public void TestBasic()
{
var memoryCache = new MemoryCache("Foo");
var policy = new CacheItemPolicy();
memoryCache.AddOrGetExisting("Pop", 123, DateTimeOffset.MaxValue);
memoryCache.AddOrGetExisting("Top", "Gun", DateTimeOffset.MaxValue);
memoryCache.Add("Pop", 12, DateTime.MaxValue);
Assert.AreEqual("Gun", memoryCache.Get("Top"));
Assert.AreEqual(123, memoryCache.Get("Pop"));
}
public void AddOrGetExisting()
{
var cache2 = new CacheTest();
var cache3 = new CacheTest();
var cache4 = new CacheTest();
System.Runtime.Caching.MemoryCache cache = System.Runtime.Caching.MemoryCache.Default;
int cache1_1 = cache.AddOrGetExisting("cache1", 1);
int cache1_2 = cache.AddOrGetExisting("cache1", 2);
int cache2_1 = cache.AddOrGetExisting("cache2", i => cache2.Increment());
int cache2_2 = cache.AddOrGetExisting("cache2", i => cache2.Increment());
int cache3_1 = cache.AddOrGetExisting("cache3", i => cache3.Increment(), new CacheItemPolicy());
int cache3_2 = cache.AddOrGetExisting("cache3", i => cache3.Increment(), new CacheItemPolicy());
int cache4_1 = cache.AddOrGetExisting("cache4", i => cache4.Increment(), new DateTimeOffset(new DateTime(2100, 01, 01)));
int cache4_2 = cache.AddOrGetExisting("cache4", i => cache4.Increment(), new DateTimeOffset(new DateTime(2100, 01, 01)));
Assert.AreEqual(1, cache1_1);
Assert.AreEqual(1, cache1_2);
Assert.AreEqual(1, cache2_1);
Assert.AreEqual(1, cache2_2);
Assert.AreEqual(1, cache3_1);
Assert.AreEqual(1, cache3_2);
Assert.AreEqual(1, cache4_1);
Assert.AreEqual(1, cache4_2);
}
/// <summary>
/// Gets or adds the item into the memory cache.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="source">The source.</param>
/// <param name="key">The key.</param>
/// <param name="addItem">The function delegate used to add the item into the cache.</param>
/// <param name="policy">The policy.</param>
/// <returns>Returns a <see cref="T" /> representing the item in the cache.</returns>
public static T GetOrAdd <T>(this MemoryCache source, string key, Func <string, T> addItem, CacheItemPolicy policy)
{
ValidateKey(key);
var lazyCacheItem = new Lazy <T>(() => addItem(key));
EnsureRemovedCallback <T>(policy);
var cacheItem = source.AddOrGetExisting(key, lazyCacheItem, policy);
if (cacheItem != null)
{
return(Unwrap <T>(cacheItem));
}
try
{
return(lazyCacheItem.Value);
}
catch
{
source.Remove(key);
throw;
}
}
public bool SetNX <T>(string key, T value, TimeSpan?slidingExpireTime = default(TimeSpan?))
{
if (value == null)
{
throw new Exception("Can not insert null values to the cache!");
}
return(_memoryCache.AddOrGetExisting(
key,
value,
new CacheItemPolicy
{
SlidingExpiration = slidingExpireTime ?? _defaultExpireTimeSpan
}) != null);
}
