LogHandler.hpp

/*
   Copyright (C) 2003-2006, 2008 MySQL AB, 2008 Sun Microsystems, Inc.
    All rights reserved. Use is subject to license terms.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
*/

#ifndef LOGHANDLER_H
#define LOGHANDLER_H

#include "Logger.hpp"

class LogHandler
{
public:  
  LogHandler();
  
  virtual ~LogHandler();

  virtual const char* handler_type() {return "NONE";};

  virtual bool open() = 0;

  virtual bool close() = 0;

  virtual bool is_open() = 0;

  void append(const char* pCategory, Logger::LoggerLevel level,
              const char* pMsg);
  void append_impl(const char* pCategory, Logger::LoggerLevel level,
                   const char* pMsg);

  const char* getDefaultHeader(char* pStr, const char* pCategory, 
                               Logger::LoggerLevel level) const;
  
  const char* getDefaultFooter() const;
  
  const char* getDateTimeFormat() const;

  void setDateTimeFormat(const char* pFormat);
  
  int getErrorCode() const;

  void setErrorCode(int code);

  char* getErrorStr();

  void setErrorStr(const char* str);

  bool parseParams(const BaseString &params);

  virtual bool setParam(const BaseString &param, const BaseString &value) = 0;

  virtual bool checkParams();

  /*
   * Set repeat frequency, 0 means disable special repeated message handling
   */
  virtual void setRepeatFrequency(unsigned val);

  virtual bool getParams(BaseString &config) {return false;};

  virtual off_t getCurrentSize() {return -1;};
  virtual off_t getMaxSize() {return -1;};

protected:
  STATIC_CONST( MAX_DATE_TIME_HEADER_LENGTH = 64 );
  STATIC_CONST( MAX_HEADER_LENGTH = 128 );
  STATIC_CONST( MAX_FOOTER_LENGTH = 128 );

  virtual void writeHeader(const char* category, Logger::LoggerLevel level) = 0;

  virtual void writeMessage(const char* pMsg) = 0;

  virtual void writeFooter() = 0;
  
private: 
  char* getTimeAsString(char* pStr) const;
  time_t m_now;

  LogHandler(const LogHandler&);
  LogHandler* operator = (const LogHandler&);
  bool operator == (const LogHandler&);

  const char* m_pDateTimeFormat;
  int m_errorCode;
  char* m_errorStr;

  // for handling repeated messages
  unsigned m_count_repeated_messages;
  unsigned m_max_repeat_frequency;
  time_t m_last_log_time;
  char m_last_category[MAX_HEADER_LENGTH];
  char m_last_message[MAX_LOG_MESSAGE_SIZE];
  Logger::LoggerLevel m_last_level;
};

#endif