soa/logger/rotating_output.h

/* rotating_output.h                                               -*- C++ -*-
   Jeremy Barnes, 19 September 2012
   Copyright (c) 2012 Datacratic.  All rights reserved.

   Output that writes to an output source and rotates it.
*/

#ifndef __logger__rotating_output_h__
#define __logger__rotating_output_h__

#include "logger.h"
#include "soa/types/date.h"
#include <boost/thread/recursive_mutex.hpp>
#include "soa/types/periodic_utils.h"
#include "soa/gc/rcu_protected.h"

namespace Datacratic {


/*****************************************************************************/
/* ROTATING OUTPUT                                                           */
/*****************************************************************************/

struct RotatingOutput : public LogOutput {

    RotatingOutput();

    virtual ~RotatingOutput();
    
    void open(const std::string & periodPattern);

    virtual void performRotation();

    virtual void close();

protected:
    typedef boost::recursive_mutex Lock;
    mutable Lock lock;
    typedef boost::unique_lock<Lock> Guard;

    TimeGranularity granularity;
    int number;

    Date currentPeriodStart;  
    double interval;   

    virtual void openSubordinate(Date newDate) = 0;
    
    virtual void rotateSubordinate(Date newDate) = 0;

    virtual void closeSubordinate() = 0;
    
private:
    boost::scoped_ptr<boost::thread> rotateThread;

    volatile int shutdown_;

    volatile int up_;

    void runRotateThread();
};


/*****************************************************************************/
/* ROTATING OUTPUT ADAPTOR                                                   */
/*****************************************************************************/

struct RotatingOutputAdaptor : public RotatingOutput {
    typedef std::function<LogOutput * (std::string)>
        LoggerFactory;

    RotatingOutputAdaptor(LoggerFactory factory);

    virtual ~RotatingOutputAdaptor();

    
    void open(const std::string & filenamePattern,
              const std::string & periodPattern);
    
    virtual void logMessage(const std::string & channel,
                            const std::string & message);
    
    virtual Json::Value stats() const;

    virtual void clearStats();

    virtual void close();

    boost::function<void (std::string)> onPreFileOpen;
    boost::function<void (std::string)> onPostFileOpen;
    boost::function<void (std::string)> onPreFileClose;
    boost::function<void (std::string)> onPostFileClose;
    boost::function<void (std::string, std::size_t)> onFileWrite;

    boost::function<void (std::string, std::string)> onBeforeLogRotation;
    boost::function<void (std::string, std::string)> onAfterLogRotation;

private:
    LoggerFactory loggerFactory;

    std::string filenamePattern;

    GcLock gcLock;

    RcuProtected<LogOutput> logger;

    std::string currentFilename;

    virtual void openSubordinate(Date newDate);

    virtual void rotateSubordinate(Date newDate);

    virtual void closeSubordinate();
};


} // namespace Datacratic

#endif /* __logger__rotating_output_h__ */