vector_u8 cpc_sketch_alloc::serialize()

in cpc/include/cpc_sketch_impl.hpp [461:516]

• 52 lines of code
• 16 McCabe index (conditional complexity)

vector_u8<A> cpc_sketch_alloc<A>::serialize(unsigned header_size_bytes) const {
  compressed_state<A> compressed(sliding_window.get_allocator());
  compressed.table_data_words = 0;
  compressed.table_num_entries = 0;
  compressed.window_data_words = 0;
  get_compressor<A>().compress(*this, compressed);
  const bool has_hip = !was_merged;
  const bool has_table = compressed.table_data.size() > 0;
  const bool has_window = compressed.window_data.size() > 0;
  const uint8_t preamble_ints = get_preamble_ints(num_coupons, has_hip, has_table, has_window);
  const size_t size = header_size_bytes + (preamble_ints + compressed.table_data_words + compressed.window_data_words) * sizeof(uint32_t);
  vector_u8<A> bytes(size, 0, sliding_window.get_allocator());
  uint8_t* ptr = bytes.data() + header_size_bytes;
  ptr += copy_to_mem(preamble_ints, ptr);
  const uint8_t serial_version = SERIAL_VERSION;
  ptr += copy_to_mem(serial_version, ptr);
  const uint8_t family = FAMILY;
  ptr += copy_to_mem(family, ptr);
  ptr += copy_to_mem(lg_k, ptr);
  ptr += copy_to_mem(first_interesting_column, ptr);
  const uint8_t flags_byte(
    (1 << flags::IS_COMPRESSED)
    | (has_hip ? 1 << flags::HAS_HIP : 0)
    | (has_table ? 1 << flags::HAS_TABLE : 0)
    | (has_window ? 1 << flags::HAS_WINDOW : 0)
  );
  ptr += copy_to_mem(flags_byte, ptr);
  const uint16_t seed_hash = compute_seed_hash(seed);
  ptr += copy_to_mem(seed_hash, ptr);
  if (!is_empty()) {
    ptr += copy_to_mem(num_coupons, ptr);
    if (has_table && has_window) {
      // if there is no window it is the same as number of coupons
      ptr += copy_to_mem(compressed.table_num_entries, ptr);
      // HIP values can be in two different places in the sequence of fields
      // this is the first HIP decision point
      if (has_hip) ptr += copy_hip_to_mem(ptr);
    }
    if (has_table) {
      ptr += copy_to_mem(compressed.table_data_words, ptr);
    }
    if (has_window) {
      ptr += copy_to_mem(compressed.window_data_words, ptr);
    }
    // this is the second HIP decision point
    if (has_hip && !(has_table && has_window)) ptr += copy_hip_to_mem(ptr);
    if (has_window) {
      ptr += copy_to_mem(compressed.window_data.data(), ptr, compressed.window_data_words * sizeof(uint32_t));
    }
    if (has_table) {
      ptr += copy_to_mem(compressed.table_data.data(), ptr, compressed.table_data_words * sizeof(uint32_t));
    }
  }
  if (ptr != bytes.data() + size) throw std::logic_error("serialized size mismatch");
  return bytes;
}