/// <summary>
/// Initializes a new instance of the <see cref="TridionChangeMonitor"/> class.
/// </summary>
/// <param name="tridionDependency">Associated <see cref="T:TcmCDService.Cache.TridionDependency" /></param>
/// <exception cref="System.ArgumentNullException">tridionDependency</exception>
public TridionChangeMonitor(TridionDependency tridionDependency)
{
if (tridionDependency == null)
{
throw new ArgumentNullException("tridionDependency");
}
bool flag = true;
try
{
mTridionDependency = tridionDependency;
mTridionDependency.OnChange += new EventHandler(this.OnDependencyChanged);
mUniqueId = Guid.NewGuid().ToString("N", CultureInfo.InvariantCulture);
flag = false;
}
finally
{
base.InitializationComplete();
if (flag)
{
base.Dispose();
}
}
}
/// <summary>
/// Initializes a new instance of the <see cref="TridionChangeMonitor"/> class.
/// </summary>
/// <param name="tridionDependency">Associated <see cref="T:TcmCDService.Cache.TridionDependency" /></param>
/// <exception cref="System.ArgumentNullException">tridionDependency</exception>
public TridionChangeMonitor(TridionDependency tridionDependency)
{
if (tridionDependency == null)
throw new ArgumentNullException("tridionDependency");
bool flag = true;
try
{
mTridionDependency = tridionDependency;
mTridionDependency.OnChange += new EventHandler(this.OnDependencyChanged);
mUniqueId = Guid.NewGuid().ToString("N", CultureInfo.InvariantCulture);
flag = false;
}
finally
{
base.InitializationComplete();
if (flag)
base.Dispose();
}
}
/// <summary>
/// Gets the specified key.
/// </summary>
/// <typeparam name="T">Cache item type</typeparam>
/// <param name="key">Cache item key</param>
/// <param name="valueInitializer">Cache item value initializer.</param>
/// <returns>Cached item or newly created item</returns>
public static T Get <T>(String key, Func <T> valueInitializer, CacheRegion cacheRegion, TcmUri cacheUri) where T : class
{
// No caching is applied
if (mExpiration == -1)
{
return(valueInitializer());
}
MemoryCache cache = MemoryCache.Default;
// Retrieve the value from the cache as the generic requested type
var value = cache.Get(key);
if (value != null)
{
T cachedItem = value as T;
if (cachedItem != null)
{
return(cachedItem);
}
return(default(T));
}
// Initialize the value if its not existing in the cache
if (valueInitializer != null)
{
T initializedValue = valueInitializer();
// Store the item in cache only if it returned an actual value
if (!EqualityComparer <T> .Default.Equals(initializedValue, default(T)))
{
CacheItemPolicy cacheItemPolicy = new CacheItemPolicy()
{
AbsoluteExpiration = DateTimeOffset.UtcNow.AddMinutes(Expiration),
RemovedCallback = new CacheEntryRemovedCallback(ItemRemovedCallback)
};
if (cacheRegion != CacheRegion.Unknown)
{
String cacheKey = cacheUri.ToCacheKey();
TridionDependency dependency = mDependencies.FirstOrDefault(d => d.CacheRegion == cacheRegion && d.Key == cacheKey);
// Dependency did not exist yet, create it and add it to the cache dependencies list
if (dependency == null)
{
dependency = new TridionDependency(cacheRegion, cacheKey);
mDependencies.Add(dependency);
}
cacheItemPolicy.ChangeMonitors.Add(new TridionChangeMonitor(dependency));
}
cache.Set(key, initializedValue, cacheItemPolicy);
return(initializedValue);
}
}
return(default(T));
}
