Iam*_*per 15 .net c# memorycache
我需要添加缓存功能,并找到一个名为MemoryCache的新闪亮类.但是,我发现MemoryCache有点瘫痪(我需要区域功能).除了其他东西,我需要添加像ClearAll(区域)这样的东西.作者努力保持这个类没有区域支持,代码如下:
if (regionName != null)
{
throw new NotSupportedException(R.RegionName_not_supported);
}
几乎每种方法都有.我没有看到一种简单的方法来覆盖这种行为.我能想到的添加区域支持的唯一方法是添加一个新类作为MemoryCache的包装,而不是作为一个继承自MemoryCache的类.然后在这个新类中创建一个Dictionary并让每个方法"缓冲"区域调用.听起来很讨厌和错误,但最终......
你知道更好的方法来添加区域到MemoryCache吗？
Jak*_*ner 10
我知道你问这个问题已经很久了,所以这不是你真正的答案,而是未来读者的补充.
我也惊讶地发现MemoryCache的标准实现不支持区域.它很容易立即提供.因此,我决定将MemoryCache包装在我自己的简单类中,以提供我经常需要的功能.
我把我的代码放在这里,为有同样需要的人节省时间!
/// <summary>
/// =================================================================================================================
/// This is a static encapsulation of the Framework provided MemoryCache to make it easier to use.
/// - Keys can be of any type, not just strings.
/// - A typed Get method is provided for the common case where type of retrieved item actually is known.
/// - Exists method is provided.
/// - Except for the Set method with custom policy, some specific Set methods are also provided for convenience.
/// - One SetAbsolute method with remove callback is provided as an example.
/// The Set method can also be used for custom remove/update monitoring.
/// - Domain (or "region") functionality missing in default MemoryCache is provided.
/// This is very useful when adding items with identical keys but belonging to different domains.
/// Example: "Customer" with Id=1, and "Product" with Id=1
/// =================================================================================================================
/// </summary>
public static class MyCache
{
private const string KeySeparator = "_";
private const string DefaultDomain = "DefaultDomain";
private static MemoryCache Cache
{
get { return MemoryCache.Default; }
}
// -----------------------------------------------------------------------------------------------------------------------------
// The default instance of the MemoryCache is used.
// Memory usage can be configured in standard config file.
// -----------------------------------------------------------------------------------------------------------------------------
// cacheMemoryLimitMegabytes: The amount of maximum memory size to be used. Specified in megabytes.
// The default is zero, which indicates that the MemoryCache instance manages its own memory
// based on the amount of memory that is installed on the computer.
// physicalMemoryPercentage: The percentage of physical memory that the cache can use. It is specified as an integer value from 1 to 100.
// The default is zero, which indicates that the MemoryCache instance manages its own memory
// based on the amount of memory that is installed on the computer.
// pollingInterval: The time interval after which the cache implementation compares the current memory load with the
// absolute and percentage-based memory limits that are set for the cache instance.
// The default is two minutes.
// -----------------------------------------------------------------------------------------------------------------------------
// <configuration>
// <system.runtime.caching>
// <memoryCache>
// <namedCaches>
// <add name="default" cacheMemoryLimitMegabytes="0" physicalMemoryPercentage="0" pollingInterval="00:02:00" />
// </namedCaches>
// </memoryCache>
// </system.runtime.caching>
// </configuration>
// -----------------------------------------------------------------------------------------------------------------------------
/// <summary>
/// Store an object and let it stay in cache until manually removed.
/// </summary>
public static void SetPermanent(string key, object data, string domain = null)
{
CacheItemPolicy policy = new CacheItemPolicy { };
Set(key, data, policy, domain);
}
/// <summary>
/// Store an object and let it stay in cache x minutes from write.
/// </summary>
public static void SetAbsolute(string key, object data, double minutes, string domain = null)
{
CacheItemPolicy policy = new CacheItemPolicy { AbsoluteExpiration = DateTime.Now + TimeSpan.FromMinutes(minutes) };
Set(key, data, policy, domain);
}
/// <summary>
/// Store an object and let it stay in cache x minutes from write.
/// callback is a method to be triggered when item is removed
/// </summary>
public static void SetAbsolute(string key, object data, double minutes, CacheEntryRemovedCallback callback, string domain = null)
{
CacheItemPolicy policy = new CacheItemPolicy { AbsoluteExpiration = DateTime.Now + TimeSpan.FromMinutes(minutes), RemovedCallback = callback };
Set(key, data, policy, domain);
}
/// <summary>
/// Store an object and let it stay in cache x minutes from last write or read.
/// </summary>
public static void SetSliding(object key, object data, double minutes, string domain = null)
{
CacheItemPolicy policy = new CacheItemPolicy { SlidingExpiration = TimeSpan.FromMinutes(minutes) };
Set(key, data, policy, domain);
}
/// <summary>
/// Store an item and let it stay in cache according to specified policy.
/// </summary>
/// <param name="key">Key within specified domain</param>
/// <param name="data">Object to store</param>
/// <param name="policy">CacheItemPolicy</param>
/// <param name="domain">NULL will fallback to default domain</param>
public static void Set(object key, object data, CacheItemPolicy policy, string domain = null)
{
Cache.Add(CombinedKey(key, domain), data, policy);
}
/// <summary>
/// Get typed item from cache.
/// </summary>
/// <param name="key">Key within specified domain</param>
/// <param name="domain">NULL will fallback to default domain</param>
public static T Get<T>(object key, string domain = null)
{
return (T)Get(key, domain);
}
/// <summary>
/// Get item from cache.
/// </summary>
/// <param name="key">Key within specified domain</param>
/// <param name="domain">NULL will fallback to default domain</param>
public static object Get(object key, string domain = null)
{
return Cache.Get(CombinedKey(key, domain));
}
/// <summary>
/// Check if item exists in cache.
/// </summary>
/// <param name="key">Key within specified domain</param>
/// <param name="domain">NULL will fallback to default domain</param>
public static bool Exists(object key, string domain = null)
{
return Cache[CombinedKey(key, domain)] != null;
}
/// <summary>
/// Remove item from cache.
/// </summary>
/// <param name="key">Key within specified domain</param>
/// <param name="domain">NULL will fallback to default domain</param>
public static void Remove(object key, string domain = null)
{
Cache.Remove(CombinedKey(key, domain));
}
#region Support Methods
/// <summary>
/// Parse domain from combinedKey.
/// This method is exposed publicly because it can be useful in callback methods.
/// The key property of the callback argument will in our case be the combinedKey.
/// To be interpreted, it needs to be split into domain and key with these parse methods.
/// </summary>
public static string ParseDomain(string combinedKey)
{
return combinedKey.Substring(0, combinedKey.IndexOf(KeySeparator));
}
/// <summary>
/// Parse key from combinedKey.
/// This method is exposed publicly because it can be useful in callback methods.
/// The key property of the callback argument will in our case be the combinedKey.
/// To be interpreted, it needs to be split into domain and key with these parse methods.
/// </summary>
public static string ParseKey(string combinedKey)
{
return combinedKey.Substring(combinedKey.IndexOf(KeySeparator) + KeySeparator.Length);
}
/// <summary>
/// Create a combined key from given values.
/// The combined key is used when storing and retrieving from the inner MemoryCache instance.
/// Example: Product_76
/// </summary>
/// <param name="key">Key within specified domain</param>
/// <param name="domain">NULL will fallback to default domain</param>
private static string CombinedKey(object key, string domain)
{
return string.Format("{0}{1}{2}", string.IsNullOrEmpty(domain) ? DefaultDomain : domain, KeySeparator, key);
}
#endregion
}
您可以创建多个MemoryCache实例,每个实例对应一个数据分区.
http://msdn.microsoft.com/en-us/library/system.runtime.caching.memorycache.aspx:
您可以创建MemoryCache类的多个实例,以便在同一个应用程序和同一AppDomain实例中使用