Pinsave/counterstrike

1/* -*- Mode: js; js-indent-level: 2; -*- */2/*3 * Copyright 2011 Mozilla Foundation and contributors4 * Licensed under the New BSD license. See LICENSE or:5 * http://opensource.org/licenses/BSD-3-Clause6 */7 8var util = require('./util');9var has = Object.prototype.hasOwnProperty;10var hasNativeMap = typeof Map !== "undefined";11 12/**13 * A data structure which is a combination of an array and a set. Adding a new14 * member is O(1), testing for membership is O(1), and finding the index of an15 * element is O(1). Removing elements from the set is not supported. Only16 * strings are supported for membership.17 */18function ArraySet() {19  this._array = [];20  this._set = hasNativeMap ? new Map() : Object.create(null);21}22 23/**24 * Static method for creating ArraySet instances from an existing array.25 */26ArraySet.fromArray = function ArraySet_fromArray(aArray, aAllowDuplicates) {27  var set = new ArraySet();28  for (var i = 0, len = aArray.length; i < len; i++) {29    set.add(aArray[i], aAllowDuplicates);30  }31  return set;32};33 34/**35 * Return how many unique items are in this ArraySet. If duplicates have been36 * added, than those do not count towards the size.37 *38 * @returns Number39 */40ArraySet.prototype.size = function ArraySet_size() {41  return hasNativeMap ? this._set.size : Object.getOwnPropertyNames(this._set).length;42};43 44/**45 * Add the given string to this set.46 *47 * @param String aStr48 */49ArraySet.prototype.add = function ArraySet_add(aStr, aAllowDuplicates) {50  var sStr = hasNativeMap ? aStr : util.toSetString(aStr);51  var isDuplicate = hasNativeMap ? this.has(aStr) : has.call(this._set, sStr);52  var idx = this._array.length;53  if (!isDuplicate || aAllowDuplicates) {54    this._array.push(aStr);55  }56  if (!isDuplicate) {57    if (hasNativeMap) {58      this._set.set(aStr, idx);59    } else {60      this._set[sStr] = idx;61    }62  }63};64 65/**66 * Is the given string a member of this set?67 *68 * @param String aStr69 */70ArraySet.prototype.has = function ArraySet_has(aStr) {71  if (hasNativeMap) {72    return this._set.has(aStr);73  } else {74    var sStr = util.toSetString(aStr);75    return has.call(this._set, sStr);76  }77};78 79/**80 * What is the index of the given string in the array?81 *82 * @param String aStr83 */84ArraySet.prototype.indexOf = function ArraySet_indexOf(aStr) {85  if (hasNativeMap) {86    var idx = this._set.get(aStr);87    if (idx >= 0) {88        return idx;89    }90  } else {91    var sStr = util.toSetString(aStr);92    if (has.call(this._set, sStr)) {93      return this._set[sStr];94    }95  }96 97  throw new Error('"' + aStr + '" is not in the set.');98};99 100/**101 * What is the element at the given index?102 *103 * @param Number aIdx104 */105ArraySet.prototype.at = function ArraySet_at(aIdx) {106  if (aIdx >= 0 && aIdx < this._array.length) {107    return this._array[aIdx];108  }109  throw new Error('No element indexed by ' + aIdx);110};111 112/**113 * Returns the array representation of this set (which has the proper indices114 * indicated by indexOf). Note that this is a copy of the internal array used115 * for storing the members so that no one can mess with internal state.116 */117ArraySet.prototype.toArray = function ArraySet_toArray() {118  return this._array.slice();119};120 121exports.ArraySet = ArraySet;122