Function CopyBitfieldBytesToSegments

src/types/redis_bitmap.cc:788–819

}

static rocksdb::Status CopyBitfieldBytesToSegments(engine::Context &ctx, Bitmap::SegmentCacheStore &store,
                                                   const ArrayBitfieldBitmap &bitfield, uint32_t byte_offset,
                                                   uint32_t bytes) {
  uint32_t segment_index = byte_offset / kBitmapSegmentBytes;
  auto segment_byte_offset = static_cast<int>(byte_offset % kBitmapSegmentBytes);
  auto remain_bytes = static_cast<int32_t>(bytes);
  for (; remain_bytes > 0; ++segment_index) {
    std::string *cache = nullptr;
    auto cache_status = store.GetMut(ctx, segment_index, &cache);
    if (!cache_status.ok()) {
      return cache_status;
    }

    auto copy_count = std::min(remain_bytes, static_cast<int32_t>(kBitmapSegmentBytes - segment_byte_offset));
    if (static_cast<int>(cache->size()) < segment_byte_offset + copy_count) {
      cache->resize(segment_byte_offset + copy_count);
    }

    auto dst = reinterpret_cast<uint8_t *>(cache->data()) + segment_byte_offset;
    auto status = bitfield.Get(byte_offset, copy_count, dst);
    if (!status) {
      return rocksdb::Status::InvalidArgument();
    }

    // next segment will copy from its front.
    byte_offset = (segment_index + 1) * kBitmapSegmentBytes;
    // maybe negative, but still correct.
    remain_bytes -= static_cast<int32_t>(kBitmapSegmentBytes - segment_byte_offset);
    segment_byte_offset = 0;
  }
  return rocksdb::Status::OK();
}

template <bool ReadOnly>
rocksdb::Status Bitmap::bitfield(engine::Context &ctx, const Slice &user_key, const std::vector<BitfieldOperation> &ops,