1 /* 2 * Copyright (C) 2009 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package android.util; 18 19 /** 20 * @hide 21 */ 22 class FinitePool<T extends Poolable<T>> implements Pool<T> { 23 /** 24 * Factory used to create new pool objects 25 */ 26 private final PoolableManager<T> mManager; 27 /** 28 * Maximum number of objects in the pool 29 */ 30 private final int mLimit; 31 /** 32 * If true, mLimit is ignored 33 */ 34 private final boolean mInfinite; 35 36 /** 37 * Next object to acquire 38 */ 39 private T mRoot; 40 /** 41 * Number of objects in the pool 42 */ 43 private int mPoolCount; 44 FinitePool(PoolableManager<T> manager)45 FinitePool(PoolableManager<T> manager) { 46 mManager = manager; 47 mLimit = 0; 48 mInfinite = true; 49 } 50 FinitePool(PoolableManager<T> manager, int limit)51 FinitePool(PoolableManager<T> manager, int limit) { 52 if (limit <= 0) throw new IllegalArgumentException("The pool limit must be > 0"); 53 54 mManager = manager; 55 mLimit = limit; 56 mInfinite = false; 57 } 58 acquire()59 public T acquire() { 60 T element; 61 62 if (mRoot != null) { 63 element = mRoot; 64 mRoot = element.getNextPoolable(); 65 mPoolCount--; 66 } else { 67 element = mManager.newInstance(); 68 } 69 70 if (element != null) { 71 element.setNextPoolable(null); 72 mManager.onAcquired(element); 73 } 74 75 return element; 76 } 77 release(T element)78 public void release(T element) { 79 if (mInfinite || mPoolCount < mLimit) { 80 mPoolCount++; 81 element.setNextPoolable(mRoot); 82 mRoot = element; 83 } 84 mManager.onReleased(element); 85 } 86 } 87