/**
* @license
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
goog.provide('shaka.util.MultiMap');
/**
* A simple multimap template.
* @constructor
* @struct
* @template T
*/
shaka.util.MultiMap = function() {
/** @private {!Object.<string, !Array.<T>>} */
this.map_ = {};
};
/**
* Add a key, value pair to the map.
* @param {string} key
* @param {T} value
*/
shaka.util.MultiMap.prototype.push = function(key, value) {
if (this.map_.hasOwnProperty(key)) {
this.map_[key].push(value);
} else {
this.map_[key] = [value];
}
};
/**
* Get a list of values by key.
* @param {string} key
* @return {Array.<T>} or null if no such key exists.
*/
shaka.util.MultiMap.prototype.get = function(key) {
let list = this.map_[key];
// slice() clones the list so that it and the map can each be modified
// without affecting the other.
return list ? list.slice() : null;
};
/**
* Get a list of all values.
* @return {!Array.<T>}
*/
shaka.util.MultiMap.prototype.getAll = function() {
let list = [];
for (let key in this.map_) {
list.push.apply(list, this.map_[key]);
}
return list;
};
/**
* Remove a specific value, if it exists.
* @param {string} key
* @param {T} value
*/
shaka.util.MultiMap.prototype.remove = function(key, value) {
let list = this.map_[key];
if (!list) return;
for (let i = 0; i < list.length; ++i) {
if (list[i] == value) {
list.splice(i, 1);
--i;
}
}
};
/**
* Clear all keys and values from the multimap.
*/
shaka.util.MultiMap.prototype.clear = function() {
this.map_ = {};
};
/**
* @param {function(string, !Array.<T>)} callback
*/
shaka.util.MultiMap.prototype.forEach = function(callback) {
for (let key in this.map_) {
callback(key, this.map_[key]);
}
};
/**
* Returns the number of elements in the multimap.
* @return {number}
*/
shaka.util.MultiMap.prototype.size = function() {
return Object.keys(this.map_).length;
};