Datum pg_aod_sketch_union_agg()

in src/aod_sketch_pg_functions.c [161:198]

• 31 lines of code
• 9 McCabe index (conditional complexity)

Datum pg_aod_sketch_union_agg(PG_FUNCTION_ARGS) {
  struct aod_agg_state* stateptr;
  bytea* sketch_bytes;
  void* sketchptr;

  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, "aod_sketch_union_agg called in non-aggregate context");
  }
  oldcontext = MemoryContextSwitchTo(aggcontext);

  if (PG_ARGISNULL(0)) {
    stateptr = palloc(sizeof(struct aod_agg_state));
    stateptr->type = UNION;
    stateptr->num_values = PG_NARGS() > 2 ? PG_GETARG_INT32(2) : 1;
    stateptr->lg_k = PG_NARGS() > 3 ? PG_GETARG_INT32(3) : 0;
    stateptr->ptr = stateptr->lg_k ? aod_union_new_lgk(stateptr->num_values, stateptr->lg_k) : aod_union_new(stateptr->num_values);
  } else {
    stateptr = (struct aod_agg_state*) PG_GETARG_POINTER(0);
  }

  sketch_bytes = PG_GETARG_BYTEA_P(1);
  sketchptr = aod_sketch_deserialize(VARDATA(sketch_bytes), VARSIZE(sketch_bytes) - VARHDRSZ);
  aod_union_update(stateptr->ptr, sketchptr);
  compact_aod_sketch_delete(sketchptr);

  MemoryContextSwitchTo(oldcontext);

  PG_RETURN_POINTER(stateptr);
}