| // Copyright 2015 The Closure Library Authors. All Rights Reserved. |
| // |
| // 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. |
| |
| /** |
| * @fileoverview Simple freelist. |
| * |
| * An anterative to goog.structs.SimplePool, it imposes the requirement that the |
| * objects in the list contain a "next" property that can be used to maintain |
| * the pool. |
| */ |
| |
| goog.provide('goog.async.FreeList'); |
| |
| |
| /** |
| * @template ITEM |
| */ |
| goog.async.FreeList = goog.defineClass(null, { |
| /** |
| * @param {function():ITEM} create |
| * @param {function(ITEM):void} reset |
| * @param {number} limit |
| */ |
| constructor: function(create, reset, limit) { |
| /** @private @const {number} */ |
| this.limit_ = limit; |
| /** @private @const {function()} */ |
| this.create_ = create; |
| /** @private @const {function(ITEM):void} */ |
| this.reset_ = reset; |
| |
| /** @private {number} */ |
| this.occupants_ = 0; |
| /** @private {ITEM} */ |
| this.head_ = null; |
| }, |
| |
| /** |
| * @return {ITEM} |
| */ |
| get: function() { |
| var item; |
| if (this.occupants_ > 0) { |
| this.occupants_--; |
| item = this.head_; |
| this.head_ = item.next; |
| item.next = null; |
| } else { |
| item = this.create_(); |
| } |
| return item; |
| }, |
| |
| /** |
| * @param {ITEM} item An item available for possible future reuse. |
| */ |
| put: function(item) { |
| this.reset_(item); |
| if (this.occupants_ < this.limit_) { |
| this.occupants_++; |
| item.next = this.head_; |
| this.head_ = item; |
| } |
| }, |
| |
| /** |
| * Visible for testing. |
| * @package |
| * @return {number} |
| */ |
| occupants: function() { return this.occupants_; } |
| }); |