onnxruntime/server/http/json_handling.cc

// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License.

#include <sstream>
#include <iomanip>

#include <boost/beast/core.hpp>
#include <google/protobuf/util/json_util.h>

#include "predict.pb.h"
#include "json_handling.h"

namespace protobufutil = google::protobuf::util;

namespace onnxruntime {
namespace server {

protobufutil::Status GetRequestFromJson(const std::string& json_string, /* out */ onnxruntime::server::PredictRequest& request) {
  protobufutil::JsonParseOptions options;
  options.ignore_unknown_fields = true;

  protobufutil::Status result = JsonStringToMessage(json_string, &request, options);
  return result;
}

protobufutil::Status GenerateResponseInJson(const onnxruntime::server::PredictResponse& response, /* out */ std::string& json_string) {
  protobufutil::JsonPrintOptions options;
  options.add_whitespace = false;
  options.always_print_primitive_fields = false;
  options.always_print_enums_as_ints = false;
  options.preserve_proto_field_names = false;

  protobufutil::Status result = MessageToJsonString(response, &json_string, options);
  return result;
}

std::string CreateJsonError(const http::status error_code, const std::string& error_message) {
  auto escaped_message = escape_string(error_message);
  return R"({"error_code": )" + std::to_string(int(error_code)) + R"(, "error_message": ")" + escaped_message + R"("})" + "\n";
}

std::string escape_string(const std::string& message) {
  std::ostringstream o;
  for (char c : message) {
    switch (c) {
      case '"':
        o << "\\\"";
        break;
      case '\\':
        o << "\\\\";
        break;
      case '\b':
        o << "\\b";
        break;
      case '\f':
        o << "\\f";
        break;
      case '\n':
        o << "\\n";
        break;
      case '\r':
        o << "\\r";
        break;
      case '\t':
        o << "\\t";
        break;
      default:
        if ('\x00' <= c && c <= '\x1f') {
          o << "\\u"
            << std::hex << std::setw(4) << std::setfill('0') << (int)c;
        } else {
          o << c;
        }
    }
  }
  return o.str();
}

}  // namespace server
}  // namespace onnxruntime