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所属分类:.NET技术
使用背景:
项目中用户频繁访问数据库会导致程序的卡顿,甚至堵塞。使用缓存可以有效的降低用户访问数据库的频次,有效的减少并发的压力。保护后端真实的服务器。
对于开发人员需要方便调用,所以本文提供了helper类对缓存有了封装。分了三个Cache,SystemCache,RedisCache(默认缓存,系统缓存,Redis缓存)。话不多说,开撸!
使用方法:
1,引用CSRedisCore
可以看到,csredis支持.net40/.net45/.netstandard平台,还是比较友好的。
2,增加helper类代码
CacheHelper.cs
/// <summary> /// 缓存帮助类 /// </summary> public class CacheHelper { /// <summary> /// 静态构造函数,初始化缓存类型 /// </summary> static CacheHelper() { SystemCache = new SystemCache();
if(true)
//项目全局变量类,可自行定义
// if (GlobalSwitch.OpenRedisCache) { try { RedisCache = new RedisCache(GlobalSwitch.RedisConfig); } catch { } } switch (GlobalSwitch.CacheType) { case CacheType.SystemCache:Cache = SystemCache;break; case CacheType.RedisCache:Cache = RedisCache;break; default:throw new Exception("请指定缓存类型!"); } } /// <summary> /// 默认缓存 /// </summary> public static ICache Cache { get; } /// <summary> /// 系统缓存 /// </summary> public static ICache SystemCache { get; } /// <summary> /// Redis缓存 /// </summary> public static ICache RedisCache { get; } }
ICache.cs:
/// <summary> /// 缓存操作接口类 /// </summary> public interface ICache { #region 设置缓存 /// <summary> /// 设置缓存 /// </summary> /// <param name="key">主键</param> /// <param name="value">值</param> void SetCache(string key, object value); /// <summary> /// 设置缓存 /// 注:默认过期类型为绝对过期 /// </summary> /// <param name="key">主键</param> /// <param name="value">值</param> /// <param name="timeout">过期时间间隔</param> void SetCache(string key, object value, TimeSpan timeout); /// <summary> /// 设置缓存 /// 注:默认过期类型为绝对过期 /// </summary> /// <param name="key">主键</param> /// <param name="value">值</param> /// <param name="timeout">过期时间间隔</param> /// <param name="expireType">过期类型</param> void SetCache(string key, object value, TimeSpan timeout, ExpireType expireType); /// <summary> /// 设置键失效时间 /// </summary> /// <param name="key">键值</param> /// <param name="expire">从现在起时间间隔</param> void SetKeyExpire(string key, TimeSpan expire); #endregion #region 获取缓存 /// <summary> /// 获取缓存 /// </summary> /// <param name="key">主键</param> object GetCache(string key); /// <summary> /// 获取缓存 /// </summary> /// <param name="key">主键</param> /// <typeparam name="T">数据类型</typeparam> T GetCache<T>(string key) where T : class; /// <summary> /// 是否存在键值 /// </summary> /// <param name="key">主键</param> /// <returns></returns> bool ContainsKey(string key); #endregion #region 删除缓存 /// <summary> /// 清除缓存 /// </summary> /// <param name="key">主键</param> void RemoveCache(string key); #endregion } #region 类型定义 /// <summary> /// 值信息 /// </summary> public struct ValueInfoEntry { public string Value { get; set; } public string TypeName { get; set; } public TimeSpan? ExpireTime { get; set; } public ExpireType? ExpireType { get; set; } } /// <summary> /// 过期类型 /// </summary> public enum ExpireType { /// <summary> /// 绝对过期 /// 注:即自创建一段时间后就过期 /// </summary> Absolute, /// <summary> /// 相对过期 /// 注:即该键未被访问后一段时间后过期,若此键一直被访问则过期时间自动延长 /// </summary> Relative, } #endregion
RedisCache.cs
/// <summary> /// Redis缓存 /// </summary> public class RedisCache : ICache { /// <summary> /// 构造函数 /// 注意:请以单例使用 /// </summary> /// <param name="config">配置字符串</param> public RedisCache(string config) { _redisCLient = new CSRedisClient(config); } private CSRedisClient _redisCLient { get; } public bool ContainsKey(string key) { return _redisCLient.Exists(key); } public object GetCache(string key) { object value = null; var redisValue = _redisCLient.Get(key); if (redisValue.IsNullOrEmpty()) return null; ValueInfoEntry valueEntry = redisValue.ToString().ToObject<ValueInfoEntry>(); if (valueEntry.TypeName == typeof(string).AssemblyQualifiedName) value = valueEntry.Value; else value = valueEntry.Value.ToObject(Type.GetType(valueEntry.TypeName)); if (valueEntry.ExpireTime != null && valueEntry.ExpireType == ExpireType.Relative) SetKeyExpire(key, valueEntry.ExpireTime.Value); return value; } public T GetCache<T>(string key) where T : class { return (T)GetCache(key); } public void SetKeyExpire(string key, TimeSpan expire) { _redisCLient.Expire(key, expire); } public void RemoveCache(string key) { _redisCLient.Del(key); } public void SetCache(string key, object value) { _SetCache(key, value, null, null); } public void SetCache(string key, object value, TimeSpan timeout) { _SetCache(key, value, timeout, ExpireType.Absolute); } public void SetCache(string key, object value, TimeSpan timeout, ExpireType expireType) { _SetCache(key, value, timeout, expireType); } private void _SetCache(string key, object value, TimeSpan? timeout, ExpireType? expireType) { string jsonStr = string.Empty; if (value is string) jsonStr = value as string; else jsonStr = value.ToJson(); ValueInfoEntry entry = new ValueInfoEntry { Value = jsonStr, TypeName = value.GetType().AssemblyQualifiedName, ExpireTime = timeout, ExpireType = expireType }; string theValue = entry.ToJson(); if (timeout == null) _redisCLient.Set(key, theValue); else _redisCLient.Set(key, theValue, (int)timeout.Value.TotalSeconds); } }
SystemCache.cs
/// <summary> /// 系统缓存帮助类 /// </summary> public class SystemCache : ICache { public object GetCache(string key) { return HttpRuntime.Cache[key]; } public T GetCache<T>(string key) where T : class { return (T)HttpRuntime.Cache[key]; } public bool ContainsKey(string key) { return GetCache(key) != null; } public void RemoveCache(string key) { HttpRuntime.Cache.Remove(key); } public void SetKeyExpire(string key, TimeSpan expire) { object value = GetCache(key); SetCache(key, value, expire); } public void SetCache(string key, object value) { _SetCache(key, value, null, null); } public void SetCache(string key, object value, TimeSpan timeout) { _SetCache(key, value, timeout, ExpireType.Absolute); } public void SetCache(string key, object value, TimeSpan timeout, ExpireType expireType) { _SetCache(key, value, timeout, expireType); } private void _SetCache(string key, object value, TimeSpan? timeout, ExpireType? expireType) { if (timeout == null) HttpRuntime.Cache[key] = value; else { if (expireType == ExpireType.Absolute) { DateTime endTime = DateTime.Now.AddTicks(timeout.Value.Ticks); HttpRuntime.Cache.Insert(key, value, null, endTime, Cache.NoSlidingExpiration); } else { HttpRuntime.Cache.Insert(key, value, null, Cache.NoAbsoluteExpiration, timeout.Value); } } } }
3,使用
4,说明:
Redis 是一个开源(BSD许可)的,内存中的数据结构存储系统,它可以用作数据库、缓存和消息中间件。
它是基于高性能的Key-Value、并提供多种语言的 API的非关系型数据库。不过与传统数据库不同的是 redis 的数据是存在内存中的,所以存写速度非常快。
它支持多种类型的数据结构,如 字符串(strings), 散列(hashes), 列表(lists), 集合(sets), 有序集合(sorted sets)
结语:
这里提供了helper类,主要是为了封装缓存,使用起来更加方便。具体可以在其基础上进行扩展。