Datum pg_kll_float_sketch_build_agg()

in src/kll_float_sketch_pg_functions.c [61:93]


Datum pg_kll_float_sketch_build_agg(PG_FUNCTION_ARGS) {
  void* sketchptr;
  float value;
  int k;

  MemoryContext oldcontext;
  MemoryContext aggcontext;

  if (PG_ARGISNULL(0) && PG_ARGISNULL(1)) {
    PG_RETURN_NULL();
  } else if (PG_ARGISNULL(1)) {
    PG_RETURN_POINTER(PG_GETARG_POINTER(0)); // no update value. return unmodified state
  }

  if (!AggCheckCallContext(fcinfo, &aggcontext)) {
    elog(ERROR, "kll_float_sketch_build_agg called in non-aggregate context");
  }
  oldcontext = MemoryContextSwitchTo(aggcontext);

  if (PG_ARGISNULL(0)) {
    k = PG_NARGS() > 2 ? PG_GETARG_INT32(2) : DEFAULT_K;
    sketchptr = kll_float_sketch_new(k);
  } else {
    sketchptr = PG_GETARG_POINTER(0);
  }

  value = PG_GETARG_FLOAT4(1);
  kll_float_sketch_update(sketchptr, value);

  MemoryContextSwitchTo(oldcontext);

  PG_RETURN_POINTER(sketchptr);
}