详解Asp.net Core 使用Redis存储Session
前言
Asp.netCore改变了之前的封闭,现在开源且开放,下面我们来用Redis存储Session来做一个简单的测试,或者叫做中间件(middleware)。
对于Session来说褒贬不一,很多人直接说不要用,也有很多人在用,这个也没有绝对的这义,个人认为只要不影什么且又可以方便实现的东西是可以用的,现在不对可不可用做表态,我们只关心实现。
类库引用
这个相对于之前的.net是方便了不少,需要在project.json中的dependencies节点中添加如下内容:
"StackExchange.Redis":"1.1.604-alpha", "Microsoft.AspNetCore.Session":"1.1.0-alpha1-21694"
Redis实现
这里并非我实现,而是借用不知道为什么之前还有这个类库,而现在NUGET止没有了,为了不影响日后升级我的命名空间也用Microsoft.Extensions.Caching.Redis
可以看到微软这里有四个类,其实我们只需要三个,第四个拿过来反而会出错:
usingSystem; usingSystem.Threading.Tasks; usingMicrosoft.Extensions.Caching.Distributed; usingMicrosoft.Extensions.Options; usingStackExchange.Redis; namespaceMicrosoft.Extensions.Caching.Redis { publicclassRedisCache:IDistributedCache,IDisposable { //KEYS[1]==key //ARGV[1]=absolute-expiration-ticksaslong(-1fornone) //ARGV[2]=sliding-expiration-ticksaslong(-1fornone) //ARGV[3]=relative-expiration(long,inseconds,-1fornone)-Min(absolute-expiration-Now,sliding-expiration) //ARGV[4]=data-byte[] //thisordershouldnotchangeLUAscriptdependsonit privateconststringSetScript=(@" redis.call('HMSET',KEYS[1],'absexp',ARGV[1],'sldexp',ARGV[2],'data',ARGV[4]) ifARGV[3]~='-1'then redis.call('EXPIRE',KEYS[1],ARGV[3]) end return1"); privateconststringAbsoluteExpirationKey="absexp"; privateconststringSlidingExpirationKey="sldexp"; privateconststringDataKey="data"; privateconstlongNotPresent=-1; privateConnectionMultiplexer_connection; privateIDatabase_cache; privatereadonlyRedisCacheOptions_options; privatereadonlystring_instance; publicRedisCache(IOptions<RedisCacheOptions>optionsAccessor) { if(optionsAccessor==null) { thrownewArgumentNullException(nameof(optionsAccessor)); } _options=optionsAccessor.Value; //Thisallowspartitioningasinglebackendcacheforusewithmultipleapps/services. _instance=_options.InstanceName??string.Empty; } publicbyte[]Get(stringkey) { if(key==null) { thrownewArgumentNullException(nameof(key)); } returnGetAndRefresh(key,getData:true); } publicasyncTask<byte[]>GetAsync(stringkey) { if(key==null) { thrownewArgumentNullException(nameof(key)); } returnawaitGetAndRefreshAsync(key,getData:true); } publicvoidSet(stringkey,byte[]value,DistributedCacheEntryOptionsoptions) { if(key==null) { thrownewArgumentNullException(nameof(key)); } if(value==null) { thrownewArgumentNullException(nameof(value)); } if(options==null) { thrownewArgumentNullException(nameof(options)); } Connect(); varcreationTime=DateTimeOffset.UtcNow; varabsoluteExpiration=GetAbsoluteExpiration(creationTime,options); varresult=_cache.ScriptEvaluate(SetScript,newRedisKey[]{_instance+key}, newRedisValue[] { absoluteExpiration?.Ticks??NotPresent, options.SlidingExpiration?.Ticks??NotPresent, GetExpirationInSeconds(creationTime,absoluteExpiration,options)??NotPresent, value }); } publicasyncTaskSetAsync(stringkey,byte[]value,DistributedCacheEntryOptionsoptions) { if(key==null) { thrownewArgumentNullException(nameof(key)); } if(value==null) { thrownewArgumentNullException(nameof(value)); } if(options==null) { thrownewArgumentNullException(nameof(options)); } awaitConnectAsync(); varcreationTime=DateTimeOffset.UtcNow; varabsoluteExpiration=GetAbsoluteExpiration(creationTime,options); await_cache.ScriptEvaluateAsync(SetScript,newRedisKey[]{_instance+key}, newRedisValue[] { absoluteExpiration?.Ticks??NotPresent, options.SlidingExpiration?.Ticks??NotPresent, GetExpirationInSeconds(creationTime,absoluteExpiration,options)??NotPresent, value }); } publicvoidRefresh(stringkey) { if(key==null) { thrownewArgumentNullException(nameof(key)); } GetAndRefresh(key,getData:false); } publicasyncTaskRefreshAsync(stringkey) { if(key==null) { thrownewArgumentNullException(nameof(key)); } awaitGetAndRefreshAsync(key,getData:false); } privatevoidConnect() { if(_connection==null) { _connection=ConnectionMultiplexer.Connect(_options.Configuration); _cache=_connection.GetDatabase(); } } privateasyncTaskConnectAsync() { if(_connection==null) { _connection=awaitConnectionMultiplexer.ConnectAsync(_options.Configuration); _cache=_connection.GetDatabase(); } } privatebyte[]GetAndRefresh(stringkey,boolgetData) { if(key==null) { thrownewArgumentNullException(nameof(key)); } Connect(); //ThisalsoresetstheLRUstatusasdesired. //TODO:Canthisbedoneinoneoperationontheserverside?Probably,thetrickwouldjustbetheDateTimeOffsetmath. RedisValue[]results; if(getData) { results=_cache.HashMemberGet(_instance+key,AbsoluteExpirationKey,SlidingExpirationKey,DataKey); } else { results=_cache.HashMemberGet(_instance+key,AbsoluteExpirationKey,SlidingExpirationKey); } //TODO:Errorhandling if(results.Length>=2) { //Notewealwaysgetbacktworesults,eveniftheyareallnull. //Theseoperationswillno-opinthenullscenario. DateTimeOffset?absExpr; TimeSpan?sldExpr; MapMetadata(results,outabsExpr,outsldExpr); Refresh(key,absExpr,sldExpr); } if(results.Length>=3&&results[2].HasValue) { returnresults[2]; } returnnull; } privateasyncTask<byte[]>GetAndRefreshAsync(stringkey,boolgetData) { if(key==null) { thrownewArgumentNullException(nameof(key)); } awaitConnectAsync(); //ThisalsoresetstheLRUstatusasdesired. //TODO:Canthisbedoneinoneoperationontheserverside?Probably,thetrickwouldjustbetheDateTimeOffsetmath. RedisValue[]results; if(getData) { results=await_cache.HashMemberGetAsync(_instance+key,AbsoluteExpirationKey,SlidingExpirationKey,DataKey); } else { results=await_cache.HashMemberGetAsync(_instance+key,AbsoluteExpirationKey,SlidingExpirationKey); } //TODO:Errorhandling if(results.Length>=2) { //Notewealwaysgetbacktworesults,eveniftheyareallnull. //Theseoperationswillno-opinthenullscenario. DateTimeOffset?absExpr; TimeSpan?sldExpr; MapMetadata(results,outabsExpr,outsldExpr); awaitRefreshAsync(key,absExpr,sldExpr); } if(results.Length>=3&&results[2].HasValue) { returnresults[2]; } returnnull; } publicvoidRemove(stringkey) { if(key==null) { thrownewArgumentNullException(nameof(key)); } Connect(); _cache.KeyDelete(_instance+key); //TODO:Errorhandling } publicasyncTaskRemoveAsync(stringkey) { if(key==null) { thrownewArgumentNullException(nameof(key)); } awaitConnectAsync(); await_cache.KeyDeleteAsync(_instance+key); //TODO:Errorhandling } privatevoidMapMetadata(RedisValue[]results,outDateTimeOffset?absoluteExpiration,outTimeSpan?slidingExpiration) { absoluteExpiration=null; slidingExpiration=null; varabsoluteExpirationTicks=(long?)results[0]; if(absoluteExpirationTicks.HasValue&&absoluteExpirationTicks.Value!=NotPresent) { absoluteExpiration=newDateTimeOffset(absoluteExpirationTicks.Value,TimeSpan.Zero); } varslidingExpirationTicks=(long?)results[1]; if(slidingExpirationTicks.HasValue&&slidingExpirationTicks.Value!=NotPresent) { slidingExpiration=newTimeSpan(slidingExpirationTicks.Value); } } privatevoidRefresh(stringkey,DateTimeOffset?absExpr,TimeSpan?sldExpr) { if(key==null) { thrownewArgumentNullException(nameof(key)); } //NoteRefreshhasnoeffectifthereisjustanabsoluteexpiration(orneither). TimeSpan?expr=null; if(sldExpr.HasValue) { if(absExpr.HasValue) { varrelExpr=absExpr.Value-DateTimeOffset.Now; expr=relExpr<=sldExpr.Value?relExpr:sldExpr; } else { expr=sldExpr; } _cache.KeyExpire(_instance+key,expr); //TODO:Errorhandling } } privateasyncTaskRefreshAsync(stringkey,DateTimeOffset?absExpr,TimeSpan?sldExpr) { if(key==null) { thrownewArgumentNullException(nameof(key)); } //NoteRefreshhasnoeffectifthereisjustanabsoluteexpiration(orneither). TimeSpan?expr=null; if(sldExpr.HasValue) { if(absExpr.HasValue) { varrelExpr=absExpr.Value-DateTimeOffset.Now; expr=relExpr<=sldExpr.Value?relExpr:sldExpr; } else { expr=sldExpr; } await_cache.KeyExpireAsync(_instance+key,expr); //TODO:Errorhandling } } privatestaticlong?GetExpirationInSeconds(DateTimeOffsetcreationTime,DateTimeOffset?absoluteExpiration,DistributedCacheEntryOptionsoptions) { if(absoluteExpiration.HasValue&&options.SlidingExpiration.HasValue) { return(long)Math.Min( (absoluteExpiration.Value-creationTime).TotalSeconds, options.SlidingExpiration.Value.TotalSeconds); } elseif(absoluteExpiration.HasValue) { return(long)(absoluteExpiration.Value-creationTime).TotalSeconds; } elseif(options.SlidingExpiration.HasValue) { return(long)options.SlidingExpiration.Value.TotalSeconds; } returnnull; } privatestaticDateTimeOffset?GetAbsoluteExpiration(DateTimeOffsetcreationTime,DistributedCacheEntryOptionsoptions) { if(options.AbsoluteExpiration.HasValue&&options.AbsoluteExpiration<=creationTime) { thrownewArgumentOutOfRangeException( nameof(DistributedCacheEntryOptions.AbsoluteExpiration), options.AbsoluteExpiration.Value, "Theabsoluteexpirationvaluemustbeinthefuture."); } varabsoluteExpiration=options.AbsoluteExpiration; if(options.AbsoluteExpirationRelativeToNow.HasValue) { absoluteExpiration=creationTime+options.AbsoluteExpirationRelativeToNow; } returnabsoluteExpiration; } publicvoidDispose() { if(_connection!=null) { _connection.Close(); } } } }
usingMicrosoft.Extensions.Options; namespaceMicrosoft.Extensions.Caching.Redis { ///<summary> ///Configurationoptionsfor<seecref="RedisCache"/>. ///</summary> publicclassRedisCacheOptions:IOptions<RedisCacheOptions> { ///<summary> ///TheconfigurationusedtoconnecttoRedis. ///</summary> publicstringConfiguration{get;set;} ///<summary> ///TheRedisinstancename. ///</summary> publicstringInstanceName{get;set;} RedisCacheOptionsIOptions<RedisCacheOptions>.Value { get{returnthis;} } } }
usingSystem.Threading.Tasks; usingStackExchange.Redis; namespaceMicrosoft.Extensions.Caching.Redis { internalstaticclassRedisExtensions { privateconststringHmGetScript=(@"returnredis.call('HMGET',KEYS[1],unpack(ARGV))"); internalstaticRedisValue[]HashMemberGet(thisIDatabasecache,stringkey,paramsstring[]members) { varresult=cache.ScriptEvaluate( HmGetScript, newRedisKey[]{key}, GetRedisMembers(members)); //TODO:Errorchecking? return(RedisValue[])result; } internalstaticasyncTask<RedisValue[]>HashMemberGetAsync( thisIDatabasecache, stringkey, paramsstring[]members) { varresult=awaitcache.ScriptEvaluateAsync( HmGetScript, newRedisKey[]{key}, GetRedisMembers(members)); //TODO:Errorchecking? return(RedisValue[])result; } privatestaticRedisValue[]GetRedisMembers(paramsstring[]members) { varredisMembers=newRedisValue[members.Length]; for(inti=0;i<members.Length;i++) { redisMembers[i]=(RedisValue)members[i]; } returnredisMembers; } } }
配置启用Session
我们在Startup中ConfigureServices增加
services.AddSingleton<IDistributedCache>( serviceProvider=> newRedisCache(newRedisCacheOptions { Configuration="192.168.178.141:6379", InstanceName="Sample:" })); services.AddSession();
在Startup中Configure增加
app.UseSession(newSessionOptions(){IdleTimeout=TimeSpan.FromMinutes(30)});
到此我们的配置完毕,可以测试一下是否写到了Redis中
验证结果
在Mvc项目中,我们来实现如下代码
if(string.IsNullOrEmpty(HttpContext.Session.GetString("D"))) { vard=DateTime.Now.ToString(); HttpContext.Session.SetString("D",d); HttpContext.Response.ContentType="text/plain"; awaitHttpContext.Response.WriteAsync("HelloFirsttimer///"+d); } else { HttpContext.Response.ContentType="text/plain"; awaitHttpContext.Response.WriteAsync("Hellooldtimer///"+HttpContext.Session.GetString("D")); }
运行我们发现第一次出现了HelloFirsttimer字样,刷新后出现了Hellooldtimer字样,证明Session成功,再查看一下Redis看一下,有值了,这样一个分布式的Session就成功实现了。
对于上面的实例我把源码放在了:demo下载
Tianwei.Microsoft.Extensions.Caching.Redis,只是ID加了Tianwei空间名还是Microsoft.Extensions.Caching.Redis
从上面的实例我们发现微软这次是真的开放了,这也意味着如果我们使用某些类不顺手或不合适时可以自已写自已扩展
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持毛票票。