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comparison src/org/tmatesoft/hg/internal/RevlogChangeMonitor.java @ 607:66f1cc23b906

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Refresh revlogs if a change to a file has been detected; do not force reload of the whole repository
author Artem Tikhomirov <tikhomirov.artem@gmail.com>
date Tue, 07 May 2013 16:52:46 +0200
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children 99ad1e3a4e4d
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606:5daa42067e7c 607:66f1cc23b906
1 /*
2 * Copyright (c) 2013 TMate Software Ltd
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; version 2 of the License.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * For information on how to redistribute this software under
14 * the terms of a license other than GNU General Public License
15 * contact TMate Software at support@hg4j.com
16 */
17 package org.tmatesoft.hg.internal;
18
19 import java.io.File;
20 import java.util.WeakHashMap;
21
22 /**
23 * Detect changes to revlog files. Not a general file change monitoring as we utilize the fact revlogs are append-only (and even in case
24 * of stripped-off tail revisions, with e.g. mq, detection approach is still valid).
25 *
26 * @author Artem Tikhomirov
27 * @author TMate Software Ltd.
28 */
29 public class RevlogChangeMonitor {
30
31 private final WeakHashMap<File, Long> lastKnownSize;
32 private final File soleFile;
33 private long soleFileLength = -1;
34
35 // use single for multiple files. TODO repository/session context shall provide
36 // alternative (configurable) implementations, so that Java7 users may supply better one
37 public RevlogChangeMonitor() {
38 lastKnownSize = new WeakHashMap<File, Long>();
39 soleFile = null;
40 }
41
42 public RevlogChangeMonitor(File f) {
43 assert f != null;
44 lastKnownSize = null;
45 soleFile = f;
46 }
47
48 public void touch(File f) {
49 assert f != null;
50 if (lastKnownSize == null) {
51 assert f == soleFile;
52 soleFileLength = f.length();
53 } else {
54 lastKnownSize.put(f, f.length());
55 }
56 }
57
58 public boolean hasChanged(File f) {
59 assert f != null;
60 if (lastKnownSize == null) {
61 assert f == soleFile;
62 return soleFileLength != f.length();
63 } else {
64 Long lastSize = lastKnownSize.get(f);
65 if (lastSize == null) {
66 return true;
67 }
68 return f.length() != lastSize;
69 }
70 }
71 }