log.h

/* Copyright (C) 2020-2021 IBM Corp.
 * This program is 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. See accompanying LICENSE file.
 */
 
#ifndef HELIB_LOG_H
#define HELIB_LOG_H
 
#include <iomanip>
#include <ctime>
#include <ostream>
#include <sstream>
#include <string>
 
namespace helib {
 
class Logger
{
private:
  // A stream pointer to be set for the logs to go to.
  std::ostream* logStream_p;
 
public:
  void setLogToStderr();
 
  void setLogToFile(const std::string& filepath, bool overwrite = false);
 
  Logger() = default;
 
  Logger(const Logger& other) = default;
 
  Logger(Logger&& other) = default;
 
  Logger& operator=(Logger& other) = default;
 
  Logger& operator=(Logger&& other) = default;
 
  ~Logger();
 
  friend inline void Warning(const char* msg);
};
 
extern Logger helog;
 
inline const std::string timestamp()
{
  auto t = std::time(nullptr);
  auto now = *std::localtime(&t);
  std::ostringstream oss;
  oss << std::put_time(&now, "[ %T ]");
  return oss.str();
}
 
inline void Warning(const char* msg)
{
  *helog.logStream_p << timestamp() << " WARNING: " << msg << std::endl;
}
 
inline void Warning(const std::string& msg) { Warning(msg.c_str()); }
 
// Errors should raise exceptions through throw or assertion functions
// in helib/assertions.h
 
// TODO Info Debug
// inline void Info(const std::string& msg)
// inline void Debug(const std::string& msg)
 
} // namespace helib
 
#endif // ifndef HELIB_LOG_H