1 /* 2 * Copyright (C) 2010 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 package com.replica.replicaisland; 17 18 /** 19 * A general-purpose pool of objects. Objects in the pool are allocated up front and then 20 * passed out to requesting objects until the pool is exhausted (at which point an error is thrown). 21 * Code that requests objects from the pool should return them to the pool when they are finished. 22 * This class is abstract; derivations need to implement the fill() function to fill the pool, and 23 * may wish to override release() to clear state on objects as they are returned to the pool. 24 */ 25 public abstract class ObjectPool extends BaseObject { 26 private FixedSizeArray<Object> mAvailable; 27 private int mSize; 28 29 private static final int DEFAULT_SIZE = 32; 30 ObjectPool()31 public ObjectPool() { 32 super(); 33 setSize(DEFAULT_SIZE); 34 } 35 ObjectPool(int size)36 public ObjectPool(int size) { 37 super(); 38 setSize(size); 39 } 40 41 @Override reset()42 public void reset() { 43 } 44 45 /** Allocates an object from the pool */ allocate()46 protected Object allocate() { 47 Object result = mAvailable.removeLast(); 48 assert result != null : "Object pool of type " + this.getClass().getSimpleName() 49 + " exhausted!!"; 50 return result; 51 } 52 53 /** Returns an object to the pool. */ release(Object entry)54 public void release(Object entry) { 55 mAvailable.add(entry); 56 } 57 58 /** Returns the number of pooled elements that have been allocated but not released. */ getAllocatedCount()59 public int getAllocatedCount() { 60 return mAvailable.getCapacity() - mAvailable.getCount(); 61 } 62 setSize(int size)63 private void setSize(int size) { 64 mSize = size; 65 mAvailable = new FixedSizeArray<Object>(mSize); 66 67 fill(); 68 } 69 fill()70 protected abstract void fill(); 71 getAvailable()72 protected FixedSizeArray<Object> getAvailable() { 73 return mAvailable; 74 } 75 getSize()76 protected int getSize() { 77 return mSize; 78 } 79 80 81 } 82