cachemanager.cxx

vovida的软交换

/* ====================================================================
 * The Vovida Software License, Version 1.0 
 * 
 * Copyright (c) 2000 Vovida Networks, Inc.  All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 
 * 3. The names "VOCAL", "Vovida Open Communication Application Library",
 *    and "Vovida Open Communication Application Library (VOCAL)" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact [e-mail].
 *
 * 4. Products derived from this software may not be called "VOCAL", nor
 *    may "VOCAL" appear in their name, without prior written
 *    permission of Vovida Networks, Inc.
 * 
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE AND
 * NON-INFRINGEMENT ARE DISCLAIMED.  IN NO EVENT SHALL VOVIDA
 * NETWORKS, INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT DAMAGES
 * IN EXCESS OF $1,000, NOR FOR ANY INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 * 
 * ====================================================================
 * 
 * This software consists of voluntary contributions made by Vovida
 * Networks, Inc. and many individuals on behalf of Vovida Networks,
 * Inc.  For more information on Vovida Networks, Inc., please see
 * <http://www.vovida.org/>.
 *
 */
 
 
/**
 * CacheManager.cxx -- 13/03/03
 *
 * This class provides a seperate thread that keeps watch on the current cache
 * and removes any old objects
 */

// Include the standard vocal thread interface
#include "ThreadIf.hxx" 
#include "CacheManager.hxx"
#include "Record.hxx"
#include "cpLog.h"

#include <ctime>
#include <unistd.h>

void CacheManager::thread() { 

  int sleepTime = 0;

  cpLog(LOG_DEBUG, "Starting CacheManager thread");

  while (!(isShutdown())) { 

    // Sleep for a second, this ensures that the shutdown command will not
    // block for too long
    sleep(1); sleepTime ++;

    // Check if it's time for an update
    if (sleepTime > CACHE_MANAGER_WAIT) { 
      sleepTime = 0;
    
      int size = myCache->size();
    
      if (size > CACHE_RECORD_LIMIT) { 
	// We need to purge the oldest records from the cache
	cpLog(LOG_DEBUG,
	      "Cache has %d elements, limit is %d, starting purge",
	      size, CACHE_RECORD_LIMIT);

	if (CACHE_RECORD_VALIDITY == 0) {
	  // Records never expire 
	  myCache->purge();
	} else { 
	  // Supply the expiry time for records as well
	  myCache->purge( (time(NULL) - CACHE_RECORD_VALIDITY) );
	}
	
	// Force another check next second
	sleepTime = CACHE_MANAGER_WAIT;
      }
    
    }
  }

} 
  

CacheManager::~CacheManager() {
  shutdown();
  cpLog(LOG_DEBUG, "Joing CacheManager thread waiting for shutdown");
  join();
  cpLog(LOG_DEBUG, "CacheManager thread shutdown");
}