Source: lib/offline/indexeddb/db_operation.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.DBOperation');
  21. goog.require('shaka.util.PublicPromise');
  25. /**
  26.  * A DBOperation wraps an IndexedDB transaction in a promise.
  27.  */
  28. shaka.offline.indexeddb.DBOperation = class {
  29.   /**
  30.    * @param {IDBTransaction} transaction
  31.    * @param {string} storeName
  32.    */
  33.   constructor(transaction, storeName) {
  34.     /** @private {IDBTransaction} */
  35.     this.transaction_ = transaction;
  36.     /** @private {IDBObjectStore} */
  37.     this.store_ = transaction.objectStore(storeName);
  38.     /** @private {!shaka.util.PublicPromise} */
  39.     this.promise_ = new shaka.util.PublicPromise();
  41.     // Connect the transaction and the promise together.
  42.     // |event.preventDefault()| is used on all non-successful callbacks to
  43.     // prevent Firefox from surfacing the error on the main thread.
  44.     transaction.onabort = (event) => {
  45.       event.preventDefault();
  46.       this.promise_.reject();
  47.     };
  48.     transaction.onerror = (event) => {
  49.       event.preventDefault();
  50.       this.promise_.reject();
  51.     };
  52.     transaction.oncomplete = (event) => {
  53.       this.promise_.resolve();
  54.     };
  55.   }
  57.   /**
  58.    * @return {!Promise}
  59.    */
  60.   abort() {
  61.     try {
  62.       this.transaction_.abort();
  63.     } catch (e) {
  64.       // Ignore any exceptions that may be thrown as a result of aborting
  65.       // the transaction.
  66.     }
  68.     // Wait for the promise to be rejected, but ignore the rejection error.
  69.     return this.promise_.catch(() => {});
  70.   }
  72.   /**
  73.    * Get the store that the operation can interact with. Requests can be made
  74.    * on the store. All requests made on the store will complete successfully
  75.    * before the operation's promise will resolve. If any request fails, the
  76.    * operation's promise will be rejected.
  77.    *
  78.    * @return {IDBObjectStore}
  79.    */
  80.   store() { return this.store_; }
  82.   /**
  83.    * Get the promise that wraps the transaction. This promise will resolve when
  84.    * all requests on the object store complete successfully and the transaction
  85.    * completes. If any request fails or the operation is aborted, the promise
  86.    * will be rejected.
  87.    *
  88.    * @return {!Promise}
  89.    */
  90.   promise() { return this.promise_; }
  91. };