public IChangeSet <TObject, TKey> Change(IChangeSet <ExpirableItem <TObject, TKey>, TKey> updates)
{
_cache.Clone(updates);
var itemstoexpire = _cache.KeyValues
.OrderByDescending(exp => exp.Value.ExpireAt)
.Skip(_sizeLimit)
.Select(exp => new Change <TObject, TKey>(ChangeReason.Remove, exp.Key, exp.Value.Value))
.ToList();
if (itemstoexpire.Count > 0)
{
_cache.Remove(itemstoexpire.Select(exp => exp.Key));
}
var notifications = _cache.CaptureChanges();
var changed = notifications.Select(update => new Change <TObject, TKey>
(
update.Reason,
update.Key,
update.Current.Value,
update.Previous.HasValue ? update.Previous.Value.Value : Optional <TObject> .None
));
return(new ChangeSet <TObject, TKey>(changed));
}
/// <summary>
/// Initializes a new instance of the <see cref="LockFreeObservableCache{TObject, TKey}"/> class.
/// </summary>
/// <param name="source">The source.</param>
public LockFreeObservableCache(IObservable <IChangeSet <TObject, TKey> > source)
{
_updater = new CacheUpdater <TObject, TKey>(_innerCache);
var loader = source.Select(changes =>
{
_innerCache.Clone(changes);
return(_innerCache.CaptureChanges());
}).SubscribeSafe(_changes);
_cleanUp = Disposable.Create(() =>
{
loader.Dispose();
_changes.OnCompleted();
_countChanged.OnCompleted();
});
}
private IObservable <IChangeSet <TDestination, TDestinationKey> > CreateWithChangeset()
{
return(Observable.Create <IChangeSet <TDestination, TDestinationKey> >(observer =>
{
var result = new ChangeAwareCache <TDestination, TDestinationKey>();
var transformed = _source.Transform((t, key) =>
{
//Only skip initial for first time Adds where there is isinitial data records
var locker = new object();
var collection = _manyselector(t);
var changes = _childChanges(t).Synchronize(locker).Skip(1);
return new ManyContainer(() =>
{
lock (locker)
return collection.Select(m => new DestinationContainer(m, _keySelector(m)));
}, changes);
}).Publish();
var outerLock = new object();
var intial = transformed
.Synchronize(outerLock)
.Select(changes => new ChangeSet <TDestination, TDestinationKey>(new DestinationEnumerator(changes)));
var subsequent = transformed
.MergeMany(x => x.Changes)
.Synchronize(outerLock);
var allChanges = intial.Merge(subsequent).Select(changes =>
{
result.Clone(changes);
return result.CaptureChanges();
});
return new CompositeDisposable(allChanges.SubscribeSafe(observer), transformed.Connect());
}));
}
/// <summary>
/// Sorts using the specified sorter. Will return null if there are no changes
/// </summary>
/// <param name="sortReason">The sort reason.</param>
/// <param name="changes">The changes.</param>
/// <returns></returns>
private ISortedChangeSet <TObject, TKey> DoSort(SortReason sortReason, IChangeSet <TObject, TKey> changes = null)
{
if (changes != null)
{
_cache.Clone(changes);
changes = _cache.CaptureChanges();
_haveReceivedData = true;
if (_comparer == null)
{
return(null);
}
}
//if the comparer is not set, return nothing
if (_comparer == null || !_haveReceivedData)
{
return(null);
}
if (!_initialised)
{
sortReason = SortReason.InitialLoad;
_initialised = true;
}
else if (changes != null && (_resetThreshold > 0 && changes.Count >= _resetThreshold))
{
sortReason = SortReason.Reset;
}
IChangeSet <TObject, TKey> changeSet;
switch (sortReason)
{
case SortReason.InitialLoad:
{
//For the first batch, changes may have arrived before the comparer was set.
//therefore infer the first batch of changes from the cache
_calculator = new IndexCalculator <TObject, TKey>(_comparer, _optimisations);
changeSet = _calculator.Load(_cache);
}
break;
case SortReason.Reset:
{
_calculator.Reset(_cache);
changeSet = changes;
}
break;
case SortReason.DataChanged:
{
changeSet = _calculator.Calculate(changes);
}
break;
case SortReason.ComparerChanged:
{
changeSet = _calculator.ChangeComparer(_comparer);
if (_resetThreshold > 0 && _cache.Count >= _resetThreshold)
{
sortReason = SortReason.Reset;
_calculator.Reset(_cache);
}
else
{
sortReason = SortReason.Reorder;
changeSet = _calculator.Reorder();
}
}
break;
case SortReason.Reorder:
{
changeSet = _calculator.Reorder();
}
break;
default:
throw new ArgumentOutOfRangeException(nameof(sortReason));
}
Debug.Assert(changeSet != null, "changeSet != null");
if ((sortReason == SortReason.InitialLoad || sortReason == SortReason.DataChanged) &&
changeSet.Count == 0)
{
return(null);
}
if (sortReason == SortReason.Reorder && changeSet.Count == 0)
{
return(null);
}
_sorted = new KeyValueCollection <TObject, TKey>(_calculator.List, _comparer, sortReason, _optimisations);
return(new SortedChangeSet <TObject, TKey>(_sorted, changeSet));
}
public void Update(IChangeSet <TObject, TKey> changes)
{
_cache.Clone(changes);
}
public IObservable <IChangeSet <TObject, TKey> > Run()
{
return(Observable.Create <IChangeSet <TObject, TKey> >
(
observer =>
{
var result = new ChangeAwareCache <TObject, TKey>();
var locker = new object();
var paused = _intialPauseState;
var timeoutDisposer = new SerialDisposable();
var intervalTimerDisposer = new SerialDisposable();
void ResumeAction()
{
//publish changes (if there are any)
var changes = result.CaptureChanges();
if (changes.Count > 0)
{
observer.OnNext(changes);
}
}
IDisposable IntervalFunction()
{
return _intervalTimer
.Synchronize(locker)
.Finally(() => paused = false)
.Subscribe(_ =>
{
paused = false;
ResumeAction();
if (_intervalTimer != null)
{
paused = true;
}
});
}
if (_intervalTimer != null)
{
intervalTimerDisposer.Disposable = IntervalFunction();
}
var pausedHander = _pauseIfTrueSelector
// .StartWith(initalp)
.Synchronize(locker)
.Subscribe(p =>
{
paused = p;
if (!p)
{
//pause window has closed, so reset timer
if (_timeOut.HasValue)
{
timeoutDisposer.Disposable = Disposable.Empty;
}
ResumeAction();
}
else
{
if (_timeOut.HasValue)
{
timeoutDisposer.Disposable = Observable.Timer(_timeOut.Value, _scheduler)
.Synchronize(locker)
.Subscribe(_ =>
{
paused = false;
ResumeAction();
});
}
}
});
var publisher = _source
.Synchronize(locker)
.Subscribe(changes =>
{
result.Clone(changes);
//publish if not paused
if (!paused)
{
observer.OnNext(result.CaptureChanges());
}
});
return new CompositeDisposable(publisher, pausedHander, timeoutDisposer, intervalTimerDisposer);
}
));
}
