SystemBackupAgent.java revision 61f57379ca2c5b6290c8da7548fa17128f7ab24f 
1/*
2 * Copyright (C) 2009 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.server;
18
19
20import android.app.backup.BackupDataInput;
21import android.app.backup.BackupDataOutput;
22import android.app.backup.BackupAgentHelper;
23import android.app.backup.FullBackup;
24import android.app.backup.FullBackupDataOutput;
25import android.app.backup.WallpaperBackupHelper;
26import android.content.Context;
27import android.os.Environment;
28import android.os.ParcelFileDescriptor;
29import android.os.ServiceManager;
30import android.os.UserHandle;
31import android.util.Slog;
32
33
34import java.io.File;
35import java.io.IOException;
36
37/**
38 * Backup agent for various system-managed data, currently just the system wallpaper
39 */
40public class SystemBackupAgent extends BackupAgentHelper {
41    private static final String TAG = "SystemBackupAgent";
42
43    // These paths must match what the WallpaperManagerService uses.  The leaf *_FILENAME
44    // are also used in the full-backup file format, so must not change unless steps are
45    // taken to support the legacy backed-up datasets.
46    private static final String WALLPAPER_IMAGE_FILENAME = "wallpaper";
47    private static final String WALLPAPER_INFO_FILENAME = "wallpaper_info.xml";
48
49    // TODO: Will need to change if backing up non-primary user's wallpaper
50    private static final String WALLPAPER_IMAGE_DIR =
51            Environment.getUserSystemDirectory(UserHandle.USER_OWNER).getAbsolutePath();
52    private static final String WALLPAPER_IMAGE = WallpaperBackupHelper.WALLPAPER_IMAGE;
53
54    // TODO: Will need to change if backing up non-primary user's wallpaper
55    private static final String WALLPAPER_INFO_DIR =
56            Environment.getUserSystemDirectory(UserHandle.USER_OWNER).getAbsolutePath();
57    private static final String WALLPAPER_INFO = WallpaperBackupHelper.WALLPAPER_INFO;
58    // Use old keys to keep legacy data compatibility and avoid writing two wallpapers
59    private static final String WALLPAPER_IMAGE_KEY = WallpaperBackupHelper.WALLPAPER_IMAGE_KEY;
60    private static final String WALLPAPER_INFO_KEY = WallpaperBackupHelper.WALLPAPER_INFO_KEY;
61
62    @Override
63    public void onBackup(ParcelFileDescriptor oldState, BackupDataOutput data,
64            ParcelFileDescriptor newState) throws IOException {
65        // We only back up the data under the current "wallpaper" schema with metadata
66        WallpaperManagerService wallpaper = (WallpaperManagerService)ServiceManager.getService(
67                Context.WALLPAPER_SERVICE);
68        String[] files = new String[] { WALLPAPER_IMAGE, WALLPAPER_INFO };
69        String[] keys = new String[] { WALLPAPER_IMAGE_KEY, WALLPAPER_INFO_KEY };
70        if (wallpaper != null && wallpaper.getName() != null && wallpaper.getName().length() > 0) {
71            // When the wallpaper has a name, back up the info by itself.
72            // TODO: Don't rely on the innards of the service object like this!
73            // TODO: Send a delete for any stored wallpaper image in this case?
74            files = new String[] { WALLPAPER_INFO };
75            keys = new String[] { WALLPAPER_INFO_KEY };
76        }
77        addHelper("wallpaper", new WallpaperBackupHelper(SystemBackupAgent.this, files, keys));
78        super.onBackup(oldState, data, newState);
79    }
80
81    @Override
82    public void onFullBackup(FullBackupDataOutput data) throws IOException {
83        // At present we back up only the wallpaper
84        fullWallpaperBackup(data);
85    }
86
87    private void fullWallpaperBackup(FullBackupDataOutput output) {
88        // Back up the data files directly.  We do them in this specific order --
89        // info file followed by image -- because then we need take no special
90        // steps during restore; the restore will happen properly when the individual
91        // files are restored piecemeal.
92        FullBackup.backupToTar(getPackageName(), FullBackup.ROOT_TREE_TOKEN, null,
93                WALLPAPER_INFO_DIR, WALLPAPER_INFO, output.getData());
94        FullBackup.backupToTar(getPackageName(), FullBackup.ROOT_TREE_TOKEN, null,
95                WALLPAPER_IMAGE_DIR, WALLPAPER_IMAGE, output.getData());
96    }
97
98    @Override
99    public void onRestore(BackupDataInput data, int appVersionCode, ParcelFileDescriptor newState)
100            throws IOException {
101        // On restore, we also support a previous data schema "system_files"
102        addHelper("wallpaper", new WallpaperBackupHelper(SystemBackupAgent.this,
103                new String[] { WALLPAPER_IMAGE, WALLPAPER_INFO },
104                new String[] { WALLPAPER_IMAGE_KEY, WALLPAPER_INFO_KEY} ));
105        addHelper("system_files", new WallpaperBackupHelper(SystemBackupAgent.this,
106                new String[] { WALLPAPER_IMAGE },
107                new String[] { WALLPAPER_IMAGE_KEY} ));
108
109        try {
110            super.onRestore(data, appVersionCode, newState);
111
112            WallpaperManagerService wallpaper = (WallpaperManagerService)ServiceManager.getService(
113                    Context.WALLPAPER_SERVICE);
114            wallpaper.settingsRestored();
115        } catch (IOException ex) {
116            // If there was a failure, delete everything for the wallpaper, this is too aggressive,
117            // but this is hopefully a rare failure.
118            Slog.d(TAG, "restore failed", ex);
119            (new File(WALLPAPER_IMAGE)).delete();
120            (new File(WALLPAPER_INFO)).delete();
121        }
122    }
123
124    @Override
125    public void onRestoreFile(ParcelFileDescriptor data, long size,
126            int type, String domain, String path, long mode, long mtime)
127            throws IOException {
128        Slog.i(TAG, "Restoring file domain=" + domain + " path=" + path);
129
130        // Bits to indicate postprocessing we may need to perform
131        boolean restoredWallpaper = false;
132
133        File outFile = null;
134        // Various domain+files we understand a priori
135        if (domain.equals(FullBackup.ROOT_TREE_TOKEN)) {
136            if (path.equals(WALLPAPER_INFO_FILENAME)) {
137                outFile = new File(WALLPAPER_INFO);
138                restoredWallpaper = true;
139            } else if (path.equals(WALLPAPER_IMAGE_FILENAME)) {
140                outFile = new File(WALLPAPER_IMAGE);
141                restoredWallpaper = true;
142            }
143        }
144
145        try {
146            if (outFile == null) {
147                Slog.w(TAG, "Skipping unrecognized system file: [ " + domain + " : " + path + " ]");
148            }
149            FullBackup.restoreFile(data, size, type, mode, mtime, outFile);
150
151            if (restoredWallpaper) {
152                WallpaperManagerService wallpaper =
153                        (WallpaperManagerService)ServiceManager.getService(
154                        Context.WALLPAPER_SERVICE);
155                wallpaper.settingsRestored();
156            }
157        } catch (IOException e) {
158            if (restoredWallpaper) {
159                // Make sure we wind up in a good state
160                (new File(WALLPAPER_IMAGE)).delete();
161                (new File(WALLPAPER_INFO)).delete();
162            }
163        }
164    }
165}
166