NULL;
*nulls = NULL;
if (variadic)
{
ArrayType *array_in;
Oid element_type;
bool typbyval;
char typalign;
int16 typlen;
Assert(PG_NARGS() == variadic_start + 1);
if (PG_ARGISNULL(variadic_start))
return -1;
array_in = PG_GETARG_ARRAYTYPE_P(variadic_start);
element_type = ARR_ELEMTYPE(array_in);
get_typlenbyvalalign(element_type,
&typlen, &typbyval, &typalign);
deconstruct_array(array_in, element_type, typlen, typbyval,
typalign, &args_res, &nulls_res,
&nargs);
/* All the elements of the array have the same type */
types_res = (Oid *) palloc0(nargs * sizeof(Oid));
for (i = 0; i < nargs; i++)
types_res[i] = element_type;
}
else
{
nargs = PG_NARGS() - variadic_start;
Assert(nargs > 0);
nulls_res = (bool *) palloc0(nargs * sizeof(bool));
args_res = (Datum *) palloc0(nargs * sizeof(Datum));
types_res = (Oid *) palloc0(nargs * sizeof(Oid));
for (i = 0; i < nargs; i++)
{
nulls_res[i] = PG_ARGISNULL(i + variadic_start);
types_res[i] = get_fn_expr_argtype(fcinfo->flinfo,
i + variadic_start);
/*
* Turn a constant (more or less literal) value that's of unknown
* type into text if required. Unknowns come in as a cstring
* pointer. Note: for functions declared as taking type "any", the
* parser will not do any type conversion on unknown-type literals
* (that is, undecorated strings or NULLs).
*/
if (convert_unknown &&
types_res[i] == UNKNOWNOID &&
get_fn_expr_arg_stable(fcinfo->flinfo, i + variadic_start))
{
types_res[i] = TEXTOID;
if (PG_ARGISNULL(i + variadic_start))
args_res[i] = (Datum) 0;
else
args_res[i] =
CStringGetTextDatum(PG_GETARG_POINTER(i + variadic_start));
}
else
{
/* no conversion needed, just take the datum as given */
args_res[i] = PG_GETARG_DATUM(i + variadic_start);
}
if (!OidIsValid(types_res[i]) ||
(convert_unknown && types_res[i] == UNKNOWNOID))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not determine data type for argument %d",
i + 1)));
}
}
/* Fill in results */
*args = args_res;
*nulls = nulls_res;
*types = types_res;
return nargs;
}
