chrome/test/data/indexeddb/endure/app.js

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 // This file simulates a typical foreground process of an offline-capable
   6 // authoring application. When in an "offline" state, simulated user actions
   7 // are recorded for later playback in an IDB data store. When in an "online"
   8 // state, the recorded actions are drained from the store (as if being sent
   9 // to the server).
  10
  11 var $ = function(s) {
  12   return document.querySelector(s);
  13 };
  14
  15 function status(message) {
  16   var elem = $('#status');
  17   while (elem.firstChild)
  18     elem.removeChild(elem.firstChild);
  19   elem.appendChild(document.createTextNode(message));
  20 }
  21
  22 function log(message) {
  23   status(message);
  24 }
  25
  26 function error(message) {
  27   status(message);
  28   console.error(message);
  29 }
  30
  31 function unexpectedErrorCallback(e) {
  32   error("Unexpected error callback: (" + e.target.error.name + ") " +
  33         e.target.error.message);
  34 }
  35
  36 function unexpectedAbortCallback(e) {
  37   error("Unexpected abort callback: (" + e.target.error.name + ") " +
  38         e.target.error.message);
  39 }
  40
  41 function unexpectedBlockedCallback(e) {
  42   error("Unexpected blocked callback!");
  43 }
  44
  45 var DBNAME = 'endurance-db';
  46 var DBVERSION = 1;
  47 var MAX_DOC_ID = 25;
  48
  49 var db;
  50
  51 function initdb() {
  52   var request = indexedDB.deleteDatabase(DBNAME);
  53   request.onerror = unexpectedErrorCallback;
  54   request.onblocked = unexpectedBlockedCallback;
  55   request.onsuccess = function () {
  56     request = indexedDB.open(DBNAME, DBVERSION);
  57     request.onerror = unexpectedErrorCallback;
  58     request.onblocked = unexpectedBlockedCallback;
  59     request.onupgradeneeded = function () {
  60       db = request.result;
  61       request.transaction.onabort = unexpectedAbortCallback;
  62
  63       var syncStore = db.createObjectStore(
  64         'sync-chunks', {keyPath: 'sequence', autoIncrement: true});
  65       syncStore.createIndex('doc-index', 'docid');
  66
  67       var docStore = db.createObjectStore(
  68         'docs', {keyPath: 'docid'});
  69       docStore.createIndex(
  70         'owner-index', 'owner', {multiEntry: true});
  71
  72       var userEventStore = db.createObjectStore(
  73         'user-events', {keyPath: 'sequence', autoIncrement: true});
  74       userEventStore.createIndex('doc-index', 'docid');
  75     };
  76     request.onsuccess = function () {
  77       log('initialized');
  78       $('#offline').disabled = true;
  79       $('#online').disabled = false;
  80     };
  81   };
  82 }
  83
  84 var offline = true;
  85 var worker = new Worker('app-worker.js?cachebust');
  86 worker.onmessage = function (event) {
  87   var data = event.data;
  88   switch (data.type) {
  89     case 'ABORT':
  90       unexpectedAbortCallback({target: {error: data.error}});
  91       break;
  92     case 'ERROR':
  93       unexpectedErrorCallback({target: {error: data.error}});
  94       break;
  95     case 'BLOCKED':
  96       unexpectedBlockedCallback({target: {error: data.error}});
  97       break;
  98     case 'LOG':
  99       log('WORKER: ' + data.message);
 100       break;
 101     case 'ERROR':
 102       error('WORKER: ' + data.message);
 103       break;
 104     }
 105 };
 106 worker.onerror = function (event) {
 107   error("Error in: " + event.filename + "(" + event.lineno + "): " +
 108         event.message);
 109 };
 110
 111 $('#offline').addEventListener('click', goOffline);
 112 $('#online').addEventListener('click', goOnline);
 113
 114 var EVENT_INTERVAL = 100;
 115 var eventIntervalId = 0;
 116
 117 function goOffline() {
 118   if (offline)
 119     return;
 120   offline = true;
 121   $('#offline').disabled = offline;
 122   $('#online').disabled = !offline;
 123   $('#state').innerHTML = 'offline';
 124   log('offline');
 125
 126   worker.postMessage({type: 'offline'});
 127
 128   eventIntervalId = setInterval(recordEvent, EVENT_INTERVAL);
 129 }
 130
 131 function goOnline() {
 132   if (!offline)
 133     return;
 134   offline = false;
 135   $('#offline').disabled = offline;
 136   $('#online').disabled = !offline;
 137   $('#state').innerHTML = 'online';
 138   log('online');
 139
 140   worker.postMessage({type: 'online'});
 141
 142   setTimeout(playbackEvents, 100);
 143   clearInterval(eventIntervalId);
 144   eventIntervalId = 0;
 145 };
 146
 147 function recordEvent() {
 148   if (!db) {
 149     error("Database not initialized");
 150     return;
 151   }
 152
 153   var transaction = db.transaction(['user-events'], 'readwrite');
 154   var store = transaction.objectStore('user-events');
 155   var record = {
 156     // 'sequence' key will be generated
 157     docid: Math.floor(Math.random() * MAX_DOC_ID),
 158     timestamp: new Date(),
 159     data: randomString(256)
 160   };
 161
 162   log('putting user event');
 163   var request = store.put(record);
 164   request.onerror = unexpectedErrorCallback;
 165   transaction.onabort = unexpectedAbortCallback;
 166   transaction.oncomplete = function () {
 167     log('put user event');
 168   };
 169 }
 170
 171 function sendEvent(record, callback) {
 172   setTimeout(
 173     function () {
 174       if (offline)
 175         callback(false);
 176       else {
 177         var serialization = JSON.stringify(record);
 178         callback(true);
 179       }
 180     },
 181     Math.random() * 200); // Simulate network jitter
 182 }
 183
 184 var PLAYBACK_NONE = 0;
 185 var PLAYBACK_SUCCESS = 1;
 186 var PLAYBACK_FAILURE = 2;
 187
 188 function playbackEvent(callback) {
 189   log('playbackEvent');
 190   var result = false;
 191   var transaction = db.transaction(['user-events'], 'readonly');
 192   transaction.onabort = unexpectedAbortCallback;
 193   var store = transaction.objectStore('user-events');
 194   var cursorRequest = store.openCursor();
 195   cursorRequest.onerror = unexpectedErrorCallback;
 196   cursorRequest.onsuccess = function () {
 197     var cursor = cursorRequest.result;
 198     if (cursor) {
 199       var record = cursor.value;
 200       var key = cursor.key;
 201       // NOTE: sendEvent is asynchronous so transaction should finish
 202       sendEvent(
 203         record,
 204         function (success) {
 205           if (success) {
 206             // Use another transaction to delete event
 207             var transaction = db.transaction(['user-events'], 'readwrite');
 208             transaction.onabort = unexpectedAbortCallback;
 209             var store = transaction.objectStore('user-events');
 210             var deleteRequest = store.delete(key);
 211             deleteRequest.onerror = unexpectedErrorCallback;
 212             transaction.oncomplete = function () {
 213               // successfully sent and deleted event
 214               callback(PLAYBACK_SUCCESS);
 215             };
 216           } else {
 217             // No progress made
 218             callback(PLAYBACK_FAILURE);
 219           }
 220         });
 221     } else {
 222       callback(PLAYBACK_NONE);
 223     }
 224   };
 225 }
 226
 227 var playback = false;
 228
 229 function playbackEvents() {
 230   log('playbackEvents');
 231   if (!db) {
 232     error("Database not initialized");
 233     return;
 234   }
 235
 236   if (playback)
 237     return;
 238
 239   playback = true;
 240   log("Playing back events");
 241
 242   function nextEvent() {
 243     playbackEvent(
 244       function (result) {
 245         switch (result) {
 246           case PLAYBACK_NONE:
 247             playback = false;
 248             log("Done playing back events");
 249             return;
 250           case PLAYBACK_SUCCESS:
 251             setTimeout(nextEvent, 0);
 252             return;
 253           case PLAYBACK_FAILURE:
 254             playback = false;
 255             log("Failure during playback (dropped offline?)");
 256             return;
 257         }
 258       });
 259   }
 260
 261   nextEvent();
 262 }
 263
 264 function randomString(len) {
 265   var s = '';
 266   while (len--)
 267     s += Math.floor((Math.random() * 36)).toString(36);
 268   return s;
 269 }
 270
 271 window.onload = function () {
 272   log("initializing...");
 273   initdb();
 274 };