1 /***
2 *
3 * Copyright 2005 LogicBlaze, Inc. http://www.logicblaze.com
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 **/
18 package org.logicblaze.lingo;
19
20 import org.springframework.remoting.support.RemoteInvocationResult;
21
22 /***
23 * A Strategy pattern describing how to join multiple results together, to decide when it is safe to unblock the calling
24 * client thread and when a request can be considered to be complete.
25 *
26 * @version $Revision$
27 */
28 public interface ResultJoinStrategy {
29
30 /***
31 * Returns true if the calling thread should be unblocked after calling the method and so returning the current value of the
32 * invocation result; future responses could still mutate the result object if required. The default implementation
33 * will return true after a single response is returned.
34 */
35 public abstract boolean unblockCallerThread(RemoteInvocationResult response, int responseCount);
36
37 /***
38 * Returns true if there have been sufficient responses to remove the handler from the system.
39 * Typically handlers should expire after some inactivity timeout.
40 */
41 public abstract boolean removeHandler(RemoteInvocationResult response, int responseCount);
42
43 /***
44 * Merges the new response with the previous response object. The default implementation just merges collections together
45 * otherwise the first response wins.
46 */
47 public abstract RemoteInvocationResult mergeResponses(RemoteInvocationResult currentResult, RemoteInvocationResult newResult, int responseCount);
48
49 }