json_util.h

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// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.  All rights reserved.
// https://developers.google.com/protocol-buffers/
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// Utility functions to convert between protobuf binary format and proto3 JSON
// format.
#ifndef GOOGLE_PROTOBUF_UTIL_JSON_UTIL_H__
#define GOOGLE_PROTOBUF_UTIL_JSON_UTIL_H__

#include <google/protobuf/util/type_resolver.h>
#include <google/protobuf/stubs/bytestream.h>

namespace google {
namespace protobuf {
namespace io {
class ZeroCopyInputStream;
class ZeroCopyOutputStream;
}  // namespace io
namespace util {

struct JsonOptions {
  // Whether to add spaces, line breaks and indentation to make the JSON output
  // easy to read.
  bool add_whitespace;
  // Whether to always print primitive fields. By default primitive fields with
  // default values will be omitted in JSON joutput. For example, an int32 field
  // set to 0 will be omitted. Set this flag to true will override the default
  // behavior and print primitive fields regardless of their values.
  bool always_print_primitive_fields;

  JsonOptions() : add_whitespace(false),
                  always_print_primitive_fields(false) {
  }
};

// Converts protobuf binary data to JSON.
// The conversion will fail if:
//   1. TypeResolver fails to resolve a type.
//   2. input is not valid protobuf wire format, or conflicts with the type
//      information returned by TypeResolver.
// Note that unknown fields will be discarded silently.
util::Status BinaryToJsonStream(
    TypeResolver* resolver,
    const string& type_url,
    io::ZeroCopyInputStream* binary_input,
    io::ZeroCopyOutputStream* json_output,
    const JsonOptions& options);

inline util::Status BinaryToJsonStream(
    TypeResolver* resolver, const string& type_url,
    io::ZeroCopyInputStream* binary_input,
    io::ZeroCopyOutputStream* json_output) {
  return BinaryToJsonStream(resolver, type_url, binary_input, json_output,
                            JsonOptions());
}

LIBPROTOBUF_EXPORT util::Status BinaryToJsonString(
    TypeResolver* resolver,
    const string& type_url,
    const string& binary_input,
    string* json_output,
    const JsonOptions& options);

inline util::Status BinaryToJsonString(TypeResolver* resolver,
                                         const string& type_url,
                                         const string& binary_input,
                                         string* json_output) {
  return BinaryToJsonString(resolver, type_url, binary_input, json_output,
                            JsonOptions());
}

// Converts JSON data to protobuf binary format.
// The conversion will fail if:
//   1. TypeResolver fails to resolve a type.
//   2. input is not valid JSON format, or conflicts with the type
//      information returned by TypeResolver.
//   3. input has unknown fields.
util::Status JsonToBinaryStream(
    TypeResolver* resolver,
    const string& type_url,
    io::ZeroCopyInputStream* json_input,
    io::ZeroCopyOutputStream* binary_output);

LIBPROTOBUF_EXPORT util::Status JsonToBinaryString(
    TypeResolver* resolver,
    const string& type_url,
    const string& json_input,
    string* binary_output);

namespace internal {
// Internal helper class. Put in the header so we can write unit-tests for it.
class LIBPROTOBUF_EXPORT ZeroCopyStreamByteSink : public strings::ByteSink {
 public:
  explicit ZeroCopyStreamByteSink(io::ZeroCopyOutputStream* stream)
      : stream_(stream) {}

  virtual void Append(const char* bytes, size_t len);

 private:
  io::ZeroCopyOutputStream* stream_;

  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(ZeroCopyStreamByteSink);
};
}  // namespace internal

}  // namespace util
}  // namespace protobuf

}  // namespace google
#endif  // GOOGLE_PROTOBUF_UTIL_JSON_UTIL_H__