1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
|
/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.browser;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.os.Parcel;
import android.util.Log;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
public class CrashRecoveryHandler {
private static final String LOGTAG = "BrowserCrashRecovery";
private static final String STATE_FILE = "browser_state.parcel";
private static final String RECOVERY_PREFERENCES = "browser_recovery_prefs";
private static final String KEY_LAST_RECOVERED = "last_recovered";
private static final int BUFFER_SIZE = 4096;
private static final long BACKUP_DELAY = 500; // 500ms between writes
/* This is the duration for which we will prompt to restore
* instead of automatically restoring. The first time the browser crashes,
* we will automatically restore. If we then crash again within XX minutes,
* we will prompt instead of automatically restoring.
*/
private static final long PROMPT_INTERVAL = 5 * 60 * 1000; // 5 minutes
private static final int MSG_WRITE_STATE = 1;
private static final int MSG_CLEAR_STATE = 2;
private static final int MSG_PRELOAD_STATE = 3;
private static CrashRecoveryHandler sInstance;
private Controller mController;
private Context mContext;
private Handler mForegroundHandler;
private Handler mBackgroundHandler;
private boolean mIsPreloading = false;
private boolean mDidPreload = false;
private Bundle mRecoveryState = null;
public static CrashRecoveryHandler initialize(Controller controller) {
if (sInstance == null) {
sInstance = new CrashRecoveryHandler(controller);
} else {
sInstance.mController = controller;
}
return sInstance;
}
public static CrashRecoveryHandler getInstance() {
return sInstance;
}
private CrashRecoveryHandler(Controller controller) {
mController = controller;
mContext = mController.getActivity().getApplicationContext();
mForegroundHandler = new Handler();
mBackgroundHandler = new Handler(BackgroundHandler.getLooper()) {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MSG_WRITE_STATE:
Parcel p = Parcel.obtain();
try {
Bundle state = (Bundle) msg.obj;
state.writeToParcel(p, 0);
File stateFile = new File(mContext.getCacheDir(), STATE_FILE);
FileOutputStream fout = new FileOutputStream(stateFile);
fout.write(p.marshall());
fout.close();
} catch (Throwable e) {
Log.i(LOGTAG, "Failed to save persistent state", e);
} finally {
p.recycle();
}
break;
case MSG_CLEAR_STATE:
File state = new File(mContext.getCacheDir(), STATE_FILE);
if (state.exists()) {
state.delete();
}
break;
case MSG_PRELOAD_STATE:
mRecoveryState = loadCrashState();
synchronized (CrashRecoveryHandler.this) {
mIsPreloading = false;
mDidPreload = true;
CrashRecoveryHandler.this.notifyAll();
}
break;
}
}
};
}
public void backupState() {
mForegroundHandler.postDelayed(mCreateState, BACKUP_DELAY);
}
private Runnable mCreateState = new Runnable() {
@Override
public void run() {
try {
final Bundle state = new Bundle();
mController.onSaveInstanceState(state);
Message.obtain(mBackgroundHandler, MSG_WRITE_STATE, state)
.sendToTarget();
// Remove any queued up saves
mForegroundHandler.removeCallbacks(mCreateState);
} catch (Throwable t) {
Log.w(LOGTAG, "Failed to save state", t);
return;
}
}
};
public void clearState() {
mBackgroundHandler.sendEmptyMessage(MSG_CLEAR_STATE);
updateLastRecovered(0);
}
private boolean shouldRestore() {
SharedPreferences prefs = mContext.getSharedPreferences(
RECOVERY_PREFERENCES, Context.MODE_PRIVATE);
long lastRecovered = prefs.getLong(KEY_LAST_RECOVERED, 0);
long timeSinceLastRecover = System.currentTimeMillis() - lastRecovered;
if (timeSinceLastRecover > PROMPT_INTERVAL) {
return true;
}
return false;
}
private void updateLastRecovered(long time) {
SharedPreferences prefs = mContext.getSharedPreferences(
RECOVERY_PREFERENCES, Context.MODE_PRIVATE);
prefs.edit()
.putLong(KEY_LAST_RECOVERED, time)
.apply();
}
private Bundle loadCrashState() {
if (!shouldRestore()) {
return null;
}
Bundle state = null;
Parcel parcel = Parcel.obtain();
FileInputStream fin = null;
try {
File stateFile = new File(mContext.getCacheDir(), STATE_FILE);
fin = new FileInputStream(stateFile);
ByteArrayOutputStream dataStream = new ByteArrayOutputStream();
byte[] buffer = new byte[BUFFER_SIZE];
int read;
while ((read = fin.read(buffer)) > 0) {
dataStream.write(buffer, 0, read);
}
byte[] data = dataStream.toByteArray();
parcel.unmarshall(data, 0, data.length);
parcel.setDataPosition(0);
state = parcel.readBundle();
} catch (FileNotFoundException e) {
// No state to recover
state = null;
} catch (Throwable e) {
Log.w(LOGTAG, "Failed to recover state!", e);
state = null;
} finally {
parcel.recycle();
if (fin != null) {
try {
fin.close();
} catch (IOException e) { }
}
}
if (state != null && !state.isEmpty()) {
return state;
}
return null;
}
public void startRecovery(Intent intent) {
synchronized (CrashRecoveryHandler.this) {
while (mIsPreloading) {
try {
CrashRecoveryHandler.this.wait();
} catch (InterruptedException e) {}
}
}
if (!mDidPreload) {
mRecoveryState = loadCrashState();
}
updateLastRecovered(mRecoveryState != null
? System.currentTimeMillis() : 0);
mController.doStart(mRecoveryState, intent);
mRecoveryState = null;
}
public void preloadCrashState() {
synchronized (CrashRecoveryHandler.this) {
if (mIsPreloading) {
return;
}
mIsPreloading = true;
}
mBackgroundHandler.sendEmptyMessage(MSG_PRELOAD_STATE);
}
}
|
