SystemBackupAgent.java revision 8def5cbb3a1a68bb66fbe7ce63fcc8eadcbb238d 
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.backup;
18
19
20import android.app.IWallpaperManager;
21import android.app.backup.BackupDataInput;
22import android.app.backup.BackupDataOutput;
23import android.app.backup.BackupAgentHelper;
24import android.app.backup.FullBackup;
25import android.app.backup.FullBackupDataOutput;
26import android.app.backup.WallpaperBackupHelper;
27import android.content.Context;
28import android.os.Environment;
29import android.os.ParcelFileDescriptor;
30import android.os.RemoteException;
31import android.os.ServiceManager;
32import android.os.UserHandle;
33import android.util.Slog;
34
35import java.io.File;
36import java.io.IOException;
37
38/**
39 * Backup agent for various system-managed data, currently just the system wallpaper
40 */
41public class SystemBackupAgent extends BackupAgentHelper {
42    private static final String TAG = "SystemBackupAgent";
43
44    // These paths must match what the WallpaperManagerService uses.  The leaf *_FILENAME
45    // are also used in the full-backup file format, so must not change unless steps are
46    // taken to support the legacy backed-up datasets.
47    private static final String WALLPAPER_IMAGE_FILENAME = "wallpaper";
48    private static final String WALLPAPER_INFO_FILENAME = "wallpaper_info.xml";
49
50    // TODO: Will need to change if backing up non-primary user's wallpaper
51    private static final String WALLPAPER_IMAGE_DIR =
52            Environment.getUserSystemDirectory(UserHandle.USER_OWNER).getAbsolutePath();
53    private static final String WALLPAPER_IMAGE = WallpaperBackupHelper.WALLPAPER_IMAGE;
54
55    // TODO: Will need to change if backing up non-primary user's wallpaper
56    private static final String WALLPAPER_INFO_DIR =
57            Environment.getUserSystemDirectory(UserHandle.USER_OWNER).getAbsolutePath();
58    private static final String WALLPAPER_INFO = WallpaperBackupHelper.WALLPAPER_INFO;
59    // Use old keys to keep legacy data compatibility and avoid writing two wallpapers
60    private static final String WALLPAPER_IMAGE_KEY = WallpaperBackupHelper.WALLPAPER_IMAGE_KEY;
61    private static final String WALLPAPER_INFO_KEY = WallpaperBackupHelper.WALLPAPER_INFO_KEY;
62
63    @Override
64    public void onBackup(ParcelFileDescriptor oldState, BackupDataOutput data,
65            ParcelFileDescriptor newState) throws IOException {
66        // We only back up the data under the current "wallpaper" schema with metadata
67        IWallpaperManager wallpaper = (IWallpaperManager)ServiceManager.getService(
68                Context.WALLPAPER_SERVICE);
69        String[] files = new String[] { WALLPAPER_IMAGE, WALLPAPER_INFO };
70        String[] keys = new String[] { WALLPAPER_IMAGE_KEY, WALLPAPER_INFO_KEY };
71        if (wallpaper != null) {
72            try {
73                final String wallpaperName = wallpaper.getName();
74                if (wallpaperName != null && wallpaperName.length() > 0) {
75                    // When the wallpaper has a name, back up the info by itself.
76                    // TODO: Don't rely on the innards of the service object like this!
77                    // TODO: Send a delete for any stored wallpaper image in this case?
78                    files = new String[] { WALLPAPER_INFO };
79                    keys = new String[] { WALLPAPER_INFO_KEY };
80                }
81            } catch (RemoteException re) {
82                Slog.e(TAG, "Couldn't get wallpaper name\n" + re);
83            }
84        }
85        addHelper("wallpaper", new WallpaperBackupHelper(SystemBackupAgent.this, files, keys));
86        super.onBackup(oldState, data, newState);
87    }
88
89    @Override
90    public void onFullBackup(FullBackupDataOutput data) throws IOException {
91        // At present we back up only the wallpaper
92        fullWallpaperBackup(data);
93    }
94
95    private void fullWallpaperBackup(FullBackupDataOutput output) {
96        // Back up the data files directly.  We do them in this specific order --
97        // info file followed by image -- because then we need take no special
98        // steps during restore; the restore will happen properly when the individual
99        // files are restored piecemeal.
100        FullBackup.backupToTar(getPackageName(), FullBackup.ROOT_TREE_TOKEN, null,
101                WALLPAPER_INFO_DIR, WALLPAPER_INFO, output.getData());
102        FullBackup.backupToTar(getPackageName(), FullBackup.ROOT_TREE_TOKEN, null,
103                WALLPAPER_IMAGE_DIR, WALLPAPER_IMAGE, output.getData());
104    }
105
106    @Override
107    public void onRestore(BackupDataInput data, int appVersionCode, ParcelFileDescriptor newState)
108            throws IOException {
109        // On restore, we also support a previous data schema "system_files"
110        addHelper("wallpaper", new WallpaperBackupHelper(SystemBackupAgent.this,
111                new String[] { WALLPAPER_IMAGE, WALLPAPER_INFO },
112                new String[] { WALLPAPER_IMAGE_KEY, WALLPAPER_INFO_KEY} ));
113        addHelper("system_files", new WallpaperBackupHelper(SystemBackupAgent.this,
114                new String[] { WALLPAPER_IMAGE },
115                new String[] { WALLPAPER_IMAGE_KEY} ));
116
117        try {
118            super.onRestore(data, appVersionCode, newState);
119
120            IWallpaperManager wallpaper = (IWallpaperManager) ServiceManager.getService(
121                    Context.WALLPAPER_SERVICE);
122            if (wallpaper != null) {
123                try {
124                    wallpaper.settingsRestored();
125                } catch (RemoteException re) {
126                    Slog.e(TAG, "Couldn't restore settings\n" + re);
127                }
128            }
129        } catch (IOException ex) {
130            // If there was a failure, delete everything for the wallpaper, this is too aggressive,
131            // but this is hopefully a rare failure.
132            Slog.d(TAG, "restore failed", ex);
133            (new File(WALLPAPER_IMAGE)).delete();
134            (new File(WALLPAPER_INFO)).delete();
135        }
136    }
137
138    @Override
139    public void onRestoreFile(ParcelFileDescriptor data, long size,
140            int type, String domain, String path, long mode, long mtime)
141            throws IOException {
142        Slog.i(TAG, "Restoring file domain=" + domain + " path=" + path);
143
144        // Bits to indicate postprocessing we may need to perform
145        boolean restoredWallpaper = false;
146
147        File outFile = null;
148        // Various domain+files we understand a priori
149        if (domain.equals(FullBackup.ROOT_TREE_TOKEN)) {
150            if (path.equals(WALLPAPER_INFO_FILENAME)) {
151                outFile = new File(WALLPAPER_INFO);
152                restoredWallpaper = true;
153            } else if (path.equals(WALLPAPER_IMAGE_FILENAME)) {
154                outFile = new File(WALLPAPER_IMAGE);
155                restoredWallpaper = true;
156            }
157        }
158
159        try {
160            if (outFile == null) {
161                Slog.w(TAG, "Skipping unrecognized system file: [ " + domain + " : " + path + " ]");
162            }
163            FullBackup.restoreFile(data, size, type, mode, mtime, outFile);
164
165            if (restoredWallpaper) {
166                IWallpaperManager wallpaper =
167                        (IWallpaperManager)ServiceManager.getService(
168                        Context.WALLPAPER_SERVICE);
169                if (wallpaper != null) {
170                    try {
171                        wallpaper.settingsRestored();
172                    } catch (RemoteException re) {
173                        Slog.e(TAG, "Couldn't restore settings\n" + re);
174                    }
175                }
176            }
177        } catch (IOException e) {
178            if (restoredWallpaper) {
179                // Make sure we wind up in a good state
180                (new File(WALLPAPER_IMAGE)).delete();
181                (new File(WALLPAPER_INFO)).delete();
182            }
183        }
184    }
185}
186