sharp-oodb/persistence/PersistenceCache.cs

using System;
using System.Collections.Generic;
using oodb.descriptor;
using System.Dynamic;
namespace oodb.persistence
{
    public class PersistenceCache
    {
        public OODB OODB { get; }


        Dictionary<Type, TypeCache> typeCaches = new Dictionary<Type, TypeCache>();


        public PersistenceCache(OODB oodb)
        {
            OODB = oodb;
        }

        private TypeCache GetTypeCache(Type type)
        {
            if (!typeCaches.ContainsKey(type))
                typeCaches[type] = new TypeCache(this,type);
            return typeCaches[type];
        }

        public Persistent Get(Type type,Guid persistenceID)
        {
            return GetTypeCache(type).Get(persistenceID);
        }

        public void Touch(Persistent persistent)
        {
            GetTypeCache(persistent.GetType()).Touch(persistent);
        }

        public void Remove(Persistent persistent)
        {
            GetTypeCache(persistent.GetType()).Remove(persistent);
        }



        class TypeCache
        {
            PersistenceCache PersistenceCache { get; }
            TypeCache BaseCache { get; }

            Type CacheType { get; }

            Descriptor Descriptor { get; }

            Dictionary<Guid, WeakReference> cache = new Dictionary<Guid, WeakReference>();

            public TypeCache(PersistenceCache persistenceCache,Type type)
            {
                PersistenceCache = persistenceCache;
                CacheType = type;
                Descriptor = persistenceCache.OODB.GetDescriptor(type);

                if (Descriptor.BaseDescriptor != null)
                    BaseCache = persistenceCache.GetTypeCache(Descriptor.BaseDescriptor.NativeType);
            }

            public Persistent Get(Guid persistenceID)
            {
                WeakReference weakReference = cache[persistenceID];
                if (!weakReference.IsAlive)
                {
                    Remove(persistenceID);
                    throw new KeyNotFoundException(persistenceID.ToString());
                }
                return weakReference.Target as Persistent;
            }

            public void Touch(Persistent persistent)
            {
                cache[persistent.PersistenceID] = new WeakReference(persistent);
                if (Descriptor.BaseDescriptor != null)
                    PersistenceCache.GetTypeCache(Descriptor.BaseDescriptor.NativeType).Touch(persistent);
            }

            public void Remove(Persistent persistent)
            {
                Remove(persistent.PersistenceID);
            }
            public void Remove(Guid persistenceID)
            {
                cache.Remove(persistenceID);
                if (Descriptor.BaseDescriptor != null)
                {
                    PersistenceCache.GetTypeCache(Descriptor.BaseDescriptor.NativeType).Remove(persistenceID);
                }
            }
        }


    }
}