stream_logger.hpp

#ifndef STAN_CALLBACKS_STREAM_LOGGER_HPP
#define STAN_CALLBACKS_STREAM_LOGGER_HPP

#include <stan/callbacks/logger.hpp>
#include <ostream>
#include <string>
#include <sstream>

namespace stan {
namespace callbacks {

/**
 * <code>stream_logger</code> is an implementation of
 * <code>logger</code> that writes messages to separate
 * std::stringstream outputs.
 */
class stream_logger final : public logger {
 private:
  std::ostream& debug_;
  std::ostream& info_;
  std::ostream& warn_;
  std::ostream& error_;
  std::ostream& fatal_;

 public:
  /**
   * Constructs a <code>stream_logger</code> with an output
   * stream for each log level.
   *
   * @param[in,out] debug stream to output debug messages
   * @param[in,out] info stream to output info messages
   * @param[in,out] warn stream to output warn messages
   * @param[in,out] error stream to output error messages
   * @param[in,out] fatal stream to output fatal messages
   */
  stream_logger(std::ostream& debug, std::ostream& info, std::ostream& warn,
                std::ostream& error, std::ostream& fatal)
      : debug_(debug), info_(info), warn_(warn), error_(error), fatal_(fatal) {}

  void debug(const std::string& message) { debug_ << message << std::endl; }

  void debug(const std::stringstream& message) {
    debug_ << message.str() << std::endl;
  }

  void info(const std::string& message) { info_ << message << std::endl; }

  void info(const std::stringstream& message) {
    if (message.str().length() > 0)
      info_ << message.str() << std::endl;
  }

  void warn(const std::string& message) { warn_ << message << std::endl; }

  void warn(const std::stringstream& message) {
    warn_ << message.str() << std::endl;
  }

  void error(const std::string& message) { error_ << message << std::endl; }

  void error(const std::stringstream& message) {
    error_ << message.str() << std::endl;
  }

  void fatal(const std::string& message) { fatal_ << message << std::endl; }

  void fatal(const std::stringstream& message) {
    fatal_ << message.str() << std::endl;
  }
};

}  // namespace callbacks
}  // namespace stan
#endif