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1
5 package org.prevayler.implementation.logging;
6
7 import java.io.IOException  ;
8 import java.util.ArrayList ;
9 import java.util.Date ;
10 import java.util.List ;
11
12 import org.prevayler.Transaction;
13 import org.prevayler.foundation.Turn;
14 import org.prevayler.implementation.*;
15 import org.prevayler.implementation.publishing.TransactionSubscriber;
16
17
18 public class TransientLogger implements TransactionLogger {
19
20 private final List log = new ArrayList ();
21 private long _initialTransaction;
22 private boolean _initialTransactionInitialized = false;
23
24
25 public void log(Transaction transaction, Date executionTime, Turn myTurn) {
26 if (!_initialTransactionInitialized) throw new IllegalStateException ("TransactionLogger.update() has to be called at least once before TransactionLogger.log().");
27
28 try {
29 myTurn.start();
30 log.add(new TransactionTimestamp(transaction, executionTime));
31 } finally {
32 myTurn.end();
33 }
34 }
35
36 public synchronized void update(TransactionSubscriber subscriber, long initialTransaction) throws IOException {
37 if (!_initialTransactionInitialized) {
38 _initialTransactionInitialized = true;
39 _initialTransaction = initialTransaction;
40 return;
41 }
42 if (initialTransaction < _initialTransaction) throw new IOException ("Unable to recover transaction " + initialTransaction + ". The oldest recoverable transaction is " + _initialTransaction + ".");
43
44 int i = (int)(initialTransaction - _initialTransaction);
45 if (i > log.size()) throw new IOException ("The transaction log has not yet reached transaction " + initialTransaction + ". The last logged transaction was " + (_initialTransaction + log.size() - 1) + ".");
46
47 while (i != log.size()) {
48 TransactionTimestamp entry = (TransactionTimestamp)log.get(i);
49 subscriber.receive(entry.transaction(), entry.timestamp());
50 i++;
51 }
52 }
53
54 public void close() {}
55
56 }
57 |
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