1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
|
/*******************************************************************************
* Copyright (c) 2004, 2010 Tasktop Technologies and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Tasktop Technologies - initial API and implementation
*******************************************************************************/
package org.eclipse.mylyn.internal.tasks.core.externalization;
import java.io.File;
import org.eclipse.core.runtime.Assert;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.jobs.ISchedulingRule;
import org.eclipse.mylyn.commons.core.StatusHandler;
import org.eclipse.mylyn.commons.net.Policy;
import org.eclipse.mylyn.internal.tasks.core.ITasksCoreConstants;
/**
* File based externalization participant
*
* @author Rob Elves
*/
public abstract class AbstractExternalizationParticipant implements IExternalizationParticipant {
public static final String SNAPSHOT_PREFIX = "."; //$NON-NLS-1$
public abstract void load(File sourceFile, IProgressMonitor monitor) throws CoreException;
public abstract void save(File targetFile, IProgressMonitor monitor) throws CoreException;
public abstract String getDescription();
public abstract ISchedulingRule getSchedulingRule();
public abstract boolean isDirty();
public abstract String getFileName();
public AbstractExternalizationParticipant() {
super();
}
protected boolean takeSnapshot(File file) {
if (file.length() > 0) {
File originalFile = file.getAbsoluteFile();
File backup = new File(file.getParentFile(), SNAPSHOT_PREFIX + file.getName());
backup.delete();
return originalFile.renameTo(backup);
}
return false;
}
public void execute(IExternalizationContext context, IProgressMonitor monitor) throws CoreException {
Assert.isNotNull(context);
monitor = Policy.monitorFor(monitor);
final File dataFile = getFile(context.getRootPath());
switch (context.getKind()) {
case SAVE:
if (dataFile != null) {
takeSnapshot(dataFile);
}
save(dataFile, monitor);
break;
case LOAD:
performLoad(dataFile, monitor);
break;
case SNAPSHOT:
break;
}
}
protected boolean performLoad(final File dataFile, IProgressMonitor monitor) throws CoreException {
try {
load(dataFile, monitor);
return true;
} catch (CoreException e) {
if (dataFile != null) {
File backup = new File(dataFile.getParentFile(), SNAPSHOT_PREFIX + dataFile.getName());
if (backup.exists()) {
StatusHandler.log(new Status(IStatus.WARNING, ITasksCoreConstants.ID_PLUGIN, "Failed to load " //$NON-NLS-1$
+ dataFile.getName() + ", restoring from snapshot", e)); //$NON-NLS-1$
load(backup, monitor);
return true;
}
}
}
return false;
}
public File getFile(String rootPath) throws CoreException {
String fileName = getFileName();
if (fileName != null) {
String filePath = rootPath + File.separator + getFileName();
return new File(filePath);
}
return null;
}
/**
* @param full
* true when the workbench is shutting down and any time-based dirty states should be ignore
*/
public boolean isDirty(boolean full) {
return isDirty();
}
}
|