public TValue Get(TKey key, CacheFallBack <TKey, TValue> fallback)
{
lock (mLocker)
{
#if TEST
TotalFetch++;
#endif
if (mDictionary.TryGetValue(key, out TValue value))
{
#if TEST
HitCount++;
#endif
UpdateCounter(key);
return(value);
}
if (fallback == null)
{
throw new ArgumentNullException(nameof(fallback));
}
CacheValue <TValue> cacheValue = fallback(key);
if (!cacheValue.AddToCache)
{
return(cacheValue.Value);
}
TValue result = cacheValue.Value;
Counter currentCounter;
if (mDictionary.Count >= mCapacity)
{
mDictionary.Remove(mMaxKey);
mUsageCounters.Remove(mMaxKey);
currentCounter = mMaxCounter;
currentCounter.Reset();
IncreaseAllCounters();
FindMaxKey();
mDictionary.Add(key, result);
mUsageCounters.Add(key, currentCounter);
}
else
{
IncreaseAllCounters();
FindMaxKey();
mDictionary.Add(key, result);
currentCounter = mCounterPool.Pop();
currentCounter.Reset();
mUsageCounters.Add(key, currentCounter);
}
return(result);
}
}
public void TestCache()
{
CacheFallBack <string, string> fallback = (key) => CacheValue <string> .From(key);
int times = 500;
List <string> data = GenerateData(100);
ICache <string, string> cache = new Cache <string, string>(50);
Random random = new Random(Guid.NewGuid().GetHashCode());
while (times > 0)
{
int index = random.Next(0, data.Count);
string input = data[index];
string result = cache.Get(input, fallback);
Assert.AreEqual(input, result);
times--;
}
int total = cache.TotalFetch;
int hit = cache.HitCount;
Console.WriteLine($"Hit rate: {hit * 1.0 / total}");
}
