content: /**
   * Copyright (C) 2010 Alibaba.com Inc.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
   package com.alibaba.cobar.client.router.aspects;
  
  import java.util.Arrays;
  
  import org.aopalliance.intercept.MethodInterceptor;
  import org.aopalliance.intercept.MethodInvocation;
  
  import com.alibaba.cobar.client.router.DefaultCobarClientInternalRouter;
  import com.alibaba.cobar.client.router.ICobarRouter;
  import com.alibaba.cobar.client.router.config.AbstractCobarClientInternalRouterFactoryBean;
  import com.alibaba.cobar.client.router.config.StaticCobarClientInternalRouterFactoryBean;
  import com.alibaba.cobar.client.support.LRUMap;
  
  /**
   * An advice that will provide cache service for {@link ICobarRouter} to improve
   * the routing performance if necessary.<br>
   * 
   * @author fujohnwang
   * @since 1.0
   * @see {@link ICobarRouter}
   * @see {@link AbstractCobarClientInternalRouterFactoryBean}
   * @see {@link DefaultCobarClientInternalRouter}
   * @see {@link StaticCobarClientInternalRouterFactoryBean}
   */
  public class RoutingResultCacheAspect implements MethodInterceptor {
  
      private LRUMap internalCache = new LRUMap(1000);
  
      public Object invoke(MethodInvocation invocation) throws Throwable {
          Object[] args = invocation.getArguments();
          if (args.length != 1) {
              throw new IllegalArgumentException("unexpected argument status on method:"
                      + invocation.getMethod() + ", args:" + Arrays.toString(args));
          }
  
          synchronized (internalCache) {
              if (internalCache.containsKey(args[0])) {
                  return internalCache.get(args[0]);
              }
          }
  
          Object result = null;
          try {
              result = invocation.proceed();
          } finally {
              synchronized (internalCache) {
                  internalCache.put(args[0], result);
              }
          }
  
          return result;
      }
  
      public void setInternalCache(LRUMap internalCache) {
          if (internalCache == null) {
              throw new IllegalArgumentException("Null Cache Map is not allowed.");
          }
          this.internalCache = internalCache;
      }
  
      public LRUMap getInternalCache() {
          return internalCache;
      }
  
  }
  