Source: lib/offline/indexeddb/db_connection.js

  1. /**
  2.  * @license
  3.  * Copyright 2016 Google Inc.
  4.  *
  5.  * Licensed under the Apache License, Version 2.0 (the "License");
  6.  * you may not use this file except in compliance with the License.
  7.  * You may obtain a copy of the License at
  8.  *
  9.  *     http://www.apache.org/licenses/LICENSE-2.0
  10.  *
  11.  * Unless required by applicable law or agreed to in writing, software
  12.  * distributed under the License is distributed on an "AS IS" BASIS,
  13.  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14.  * See the License for the specific language governing permissions and
  15.  * limitations under the License.
  16.  */
  18. goog.provide('shaka.offline.indexeddb.DBConnection');
  20. goog.require('shaka.offline.indexeddb.DBOperation');
  21. goog.require('shaka.util.ArrayUtils');
  25. /**
  26.  * DBConnection is used to manage an IndexedDB connection. It can create new
  27.  * operations. If the connection is killed (via |destroy|) all pending
  28.  * operations will be cancelled.
  29.  */
  30. shaka.offline.indexeddb.DBConnection = class {
  31.   /**
  32.    * @param {IDBDatabase} connection A connection to an IndexedDB instance.
  33.    */
  34.   constructor(connection) {
  35.     /** @private {IDBDatabase} */
  36.     this.connection_ = connection;
  37.     /** @private {!Array.<shaka.offline.indexeddb.DBOperation>} */
  38.     this.pending_ = [];
  39.   }
  41.   /**
  42.    * @return {!Promise}
  43.    */
  44.   destroy() {
  45.     return Promise.all(this.pending_.map((op) => {
  46.       return op.abort();
  47.     }));
  48.   }
  50.   /**
  51.    * @param {string} store The name of the store that the operation should
  52.    *                       occur on.
  53.    * @return {!shaka.offline.indexeddb.DBOperation}
  54.    */
  55.   startReadOnlyOperation(store) {
  56.     return this.startOperation_(store, 'readonly');
  57.   }
  59.   /**
  60.    * @param {string} store The name of the store that the operation should
  61.    *                       occur on.
  62.    * @return {!shaka.offline.indexeddb.DBOperation}
  63.    */
  64.   startReadWriteOperation(store) {
  65.     return this.startOperation_(store, 'readwrite');
  66.   }
  68.   /**
  69.    * @param {string} store The name of the store that the operation should
  70.    *                       occur on.
  71.    * @param {string} type The type of operation being performed on the store.
  72.    *                      This determines what commands may be performed. This
  73.    *                      can either be "readonly" or "readwrite".
  74.    * @return {!shaka.offline.indexeddb.DBOperation}
  75.    * @private
  76.    */
  77.   startOperation_(store, type) {
  78.     let transaction = this.connection_.transaction([store], type);
  79.     let operation = new shaka.offline.indexeddb.DBOperation(transaction, store);
  81.     this.pending_.push(operation);
  83.     // Once the operation is done (regardless of outcome) stop tracking it.
  84.     operation.promise().then(
  85.         () => this.stopTracking_(operation),
  86.         () => this.stopTracking_(operation)
  87.     );
  89.     return operation;
  90.   }
  92.   /**
  93.    * @param {!shaka.offline.indexeddb.DBOperation} operation
  94.    * @private
  95.    */
  96.   stopTracking_(operation) {
  97.     shaka.util.ArrayUtils.remove(this.pending_, operation);
  98.   }
  99. };