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 token Opaque token identifying this transaction.  This must
45     *        be echoed back to the backup service binder once the new
46     *        data has been written to the data and newState files.
47     *
48     * @param callbackBinder Binder on which to indicate operation completion,
49     *        passed here as a convenience to the agent.
50     */
51    void doBackup(in ParcelFileDescriptor oldState,
52            in ParcelFileDescriptor data,
53            in ParcelFileDescriptor newState,
54            int token, IBackupManager callbackBinder);
55
56    /**
57     * Restore an entire data snapshot to the application.
58     *
59     * @param data Read-only file containing the full data snapshot of the
60     *        app's backup.  This is to be a <i>replacement</i> of the app's
61     *        current data, not to be merged into it.
62     *
63     * @param appVersionCode The android:versionCode attribute of the application
64     *        that created this data set.  This can help the agent distinguish among
65     *        various historical backup content possibilities.
66     *
67     * @param newState Read-write file, empty when onRestore() is called,
68     *        that is to be written with the state description that holds after
69     *        the restore has been completed.
70     *
71     * @param token Opaque token identifying this transaction.  This must
72     *        be echoed back to the backup service binder once the agent is
73     *        finished restoring the application based on the restore data
74     *        contents.
75     *
76     * @param callbackBinder Binder on which to indicate operation completion,
77     *        passed here as a convenience to the agent.
78     */
79    void doRestore(in ParcelFileDescriptor data,
80            int appVersionCode, in ParcelFileDescriptor newState,
81            int token, IBackupManager callbackBinder);
82
83    /**
84     * Perform a "full" backup to the given file descriptor.  The output file is presumed
85     * to be a socket or other non-seekable, write-only data sink.  When this method is
86     * called, the app should write all of its files to the output.
87     *
88     * @param data Write-only file to receive the backed-up file content stream.
89     *        The data must be formatted correctly for the resulting archive to be
90     *        legitimate, so that will be tightly controlled by the available API.
91     *
92     * @param token Opaque token identifying this transaction.  This must
93     *        be echoed back to the backup service binder once the agent is
94     *        finished restoring the application based on the restore data
95     *        contents.
96     *
97     * @param callbackBinder Binder on which to indicate operation completion,
98     *        passed here as a convenience to the agent.
99     */
100    void doFullBackup(in ParcelFileDescriptor data, int token, IBackupManager callbackBinder);
101
102    /**
103     * Restore a single "file" to the application.  The file was typically obtained from
104     * a full-backup dataset.  The agent reads 'size' bytes of file content
105     * from the provided file descriptor.
106     *
107     * @param data Read-only pipe delivering the file content itself.
108     *
109     * @param size Size of the file being restored.
110     * @param type Type of file system entity, e.g. FullBackup.TYPE_DIRECTORY.
111     * @param domain Name of the file's semantic domain to which the 'path' argument is a
112     *        relative path.  e.g. FullBackup.DATABASE_TREE_TOKEN.
113     * @param path Relative path of the file within its semantic domain.
114     * @param mode Access mode of the file system entity, e.g. 0660.
115     * @param mtime Last modification time of the file system entity.
116     * @param token Opaque token identifying this transaction.  This must
117     *        be echoed back to the backup service binder once the agent is
118     *        finished restoring the application based on the restore data
119     *        contents.
120     * @param callbackBinder Binder on which to indicate operation completion,
121     *        passed here as a convenience to the agent.
122     */
123    void doRestoreFile(in ParcelFileDescriptor data, long size,
124            int type, String domain, String path, long mode, long mtime,
125            int token, IBackupManager callbackBinder);
126
127    /**
128     * Provide the app with a canonical "all data has been delivered" end-of-restore
129     * callback so that it can do any postprocessing of the restored data that might
130     * be appropriate.  This is issued after both key/value and full data restore
131     * operations have completed.
132     *
133     * @param token Opaque token identifying this transaction.  This must
134     *        be echoed back to the backup service binder once the agent is
135     *        finished restoring the application based on the restore data
136     *        contents.
137     * @param callbackBinder Binder on which to indicate operation completion,
138     *        passed here as a convenience to the agent.
139     */
140    void doRestoreFinished(int token, IBackupManager callbackBinder);
141
142    /**
143     * Out of band: instruct the agent to crash within the client process.  This is used
144     * when the backup infrastructure detects a semantic error post-hoc and needs to
145     * pass the problem back to the app.
146     *
147     * @param message The message to be passed to the agent's application in an exception.
148     */
149    void fail(String message);
150}
151