IOS ID生成器

//

//  IdGenerator.m

//  Copyright (c) 2014年 青岛拓宇网络科技有限公司. All rights reserved.

//



#import "IdGenerator.h"



static long long time_stamp = 0;

static long long time_stamp_now = 0;

static NSMutableArray *temp = NULL;

static NSNumber *random_n = NULL;

static NSLock *theLock = NULL;



@implementation IdGenerator



/*

 *  获取下一个Id

 */

+ (long long)next{

    

    if(theLock == NULL)

        theLock = [[NSLock alloc]init];

    

    if(temp == NULL)

        temp = [[NSMutableArray alloc]init];

    

    @synchronized(theLock){

        time_stamp_now = [[NSDate date] timeIntervalSince1970];

        if(time_stamp_now != time_stamp){

            //清空缓存，更新时间戳

            [temp removeAllObjects];

            time_stamp = time_stamp_now;

        }

        

        //判断缓存中是否存在当前随机数

        while ([temp containsObject:(random_n = [NSNumber numberWithLong:arc4random() % 8999 + 1000])])

            ;

        

        if ([temp containsObject:random_n]) {

            return -1;

        }

        

        [temp addObject:[NSNumber numberWithLong:[random_n longValue]]];

    }

    

    return (time_stamp * 10000) + [random_n longValue];

}



@end

不重复的Id生成器，理论上每秒钟最多可以生成8999条Id，实际上每秒钟约能生成6000条Id。

转载请标明出处：http://www.cnblogs.com/anxin1225/p/3660506.html

友情链接地址：http://c.jinhusns.com/