.NetCore使用Redis，StackExchange.Redis队列，发布与订阅，分布式锁的简单使用-轻识

https://www.cnblogs.com/Fengge518/p/13556182.html

环境：之前一直是使用serverStack.Redis的客服端，

今天来使用一下StackExchange.Redis(个人感觉更加的人性化一些，也是免费的，性能也不会差太多)，
版本为StackExchange.Redis V2.1.58 ,Core3.1

简单的说明(专业的术语参考资料网络和官网)：官网地址：https://www.redis.net.cn/

Redis（Remote Dictionary Server )，即远程字典服务是一个开源的，由C语言编写、支持网络、可基于内存亦可持久化的日志型、Key-Value数据库，并提供多种语言的API。

Redis 是一个高性能的key-value数据库。Redis的出现，很大程度补偿了memcached这类key/value存储的不足，

提供了Java，C/C++，C#，PHP，JavaScript，Perl，Object-C，Python，Ruby，Erlang等客户端，使用很方便。

优点：

1 Redis读写性能优异，从内存当中进行IO读写速度快，支持超过100K+每秒的读写频率。

2 Redis支持Strings,

Lists, Hashes, Sets,Ordered Sets等数据类型操作。

3 Redis支持数据持久化，支持AOF和RDB两种持久化方式

4 Redis支持主从复制，主机会自动将数据同步到从机，可以进行读写分离。

5 Redis的所有操作都是原子性的，同时Redis还支持对几个操作全并后的原子性执行。

6 Redis是单线程多CPU，不需要考虑加锁释放锁，也就没有死锁的问题，效率高。

1：redis队列值入队出队,截图效果：

优化之前入队1000条数据，测试结果将近50秒，这实在太慢，不可忍受！

优化后的效果：为5.55s的样子

2：redis发布与订阅截图效果：(一个发布者，四个订阅者) 订阅者都会收到相同的信息

3：redis秒杀，截图如下：单个进程秒杀ok

开多个进程时，会有超卖的现象：（那我加lock锁呢？结果也是会有超卖的现象，此时下面的分布式锁可以解决）

4：加上redis分布式锁的测试效果截图：

但是这样会比较耗资源，库存已经没有了，就应该不要再去执行下去了

分布式锁ok库存为零就不在请求直接抛异常即可

上面通过测试的截图，简单的介绍了，Redis的队列(入队和出队)，Redis发布与订阅，Redis分布式锁的使用，现在直接上代码：

出队入队的WebApi Core3.1

using System;using System.Collections.Generic;using System.Linq;using System.Threading.Tasks;
namespace WebApp.Controllers{    using Microsoft.AspNetCore.Mvc;    using RedisPublishAndSubHelper;    [Route("api/[Controller]")]    [ApiController]    public class RedisTestController    {        [HttpGet("EnqueueMsg")]        public async Task EnqueueMsgAsync(string rediskey, string redisValue)        {            ApiResultObject obj = new ApiResultObject();            try            {                long enqueueLong = default;                for (int i = 0; i < 1000; i++)                {                    enqueueLong = await MyRedisSubPublishHelper.EnqueueListLeftPushAsync(rediskey, redisValue + i);                }                obj.Code = ResultCode.Success;                obj.Data = "入队的数据长度：" + enqueueLong;                obj.Msg = "入队成功！";            }            catch (Exception ex)            {
                obj.Msg = $"入队异常，原因：{ex.Message}";            }            return obj;        }        [HttpGet("DequeueMsg")]        public async Task DequeueMsgAsync(string rediskey)        {            ApiResultObject obj = new ApiResultObject();            try            {                string dequeueMsg = await MyRedisSubPublishHelper.DequeueListPopRightAsync(rediskey);                obj.Code = ResultCode.Success;                obj.Data = $"出队的数据是：{dequeueMsg}";                obj.Msg = "入队成功！";            }            catch (Exception ex)            {                obj.Msg = $"入队异常，原因：{ex.Message}";            }            return obj;        }    }}

出队入队的后端code WebApi：

using System;using System.Collections.Generic;using System.Linq;using System.Threading.Tasks;
namespace WebApp.Controllers{    using Microsoft.AspNetCore.Mvc;    using RedisPublishAndSubHelper;    [Route("api/[Controller]")]    [ApiController]    public class RedisTestController    {        [HttpGet("EnqueueMsg")]        public async Task EnqueueMsgAsync(string rediskey, string redisValue)        {            ApiResultObject obj = new ApiResultObject();            try            {                long enqueueLong = default;                for (int i = 0; i < 1000; i++)                {                    enqueueLong = await MyRedisSubPublishHelper.EnqueueListLeftPushAsync(rediskey, redisValue + i);                }                obj.Code = ResultCode.Success;                obj.Data = "入队的数据长度：" + enqueueLong;                obj.Msg = "入队成功！";            }            catch (Exception ex)            {
                obj.Msg = $"入队异常，原因：{ex.Message}";            }            return obj;        }        [HttpGet("DequeueMsg")]        public async Task DequeueMsgAsync(string rediskey)        {            ApiResultObject obj = new ApiResultObject();            try            {                string dequeueMsg = await MyRedisSubPublishHelper.DequeueListPopRightAsync(rediskey);                obj.Code = ResultCode.Success;                obj.Data = $"出队的数据是：{dequeueMsg}";                obj.Msg = "入队成功！";            }            catch (Exception ex)            {                obj.Msg = $"入队异常，原因：{ex.Message}";            }            return obj;        }    }}

入队以及秒杀分布式锁的客服端的Code：

using System;using System.Threading;using System.Threading.Tasks;
namespace RedisPublishService{    using RedisPublishAndSubHelper;    class Program    {        static void Main(string[] args)        {            #region 入队的code            {                int Index = 100000;                while (Index > 0)                {                    //string msg = Console.ReadLine();                    new MyRedisSubPublishHelper().PublishMessage("nihaofengge", $"你好风哥：Guid值是：{DateTime.Now}{Guid.NewGuid().ToString()}");                    Console.WriteLine("发布成功！");                    Index -= 1;                }                Console.ReadKey();            }            #endregion
            #region 秒杀的code            {                try                {                    Console.WriteLine("秒杀开始。。。。。");                    for (int i = 0; i < 200; i++)                    {                        Task.Run(() =>                        {                            MyRedisSubPublishHelper.LockByRedis("mstest");                            string productCount = MyRedisHelper.StringGet("productcount");                            int pcount = int.Parse(productCount);                            if (pcount > 0)                            {                                long dlong = MyRedisHelper.StringDec("productcount");                                Console.WriteLine($"秒杀成功，商品库存:{dlong}");                                pcount -= 1;                                System.Threading.Thread.Sleep(30);                            }                            else                            {                                Console.WriteLine($"秒杀失败，商品库存为零了！");                                throw new Exception("产品秒杀数量为零！");//加载这里会比较保险                        }                            MyRedisSubPublishHelper.UnLockByRedis("mstest");                        }).Wait();                    }                }                catch (Exception ex)                {                    Console.WriteLine($"产品已经秒杀完毕，原因：{ex.Message}");                }                Console.ReadKey();            }            #endregion        }    }}

完整的code RedisHelper帮助类(测试并使用了部分方法的封装)，

using System;using System.Collections.Generic;using System.Linq;using System.Threading.Tasks;
namespace RedisPublishAndSubHelper{    using StackExchange.Redis;    using StackExchange;    using System.Threading;
    public class MyRedisHelper    {        private static readonly string connectionRedisStr = string.Empty;        static MyRedisHelper()        {            //在这里来初始化一些配置信息            connectionRedisStr = "12.23.45.12:6379,connectTimeout=1000,connectRetry=3,syncTimeout=10000";        }
        #region Redis string简单的常见同步方法操作        public static bool StringSet(string key, string stringValue, double senconds = 60)        {            using (var conn = ConnectionMultiplexer.Connect(connectionRedisStr))            {                IDatabase db = conn.GetDatabase();                return db.StringSet(key, stringValue, TimeSpan.FromSeconds(senconds));            }        }        public static string StringGet(string key)        {            using (var conn = ConnectionMultiplexer.Connect(connectionRedisStr))            {                IDatabase db = conn.GetDatabase();                return db.StringGet(key);            }        }
        public static long StringInc(string key)        {            using (var conn = ConnectionMultiplexer.Connect(connectionRedisStr))            {                IDatabase db = conn.GetDatabase();                return db.StringIncrement(key);            }        }
        public static long StringDec(string key)        {            using (var conn = ConnectionMultiplexer.Connect(connectionRedisStr))            {                IDatabase db = conn.GetDatabase();                return db.StringDecrement(key);            }        }        public static bool KeyExists(string key)        {            using (var conn = ConnectionMultiplexer.Connect(connectionRedisStr))            {                IDatabase db = conn.GetDatabase();                return db.KeyExists(key);            }        }        #endregion
        #region List Hash, Set,Zset 大同小异的使用，比较简单,后续有时间再补上
        #endregion
        #region 入队出队
        #region 入队        ///         /// 入队right        /// 
        ///         ///         ///         public static long EnqueueListRightPush(RedisKey queueName, RedisValue redisValue)        {            using (var conn = ConnectionMultiplexer.Connect(connectionRedisStr))            {                return conn.GetDatabase().ListRightPush(queueName, redisValue);            }        }        ///         /// 入队left        /// 
        ///         ///         ///         public static long EnqueueListLeftPush(RedisKey queueName, RedisValue redisvalue)        {            using (var conn = ConnectionMultiplexer.Connect(connectionRedisStr))            {                return conn.GetDatabase().ListLeftPush(queueName, redisvalue);            }        }        ///         /// 入队left异步        /// 
        ///         ///         ///         public static async Task<long> EnqueueListLeftPushAsync(RedisKey queueName, RedisValue redisvalue)        {            using (var conn = await ConnectionMultiplexer.ConnectAsync(connectionRedisStr))            {                return await conn.GetDatabase().ListLeftPushAsync(queueName, redisvalue);            }        }        ///         /// 获取队列的长度        /// 
        ///         ///         public static long EnqueueListLength(RedisKey queueName)        {            using (var conn = ConnectionMultiplexer.Connect(connectionRedisStr))            {                return conn.GetDatabase().ListLength(queueName);            }        }
        #endregion
        #region 出队        public static string DequeueListPopLeft(RedisKey queueName)        {            using (var conn = ConnectionMultiplexer.Connect(connectionRedisStr))            {                IDatabase database = conn.GetDatabase();                int count = database.ListRange(queueName).Length;                if (count <= 0)                {                    throw new Exception($"队列{queueName}数据为零");                }                string redisValue = database.ListLeftPop(queueName);                if (!string.IsNullOrEmpty(redisValue))                    return redisValue;                else                    return string.Empty;            }        }        public static string DequeueListPopRight(RedisKey queueName)        {            using (var conn = ConnectionMultiplexer.Connect(connectionRedisStr))            {                IDatabase database = conn.GetDatabase();                int count = database.ListRange(queueName).Length;                if (count <= 0)                {                    throw new Exception($"队列{queueName}数据为零");                }                string redisValue = conn.GetDatabase().ListRightPop(queueName);                if (!string.IsNullOrEmpty(redisValue))                    return redisValue;                else                    return string.Empty;            }        }        public static async Task<string> DequeueListPopRightAsync(RedisKey queueName)        {            using (var conn = await ConnectionMultiplexer.ConnectAsync(connectionRedisStr))            {                IDatabase database = conn.GetDatabase();                int count = (await database.ListRangeAsync(queueName)).Length;                if (count <= 0)                {                    throw new Exception($"队列{queueName}数据为零");                }                string redisValue = await conn.GetDatabase().ListRightPopAsync(queueName);                if (!string.IsNullOrEmpty(redisValue))                    return redisValue;                else                    return string.Empty;            }        }        #endregion
        #endregion
        #region 分布式锁        public static void LockByRedis(string key, int expireTimeSeconds = 10)        {            try            {                IDatabase database1 = ConnectionMultiplexer.Connect(connectionRedisStr).GetDatabase();                while (true)                {                    expireTimeSeconds = expireTimeSeconds > 20 ? 10 : expireTimeSeconds;                    bool lockflag = database1.LockTake(key, Thread.CurrentThread.ManagedThreadId, TimeSpan.FromSeconds(expireTimeSeconds));                    if (lockflag)                    {                        break;                    }                }            }            catch (Exception ex)            {                throw new Exception($"Redis加锁异常:原因{ex.Message}");            }        }
        public static bool UnLockByRedis(string key)        {            ConnectionMultiplexer conn = ConnectionMultiplexer.Connect(connectionRedisStr);            try            {                IDatabase database1 = conn.GetDatabase();                return database1.LockRelease(key, Thread.CurrentThread.ManagedThreadId);            }            catch (Exception ex)            {                throw new Exception($"Redis加锁异常:原因{ex.Message}");            }            finally            {                if (conn != null)                {                    conn.Close();                    conn.Dispose();                }            }        }        #endregion
    }}

using System;using System.Collections.Generic;using System.Text;
namespace RedisPublishAndSubHelper{    using StackExchange.Redis;    using System.Net.Http;    using System.Threading;    using System.Threading.Channels;    using System.Threading.Tasks;
    public class MyRedisSubPublishHelper    {        private static readonly string redisConnectionStr = "12.32.12.54:6379,connectTimeout=10000,connectRetry=3,syncTimeout=10000";        private static readonly ConnectionMultiplexer connectionMultiplexer = null;        static MyRedisSubPublishHelper()        {            connectionMultiplexer = ConnectionMultiplexer.Connect(redisConnectionStr);        }

        #region 发布订阅        public void SubScriper(string topticName, Action handler = null)        {            ISubscriber subscriber = connectionMultiplexer.GetSubscriber();            ChannelMessageQueue channelMessageQueue = subscriber.Subscribe(topticName);            channelMessageQueue.OnMessage(channelMessage =>            {                if (handler != null)                {                    string redisChannel = channelMessage.Channel;                    string msg = channelMessage.Message;                    handler.Invoke(redisChannel, msg);                }                else                {                    string msg = channelMessage.Message;                    Console.WriteLine($"订阅到消息: { msg},Channel={channelMessage.Channel}");                }            });        }        public void PublishMessage(string topticName, string message)        {            ISubscriber subscriber = connectionMultiplexer.GetSubscriber();            long publishLong = subscriber.Publish(topticName, message);            Console.WriteLine($"发布消息成功：{publishLong}");        }        #endregion
        #region 入队出队        public static async Task<long> EnqueueListLeftPushAsync(RedisKey queueName, RedisValue redisvalue)        {            return await connectionMultiplexer.GetDatabase().ListLeftPushAsync(queueName, redisvalue);        }
        public static async Task<string> DequeueListPopRightAsync(RedisKey queueName)        {            IDatabase database = connectionMultiplexer.GetDatabase();            int count = (await database.ListRangeAsync(queueName)).Length;            if (count <= 0)            {                throw new Exception($"队列{queueName}数据为零");            }            string redisValue = await database.ListRightPopAsync(queueName);            if (!string.IsNullOrEmpty(redisValue))                return redisValue;            else                return string.Empty;        }        #endregion
        #region 分布式锁        public static void LockByRedis(string key, int expireTimeSeconds = 10)        {            try            {                IDatabase database = connectionMultiplexer.GetDatabase();                while (true)                {                    expireTimeSeconds = expireTimeSeconds > 20 ? 10 : expireTimeSeconds;                    bool lockflag = database.LockTake(key, Thread.CurrentThread.ManagedThreadId, TimeSpan.FromSeconds(expireTimeSeconds));                    if (lockflag)                    {                        break;                    }                }            }            catch (Exception ex)            {                throw new Exception($"Redis加锁异常:原因{ex.Message}");            }        }
        public static bool UnLockByRedis(string key)        {            try            {                IDatabase database = connectionMultiplexer.GetDatabase();                return database.LockRelease(key, Thread.CurrentThread.ManagedThreadId);            }            catch (Exception ex)            {                throw new Exception($"Redis加锁异常:原因{ex.Message}");            }        }        #endregion    }}