public static List<Type> GetFilteredTypesFromAssemblies(string cacheName, Predicate<Type> predicate, IBuildManager buildManager)
{
HttpControllerTypeCacheSerializer serializer = new HttpControllerTypeCacheSerializer();
// first, try reading from the cache on disk
List<Type> matchingTypes = ReadTypesFromCache(cacheName, predicate, buildManager, serializer);
if (matchingTypes != null)
{
return matchingTypes;
}
// if reading from the cache failed, enumerate over every assembly looking for a matching type
matchingTypes = FilterTypesInAssemblies(buildManager, predicate).ToList();
// finally, save the cache back to disk
SaveTypesToCache(cacheName, matchingTypes, buildManager, serializer);
return matchingTypes;
}
private static void SaveTypesToCache(string cacheName, IList<Type> matchingTypes, IBuildManager buildManager, HttpControllerTypeCacheSerializer serializer)
{
try
{
Stream stream = buildManager.CreateCachedFile(cacheName);
if (stream != null)
{
using (StreamWriter writer = new StreamWriter(stream))
{
serializer.SerializeTypes(matchingTypes, writer);
}
}
}
catch
{
// cache failures are not considered fatal -- keep running.
}
}
private static List<Type> ReadTypesFromCache(string cacheName, Predicate<Type> predicate, IBuildManager buildManager, HttpControllerTypeCacheSerializer serializer)
{
try
{
Stream stream = buildManager.ReadCachedFile(cacheName);
if (stream != null)
{
using (StreamReader reader = new StreamReader(stream))
{
List<Type> deserializedTypes = serializer.DeserializeTypes(reader);
if (deserializedTypes != null && deserializedTypes.All(type => predicate(type)))
{
// If all read types still match the predicate, success!
return deserializedTypes;
}
}
}
}
catch
{
// cache failures are not considered fatal -- keep running.
}
return null;
}