1 /* 2 * Copyright (C) 2007 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 17 package android.webkit; 18 19 import android.content.Context; 20 import android.os.Handler; 21 import android.os.Looper; 22 import android.os.Message; 23 import android.os.Process; 24 import android.util.Log; 25 26 abstract class WebSyncManager implements Runnable { 27 // message code for sync message 28 private static final int SYNC_MESSAGE = 101; 29 // time delay in millisec for a sync (now) message 30 private static int SYNC_NOW_INTERVAL = 100; // 100 millisec 31 // time delay in millisec for a sync (later) message 32 private static int SYNC_LATER_INTERVAL = 5 * 60 * 1000; // 5 minutes 33 // thread for syncing 34 private Thread mSyncThread; 35 // Name of thread 36 private String mThreadName; 37 // handler of the sync thread 38 protected Handler mHandler; 39 // database for the persistent storage 40 protected WebViewDatabase mDataBase; 41 // Ref count for calls to start/stop sync 42 private int mStartSyncRefCount; 43 // log tag 44 protected static final String LOGTAG = "websync"; 45 46 private class SyncHandler extends Handler { 47 @Override handleMessage(Message msg)48 public void handleMessage(Message msg) { 49 if (msg.what == SYNC_MESSAGE) { 50 if (DebugFlags.WEB_SYNC_MANAGER) { 51 Log.v(LOGTAG, "*** WebSyncManager sync ***"); 52 } 53 syncFromRamToFlash(); 54 55 // send a delayed message to request sync later 56 Message newmsg = obtainMessage(SYNC_MESSAGE); 57 sendMessageDelayed(newmsg, SYNC_LATER_INTERVAL); 58 } 59 } 60 } 61 WebSyncManager(Context context, String name)62 protected WebSyncManager(Context context, String name) { 63 mThreadName = name; 64 if (context != null) { 65 mDataBase = WebViewDatabase.getInstance(context); 66 mSyncThread = new Thread(this); 67 mSyncThread.setName(mThreadName); 68 mSyncThread.start(); 69 } else { 70 throw new IllegalStateException( 71 "WebSyncManager can't be created without context"); 72 } 73 } 74 clone()75 protected Object clone() throws CloneNotSupportedException { 76 throw new CloneNotSupportedException("doesn't implement Cloneable"); 77 } 78 run()79 public void run() { 80 // prepare Looper for sync handler 81 Looper.prepare(); 82 mHandler = new SyncHandler(); 83 onSyncInit(); 84 // lower the priority after onSyncInit() is done 85 Process.setThreadPriority(Process.THREAD_PRIORITY_BACKGROUND); 86 87 Message msg = mHandler.obtainMessage(SYNC_MESSAGE); 88 mHandler.sendMessageDelayed(msg, SYNC_LATER_INTERVAL); 89 90 Looper.loop(); 91 } 92 93 /** 94 * sync() forces sync manager to sync now 95 */ sync()96 public void sync() { 97 if (DebugFlags.WEB_SYNC_MANAGER) { 98 Log.v(LOGTAG, "*** WebSyncManager sync ***"); 99 } 100 if (mHandler == null) { 101 return; 102 } 103 mHandler.removeMessages(SYNC_MESSAGE); 104 Message msg = mHandler.obtainMessage(SYNC_MESSAGE); 105 mHandler.sendMessageDelayed(msg, SYNC_NOW_INTERVAL); 106 } 107 108 /** 109 * resetSync() resets sync manager's timer 110 */ resetSync()111 public void resetSync() { 112 if (DebugFlags.WEB_SYNC_MANAGER) { 113 Log.v(LOGTAG, "*** WebSyncManager resetSync ***"); 114 } 115 if (mHandler == null) { 116 return; 117 } 118 mHandler.removeMessages(SYNC_MESSAGE); 119 Message msg = mHandler.obtainMessage(SYNC_MESSAGE); 120 mHandler.sendMessageDelayed(msg, SYNC_LATER_INTERVAL); 121 } 122 123 /** 124 * startSync() requests sync manager to start sync 125 */ startSync()126 public void startSync() { 127 if (DebugFlags.WEB_SYNC_MANAGER) { 128 Log.v(LOGTAG, "*** WebSyncManager startSync ***, Ref count:" + 129 mStartSyncRefCount); 130 } 131 if (mHandler == null) { 132 return; 133 } 134 if (++mStartSyncRefCount == 1) { 135 Message msg = mHandler.obtainMessage(SYNC_MESSAGE); 136 mHandler.sendMessageDelayed(msg, SYNC_LATER_INTERVAL); 137 } 138 } 139 140 /** 141 * stopSync() requests sync manager to stop sync. remove any SYNC_MESSAGE in 142 * the queue to break the sync loop 143 */ stopSync()144 public void stopSync() { 145 if (DebugFlags.WEB_SYNC_MANAGER) { 146 Log.v(LOGTAG, "*** WebSyncManager stopSync ***, Ref count:" + 147 mStartSyncRefCount); 148 } 149 if (mHandler == null) { 150 return; 151 } 152 if (--mStartSyncRefCount == 0) { 153 mHandler.removeMessages(SYNC_MESSAGE); 154 } 155 } 156 onSyncInit()157 protected void onSyncInit() { 158 } 159 syncFromRamToFlash()160 abstract void syncFromRamToFlash(); 161 } 162