upb/message/accessors.hpp

// Protocol Buffers - Google's data interchange format
// Copyright 2025 Google LLC.  All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd

// This file contains C++ wrappers for the C API in accessors.h.

#ifndef UPB_MESSAGE_ACCESSORS_HPP_
#define UPB_MESSAGE_ACCESSORS_HPP_

#include <cstddef>
#include <cstdint>
#include <string>
#include <vector>

#include "upb/base/string_view.h"
#include "upb/message/accessors.h"
#include "upb/message/array.h"
#include "upb/message/message.h"
#include "upb/mini_table/field.h"

namespace upb {

template <typename T>
T GetMessageBaseField(upb_Message* msg, const upb_MiniTableField* field,
                      T default_value);

#define F(T, Func)                                                           \
  template <>                                                                \
  inline T GetMessageBaseField<T>(                                           \
      upb_Message * msg, const upb_MiniTableField* field, T default_value) { \
    return upb_Message_Get##Func(msg, field, default_value);                 \
  }

F(int32_t, Int32);
F(int64_t, Int64);
F(uint32_t, UInt32);
F(uint64_t, UInt64);
F(float, Float);
F(double, Double);
F(bool, Bool);

#undef F

template <>
inline std::string GetMessageBaseField<std::string>(
    upb_Message* msg, const upb_MiniTableField* field,
    std::string default_value) {
  upb_StringView default_sv = upb_StringView_FromDataAndSize(
      default_value.data(), default_value.size());
  upb_StringView sv = upb_Message_GetString(msg, field, default_sv);
  return std::string(sv.data, sv.size);
}

template <typename T>
T FromMessageValue(upb_MessageValue value);

#define F(type, member)                                        \
  template <>                                                  \
  inline type FromMessageValue<type>(upb_MessageValue value) { \
    return value.member;                                       \
  }

F(bool, bool_val);
F(float, float_val);
F(double, double_val);
F(int32_t, int32_val);
F(int64_t, int64_val);
F(uint32_t, uint32_val);
F(uint64_t, uint64_val);

#undef F

template <>
inline std::string FromMessageValue<std::string>(upb_MessageValue value) {
  return std::string(value.str_val.data, value.str_val.size);
}

template <typename T>
std::vector<T> GetRepeatedField(upb_Message* msg,
                                const upb_MiniTableField* field) {
  std::vector<T> ret;
  const upb_Array* array = upb_Message_GetArray(msg, field);
  if (!array) return ret;
  size_t size = upb_Array_Size(array);
  ret.reserve(size);
  for (size_t i = 0; i < size; i++) {
    ret.push_back(FromMessageValue<T>(upb_Array_Get(array, i)));
  }
  return ret;
}

}  // namespace upb

#endif  // UPB_MESSAGE_ACCESSORS_HPP_