Enterprise Library Test Guide - Willy .Net

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Enterprise Library Test Guide
Testing the Caching Application Block
The test case checked to see that the Caching Application Block did not try to scavenge
items in the cache when the number of items to scavenge was set to zero.
Test Case
The test case checked to see that the ScavengerTask class looked at the number of
times to scavenge before it began scavenging.
Problem
The test case failed because the DoScavenging method did not check the number of
items to be scavenged before it began to scavenge. As a result, each time an item was
added, the method would unnecessarily scavenge the cache. The following is the
code that caused the problem.
public void DoScavenging()
{
Hashtable liveCacheRepresentation = cacheOperations.CurrentCacheState;
int currentNumberItemsInCache = liveCacheRepresentation.Count;
if (scavengingPolicy.IsScavengingNeeded(currentNumberItemsInCache))
{
ResetScavengingFlagInCacheItems(liveCacheRepresentation);
SortedList scavengableItems = SortItemsForScavenging(liveCacheRepresentation);
RemoveScavengableItems(scavengableItems);
}
}
Solution
The ScavengerTask.DoScavenging method was modified so that it first checked to
see if the number of items to be scavenged was set to zero. If it was, it did not scavenge
the cache. The following is the modified code.
public void DoScavenging()
{
if (NumberOfItemsToBeScavenged == 0) return;
Hashtable liveCacheRepresentation = cacheOperations.CurrentCacheState;
int currentNumberItemsInCache = liveCacheRepresentation.Count;
if (scavengingPolicy.IsScavengingNeeded(currentNumberItemsInCache))
{
ResetScavengingFlagInCacheItems(liveCacheRepresentation);
SortedList scavengableItems = SortItemsForScavenging(liveCacheRepresentation);
RemoveScavengableItems(scavengableItems);
}
}