Format.h

/*
 * Copyright (C) 2019 HERE Europe B.V.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * SPDX-License-Identifier: Apache-2.0
 * License-Filename: LICENSE
 */
 
#pragma once
 
#include <olp/core/CoreApi.h>
 
#include <chrono>
#include <cstdarg>
#include <string>
#include <vector>
 
#if (defined(__GNUC__) || defined(__clang__))
#define CHECK_PRINTF_FORMAT_STRING(format_string_pos, first_to_check) \
  __attribute__((format(printf, (format_string_pos), (first_to_check))))
#else
#define CHECK_PRINTF_FORMAT_STRING(format_string_pos, first_to_check)
#endif
 
namespace olp {
namespace logging {
using TimePoint = std::chrono::time_point<std::chrono::system_clock>;
 
CORE_API std::string format(const char* formatStr, ...)
    CHECK_PRINTF_FORMAT_STRING(1, 2);
 
CORE_API std::string formatv(const char* formatStr, va_list args);
 
CORE_API std::string formatLocalTime(const TimePoint& timestamp);
 
CORE_API std::string formatLocalTime(const TimePoint& timestamp,
                                     const char* formatStr);
 
CORE_API std::string formatUtcTime(const TimePoint& timestamp);
 
CORE_API std::string formatUtcTime(const TimePoint& timestamp,
                                   const char* formatStr);
 
class CORE_API FormatBuffer {
 public:
  FormatBuffer() = default;
 
  const char* format(const char* formatStr, ...)
      CHECK_PRINTF_FORMAT_STRING(2, 3);
 
  const char* formatv(const char* formatStr, va_list args);
 
  const char* formatLocalTime(const TimePoint& timestamp);
 
  const char* formatLocalTime(const TimePoint& timestamp,
                              const char* formatStr);
 
  const char* formatUtcTime(const TimePoint& timestamp);
 
  const char* formatUtcTime(const TimePoint& timestamp, const char* formatStr);
 
 private:
  friend std::string logging::formatv(const char* formatStr, va_list args);
 
  const char* formatTm(const struct tm& timestampTm, const char* formatStr);
 
  static const unsigned int bufferSize = 256;
  char m_buffer[bufferSize]{};
  std::vector<char> m_auxBuffer;
};
 
}  // namespace logging
}  // namespace olp