private IChangeSet <TDestination, TKey> ProcessUpdates(ChangeAwareCache <TransformedItemContainer, TKey> cache, TransformResult[] transformedItems)
{
//check for errors and callback if a handler has been specified
var errors = transformedItems.Where(t => !t.Success).ToArray();
if (errors.Any())
{
errors.ForEach(t => _exceptionCallback(new Error <TSource, TKey>(t.Error, t.Change.Current, t.Change.Key)));
}
foreach (var result in transformedItems.Where(t => t.Success))
{
var key = result.Key;
switch (result.Change.Reason)
{
case ChangeReason.Add:
case ChangeReason.Update:
cache.AddOrUpdate(result.Container.Value, key);
break;
case ChangeReason.Remove:
cache.Remove(key);
break;
case ChangeReason.Refresh:
cache.Refresh(key);
break;
}
}
var changes = cache.CaptureChanges();
var transformed = changes.Select(change => new Change <TDestination, TKey>(change.Reason,
change.Key,
change.Current.Destination,
change.Previous.Convert(x => x.Destination),
change.CurrentIndex,
change.PreviousIndex));
return(new ChangeSet <TDestination, TKey>(transformed));
}
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());
}));
}
private void ProcessItem(ChangeAwareCache <TObject, TKey> target, MergeContainer[] sourceLists, TObject item, TKey key)
{
var cached = target.Lookup(key);
var shouldBeInResult = MatchesConstraint(sourceLists, key);
if (shouldBeInResult)
{
if (!cached.HasValue)
{
target.AddOrUpdate(item, key);
}
else if (!ReferenceEquals(item, cached.Value))
{
target.AddOrUpdate(item, key);
}
}
else
{
if (cached.HasValue)
{
target.Remove(key);
}
}
}
public void Initialise()
{
_cache = new ChangeAwareCache <Person, string>();
_updater = new CacheUpdater <Person, string>(_cache);
}
private void UpdateResultList(ChangeAwareCache <TObject, TKey> target, MergeContainer[] sourceLists, IChangeSet <TObject, TKey> changes)
{
changes.ForEach(change => { ProcessItem(target, sourceLists, change.Current, change.Key); });
}
public IObservable <IChangeSet <TObject, TKey> > Run()
{
return(Observable.Create <IChangeSet <TObject, TKey> >(observer =>
{
var locker = new object();
//this is the resulting cache which produces all notifications
var resultCache = new ChangeAwareCache <TObject, TKey>();
//Transform to a merge container.
//This populates a RefTracker when the original source is subscribed to
var sourceLists = _source.Connect()
.Synchronize(locker)
.Transform(changeset => new MergeContainer(changeset))
.AsObservableList();
//merge the items back together
var allChanges = sourceLists.Connect()
.MergeMany(mc => mc.Source)
.Synchronize(locker)
.Subscribe(changes =>
{
//Populate result list and chck for changes
UpdateResultList(resultCache, sourceLists.Items.AsArray(), changes);
var notifications = resultCache.CaptureChanges();
if (notifications.Count != 0)
{
observer.OnNext(notifications);
}
});
//when an list is removed, need to
var removedItem = sourceLists.Connect()
.OnItemRemoved(mc =>
{
//Remove items if required
ProcessChanges(resultCache, sourceLists.Items.AsArray(), mc.Cache.KeyValues);
if (_type == CombineOperator.And || _type == CombineOperator.Except)
{
var itemsToCheck = sourceLists.Items.SelectMany(mc2 => mc2.Cache.KeyValues);
ProcessChanges(resultCache, sourceLists.Items.AsArray(), itemsToCheck);
}
var notifications = resultCache.CaptureChanges();
if (notifications.Count != 0)
{
observer.OnNext(notifications);
}
})
.Subscribe();
//when an list is added or removed, need to
var sourceChanged = sourceLists.Connect()
.WhereReasonsAre(ListChangeReason.Add, ListChangeReason.AddRange)
.ForEachItemChange(mc =>
{
ProcessChanges(resultCache, sourceLists.Items.AsArray(), mc.Current.Cache.KeyValues);
if (_type == CombineOperator.And || _type == CombineOperator.Except)
{
ProcessChanges(resultCache, sourceLists.Items.AsArray(), resultCache.KeyValues.ToArray());
}
var notifications = resultCache.CaptureChanges();
if (notifications.Count != 0)
{
observer.OnNext(notifications);
}
})
.Subscribe();
return new CompositeDisposable(sourceLists, allChanges, removedItem, sourceChanged);
}));
}
private void ProcessChanges(ChangeAwareCache <TObject, TKey> target, MergeContainer[] sourceLists, IEnumerable <KeyValuePair <TKey, TObject> > items)
{
//check whether the item should be removed from the list (or in the case of And, added)
items.ForEach(item => { ProcessItem(target, sourceLists, item.Value, item.Key); });
}
/// <summary>
/// Initialises the specified changes.
/// </summary>
/// <param name="cache">The cache.</param>
/// <returns></returns>
public void Reset(ChangeAwareCache <TObject, TKey> cache)
{
_list = cache.KeyValues.OrderBy(kv => kv, _comparer).ToList();
}
public SourceUpdaterFixture()
{
_cache = new ChangeAwareCache <Person, string>();
_updater = new CacheUpdater <Person, string>(_cache, new KeySelector <Person, string>(p => p.Name));
}
public PLinqFilteredUpdater(ChangeAwareCache <TObject, TKey> cache, Func <TObject, bool> filter, ParallelisationOptions parallelisationOptions)
: base(cache, filter)
{
_parallelisationOptions = parallelisationOptions;
}
public static IChangeSet <TObject, TKey> GetInitialUpdates <TObject, TKey>(this ChangeAwareCache <TObject, TKey> source, Func <TObject, bool> filter = null)
{
var filtered = filter == null ? source.KeyValues : source.KeyValues.Where(kv => filter(kv.Value));
return(new ChangeSet <TObject, TKey>(filtered.Select(i => new Change <TObject, TKey>(ChangeReason.Add, i.Key, i.Value))));
}
private async Task <IChangeSet <TDestination, TKey> > DoTransform(ChangeAwareCache <TransformedItemContainer, TKey> cache, IChangeSet <TSource, TKey> changes)
{
var transformed = await changes.SelectParallel(Transform, _maximumConcurrency);
return(ProcessUpdates(cache, transformed.ToArray()));
}
public CacheUpdater(ChangeAwareCache <TObject, TKey> cache, IKeySelector <TObject, TKey> keySelector = null)
{
_cache = cache ?? throw new ArgumentNullException(nameof(cache));
_keySelector = keySelector;
}
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);
}
));
}
public void Initialise()
{
_cache = new ChangeAwareCache <Person, string>();
_updater = new CacheUpdater <Person, string>(_cache, new KeySelector <Person, string>(p => p.Name));
}
public IObservable <IChangeSet <TObject, TKey> > Run()
{
return(Observable.Create <IChangeSet <TObject, TKey> >(observer =>
{
long orderItemWasAdded = -1;
var locker = new object();
if (_expireAfter == null && _limitSizeTo < 1)
{
return _source.Scan(new ChangeAwareCache <TObject, TKey>(), (state, latest) =>
{
latest.ForEach(t => state.AddOrUpdate(t, _keySelector(t)));
return state;
})
.Select(state => state.CaptureChanges())
.SubscribeSafe(observer);
}
var cache = new ChangeAwareCache <ExpirableItem <TObject, TKey>, TKey>();
var sizeLimited = _source.Synchronize(locker)
.Scan(cache, (state, latest) =>
{
latest.Select(t =>
{
var key = _keySelector(t);
return CreateExpirableItem(t, key, ref orderItemWasAdded);
}).ForEach(ei => cache.AddOrUpdate(ei, ei.Key));
if (_limitSizeTo > 0 && state.Count > _limitSizeTo)
{
var toRemove = state.Count - _limitSizeTo;
//remove oldest items
cache.KeyValues
.OrderBy(exp => exp.Value.Index)
.Take(toRemove)
.ForEach(ei => cache.Remove(ei.Key));
}
return state;
})
.Select(state => state.CaptureChanges())
.Publish();
var timeLimited = (_expireAfter == null ? Observable.Never <IChangeSet <ExpirableItem <TObject, TKey>, TKey> >() : sizeLimited)
.Filter(ei => ei.ExpireAt != DateTime.MaxValue)
.GroupWithImmutableState(ei => ei.ExpireAt)
.MergeMany(grouping =>
{
var expireAt = grouping.Key.Subtract(_scheduler.Now.DateTime);
return Observable.Timer(expireAt, _scheduler).Select(_ => grouping);
})
.Synchronize(locker)
.Select(grouping =>
{
cache.Remove(grouping.Keys);
return cache.CaptureChanges();
});
var publisher = sizeLimited
.Merge(timeLimited)
.Cast(ei => ei.Value)
.NotEmpty()
.SubscribeSafe(observer);
return new CompositeDisposable(publisher, sizeLimited.Connect());
}));
}
public CacheUpdaterFixture()
{
_cache = new ChangeAwareCache <Person, string>();
_updater = new CacheUpdater <Person, string>(_cache);
}
public FilteredUpdater(ChangeAwareCache <TObject, TKey> cache, Func <TObject, bool> filter)
: base(cache, filter)
{
}
public static void FilterChanges <TObject, TKey>(this ChangeAwareCache <TObject, TKey> cache,
IChangeSet <TObject, TKey> changes,
Func <TObject, bool> predicate)
{
foreach (var change in changes)
{
var key = change.Key;
switch (change.Reason)
{
case ChangeReason.Add:
{
if (predicate(change.Current))
{
cache.AddOrUpdate(change.Current, key);
}
}
break;
case ChangeReason.Update:
{
if (predicate(change.Current))
{
cache.AddOrUpdate(change.Current, key);
}
else
{
cache.Remove(key);
}
}
break;
case ChangeReason.Remove:
cache.Remove(key);
break;
case ChangeReason.Refresh:
{
var exisiting = cache.Lookup(key);
if (predicate(change.Current))
{
if (!exisiting.HasValue)
{
cache.AddOrUpdate(change.Current, key);
}
else
{
cache.Refresh(key);
}
}
else
{
if (exisiting.HasValue)
{
cache.Remove(key);
}
}
}
break;
}
}
}
