Added db4o.

Added guards against most problematic areas.

NzbDrone.Core/Datastore/IObjectDbSession.cs

@@ -0,0 +1,142 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using Db4objects.Db4o;
+using Db4objects.Db4o.Internal;
+using Db4objects.Db4o.Internal.References;
+
+namespace NzbDrone.Core.Datastore
+{
+    public interface IObjectDbSession : IObjectContainer
+    {
+        void Save(object obj);
+        void Save(object obj, int depth);
+        void SaveAll<T>(Transaction transaction, IEnumerator<T> objects);
+
+        void Update(object obj);
+        void Update(object obj, int depth);
+        void UpdateAll<T>(Transaction transaction, IEnumerator<T> objects);
+    }
+
+
+    public class ObjectDbSession : ObjectContainerSession, IObjectDbSession
+    {
+        private NoCahceRefrenceSystem _noCacheRefSystem;
+
+        public ObjectDbSession(ObjectContainerBase server)
+            : base(server, server.NewTransaction(server.SystemTransaction(), new NoCahceRefrenceSystem(), false))
+        {
+            _transaction.SetOutSideRepresentation(this);
+            _noCacheRefSystem = (NoCahceRefrenceSystem)_transaction.ReferenceSystem();
+        }
+
+        public override void Store(object obj)
+        {
+            throw new InvalidOperationException("Store is not supported. please use Save() or Update()");
+        }
+
+        public override void StoreAll(Transaction transaction, IEnumerator objects)
+        {
+            throw new InvalidOperationException("Store is not supported. please use Save() or Update()");
+
+        }
+
+        public override void Store(object obj, int depth)
+        {
+            throw new InvalidOperationException("Store is not supported. please use Save() or Update()");
+        }
+
+        public void Save(object obj)
+        {
+            ValidateSave(obj);
+            base.Store(obj);
+            Commit();
+        }
+
+        public void Save(object obj, int depth)
+        {
+            ValidateSave(obj);
+            base.Store(obj, depth);
+            Commit();
+
+        }
+
+        public void SaveAll<T>(Transaction transaction, IEnumerator<T> objects)
+        {
+            var obj = objects.ToIEnumerable().ToList();
+            obj.ForEach(c => ValidateSave(c));
+
+            base.StoreAll(transaction, obj.GetEnumerator());
+            Commit();
+
+        }
+
+
+        public void Update(object obj)
+        {
+            ValidateUpdate(obj);
+            base.Store(obj);
+            Commit();
+        }
+
+        public void Update(object obj, int depth)
+        {
+            ValidateUpdate(obj);
+            base.Store(obj, depth);
+            Commit();
+        }
+
+        public void UpdateAll<T>(Transaction transaction, IEnumerator<T> objects)
+        {
+            var obj = objects.ToIEnumerable().ToList();
+            obj.ForEach(c => ValidateUpdate(c));
+
+            base.StoreAll(transaction, obj.GetEnumerator());
+            Commit();
+        }
+
+        public void UpdateAll(Transaction transaction, IEnumerator objects)
+        {
+            throw new NotImplementedException();
+        }
+
+        public new void Purge()
+        {
+            _noCacheRefSystem.Reset();
+        }
+
+        private void ValidateSave(object obj)
+        {
+            if (IsAttached(obj))
+            {
+                throw new InvalidOperationException("Attempted to save an object that is already attached to database");
+            }
+        }
+
+        private void ValidateUpdate(object obj)
+        {
+            if (!IsAttached(obj))
+            {
+                throw new InvalidOperationException("Attempted to update an object that is not attached to database");
+            }
+        }
+
+        private bool IsAttached(object obj)
+        {
+            return base.Ext().GetID(obj) > 0;
+        }
+    }
+
+
+    public static class Ext
+    {
+        public static IEnumerable<T> ToIEnumerable<T>(this IEnumerator<T> enumerator)
+        {
+            while (enumerator.MoveNext())
+            {
+                yield return enumerator.Current;
+            }
+        }
+    }
+}