Function WrapStringTensorAsEvents

tensorflow/core/debug/debug_io_utils.cc:128–181

Breaks a string Tensor (represented as a TensorProto) as a vector of Event protos.

// Breaks a string Tensor (represented as a TensorProto) as a vector of Event
// protos.
Status WrapStringTensorAsEvents(const DebugNodeKey& debug_node_key,
                                const uint64 wall_time_us,
                                const size_t chunk_size_limit,
                                TensorProto* tensor_proto,
                                std::vector<Event>* events) {
  const protobuf::RepeatedPtrField<string>& strs = tensor_proto->string_val();
  const size_t num_strs = strs.size();
  const size_t chunk_size_ub = chunk_size_limit > 0
                                   ? chunk_size_limit
                                   : std::numeric_limits<size_t>::max();

  // E.g., if cutoffs is {j, k, l}, the chunks will have index ranges:
  //   [0:a), [a:b), [c:<end>].
  std::vector<size_t> cutoffs;
  size_t chunk_size = 0;
  for (size_t i = 0; i < num_strs; ++i) {
    // Take into account the extra bytes in proto buffer.
    if (StringValMaxBytesInProto(strs[i]) > chunk_size_ub) {
      return errors::FailedPrecondition(
          "string value at index ", i, " from debug node ",
          debug_node_key.debug_node_name,
          " does not fit gRPC message size limit (", chunk_size_ub, ")");
    }
    if (chunk_size + StringValMaxBytesInProto(strs[i]) > chunk_size_ub) {
      cutoffs.push_back(i);
      chunk_size = 0;
    }
    chunk_size += StringValMaxBytesInProto(strs[i]);
  }
  cutoffs.push_back(num_strs);
  const size_t num_chunks = cutoffs.size();

  for (size_t i = 0; i < num_chunks; ++i) {
    Event event = PrepareChunkEventProto(debug_node_key, wall_time_us,
                                         num_chunks, i, tensor_proto->dtype(),
                                         tensor_proto->tensor_shape());
    Summary::Value* value = event.mutable_summary()->mutable_value(0);

    if (cutoffs.size() == 1) {
      value->mutable_tensor()->mutable_string_val()->Swap(
          tensor_proto->mutable_string_val());
    } else {
      const size_t begin = (i == 0) ? 0 : cutoffs[i - 1];
      const size_t end = cutoffs[i];
      for (size_t j = begin; j < end; ++j) {
        value->mutable_tensor()->add_string_val(strs[j]);
      }
    }

    events->push_back(std::move(event));
  }

  return Status::OK();
}

// Encapsulates the tensor value inside a vector of Event protos. Large tensors
// are broken up to multiple protos to fit the chunk_size_limit. In each Event