SystemBackupAgent.java revision 18795a2299fefd88ee16393f22324b999ace6ce4 
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.ActivityManagerNative;
21import android.app.IWallpaperManager;
22import android.app.backup.BackupDataInput;
23import android.app.backup.BackupDataOutput;
24import android.app.backup.BackupAgentHelper;
25import android.app.backup.FullBackup;
26import android.app.backup.FullBackupDataOutput;
27import android.app.backup.RecentsBackupHelper;
28import android.app.backup.WallpaperBackupHelper;
29import android.content.Context;
30import android.os.Environment;
31import android.os.ParcelFileDescriptor;
32import android.os.RemoteException;
33import android.os.ServiceManager;
34import android.os.UserHandle;
35import android.util.Slog;
36
37import java.io.File;
38import java.io.IOException;
39
40/**
41 * Backup agent for various system-managed data, currently just the system wallpaper
42 */
43public class SystemBackupAgent extends BackupAgentHelper {
44    private static final String TAG = "SystemBackupAgent";
45
46    // These paths must match what the WallpaperManagerService uses.  The leaf *_FILENAME
47    // are also used in the full-backup file format, so must not change unless steps are
48    // taken to support the legacy backed-up datasets.
49    private static final String WALLPAPER_IMAGE_FILENAME = "wallpaper";
50    private static final String WALLPAPER_INFO_FILENAME = "wallpaper_info.xml";
51
52    // TODO: Will need to change if backing up non-primary user's wallpaper
53    private static final String WALLPAPER_IMAGE_DIR =
54            Environment.getUserSystemDirectory(UserHandle.USER_OWNER).getAbsolutePath();
55    private static final String WALLPAPER_IMAGE = WallpaperBackupHelper.WALLPAPER_IMAGE;
56
57    // TODO: Will need to change if backing up non-primary user's wallpaper
58    private static final String WALLPAPER_INFO_DIR =
59            Environment.getUserSystemDirectory(UserHandle.USER_OWNER).getAbsolutePath();
60    private static final String WALLPAPER_INFO = WallpaperBackupHelper.WALLPAPER_INFO;
61    // Use old keys to keep legacy data compatibility and avoid writing two wallpapers
62    private static final String WALLPAPER_IMAGE_KEY = WallpaperBackupHelper.WALLPAPER_IMAGE_KEY;
63    private static final String WALLPAPER_INFO_KEY = WallpaperBackupHelper.WALLPAPER_INFO_KEY;
64
65    @Override
66    public void onBackup(ParcelFileDescriptor oldState, BackupDataOutput data,
67            ParcelFileDescriptor newState) throws IOException {
68        // We only back up the data under the current "wallpaper" schema with metadata
69        IWallpaperManager wallpaper = (IWallpaperManager)ServiceManager.getService(
70                Context.WALLPAPER_SERVICE);
71        String[] files = new String[] { WALLPAPER_IMAGE, WALLPAPER_INFO };
72        String[] keys = new String[] { WALLPAPER_IMAGE_KEY, WALLPAPER_INFO_KEY };
73        if (wallpaper != null) {
74            try {
75                final String wallpaperName = wallpaper.getName();
76                if (wallpaperName != null && wallpaperName.length() > 0) {
77                    // When the wallpaper has a name, back up the info by itself.
78                    // TODO: Don't rely on the innards of the service object like this!
79                    // TODO: Send a delete for any stored wallpaper image in this case?
80                    files = new String[] { WALLPAPER_INFO };
81                    keys = new String[] { WALLPAPER_INFO_KEY };
82                }
83            } catch (RemoteException re) {
84                Slog.e(TAG, "Couldn't get wallpaper name\n" + re);
85            }
86        }
87        addHelper("wallpaper", new WallpaperBackupHelper(SystemBackupAgent.this, files, keys));
88        addHelper("recents", new RecentsBackupHelper(SystemBackupAgent.this));
89
90        super.onBackup(oldState, data, newState);
91    }
92
93    @Override
94    public void onFullBackup(FullBackupDataOutput data) throws IOException {
95        // At present we back up only the wallpaper
96        fullWallpaperBackup(data);
97    }
98
99    private void fullWallpaperBackup(FullBackupDataOutput output) {
100        // Back up the data files directly.  We do them in this specific order --
101        // info file followed by image -- because then we need take no special
102        // steps during restore; the restore will happen properly when the individual
103        // files are restored piecemeal.
104        FullBackup.backupToTar(getPackageName(), FullBackup.ROOT_TREE_TOKEN, null,
105                WALLPAPER_INFO_DIR, WALLPAPER_INFO, output.getData());
106        FullBackup.backupToTar(getPackageName(), FullBackup.ROOT_TREE_TOKEN, null,
107                WALLPAPER_IMAGE_DIR, WALLPAPER_IMAGE, output.getData());
108    }
109
110    @Override
111    public void onRestore(BackupDataInput data, int appVersionCode, ParcelFileDescriptor newState)
112            throws IOException {
113        // On restore, we also support a previous data schema "system_files"
114        addHelper("wallpaper", new WallpaperBackupHelper(SystemBackupAgent.this,
115                new String[] { WALLPAPER_IMAGE, WALLPAPER_INFO },
116                new String[] { WALLPAPER_IMAGE_KEY, WALLPAPER_INFO_KEY} ));
117        addHelper("system_files", new WallpaperBackupHelper(SystemBackupAgent.this,
118                new String[] { WALLPAPER_IMAGE },
119                new String[] { WALLPAPER_IMAGE_KEY} ));
120        addHelper("recents", new RecentsBackupHelper(SystemBackupAgent.this));
121
122        try {
123            super.onRestore(data, appVersionCode, newState);
124
125            IWallpaperManager wallpaper = (IWallpaperManager) ServiceManager.getService(
126                    Context.WALLPAPER_SERVICE);
127            if (wallpaper != null) {
128                try {
129                    wallpaper.settingsRestored();
130                } catch (RemoteException re) {
131                    Slog.e(TAG, "Couldn't restore settings\n" + re);
132                }
133            }
134        } catch (IOException ex) {
135            // If there was a failure, delete everything for the wallpaper, this is too aggressive,
136            // but this is hopefully a rare failure.
137            Slog.d(TAG, "restore failed", ex);
138            (new File(WALLPAPER_IMAGE)).delete();
139            (new File(WALLPAPER_INFO)).delete();
140        }
141    }
142
143    @Override
144    public void onRestoreFile(ParcelFileDescriptor data, long size,
145            int type, String domain, String path, long mode, long mtime)
146            throws IOException {
147        Slog.i(TAG, "Restoring file domain=" + domain + " path=" + path);
148
149        // Bits to indicate postprocessing we may need to perform
150        boolean restoredWallpaper = false;
151
152        File outFile = null;
153        // Various domain+files we understand a priori
154        if (domain.equals(FullBackup.ROOT_TREE_TOKEN)) {
155            if (path.equals(WALLPAPER_INFO_FILENAME)) {
156                outFile = new File(WALLPAPER_INFO);
157                restoredWallpaper = true;
158            } else if (path.equals(WALLPAPER_IMAGE_FILENAME)) {
159                outFile = new File(WALLPAPER_IMAGE);
160                restoredWallpaper = true;
161            }
162        }
163
164        try {
165            if (outFile == null) {
166                Slog.w(TAG, "Skipping unrecognized system file: [ " + domain + " : " + path + " ]");
167            }
168            FullBackup.restoreFile(data, size, type, mode, mtime, outFile);
169
170            if (restoredWallpaper) {
171                IWallpaperManager wallpaper =
172                        (IWallpaperManager)ServiceManager.getService(
173                        Context.WALLPAPER_SERVICE);
174                if (wallpaper != null) {
175                    try {
176                        wallpaper.settingsRestored();
177                    } catch (RemoteException re) {
178                        Slog.e(TAG, "Couldn't restore settings\n" + re);
179                    }
180                }
181            }
182        } catch (IOException e) {
183            if (restoredWallpaper) {
184                // Make sure we wind up in a good state
185                (new File(WALLPAPER_IMAGE)).delete();
186                (new File(WALLPAPER_INFO)).delete();
187            }
188        }
189    }
190
191    @Override
192    public void onRestoreFinished() {
193        try {
194            ActivityManagerNative.getDefault().systemBackupRestored();
195        } catch (RemoteException e) {
196            // Not possible since this code is running in the system process.
197        }
198    }
199}
200