/*
* cmsketch_agg transition function -
*
* adds the given element to the transition cmsketch using the given value for p and n
*/
Datum
cmsketch_agg_transp(PG_FUNCTION_ARGS)
{
MemoryContext old;
MemoryContext context;
CountMinSketch *state;
Datum incoming = PG_GETARG_DATUM(1);
float8 eps = PG_GETARG_FLOAT8(2);
float8 p = PG_GETARG_FLOAT8(3);
if (!AggCheckCallContext(fcinfo, &context))
elog(ERROR, "cmsketch_agg_transp called in non-aggregate context");
old = MemoryContextSwitchTo(context);
if (PG_ARGISNULL(0))
state = cmsketch_startup(fcinfo, eps, p);
else
state = (CountMinSketch *) PG_GETARG_VARLENA_P(0);
state = cmsketch_add_datum(fcinfo, state, incoming, 1);
MemoryContextSwitchTo(old);
PG_RETURN_POINTER(state);
}
Datum
cmsketch_add(PG_FUNCTION_ARGS)
{
CountMinSketch *cms = (CountMinSketch *) PG_GETARG_VARLENA_P(0);
fcinfo->flinfo->fn_extra = lookup_type_cache(get_fn_expr_argtype(fcinfo->flinfo, 1), 0);
cms = cmsketch_add_datum(fcinfo, cms, PG_GETARG_DATUM(1));
PG_RETURN_POINTER(cms);
}
Datum
cmsketch_addn(PG_FUNCTION_ARGS)
{
CountMinSketch *cms;
int32 n = PG_GETARG_INT32(2);
if (PG_ARGISNULL(0))
cms = CountMinSketchCreate();
else
cms = (CountMinSketch *) PG_GETARG_VARLENA_P(0);
if (n < 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("cmsketch type doesn't support negative increments")));
if (n)
{
fcinfo->flinfo->fn_extra = lookup_type_cache(get_fn_expr_argtype(fcinfo->flinfo, 1), 0);
cms = cmsketch_add_datum(fcinfo, cms, PG_GETARG_DATUM(1), n);
}
PG_RETURN_POINTER(cms);
}
