public void WeakReferenceExtensions_ArgumentChecking()
{
#pragma warning disable IDE0034 // Simplify 'default' expression (illustrative of method signature)
Assert.ThrowsException <ArgumentNullException>(() => WeakReferenceExtensions.GetTarget(default(WeakReference <string>)));
Assert.ThrowsException <ArgumentNullException>(() => WeakReferenceExtensions.GetOrSetTarget(default(WeakReference <string>), () => ""));
Assert.ThrowsException <ArgumentNullException>(() => WeakReferenceExtensions.GetOrSetTarget(new WeakReference <string>(""), default(Func <string>)));
#pragma warning restore IDE0034 // Simplify 'default' expression
}
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 void WeakReferenceExtensions_Create_Null()
{
var w = WeakReferenceExtensions.Create <string>(target: null);
Assert.IsFalse(w.TryGetTarget(out _));
Assert.IsNull(w.GetTarget());
Assert.IsNull(w.GetOrSetTarget(() => { Assert.Fail(); return(""); }));
}
private static WeakReference <string> CreateWeakString()
{
var s = GetString();
var w = WeakReferenceExtensions.Create <string>(s);
Assert.AreSame(s, w.GetTarget());
GC.KeepAlive(s);
return(w);
}
public void WeakReferenceExtensions_Create_Alive()
{
var s = "bar".ToUpper();
var w = WeakReferenceExtensions.Create <string>(s);
Assert.IsTrue(w.TryGetTarget(out string target));
Assert.AreSame(s, target);
Assert.AreSame(s, w.GetTarget());
Assert.AreSame(s, w.GetOrSetTarget(() => { Assert.Fail(); return(""); }));
GC.KeepAlive(s);
}
public Cache(Func <T, R> function, int maxCapacity, bool cacheError)
{
_function = args =>
{
var weakArgs = WeakReferenceExtensions.Create(args);
#if DEBUG
var invokeDuration = default(TimeSpan);
Interlocked.Increment(ref _invocationCount);
#endif
Trim();
var res = default(ILruCacheEntry <WeakReference <T>, R>);
try
{
#if DEBUG
var swInvoke = Stopwatch.StartNew();
#endif
var value = function(args);
#if DEBUG
invokeDuration = swInvoke.Elapsed;
#endif
res = new LruValueCacheEntry <WeakReference <T>, R>(weakArgs, value);
}
catch (Exception ex) when(_cacheError)
{
res = new LruErrorCacheEntry <WeakReference <T>, R>(weakArgs, ex);
}
Interlocked.Increment(ref _count);
#if DEBUG
res.GetMetrics().InvokeDuration = invokeDuration;
#endif
return(res);
};
_cache = new WeakCacheDictionary <T, ILruCacheEntry <WeakReference <T>, R> >();
_lock = new ReaderWriterLockSlim(LockRecursionPolicy.NoRecursion);
_maxCapacity = maxCapacity;
_cacheError = cacheError;
}
