Method EncodeProtoOp

tensorflow/core/kernels/encode_proto_op.cc:461–504

class EncodeProtoOp : public OpKernel {
 public:
  explicit EncodeProtoOp(OpKernelConstruction* context) : OpKernel(context) {
    string descriptor_source;
    OP_REQUIRES_OK(context,
                   context->GetAttr("descriptor_source", &descriptor_source));
    // We always get back a desc_pool, but we may not own it. If we own it,
    // owned_desc_pool_ will be filled in.
    DescriptorPool const* desc_pool;
    OP_REQUIRES_OK(context, GetDescriptorPool(context->env(), descriptor_source,
                                              &desc_pool, &owned_desc_pool_));

    string message_type;
    OP_REQUIRES_OK(context, context->GetAttr("message_type", &message_type));
    const Descriptor* message_desc =
        desc_pool->FindMessageTypeByName(message_type);
    OP_REQUIRES(context, message_desc != nullptr,
                errors::InvalidArgument("No descriptor found for message type ",
                                        message_type));

    OP_REQUIRES_OK(context, context->GetAttr("field_names", &field_names_));

    // Gather the field descriptors for the given field_names.
    field_descs_.resize(field_names_.size());
    for (int i = 0; i < field_names_.size(); i++) {
      const string& name = field_names_[i];
      auto field_desc = message_desc->FindFieldByName(name);
      OP_REQUIRES(context, field_desc != nullptr,
                  errors::InvalidArgument("Unknown field: ", name,
                                          " in message type ", message_type));

      field_descs_[i] = field_desc;
    }

    // Build a list of indices into field_descs sorted by increasing
    // field_number. This will be used to output fields in sorted order,
    // which is strongly encouraged when serializing protobufs.
    sorted_field_index_.resize(field_names_.size());
    // Start with the fields sorted by current index.
    for (int i = 0; i < field_names_.size(); i++) sorted_field_index_[i] = i;
    // Then sort the field indices by their proto field number.
    std::sort(sorted_field_index_.begin(), sorted_field_index_.end(),
              [this](int a, int b) -> bool {
                return field_descs_[a]->number() < field_descs_[b]->number();
              });
  }

  void Compute(OpKernelContext* ctx) override {
    const Tensor* sizes_tensor;