/**************************************************************************************
* Copyright (c) Jonas Bon�r, Alexandre Vasseur. All rights reserved. *
* http://aspectwerkz.codehaus.org *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the LGPL license *
* a copy of which has been included with this distribution in the license.txt file. *
**************************************************************************************/
package examples.attribdef.caching;
import java.util.HashMap;
import java.util.Map;
import org.codehaus.aspectwerkz.attribdef.Pointcut;
import org.codehaus.aspectwerkz.attribdef.aspect.Aspect;
import org.codehaus.aspectwerkz.joinpoint.JoinPoint;
import org.codehaus.aspectwerkz.joinpoint.MethodJoinPoint;
import org.codehaus.aspectwerkz.joinpoint.CallerSideJoinPoint;
/**
* @Aspect perInstance
*
* @author <a href="mailto:jboner@codehaus.org">Jonas Bon�r</a>
*/
public class CachingAspect extends Aspect {
// ============ Pointcuts ============
/**
* @Call examples.attribdef.caching.*->int examples.attribdef.caching.Pi.getPiDecimal(int)
*/
Pointcut invocationCount;
/**
* @Execution int examples.attribdef.caching.Pi.getPiDecimal(int)
*/
Pointcut methodsToCache;
// ============ Advices ============
/**
* @Before invocationCount
*/
public void invocationCounter(final JoinPoint joinPoint) throws Throwable {
CallerSideJoinPoint jp = (CallerSideJoinPoint)joinPoint;
CacheStatistics.addMethodInvocation(
jp.getCalleeMethodName(),
jp.getCalleeMethodParameterTypes());
joinPoint.proceed();
}
/**
* @Around methodsToCache
*/
public Object cache(final JoinPoint joinPoint) throws Throwable {
MethodJoinPoint jp = (MethodJoinPoint)joinPoint;
final Long hash = new Long(calculateHash(jp));
final Object cachedResult = m_cache.get(hash);
if (cachedResult != null) {
System.out.println("using cache");
CacheStatistics.addCacheInvocation(jp.getMethodName(), jp.getParameterTypes());
System.out.println("parameter: timeout = " + ___AW_getParameter("timeout"));
return cachedResult;
}
final Object result = joinPoint.proceed();
m_cache.put(hash, result);
return result;
}
// ============ Utility methods ============
private long calculateHash(final MethodJoinPoint jp) {
int result = 17;
result = 37 * result + jp.getMethodName().hashCode();
Object[] parameters = jp.getParameters();
for (int i = 0, j = parameters.length; i < j; i++) {
result = 37 * result + parameters[i].hashCode();
}
return result;
}
protected Map m_cache = new HashMap();
}