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18 package org.apache.activemq.transport.reliable;
19
20 import org.apache.commons.logging.Log;
21 import org.apache.commons.logging.LogFactory;
22
23 import java.io.IOException  ;
24 import java.util.HashMap ;
25 import java.util.Map ;
26
27
31 public class DefaultReplayBuffer implements ReplayBuffer {
32
33 private static final Log log = LogFactory.getLog(DefaultReplayBuffer.class);
34
35 private final int size;
36 private ReplayBufferListener listener;
37 private Map map;
38 private int lowestCommandId = 1;
39 private Object lock = new Object ();
40
41 public DefaultReplayBuffer(int size) {
42 this.size = size;
43 map = createMap(size);
44 }
45
46 public void addBuffer(int commandId, Object buffer) {
47 if (log.isDebugEnabled()) {
48 log.debug("Adding command ID: " + commandId + " to replay buffer: " + this + " object: " + buffer);
49 }
50 synchronized (lock) {
51 int max = size - 1;
52 while (map.size() >= max) {
53 Object evictedBuffer = map.remove(new Integer (++lowestCommandId));
55 onEvictedBuffer(lowestCommandId, evictedBuffer);
56 }
57 map.put(new Integer (commandId), buffer);
58 }
59 }
60
61 public void setReplayBufferListener(ReplayBufferListener bufferPoolAdapter) {
62 this.listener = bufferPoolAdapter;
63 }
64
65 public void replayMessages(int fromCommandId, int toCommandId, Replayer replayer) throws IOException {
66 if (replayer == null) {
67 throw new IllegalArgumentException ("No Replayer parameter specified");
68 }
69 if (log.isDebugEnabled()) {
70 log.debug("Buffer: " + this + " replaying messages from: " + fromCommandId + " to: " + toCommandId);
71 }
72 for (int i = fromCommandId; i <= toCommandId; i++) {
73 Object buffer = null;
74 synchronized (lock) {
75 buffer = map.get(new Integer (i));
76 }
77 replayer.sendBuffer(i, buffer);
78 }
79 }
80
81 protected Map createMap(int maximumSize) {
82 return new HashMap (maximumSize);
83 }
84
85 protected void onEvictedBuffer(int commandId, Object buffer) {
86 if (listener != null) {
87 listener.onBufferDiscarded(commandId, buffer);
88 }
89 }
90 }
91 |
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