Datum pg_hll_sketch_union()

in src/hll_sketch_pg_functions.c [391:432]

• 40 lines of code
• 10 McCabe index (conditional complexity)

Datum pg_hll_sketch_union(PG_FUNCTION_ARGS) {
  const bytea* bytes_in1;
  const bytea* bytes_in2;
  void* sketchptr1;
  void* sketchptr2;
  void* unionptr;
  void* sketchptr;
  struct ptr_with_size bytes_out;
  unsigned lg_k;
  unsigned tgt_type;

  lg_k = PG_NARGS() > 2 ? PG_GETARG_INT32(2) : HLL_DEFAULT_LG_K;
  tgt_type = PG_NARGS() > 3 ? PG_GETARG_INT32(3) : 0;
  if (tgt_type) {
    if ((tgt_type != 4) && (tgt_type != 6) && (tgt_type != 8)) {
      elog(ERROR, "hll_sketch_union: unsupported target type, must be 4, 6 or 8");
    }
  }
  unionptr = hll_union_new(lg_k);
  if (!PG_ARGISNULL(0)) {
    bytes_in1 = PG_GETARG_BYTEA_P(0);
    sketchptr1 = hll_sketch_deserialize(VARDATA(bytes_in1), VARSIZE(bytes_in1) - VARHDRSZ);
    hll_union_update(unionptr, sketchptr1);
    hll_sketch_delete(sketchptr1);
  }
  if (!PG_ARGISNULL(1)) {
    bytes_in2 = PG_GETARG_BYTEA_P(1);
    sketchptr2 = hll_sketch_deserialize(VARDATA(bytes_in2), VARSIZE(bytes_in2) - VARHDRSZ);
    hll_union_update(unionptr, sketchptr2);
    hll_sketch_delete(sketchptr2);
  }
  if (tgt_type) {
    sketchptr = hll_union_get_result_tgt_type(unionptr, tgt_type);
  } else {
    sketchptr = hll_union_get_result(unionptr);
  }
  bytes_out = hll_sketch_serialize(sketchptr, VARHDRSZ);
  hll_sketch_delete(sketchptr);
  SET_VARSIZE(bytes_out.ptr, bytes_out.size);
  
  PG_RETURN_BYTEA_P(bytes_out.ptr);
}