Function write_map_data_slow

cpp/fory/serialization/map_serializer.h:214–554

/// This is the versatile slow path that handles all edge cases
template <typename K, typename V, typename MapType>
inline void write_map_data_slow(const MapType &map, WriteContext &ctx,
                                bool has_generics) {
  // write total length
  ctx.write_var_uint32(static_cast<uint32_t>(map.size()));

  if (map.empty()) {
    return;
  }

  // Type characteristics
  constexpr bool key_is_polymorphic = is_polymorphic_v<K>;
  constexpr bool val_is_polymorphic = is_polymorphic_v<V>;
  constexpr bool key_is_shared_ref = is_shared_ref_v<K>;
  constexpr bool val_is_shared_ref = is_shared_ref_v<V>;

  const bool is_key_declared =
      has_generics && !need_to_write_type_for_field<K>();
  const bool is_val_declared =
      has_generics && !need_to_write_type_for_field<V>();

  // State for chunked writing
  size_t header_offset = 0;
  uint8_t pair_counter = 0;
  bool need_write_header = true;

  // Track current chunk's types for polymorphic handling
  const TypeInfo *current_key_type_info = nullptr;
  const TypeInfo *current_val_type_info = nullptr;

  for (const auto &[key, value] : map) {
    // Check if key or value is null (for nullable types: optional, shared_ptr,
    // unique_ptr, weak_ptr)
    bool key_is_none = false;
    bool value_is_none = false;
    if constexpr (is_nullable_v<K>) {
      key_is_none = is_null_value(key);
    }
    if constexpr (is_nullable_v<V>) {
      value_is_none = is_null_value(value);
    }

    // Handle null entries - write as separate single-entry chunks
    if (key_is_none || value_is_none) {
      // Finish current chunk if any
      if (pair_counter > 0) {
        write_chunk_size(ctx, header_offset, pair_counter);
        ctx.exit_flush_barrier();
        pair_counter = 0;
        need_write_header = true;
      }

      if (key_is_none && value_is_none) {
        ctx.write_uint8(KEY_NULL | VALUE_NULL);
        continue;
      } else if (value_is_none) {
        // Non-null key, null value
        // Java writes: chunk_header, then ref_flag, then type_info, then data
        uint8_t chunk_header = VALUE_NULL;