CAMLprim value hh_get_dep()

in source/hack_parallel/hack_parallel/heap/hh_shared.c [1430:1479]

• 33 lines of code
• 6 McCabe index (conditional complexity)

CAMLprim value hh_get_dep(value ocaml_key) {
  CAMLparam1(ocaml_key);
  check_should_exit();
  CAMLlocal2(result, cell);

  volatile deptbl_entry_t* const table = deptbl;

  // The caller is required to pass a 32-bit node ID.
  const uint64_t key64 = Long_val(ocaml_key);
  const uint32_t key = (uint32_t)key64;
  assert((key & 0x7FFFFFFF) == key64);

  result = Val_int(0); // The empty list

  for (size_t slot = (size_t)hash_uint64(key);; ++slot) {
    slot &= dep_size - 1;

    deptbl_entry_t slotval = table[slot];

    if (slotval.raw == 0) {
      // There are no entries associated with this key.
      break;
    }

    if (slotval.s.key.num == key && slotval.s.key.tag == TAG_KEY) {
      // We found the list for 'key', so walk it.

      while (slotval.s.next.tag == TAG_NEXT) {
        assert(slotval.s.next.num < dep_size);
        slotval = table[slotval.s.next.num];

        cell = caml_alloc_tuple(2);
        Field(cell, 0) = Val_long(slotval.s.key.num);
        Field(cell, 1) = result;
        result = cell;
      }

      // The tail of the list is special, "next" is really a value.
      cell = caml_alloc_tuple(2);
      Field(cell, 0) = Val_long(slotval.s.next.num);
      Field(cell, 1) = result;
      result = cell;

      // We are done!
      break;
    }
  }

  CAMLreturn(result);
}