public void MetricsErrorCacheEntry_Simple()
{
try
{
throw new Exception();
}
catch (Exception ex)
{
var entry = new MetricsErrorCacheEntry <int, int>(42, ex);
Assert.AreEqual(42, entry.Key);
Assert.AreSame(ex, entry.Exception);
var stack = ex.StackTrace;
try
{
_ = entry.Value;
}
catch (Exception ex2)
{
Assert.AreSame(ex, ex2);
Assert.AreEqual(stack, ex2.StackTrace.Substring(0, stack.Length));
}
Assert.AreEqual(0, entry.HitCount);
Assert.AreEqual(0L, entry.CreationTime.Ticks);
Assert.AreEqual(0L, entry.InvokeDuration.Ticks);
Assert.AreEqual(0L, entry.LastAccessTime.Ticks);
Assert.AreEqual(0L, entry.TotalDuration.Ticks);
//
// NB: AverageAccessTime and SpeedupFactor throw DivideByZeroException until values are
// initialized. Accesses to those properties is guaranteed to happen after the hit
// count has been incremented to 1, so this is not an issue.
//
Assert.ThrowsException <DivideByZeroException>(() => entry.AverageAccessTime);
Assert.ThrowsException <DivideByZeroException>(() => entry.SpeedupFactor);
entry.HitCount++;
Assert.AreEqual(0L, entry.AverageAccessTime.Ticks);
Assert.IsTrue(double.IsNaN(entry.SpeedupFactor)); // can only happen if access time is zero
entry.TotalDuration = TimeSpan.FromTicks(27182818284590451L);
Assert.AreEqual(27182818284590451L, entry.AverageAccessTime.Ticks);
Assert.AreEqual(0.0, entry.SpeedupFactor);
entry.InvokeDuration = TimeSpan.FromTicks(31415926535897931L);
Assert.AreEqual(27182818284590451L, entry.AverageAccessTime.Ticks);
Assert.AreEqual((double)31415926535897931L / 27182818284590451L, entry.SpeedupFactor);
entry.HitCount++;
Assert.AreEqual(27182818284590451L / 2, entry.AverageAccessTime.Ticks);
Assert.AreEqual((double)31415926535897931L / (27182818284590451L / 2), entry.SpeedupFactor);
var sb = new StringBuilder();
entry.ToDebugView(sb, "");
Assert.IsTrue(sb.ToString().Contains("="));
}
}
public Cache(Func <T, R> function, Func <IMemoizationCacheEntryMetrics, TMetric> ranker, int maxCapacity, bool descending, double ageThreshold, bool cacheError, IStopwatchFactory stopwatchFactory)
{
_function = args =>
{
var weakArgs = WeakReferenceExtensions.Create(args);
var invokeDuration = default(TimeSpan);
#if DEBUG
Interlocked.Increment(ref _invocationCount);
#endif
Trim();
var res = default(IMetricsCacheEntry <WeakReference <T>, R>);
try
{
var swInvokeStart = _stopwatch.ElapsedTicks;
var value = function(args);
invokeDuration = new TimeSpan(_stopwatch.ElapsedTicks - swInvokeStart);
res = new MetricsValueCacheEntry <WeakReference <T>, R>(weakArgs, value);
}
catch (Exception ex) when(_cacheError)
{
res = new MetricsErrorCacheEntry <WeakReference <T>, R>(weakArgs, ex);
}
res.CreationTime = new TimeSpan(_stopwatch.ElapsedTicks);
res.InvokeDuration = invokeDuration;
_lock.EnterWriteLock();
try
{
_entries.Add(res);
}
finally
{
_lock.ExitWriteLock();
}
return(res);
};
_cache = new WeakCacheDictionary <T, IMetricsCacheEntry <WeakReference <T>, R> >();
_lock = new ReaderWriterLockSlim(LockRecursionPolicy.NoRecursion);
_entries = new HashSet <IMetricsCacheEntry <WeakReference <T>, R> >();
_stopwatch = stopwatchFactory.StartNew();
//
// Exclude newest items which have statically irrelevant data, so they get a chance to become relevant.
//
var candidates = _entries.OrderBy(e => _stopwatch.ElapsedTicks - e.CreationTime.Ticks).Take(Math.Max(1, (int)(maxCapacity * ageThreshold)));
_ranker = descending ? candidates.OrderByDescending(e => ranker(e)) : candidates.OrderBy(e => ranker(e));
_maxCapacity = maxCapacity;
_cacheError = cacheError;
}
public Cache(Func <T, R> function, Func <IMemoizationCacheEntryMetrics, TMetric> ranker, int maxCapacity, bool descending, double ageThreshold, IEqualityComparer <T> comparer, bool cacheError, IStopwatchFactory stopwatchFactory)
{
_function = args =>
{
var invokeDuration = default(TimeSpan);
#if DEBUG
_invocationCount++;
#endif
Trim();
var res = default(IMetricsCacheEntry <T, R>);
try
{
var swInvokeStart = _stopwatch.ElapsedTicks;
var value = function(args);
invokeDuration = new TimeSpan(_stopwatch.ElapsedTicks - swInvokeStart);
res = new MetricsValueCacheEntry <T, R>(args, value);
}
catch (Exception ex) when(_cacheError)
{
res = new MetricsErrorCacheEntry <T, R>(args, ex);
}
res.CreationTime = new TimeSpan(_stopwatch.ElapsedTicks);
res.InvokeDuration = invokeDuration;
return(res);
};
_cache = new CacheDictionary <T, IMetricsCacheEntry <T, R> >(comparer);
_stopwatch = stopwatchFactory.StartNew();
//
// Exclude newest items which have statically irrelevant data, so they get a chance to become relevant.
//
var candidates = _cache.Values.OrderBy(e => _stopwatch.ElapsedTicks - e.CreationTime.Ticks).Take(Math.Max(1, (int)(maxCapacity * ageThreshold)));
_ranker = descending ? candidates.OrderByDescending(e => ranker(e)) : candidates.OrderBy(e => ranker(e));
_maxCapacity = maxCapacity;
_cacheError = cacheError;
}
