/// <summary>
/// Return the <see cref="IConfigurableCache"/> that uses this eviction
/// policy.
/// </summary>
/// <remarks>
/// If the <b>LocalCache</b> property has not been intialized, it is
/// set to the <b>LocalCache</b> that raised the given event.
/// </remarks>
/// <param name="evt">
/// The <see cref="CacheEventArgs"/> raised by the <b>LocalCache</b>
/// that uses this eviction policy.
/// </param>
/// <returns>
/// The <b>LocalCache</b> that uses this eviction policy.
/// </returns>
protected virtual IConfigurableCache EnsureCache(CacheEventArgs evt)
{
IConfigurableCache cache = m_cache;
if (cache == null)
{
try
{
cache = m_cache = (IConfigurableCache)evt.Cache;
}
catch (InvalidCastException)
{
throw new InvalidCastException("Illegal cache type: " +
evt.Cache.GetType().Name);
}
}
return(cache);
}
/// <summary>
/// Return the cache entry associated with the given cache event.
/// </summary>
/// <param name="evt">
/// A cache event raised by the <see cref="IConfigurableCache"/>
/// that uses this eviction policy.
/// </param>
/// <returns>
/// The cache entry associated with the given event.
/// </returns>
protected virtual IConfigurableCacheEntry GetEntry(CacheEventArgs evt)
{
IConfigurableCache cache = EnsureCache(evt);
// if the IConfigurableCache.GetCacheEntry() implementation
// causes an eviction or notifies the eviction policy that the
// entry has been touched, we'll go into an infinite recursion
try
{
return(cache.GetCacheEntry(evt.Key));
}
catch (StackOverflowException)
{
throw new StackOverflowException(cache.GetType().FullName
+ "#GetCacheEntry() implementation causes an infinite"
+ " recursion when used with " + GetType().FullName
+ "#getEntry() implementation (inherited from "
+ typeof(AbstractEvictionPolicy).FullName + ")");
}
}
