#region License
/*
* Copyright 2002-2006 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#endregion
#region Imports
using System.Collections;
using System.Reflection;
using Spring.Aop;
using Spring.Caching;
using Spring.Util;
#endregion
namespace Spring.Aspects.Cache{
/// <summary>
/// Implementation of a cache invalidation advice.
/// </summary>
/// <remarks>
/// <p>
/// This advice can be used to evict items from the cache.
/// </p>
/// <p>
/// Information that determines which items should be evicted and from which cache
/// are retrieved from the <see cref="InvalidateCacheAttribute"/>s that are defined
/// on the pointcut.
/// </p>
/// <p>
/// Items are evicted *after* target method is invoked. Return value of the method,
/// as well as method arguments, can be used to determine a list of keys for the items
/// that should be evicted (return value will be passed as a context for
/// <see cref="InvalidateCacheAttribute.Keys"/> expression evaluation, and method
/// arguments will be passed as variables, keyed by argument name).
/// </p>
/// </remarks>
/// <seealso cref="InvalidateCacheAttribute"/>
/// <author>Aleksandar Seovic</author>
public class InvalidateCacheAdvice : BaseCacheAdvice, IAfterReturningAdvice
{
#region InvalidateCacheAttribute caching
private readonly Hashtable _invalidateCacheAttributeCache = new Hashtable();
private InvalidateCacheAttribute[] GetInvalidateCacheInfo(MethodInfo method)
{
InvalidateCacheAttribute[] cacheInfoArray = (InvalidateCacheAttribute[])_invalidateCacheAttributeCache[method];
if (cacheInfoArray == null)
{
cacheInfoArray = (InvalidateCacheAttribute[])GetCustomAttributes(method, typeof(InvalidateCacheAttribute));
_invalidateCacheAttributeCache[method] = cacheInfoArray;
}
return cacheInfoArray;
}
#endregion
/// <summary>
/// Executes after <paramref name="target"/> <paramref name="method"/>
/// returns <b>successfully</b>.
/// </summary>
/// <remarks>
/// <p>
/// Note that the supplied <paramref name="returnValue"/> <b>cannot</b>
/// be changed by this type of advice... use the around advice type
/// (<see cref="AopAlliance.Intercept.IMethodInterceptor"/>) if you
/// need to change the return value of an advised method invocation.
/// The data encapsulated by the supplied <paramref name="returnValue"/>
/// can of course be modified though.
/// </p>
/// </remarks>
/// <param name="returnValue">
/// The value returned by the <paramref name="target"/>.
/// </param>
/// <param name="method">The intecepted method.</param>
/// <param name="arguments">The intercepted method's arguments.</param>
/// <param name="target">The target object.</param>
/// <seealso cref="AopAlliance.Intercept.IMethodInterceptor.Invoke"/>
public void AfterReturning(object returnValue, MethodInfo method, object[] arguments, object target)
{
#region Instrumentation
bool isLogDebugEnabled = logger.IsDebugEnabled;
#endregion
InvalidateCacheAttribute[] cacheInfoArray = GetInvalidateCacheInfo(method);
if (cacheInfoArray.Length > 0)
{
IDictionary vars = PrepareVariables(method, arguments);
foreach (InvalidateCacheAttribute cacheInfo in cacheInfoArray)
{
if (EvalCondition(cacheInfo.Condition, cacheInfo.ConditionExpression, returnValue, vars))
{
ICache cache = GetCache(cacheInfo.CacheName);
if (cacheInfo.KeysExpression != null)
{
object keys = cacheInfo.KeysExpression.GetValue(returnValue, vars);
if (keys is ICollection)
{
#region Instrumentation
if (isLogDebugEnabled)
{
logger.Debug(string.Format("Removing objects for keys [{0}] from cache [{1}].", keys, cacheInfo.CacheName));
}
#endregion
cache.RemoveAll(keys as ICollection);
}
else
{
#region Instrumentation
if (isLogDebugEnabled)
{
logger.Debug(string.Format("Removing object for key [{0}] from cache [{1}].", keys, cacheInfo.CacheName));
}
#endregion
cache.Remove(keys);
}
}
else
{
#region Instrumentation
if (isLogDebugEnabled)
{
logger.Debug(string.Format("Invalidate cache [{0}].", cacheInfo.CacheName));
}
#endregion
cache.Clear();
}
}
}
}
}
}
}
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