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