Source: lib/util/multi_map.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.util.MultiMap');
  22. /**
  23.  * A simple multimap template.
  24.  * @constructor
  25.  * @struct
  26.  * @template T
  27.  */
  28. shaka.util.MultiMap = function() {
  29.   /** @private {!Object.<string, !Array.<T>>} */
  30.   this.map_ = {};
  31. };
  34. /**
  35.  * Add a key, value pair to the map.
  36.  * @param {string} key
  37.  * @param {T} value
  38.  */
  39. shaka.util.MultiMap.prototype.push = function(key, value) {
  40.   if (this.map_.hasOwnProperty(key)) {
  41.     this.map_[key].push(value);
  42.   } else {
  43.     this.map_[key] = [value];
  44.   }
  45. };
  48. /**
  49.  * Get a list of values by key.
  50.  * @param {string} key
  51.  * @return {Array.<T>} or null if no such key exists.
  52.  */
  53. shaka.util.MultiMap.prototype.get = function(key) {
  54.   var list = this.map_[key];
  55.   // slice() clones the list so that it and the map can each be modified
  56.   // without affecting the other.
  57.   return list ? list.slice() : null;
  58. };
  61. /**
  62.  * Get a list of all values.
  63.  * @return {!Array.<T>}
  64.  */
  65. shaka.util.MultiMap.prototype.getAll = function() {
  66.   var list = [];
  67.   for (var key in this.map_) {
  68.     list.push.apply(list, this.map_[key]);
  69.   }
  70.   return list;
  71. };
  74. /**
  75.  * Remove a specific value, if it exists.
  76.  * @param {string} key
  77.  * @param {T} value
  78.  */
  79. shaka.util.MultiMap.prototype.remove = function(key, value) {
  80.   var list = this.map_[key];
  81.   if (!list) return;
  82.   for (var i = 0; i < list.length; ++i) {
  83.     if (list[i] == value) {
  84.       list.splice(i, 1);
  85.       --i;
  86.     }
  87.   }
  88. };
  91. /**
  92.  * Clear all keys and values from the multimap.
  93.  */
  94. shaka.util.MultiMap.prototype.clear = function() {
  95.   this.map_ = {};
  96. };