1/*
2 * Copyright 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 android.app;
18
19import android.app.backup.IBackupManager;
20import android.os.ParcelFileDescriptor;
21
22/**
23 * Interface presented by applications being asked to participate in the
24 * backup & restore mechanism.  End user code will not typically implement
25 * this interface directly; they subclass BackupAgent instead.
26 *
27 * {@hide}
28 */
29oneway interface IBackupAgent {
30    /**
31     * Request that the app perform an incremental backup.
32     *
33     * @param oldState Read-only file containing the description blob of the
34     *        app's data state as of the last backup operation's completion.
35     *        This file is empty or invalid when a full backup is being
36     *        requested.
37     *
38     * @param data Read-write file, empty when onBackup() is called, that
39     *        is the data destination for this backup pass's incrementals.
40     *
41     * @param newState Read-write file, empty when onBackup() is called,
42     *        where the new state blob is to be recorded.
43     *
44     * @param quota Quota reported by the transport for this backup operation (in bytes).
45     *
46     * @param token Opaque token identifying this transaction.  This must
47     *        be echoed back to the backup service binder once the new
48     *        data has been written to the data and newState files.
49     *
50     * @param callbackBinder Binder on which to indicate operation completion,
51     *        passed here as a convenience to the agent.
52     *
53     * @param transportFlags Flags with additional information about the transport.
54     */
55    void doBackup(in ParcelFileDescriptor oldState,
56            in ParcelFileDescriptor data,
57            in ParcelFileDescriptor newState,
58            long quotaBytes, int token, IBackupManager callbackBinder, int transportFlags);
59
60    /**
61     * Restore an entire data snapshot to the application.
62     *
63     * @param data Read-only file containing the full data snapshot of the
64     *        app's backup.  This is to be a <i>replacement</i> of the app's
65     *        current data, not to be merged into it.
66     *
67     * @param appVersionCode The android:versionCode attribute of the application
68     *        that created this data set.  This can help the agent distinguish among
69     *        various historical backup content possibilities.
70     *
71     * @param newState Read-write file, empty when onRestore() is called,
72     *        that is to be written with the state description that holds after
73     *        the restore has been completed.
74     *
75     * @param token Opaque token identifying this transaction.  This must
76     *        be echoed back to the backup service binder once the agent is
77     *        finished restoring the application based on the restore data
78     *        contents.
79     *
80     * @param callbackBinder Binder on which to indicate operation completion,
81     *        passed here as a convenience to the agent.
82     */
83    void doRestore(in ParcelFileDescriptor data,
84            long appVersionCode, in ParcelFileDescriptor newState,
85            int token, IBackupManager callbackBinder);
86
87    /**
88     * Perform a "full" backup to the given file descriptor.  The output file is presumed
89     * to be a socket or other non-seekable, write-only data sink.  When this method is
90     * called, the app should write all of its files to the output.
91     *
92     * @param data Write-only file to receive the backed-up file content stream.
93     *        The data must be formatted correctly for the resulting archive to be
94     *        legitimate, so that will be tightly controlled by the available API.
95     *
96     * @param quota Quota reported by the transport for this backup operation (in bytes).
97     *
98     * @param token Opaque token identifying this transaction.  This must
99     *        be echoed back to the backup service binder once the agent is
100     *        finished restoring the application based on the restore data
101     *        contents.
102     *
103     * @param callbackBinder Binder on which to indicate operation completion,
104     *        passed here as a convenience to the agent.
105     *
106     * @param transportFlags Flags with additional information about transport.
107     */
108    void doFullBackup(in ParcelFileDescriptor data, long quotaBytes, int token,
109            IBackupManager callbackBinder, int transportFlags);
110
111    /**
112     * Estimate how much data a full backup will deliver
113     */
114    void doMeasureFullBackup(long quotaBytes, int token, IBackupManager callbackBinder,
115            int transportFlags);
116
117    /**
118     * Tells the application agent that the backup data size exceeded current transport quota.
119     * Later calls to {@link #onBackup(ParcelFileDescriptor, BackupDataOutput, ParcelFileDescriptor)}
120     * and {@link #onFullBackup(FullBackupDataOutput)} could use this information
121     * to reduce backup size under the limit.
122     * However, the quota can change, so do not assume that the value passed in here is absolute,
123     * similarly all subsequent backups should not be restricted to this size.
124     * This callback will be invoked before data has been put onto the wire in a preflight check,
125     * so it is relatively inexpensive to hit your quota.
126     * Apps that hit quota repeatedly without dealing with it can be subject to having their backup
127     * schedule reduced.
128     * The {@code quotaBytes} is a loose guideline b/c of metadata added by the backupmanager
129     * so apps should be more aggressive in trimming their backup set.
130     *
131     * @param backupDataBytes Expected or already processed amount of data.
132     *                        Could be less than total backup size if backup process was interrupted
133     *                        before finish of processing all backup data.
134     * @param quotaBytes Current amount of backup data that is allowed for the app.
135     */
136    void doQuotaExceeded(long backupDataBytes, long quotaBytes);
137
138    /**
139     * Restore a single "file" to the application.  The file was typically obtained from
140     * a full-backup dataset.  The agent reads 'size' bytes of file content
141     * from the provided file descriptor.
142     *
143     * @param data Read-only pipe delivering the file content itself.
144     *
145     * @param size Size of the file being restored.
146     * @param type Type of file system entity, e.g. FullBackup.TYPE_DIRECTORY.
147     * @param domain Name of the file's semantic domain to which the 'path' argument is a
148     *        relative path.  e.g. FullBackup.DATABASE_TREE_TOKEN.
149     * @param path Relative path of the file within its semantic domain.
150     * @param mode Access mode of the file system entity, e.g. 0660.
151     * @param mtime Last modification time of the file system entity.
152     * @param token Opaque token identifying this transaction.  This must
153     *        be echoed back to the backup service binder once the agent is
154     *        finished restoring the application based on the restore data
155     *        contents.
156     * @param callbackBinder Binder on which to indicate operation completion,
157     *        passed here as a convenience to the agent.
158     */
159    void doRestoreFile(in ParcelFileDescriptor data, long size,
160            int type, String domain, String path, long mode, long mtime,
161            int token, IBackupManager callbackBinder);
162
163    /**
164     * Provide the app with a canonical "all data has been delivered" end-of-restore
165     * callback so that it can do any postprocessing of the restored data that might
166     * be appropriate.  This is issued after both key/value and full data restore
167     * operations have completed.
168     *
169     * @param token Opaque token identifying this transaction.  This must
170     *        be echoed back to the backup service binder once the agent is
171     *        finished restoring the application based on the restore data
172     *        contents.
173     * @param callbackBinder Binder on which to indicate operation completion,
174     *        passed here as a convenience to the agent.
175     */
176    void doRestoreFinished(int token, IBackupManager callbackBinder);
177
178    /**
179     * Out of band: instruct the agent to crash within the client process.  This is used
180     * when the backup infrastructure detects a semantic error post-hoc and needs to
181     * pass the problem back to the app.
182     *
183     * @param message The message to be passed to the agent's application in an exception.
184     */
185    void fail(String message);
186}
187