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#ifndef MOZC_BASE_SYNC_LOGGER_H_
#define MOZC_BASE_SYNC_LOGGER_H_

#include <iostream>
#include <string>
#include "base/base.h"
#include "base/util.h"

namespace mozc {
namespace sync {

// We provide mozc::sync::Logging module separately from the
// mozc::Logging module.
// Syncer is doing lots of complicated operations and users might
// encounter unexceptional behaviors depending on the server status,
// storage status/size, and config settings. We will receive many error
// reports in our U2U. To make a prompt reply and quick investigation of
// the cause of errors happening on the user environments, logging is
// "must" feature.
//
// sync::Logging provides a logging interface for syncer module.
// Useally, the following macro can be used for logging any actions
// of syncer modules
//
// SYNC_VLOG(1) << "Sync started";
// SYNC_VLOG(2) << "Downloaded: " << remote_proto->DebugString();
//
// The log file is generated at <user_profile_dir>/sync.log
// The verbose level is saved in FLAGS_sync_verbose_level now.
// TODO(taku): better to move this parameter to config.

class Logging {
 public:
  // Get logging stream. The log message can be written to the stream
  static ostream &GetLogStream();

  // return config.sync_verbose_level()
  static int GetVerboseLevel();

  // return the filename of sync logging.
  static string GetLogFileName();

  // clear the contents of logging file and recreate it.
  // This method is used in unittesting.
  static void Reset();
};

class LogFinalizer {
 public:
  LogFinalizer() {}
  ~LogFinalizer();

  void operator&(ostream&) {}
};
}  // sync
}  // mozc

#define SYNC_VLOG(verboselevel) \
 (mozc::sync::Logging::GetVerboseLevel() < (verboselevel)) ? (void) 0 : \
 mozc::sync::LogFinalizer() & mozc::sync::Logging::GetLogStream() \
 << mozc::Logging::GetLogMessageHeader() << " " \
 << mozc::Util::Basename(__FILE__) << "(" << __LINE__ << ") "

#endif  // MOZC_BASE_SYNC_LOGGER_H_