func drainBlockServer(putBlockServer pfsclient.BlockAPI_PutBlockServer) {
	for {
		if _, err := putBlockServer.Recv(); err != nil {
			break
		}
	}
}
func (s *localBlockAPIServer) PutBlock(putBlockServer pfsclient.BlockAPI_PutBlockServer) (retErr error) {
	result := &pfsclient.BlockRefs{}
	defer func(start time.Time) { s.Log(nil, result, retErr, time.Since(start)) }(time.Now())
	defer drainBlockServer(putBlockServer)

	putBlockRequest, err := putBlockServer.Recv()
	if err != nil {
		if err != io.EOF {
			return err
		}
		// Allow empty PutBlock requests, in this case we don't create any actual blockRefs
		return putBlockServer.SendAndClose(result)
	}

	reader := bufio.NewReader(&putBlockReader{
		server: putBlockServer,
		buffer: bytes.NewBuffer(putBlockRequest.Value),
	})

	decoder := json.NewDecoder(reader)

	for {
		blockRef, err := s.putOneBlock(putBlockRequest.Delimiter, reader, decoder)
		if err != nil {
			return err
		}
		result.BlockRef = append(result.BlockRef, blockRef)
		if (blockRef.Range.Upper - blockRef.Range.Lower) < uint64(blockSize) {
			break
		}
	}
	return putBlockServer.SendAndClose(result)
}