SystemBackupAgent.java revision ac6a3a5e9d90edb533e5b377a4a14ef514be955a 
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.RecentsBackupHelper;
27import android.app.backup.WallpaperBackupHelper;
28import android.content.Context;
29import android.os.Environment;
30import android.os.ParcelFileDescriptor;
31import android.os.RemoteException;
32import android.os.ServiceManager;
33import android.os.UserHandle;
34import android.util.Slog;
35
36import java.io.File;
37import java.io.IOException;
38
39/**
40 * Backup agent for various system-managed data, currently just the system wallpaper
41 */
42public class SystemBackupAgent extends BackupAgentHelper {
43    private static final String TAG = "SystemBackupAgent";
44
45    // These paths must match what the WallpaperManagerService uses.  The leaf *_FILENAME
46    // are also used in the full-backup file format, so must not change unless steps are
47    // taken to support the legacy backed-up datasets.
48    private static final String WALLPAPER_IMAGE_FILENAME = "wallpaper";
49    private static final String WALLPAPER_INFO_FILENAME = "wallpaper_info.xml";
50
51    // TODO: Will need to change if backing up non-primary user's wallpaper
52    private static final String WALLPAPER_IMAGE_DIR =
53            Environment.getUserSystemDirectory(UserHandle.USER_OWNER).getAbsolutePath();
54    private static final String WALLPAPER_IMAGE = WallpaperBackupHelper.WALLPAPER_IMAGE;
55
56    // TODO: Will need to change if backing up non-primary user's wallpaper
57    private static final String WALLPAPER_INFO_DIR =
58            Environment.getUserSystemDirectory(UserHandle.USER_OWNER).getAbsolutePath();
59    private static final String WALLPAPER_INFO = WallpaperBackupHelper.WALLPAPER_INFO;
60    // Use old keys to keep legacy data compatibility and avoid writing two wallpapers
61    private static final String WALLPAPER_IMAGE_KEY = WallpaperBackupHelper.WALLPAPER_IMAGE_KEY;
62    private static final String WALLPAPER_INFO_KEY = WallpaperBackupHelper.WALLPAPER_INFO_KEY;
63
64    @Override
65    public void onBackup(ParcelFileDescriptor oldState, BackupDataOutput data,
66            ParcelFileDescriptor newState) throws IOException {
67        // We only back up the data under the current "wallpaper" schema with metadata
68        IWallpaperManager wallpaper = (IWallpaperManager)ServiceManager.getService(
69                Context.WALLPAPER_SERVICE);
70        String[] files = new String[] { WALLPAPER_IMAGE, WALLPAPER_INFO };
71        String[] keys = new String[] { WALLPAPER_IMAGE_KEY, WALLPAPER_INFO_KEY };
72        if (wallpaper != null) {
73            try {
74                final String wallpaperName = wallpaper.getName();
75                if (wallpaperName != null && wallpaperName.length() > 0) {
76                    // When the wallpaper has a name, back up the info by itself.
77                    // TODO: Don't rely on the innards of the service object like this!
78                    // TODO: Send a delete for any stored wallpaper image in this case?
79                    files = new String[] { WALLPAPER_INFO };
80                    keys = new String[] { WALLPAPER_INFO_KEY };
81                }
82            } catch (RemoteException re) {
83                Slog.e(TAG, "Couldn't get wallpaper name\n" + re);
84            }
85        }
86        addHelper("wallpaper", new WallpaperBackupHelper(SystemBackupAgent.this, files, keys));
87        addHelper("recents", new RecentsBackupHelper(SystemBackupAgent.this));
88
89        super.onBackup(oldState, data, newState);
90    }
91
92    @Override
93    public void onFullBackup(FullBackupDataOutput data) throws IOException {
94        // At present we back up only the wallpaper
95        fullWallpaperBackup(data);
96    }
97
98    private void fullWallpaperBackup(FullBackupDataOutput output) {
99        // Back up the data files directly.  We do them in this specific order --
100        // info file followed by image -- because then we need take no special
101        // steps during restore; the restore will happen properly when the individual
102        // files are restored piecemeal.
103        FullBackup.backupToTar(getPackageName(), FullBackup.ROOT_TREE_TOKEN, null,
104                WALLPAPER_INFO_DIR, WALLPAPER_INFO, output.getData());
105        FullBackup.backupToTar(getPackageName(), FullBackup.ROOT_TREE_TOKEN, null,
106                WALLPAPER_IMAGE_DIR, WALLPAPER_IMAGE, output.getData());
107    }
108
109    @Override
110    public void onRestore(BackupDataInput data, int appVersionCode, ParcelFileDescriptor newState)
111            throws IOException {
112        // On restore, we also support a previous data schema "system_files"
113        addHelper("wallpaper", new WallpaperBackupHelper(SystemBackupAgent.this,
114                new String[] { WALLPAPER_IMAGE, WALLPAPER_INFO },
115                new String[] { WALLPAPER_IMAGE_KEY, WALLPAPER_INFO_KEY} ));
116        addHelper("system_files", new WallpaperBackupHelper(SystemBackupAgent.this,
117                new String[] { WALLPAPER_IMAGE },
118                new String[] { WALLPAPER_IMAGE_KEY} ));
119        addHelper("recents", new RecentsBackupHelper(SystemBackupAgent.this));
120
121        try {
122            super.onRestore(data, appVersionCode, newState);
123
124            IWallpaperManager wallpaper = (IWallpaperManager) ServiceManager.getService(
125                    Context.WALLPAPER_SERVICE);
126            if (wallpaper != null) {
127                try {
128                    wallpaper.settingsRestored();
129                } catch (RemoteException re) {
130                    Slog.e(TAG, "Couldn't restore settings\n" + re);
131                }
132            }
133        } catch (IOException ex) {
134            // If there was a failure, delete everything for the wallpaper, this is too aggressive,
135            // but this is hopefully a rare failure.
136            Slog.d(TAG, "restore failed", ex);
137            (new File(WALLPAPER_IMAGE)).delete();
138            (new File(WALLPAPER_INFO)).delete();
139        }
140    }
141
142    @Override
143    public void onRestoreFile(ParcelFileDescriptor data, long size,
144            int type, String domain, String path, long mode, long mtime)
145            throws IOException {
146        Slog.i(TAG, "Restoring file domain=" + domain + " path=" + path);
147
148        // Bits to indicate postprocessing we may need to perform
149        boolean restoredWallpaper = false;
150
151        File outFile = null;
152        // Various domain+files we understand a priori
153        if (domain.equals(FullBackup.ROOT_TREE_TOKEN)) {
154            if (path.equals(WALLPAPER_INFO_FILENAME)) {
155                outFile = new File(WALLPAPER_INFO);
156                restoredWallpaper = true;
157            } else if (path.equals(WALLPAPER_IMAGE_FILENAME)) {
158                outFile = new File(WALLPAPER_IMAGE);
159                restoredWallpaper = true;
160            }
161        }
162
163        try {
164            if (outFile == null) {
165                Slog.w(TAG, "Skipping unrecognized system file: [ " + domain + " : " + path + " ]");
166            }
167            FullBackup.restoreFile(data, size, type, mode, mtime, outFile);
168
169            if (restoredWallpaper) {
170                IWallpaperManager wallpaper =
171                        (IWallpaperManager)ServiceManager.getService(
172                        Context.WALLPAPER_SERVICE);
173                if (wallpaper != null) {
174                    try {
175                        wallpaper.settingsRestored();
176                    } catch (RemoteException re) {
177                        Slog.e(TAG, "Couldn't restore settings\n" + re);
178                    }
179                }
180            }
181        } catch (IOException e) {
182            if (restoredWallpaper) {
183                // Make sure we wind up in a good state
184                (new File(WALLPAPER_IMAGE)).delete();
185                (new File(WALLPAPER_INFO)).delete();
186            }
187        }
188    }
189}
190