学步园

//
//  ObjectPool.h
//  DragonBall
//
//  Created by user on 13-8-22.
//
//

#ifndef __DragonBall__ObjectPool__
#define __DragonBall__ObjectPool__

#include <iostream>
#include <vector>
#include "cocos2d.h"
#include <algorithm>
using namespace std;
using namespace cocos2d;

template <typename T>
class ObjectPool{
    
    
public:
    
    ObjectPool(int initSize):m_initSize(initSize)
    {
        CCAssert(m_initSize >= 4, "m_initSize should >= 4");
        allocate(initSize);
    };
    
    
    virtual ~ObjectPool()
    {
        for_each(m_usedList.begin(), m_usedList.end(), freeObject);
        for_each(m_freeList.begin(), m_freeList.end(), freeObject);
    }
    
    // 请求一个对象
    T* request(){
        
        //先检查空闲里面是否为空
        if (m_freeList.size() == 0) {
            allocate(m_initSize/2);
        }
        
        T* t = m_freeList[0];
        m_freeList.erase(m_freeList.begin());
        m_usedList.push_back(t);
        return t;
    };
    
    
    // 放回一个对象到池里面
    void putback(T* t)
    {
        for (int i = 0; i < m_usedList.size(); ++i) {
            if (t == m_usedList[i]) {
                //找到此对象
                m_usedList.erase(m_usedList.begin() + i);
                m_freeList.push_back(t);return;
            }
        }
    }
    
    
    //为了避免内存的不断增长，需要保持空间
    void garbage()
    {
        //打印下大小
        CCLog("m_usedList.size:%d",m_usedList.size());
        CCLog("m_freeList.size:%d",m_freeList.size());
        
        //如果空余的多余20则删除到初始化个数
        if (m_freeList.size() > m_initSize) {

            typename vector<T*>::iterator it = m_freeList.begin();
            int pIndex = 0;
            while (it != m_freeList.end()) {
                
                if (pIndex > m_initSize) {
                    T* t = (*it);
                    m_freeList.erase(it);
                    freeObject(t);
                    --it;
                }
                
                ++pIndex;
                ++it;
            }
        }
    }
    
private:
    
    // 分配size个空间
    void allocate(int size)
    {
        for (int i = 0; i < size; ++i) {
            T* t = new T;
            m_freeList.push_back(t);
        }
    }
    
    static void freeObject(void* p)
    {
        T* t = (T*)p;
        CCObject* temp = (CCObject*)t;
        CCLog("temp.ref : %d",temp->retainCount());
        delete t;
    }
private:
    
    
    // 使用两个list一个用来放已经使用的,一个用来放未使用的
    vector<T*> m_freeList;
    vector<T*> m_usedList;
    
    // 初始容量
    int m_initSize;
    
};


#endif /* defined(__DragonBall__ObjectPool__) */

／／初始化里面，参数为默认池的大小

当需要请求一个对象的时候：

 CCSprite* sp = m_objectPool->request();
当对象使用完毕后，
	先从屏幕上移除.,然后再放回池中
        firstSprite->removeFromParentAndCleanup(true);
	 m_objectPool->putback(firstSprite);
注意garbage方法，

为了避免内存的无限增长，需要定时检查空余内存