assertLockHeld(p.mheapLock)

	// If the searchAddr refers to a region which has a higher address than
	// any known chunk, then we know we're out of memory.
	if chunkIndex(p.searchAddr.addr()) >= p.end {
		return pageCache{}
	}
	c := pageCache{}
	ci := chunkIndex(p.searchAddr.addr()) // chunk index
	var chunk *pallocData
	if p.summary[len(p.summary)-1][ci] != 0 {
		// Fast path: there's free pages at or near the searchAddr address.

		// Fast path: we're clearing a single bit, and we know exactly
		// where it is, so mark it directly.
		i := chunkIndex(base)
		pi := chunkPageIndex(base)
		p.chunkOf(i).free1(pi)
		p.scav.index.free(i, pi, 1)
	} else {
		// Slow path: we're clearing more bits so we may need to iterate.
		sc, ec := chunkIndex(base), chunkIndex(limit)
		si, ei := chunkPageIndex(base), chunkPageIndex(limit)

		if sc == ec {

	// because it comes from the OS, so it's sufficient to align the
	// index.
	haveMin := s.min.Load()
	haveMax := s.max.Load()
	needMin := alignDown(uintptr(chunkIndex(base)), physPageSize/scSize)
	needMax := alignUp(uintptr(chunkIndex(limit)), physPageSize/scSize)

	// We need a contiguous range, so extend the range if there's no overlap.
	if needMax < haveMin {
		needMax = haveMin
	}

}

func (s *ScavengeIndex) Find(force bool) (ChunkIdx, uint) {
	ci, off := s.i.find(force)
	return ChunkIdx(ci), off
}

func (s *ScavengeIndex) AllocRange(base, limit uintptr) {
	sc, ec := chunkIndex(base), chunkIndex(limit-1)
	si, ei := chunkPageIndex(base), chunkPageIndex(limit-1)

	if sc == ec {
		// The range doesn't cross any chunk boundaries.
		s.i.alloc(sc, ei+1-si)
	} else {

	// Update minHeapIdx. Note that even if there's no mapping work to do,
	// we may still have a new, lower minimum heap address.
	minHeapIdx := s.minHeapIdx.Load()
	if baseIdx := uintptr(chunkIndex(base)); minHeapIdx == 0 || baseIdx < minHeapIdx {
		s.minHeapIdx.Store(baseIdx)
	}
	return s.sysGrow(base, limit, sysStat)
}

  std::string expected_pruned_chunked_message_text_proto = R"pb(
    chunk_index: 0
    chunked_fields {
      field_tag { field: 1 }
      message { chunk_index: 1 }
    }
    chunked_fields {
      field_tag { field: 7 }
      field_tag { map_key { boolean: true } }
      message { chunk_index: 2 }
    }
  )pb";
  ChunkedMessage expected_pruned_chunked_message;

  Type new_element_type =
      IntegerType::get(attr.getContext(), storage_bit_width_);
  return attr.mapValues(new_element_type, [&](const APFloat &old) {
    int chunk_index = flatten_index / chunk_size;
    flatten_index++;
    return converters[chunk_index % dim_size].quantizeFloatToInt(old);
  });
}

          std::string chunk,
          ReadChunk(reader, chunks_info[chunked_message.chunk_index()]));
      field_checksum = FingerprintCat64(field_checksum, Fingerprint64(chunk));
    } else if (matches == field_tags.size()) {
      // chunked_field_tags are an exact match, but chunked_field is further
      // broken down into separate chunked_fields (no chunk_index). Hash those
      // chunked_fields.
      TF_ASSIGN_OR_RETURN(uint64_t hash,