T IContextCache.GetOrAddContext <T>(ContextFactory <T> contextFactory)
{
try
{
IContextValue <T> context = null;
IContextCollection currentCollection;
do
{
T existingValue;
if (_collection.TryGetContext(out existingValue))
{
return(existingValue);
}
IContextValue <T> contextProperty = context ?? (context = new ContextValue <T>(contextFactory()));
currentCollection = Volatile.Read(ref _collection);
Interlocked.CompareExchange(ref _collection, currentCollection.Add(contextProperty), currentCollection);
} while (currentCollection == Volatile.Read(ref _collection));
return(context.Value);
}
catch (Exception exception)
{
throw new ContextFactoryException($"The payload factory faulted: {TypeCache<T>.ShortName}", exception);
}
}
ArrayContextCollection(IReadOnlyContextCollection parent, IContextValue context, IContextValue[] contexts)
: base(parent)
{
_parent = parent;
_contexts = new IContextValue[contexts.Length + 1];
_contexts[0] = context;
Array.Copy(contexts, 0, _contexts, 1, contexts.Length);
}
T IContextCache.AddOrUpdateContext <T>(ContextFactory <T> addFactory, UpdateContextFactory <T> updateFactory)
{
try
{
T previousValue = null;
IContextValue <T> context = null;
IContextCollection currentCollection;
do
{
T existingValue;
if (_collection.TryGetContext(out existingValue))
{
if (context == null || previousValue != existingValue)
{
context = new ContextValue <T>(updateFactory(existingValue));
}
previousValue = existingValue;
currentCollection = Volatile.Read(ref _collection);
Interlocked.CompareExchange(ref _collection, currentCollection.Add(context), currentCollection);
}
else
{
if (context == null)
{
context = new ContextValue <T>(addFactory());
}
currentCollection = Volatile.Read(ref _collection);
Interlocked.CompareExchange(ref _collection, currentCollection.Add(context), currentCollection);
}
} while (currentCollection == Volatile.Read(ref _collection));
return(context.Value);
}
catch (Exception exception)
{
throw new ContextFactoryException($"The payload factory faulted: {TypeCache<T>.ShortName}", exception);
}
}
public static T GetValue <T>(this IContextValue <T, NoContext> value)
{
return(value.GetValue(null));
}
public override IContextCollection Add(IContextValue context)
{
return(new SingleContextCollection(context, Parent));
}
public override IContextCollection Add(IContextValue context)
{
return(new ArrayContextCollection(_parent, context, _context));
}
public SingleContextCollection(IContextValue context, IReadOnlyContextCollection parent = null)
: base(parent)
{
_context = context;
_parent = parent;
}
public abstract IContextCollection Add(IContextValue context);
