Datum pg_kll_float_sketch_get_quantiles()

in src/kll_float_sketch_pg_functions.c [377:423]

• 35 lines of code
• 2 McCabe index (conditional complexity)

Datum pg_kll_float_sketch_get_quantiles(PG_FUNCTION_ARGS) {
  const bytea* bytes_in;
  void* sketchptr;

  // input array of fractions
  ArrayType* arr_in;
  Oid elmtype_in;
  int16 elmlen_in;
  bool elmbyval_in;
  char elmalign_in;
  Datum* data_in;
  bool* nulls_in;
  int arr_len;
  double* fractions;

  // output array of quantiles
  Datum* quantiles;
  ArrayType* arr_out;
  int16 elmlen_out;
  bool elmbyval_out;
  char elmalign_out;

  int i;

  bytes_in = PG_GETARG_BYTEA_P(0);
  sketchptr = kll_float_sketch_deserialize(VARDATA(bytes_in), VARSIZE(bytes_in) - VARHDRSZ);

  arr_in = PG_GETARG_ARRAYTYPE_P(1);
  elmtype_in = ARR_ELEMTYPE(arr_in);
  get_typlenbyvalalign(elmtype_in, &elmlen_in, &elmbyval_in, &elmalign_in);
  deconstruct_array(arr_in, elmtype_in, elmlen_in, elmbyval_in, elmalign_in, &data_in, &nulls_in, &arr_len);

  fractions = palloc(sizeof(double) * arr_len);
  for (i = 0; i < arr_len; i++) {
    fractions[i] = DatumGetFloat8(data_in[i]);
  }
  quantiles = (Datum*) kll_float_sketch_get_quantiles(sketchptr, fractions, arr_len);
  pfree(fractions);

  // construct output array of quantiles
  get_typlenbyvalalign(FLOAT4OID, &elmlen_out, &elmbyval_out, &elmalign_out);
  arr_out = construct_array(quantiles, arr_len, FLOAT4OID, elmlen_out, elmbyval_out, elmalign_out);

  kll_float_sketch_delete(sketchptr);

  PG_RETURN_ARRAYTYPE_P(arr_out);
}