Function EndTable

Libs/flatbuffers/flatbuffers.h:1518–1580

This finishes one serialized object by generating the vtable if it's a table, comparing it against existing vtables, and writing the resulting vtable offset.

  // table, comparing it against existing vtables, and writing the
  // resulting vtable offset.
  uoffset_t EndTable(uoffset_t start) {
    // If you get this assert, a corresponding StartTable wasn't called.
    FLATBUFFERS_ASSERT(nested);
    // Write the vtable offset, which is the start of any Table.
    // We fill it's value later.
    auto vtableoffsetloc = PushElement<soffset_t>(0);
    // Write a vtable, which consists entirely of voffset_t elements.
    // It starts with the number of offsets, followed by a type id, followed
    // by the offsets themselves. In reverse:
    // Include space for the last offset and ensure empty tables have a
    // minimum size.
    max_voffset_ =
        (std::max)(static_cast<voffset_t>(max_voffset_ + sizeof(voffset_t)),
                   FieldIndexToOffset(0));
    buf_.fill_big(max_voffset_);
    auto table_object_size = vtableoffsetloc - start;
    // Vtable use 16bit offsets.
    FLATBUFFERS_ASSERT(table_object_size < 0x10000);
    WriteScalar<voffset_t>(buf_.data() + sizeof(voffset_t),
                           static_cast<voffset_t>(table_object_size));
    WriteScalar<voffset_t>(buf_.data(), max_voffset_);
    // Write the offsets into the table
    for (auto it = buf_.scratch_end() - num_field_loc * sizeof(FieldLoc);
         it < buf_.scratch_end(); it += sizeof(FieldLoc)) {
      auto field_location = reinterpret_cast<FieldLoc *>(it);
      auto pos = static_cast<voffset_t>(vtableoffsetloc - field_location->off);
      // If this asserts, it means you've set a field twice.
      FLATBUFFERS_ASSERT(
          !ReadScalar<voffset_t>(buf_.data() + field_location->id));
      WriteScalar<voffset_t>(buf_.data() + field_location->id, pos);
    }
    ClearOffsets();
    auto vt1 = reinterpret_cast<voffset_t *>(buf_.data());
    auto vt1_size = ReadScalar<voffset_t>(vt1);
    auto vt_use = GetSize();
    // See if we already have generated a vtable with this exact same
    // layout before. If so, make it point to the old one, remove this one.
    if (dedup_vtables_) {
      for (auto it = buf_.scratch_data(); it < buf_.scratch_end();
           it += sizeof(uoffset_t)) {
        auto vt_offset_ptr = reinterpret_cast<uoffset_t *>(it);
        auto vt2 = reinterpret_cast<voffset_t *>(buf_.data_at(*vt_offset_ptr));
        auto vt2_size = ReadScalar<voffset_t>(vt2);
        if (vt1_size != vt2_size || 0 != memcmp(vt2, vt1, vt1_size)) continue;
        vt_use = *vt_offset_ptr;
        buf_.pop(GetSize() - vtableoffsetloc);
        break;
      }
    }
    // If this is a new vtable, remember it.
    if (vt_use == GetSize()) { buf_.scratch_push_small(vt_use); }
    // Fill the vtable offset we created above.
    // The offset points from the beginning of the object to where the
    // vtable is stored.
    // Offsets default direction is downward in memory for future format
    // flexibility (storing all vtables at the start of the file).
    WriteScalar(buf_.data_at(vtableoffsetloc),
                static_cast<soffset_t>(vt_use) -