public FilterItem(FilterChainKind kind, IFilterFactory factory, IFilter referenceFilter, FilterAccessor accessor, int perInvokeIndex = -1)
{
Kind = kind;
Factory = factory;
ReferenceFilter = referenceFilter;
Accessor = accessor;
PerInvokeIndex = perInvokeIndex;
}
public FilterItem(FilterChainKind kind, IFilterFactory factory, IFilter referenceFilter, FilterAccessor accessor, int perInvokeIndex = -1)
{
Kind = kind;
Factory = factory;
ReferenceFilter = referenceFilter;
Accessor = accessor;
PerInvokeIndex = perInvokeIndex;
}
public FilterChain Build(MethodInfo method, FilterChainKind kind)
{
var filterItems = BuildFilterItems(_type, method, kind).OrderBy(f => f.Order).ToList();
return(new FilterChain
{
PreFilterAccessors = filterItems.Where(f => f.IsPreFilter).Select(f => f.Accessor).ToArray(),
PostFilterAccessors = filterItems.Where(f => f.IsPostFilter).Select(f => f.Accessor).Reverse().ToArray(),
PerInvokeFilterFactories = filterItems.Where(f => f.IsPerInvoke).GroupBy(f => f.PerInvokeIndex)
.OrderBy(g => g.Key).Select(g => (IFilterPerInvokeFactory)g.Last().Factory).ToArray(),
Empty = filterItems.Any() == false,
AsyncFilterExists = filterItems.Any(f => f.IsAsync),
PerInstanceFilterExists = filterItems.Any(f => f.IsPerInstance),
});
}
public FilterChain Build(MethodInfo method, FilterChainKind kind)
{
var filterItems = BuildFilterItems(_type, method, kind).OrderBy(f => f.Order).ToList();
return new FilterChain
{
PreFilterAccessors = filterItems.Where(f => f.IsPreFilter).Select(f => f.Accessor).ToArray(),
PostFilterAccessors = filterItems.Where(f => f.IsPostFilter).Select(f => f.Accessor).Reverse().ToArray(),
PerInvokeFilterFactories = filterItems.Where(f => f.IsPerInvoke).GroupBy(f => f.PerInvokeIndex)
.OrderBy(g => g.Key).Select(g => (IFilterPerInvokeFactory)g.Last().Factory).ToArray(),
Empty = filterItems.Any() == false,
AsyncFilterExists = filterItems.Any(f => f.IsAsync),
PerInstanceFilterExists = filterItems.Any(f => f.IsPerInstance),
};
}
private static bool CheckFilterKind(IFilter filter, FilterChainKind kind)
{
switch (kind)
{
case FilterChainKind.Request:
return(filter is IPreRequestFilter || filter is IPreRequestAsyncFilter ||
filter is IPostRequestFilter || filter is IPostRequestAsyncFilter);
case FilterChainKind.Notification:
return(filter is IPreNotificationFilter || filter is IPreNotificationAsyncFilter ||
filter is IPostNotificationFilter || filter is IPostNotificationAsyncFilter);
case FilterChainKind.Message:
return(filter is IPreMessageFilter || filter is IPreMessageAsyncFilter ||
filter is IPostMessageFilter || filter is IPostMessageAsyncFilter);
default:
return(false);
}
}
private List <FilterItem> BuildFilterItems(Type type, MethodInfo method, FilterChainKind kind)
{
var filterItems = new List <FilterItem>();
var filterPerInvokeIndex = 0;
// scan all filters for this method and construct a list of filter item
// discard filters that doesn't provide a exact filter (such as a filter doesn't have OnPreRequest on kind=Request)
var filterFactories = type.GetCustomAttributes().Concat(method.GetCustomAttributes()).OfType <IFilterFactory>();
foreach (var filterFactory in filterFactories)
{
FilterItem filterItem = null;
if (filterFactory is IFilterPerClassFactory)
{
var factoryType = filterFactory.GetType();
if (_perClassFilterItemTable.TryGetValue(factoryType, out filterItem) == false)
{
var factory = (IFilterPerClassFactory)filterFactory;
factory.Setup(type);
var filter = factory.CreateInstance();
if (CheckFilterKind(filter, kind))
{
filterItem = new FilterItem(kind, filterFactory, filter, (_, x) => filter);
_perClassFilterItemTable.Add(factoryType, filterItem);
}
}
else if (filterItem.Kind != kind)
{
filterItem = null;
}
}
else if (filterFactory is IFilterPerClassMethodFactory)
{
var factory = (IFilterPerClassMethodFactory)filterFactory;
factory.Setup(type, method);
var filter = factory.CreateInstance();
if (CheckFilterKind(filter, kind))
{
filterItem = new FilterItem(kind, filterFactory, filter, (_, x) => filter);
}
}
else if (filterFactory is IFilterPerInstanceFactory)
{
var factoryType = filterFactory.GetType();
if (_perInstanceFilterItemTable.TryGetValue(factoryType, out filterItem) == false)
{
var factory = ((IFilterPerInstanceFactory)filterFactory);
factory.Setup(type);
var filter = factory.CreateInstance(null);
if (CheckFilterKind(filter, kind))
{
var arrayIndex = _perInstanceFilterCreators.Count;
_perInstanceFilterCreators.Add(a => factory.CreateInstance(a));
filterItem = new FilterItem(kind, filterFactory, filter,
(provider, _) => provider.GetFilter(arrayIndex));
_perInstanceFilterItemTable.Add(factoryType, filterItem);
}
}
else if (filterItem.Kind != kind)
{
filterItem = null;
}
}
else if (filterFactory is IFilterPerInstanceMethodFactory)
{
var factory = ((IFilterPerInstanceMethodFactory)filterFactory);
factory.Setup(type, method);
var filter = factory.CreateInstance(null);
if (CheckFilterKind(filter, kind))
{
var arrayIndex = _perInstanceFilterCreators.Count;
_perInstanceFilterCreators.Add(a => factory.CreateInstance(a));
filterItem = new FilterItem(kind, filterFactory, filter,
(provider, _) => provider.GetFilter(arrayIndex));
}
}
else if (filterFactory is IFilterPerInvokeFactory)
{
var factory = ((IFilterPerInvokeFactory)filterFactory);
factory.Setup(type, method);
var filter = factory.CreateInstance(null, null);
if (CheckFilterKind(filter, kind))
{
var arrayIndex = filterPerInvokeIndex++;
filterItem = new FilterItem(kind, filterFactory, filter,
(_, filters) => filters[arrayIndex], filterPerInvokeIndex);
}
}
if (filterItem != null)
{
filterItems.Add(filterItem);
}
}
return(filterItems);
}
private List<FilterItem> BuildFilterItems(Type type, MethodInfo method, FilterChainKind kind)
{
var filterItems = new List<FilterItem>();
var filterPerInvokeIndex = 0;
// scan all filters for this method and construct a list of filter item
// discard filters that doesn't provide a exact filter (such as a filter doesn't have OnPreRequest on kind=Request)
var filterFactories = type.GetCustomAttributes().Concat(method.GetCustomAttributes()).OfType<IFilterFactory>();
foreach (var filterFactory in filterFactories)
{
FilterItem filterItem = null;
if (filterFactory is IFilterPerClassFactory)
{
var factoryType = filterFactory.GetType();
if (_perClassFilterItemTable.TryGetValue(factoryType, out filterItem) == false)
{
var factory = (IFilterPerClassFactory)filterFactory;
factory.Setup(type);
var filter = factory.CreateInstance();
if (CheckFilterKind(filter, kind))
{
filterItem = new FilterItem(kind, filterFactory, filter, (_, x) => filter);
_perClassFilterItemTable.Add(factoryType, filterItem);
}
}
else if (filterItem.Kind != kind)
{
filterItem = null;
}
}
else if (filterFactory is IFilterPerClassMethodFactory)
{
var factory = (IFilterPerClassMethodFactory)filterFactory;
factory.Setup(type, method);
var filter = factory.CreateInstance();
if (CheckFilterKind(filter, kind))
{
filterItem = new FilterItem(kind, filterFactory, filter, (_, x) => filter);
}
}
else if (filterFactory is IFilterPerInstanceFactory)
{
var factoryType = filterFactory.GetType();
if (_perInstanceFilterItemTable.TryGetValue(factoryType, out filterItem) == false)
{
var factory = ((IFilterPerInstanceFactory)filterFactory);
factory.Setup(type);
var filter = factory.CreateInstance(null);
if (CheckFilterKind(filter, kind))
{
var arrayIndex = _perInstanceFilterCreators.Count;
_perInstanceFilterCreators.Add(a => factory.CreateInstance(a));
filterItem = new FilterItem(kind, filterFactory, filter,
(provider, _) => provider.GetFilter(arrayIndex));
_perInstanceFilterItemTable.Add(factoryType, filterItem);
}
}
else if (filterItem.Kind != kind)
{
filterItem = null;
}
}
else if (filterFactory is IFilterPerInstanceMethodFactory)
{
var factory = ((IFilterPerInstanceMethodFactory)filterFactory);
factory.Setup(type, method);
var filter = factory.CreateInstance(null);
if (CheckFilterKind(filter, kind))
{
var arrayIndex = _perInstanceFilterCreators.Count;
_perInstanceFilterCreators.Add(a => factory.CreateInstance(a));
filterItem = new FilterItem(kind, filterFactory, filter,
(provider, _) => provider.GetFilter(arrayIndex));
}
}
else if (filterFactory is IFilterPerInvokeFactory)
{
var factory = ((IFilterPerInvokeFactory)filterFactory);
factory.Setup(type, method);
var filter = factory.CreateInstance(null, null);
if (CheckFilterKind(filter, kind))
{
var arrayIndex = filterPerInvokeIndex++;
filterItem = new FilterItem(kind, filterFactory, filter,
(_, filters) => filters[arrayIndex], filterPerInvokeIndex);
}
}
if (filterItem != null)
filterItems.Add(filterItem);
}
return filterItems;
}
private static bool CheckFilterKind(IFilter filter, FilterChainKind kind)
{
switch (kind)
{
case FilterChainKind.Request:
return filter is IPreRequestFilter || filter is IPreRequestAsyncFilter ||
filter is IPostRequestFilter || filter is IPostRequestAsyncFilter;
case FilterChainKind.Notification:
return filter is IPreNotificationFilter || filter is IPreNotificationAsyncFilter ||
filter is IPostNotificationFilter || filter is IPostNotificationAsyncFilter;
case FilterChainKind.Message:
return filter is IPreMessageFilter || filter is IPreMessageAsyncFilter ||
filter is IPostMessageFilter || filter is IPostMessageAsyncFilter;
default:
return false;
}
}
