public void TestEviction()
{
const int MAX_SIZE = 1000;
Random r = new Random();
Cache c = new Cache(MAX_SIZE);
Hashtable ht = new Hashtable();
Hashtable ht_evicted = new Hashtable();
EventHandler eh = delegate(object o, EventArgs args) {
Cache.EvictionArgs a = (Cache.EvictionArgs)args;
ht_evicted[a.Key] = a.Value;
};
c.EvictionEvent += eh;
int i = 0;
for (i = 0; i < 50 * MAX_SIZE; i++)
{
int v = r.Next();
ht[i] = v;
c[i] = v;
int exp_size = Math.Min(i + 1, MAX_SIZE);
Assert.AreEqual(c.Count, exp_size, "Size check");
Assert.AreEqual(ht[i], c[i], "equivalence check");
//Keep the zero'th element in the cache:
object v_0 = c[0];
Assert.IsNotNull(v_0, "0th element still in the cache");
}
Assert.AreEqual(c.Count, MAX_SIZE, "Full cache");
//Now check that everything is either in the Cache or was evicted:
IDictionaryEnumerator ide = ht.GetEnumerator();
while (ide.MoveNext())
{
int key = (int)ide.Key;
int val = (int)ide.Value;
object c_val = c[key];
if (!c.Contains(key))
{
Assert.IsNull(c_val, "Evicted entry is null");
c_val = ht_evicted[key];
Assert.AreEqual(c_val, val, "Evicted lookup");
}
else
{
//Not in the cache:
Assert.AreEqual(c_val, val, "Cache lookup");
}
}
//Let's remove from the Cache and see if that worked:
int s0 = c.Count;
object rv = c.Remove(0);
Assert.AreEqual(rv, ht[0], "Removed value matches");
Assert.IsNull(c[0], "Remove really removed");
Assert.AreEqual(s0 - 1, c.Count, "Removed decreased size");
}
