fix bug #10 + commenting and refactoring

OrigoDb.Core.nuspec

@@ -22,7 +22,6 @@
   <files>
     <file src="build/OrigoDB.Core.dll" target="lib\net40" />
     <file src="build/OrigoDB.Core.pdb" target="lib\net40" />
-    <file src="build/OrigoDB.Core.XML" target="lib\net40" />
     <file src="src/OrigoDB.Core/**/*.cs" target="src" />
   </files>
-</package>
+</package>

src/OrigoDB.Core.Test/FileStoreTest.cs

@@ -2,7 +2,6 @@
 using System.Linq;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using System;
-using OrigoDB.Core;
 
 namespace OrigoDB.Core.Test
 {

src/OrigoDB.Core.UnitTests/EngineConfigurationTest.cs

@@ -8,6 +8,29 @@
 namespace OrigoDB.Core.Test
 {
 
+    [TestFixture]
+    public class EngineLoadTest
+    {
+        [Test]
+        public void CanLoadAndCreateRepeatedly()
+        {
+            var config = EngineConfiguration.Create().WithRandomLocation();
+            try
+            {
+                var engine = Engine.LoadOrCreate<TestModel>(config);
+                engine.Execute(new TestCommandWithResult());
+                engine.Close();
+                engine = Engine.LoadOrCreate<TestModel>(config);
+                engine.Close();
+            }
+            finally
+            {
+                if (config.CreateCommandStore() is FileCommandStore)
+                    Directory.Delete(config.Location.OfJournal, true);    
+            }
+        }
+    }
+
     [TestFixture]
     public class EngineConfigurationTest
     {

src/OrigoDB.Core/Engine.cs

@@ -69,7 +69,11 @@ protected Engine(Model model, EngineConfiguration config)
                 Thread.Sleep(TimeSpan.FromMilliseconds(10));
             }
 
-            CommandExecuted += (s, e) => HandleSnapshotPersistence();
+            if (_config.PersistenceMode == PersistenceMode.SnapshotPerTransaction)
+            {
+                CommandExecuted += (s, e) => CreateSnapshot();
+            }
+
 
             Core.Config.Engines.AddEngine(config.Location.OfJournal, this);
         }
@@ -124,7 +128,7 @@ public object Execute(Query query)
         /// </summary>
         public TResult Execute<TModel, TResult>(Func<TModel, TResult> lambdaQuery) where TModel : Model
         {
-            EnsureRunning();
+            EnsureNotDisposed();
             EnsureAuthorized(lambdaQuery);
             return ExecuteQuery(new DelegateQuery<TModel, TResult>(lambdaQuery));
         }
@@ -134,7 +138,7 @@ public object Execute(Query query)
         /// </summary>
         public TRresult Execute<TModel, TRresult>(Query<TModel, TRresult> query) where TModel : Model
         {
-            EnsureRunning();
+            EnsureNotDisposed();
             EnsureAuthorized(query);
             return ExecuteQuery(query);
         }
@@ -144,7 +148,7 @@ public object Execute(Query query)
         /// </summary>
         public object Execute(Command command)
         {
-            EnsureRunning();
+            EnsureNotDisposed();
             EnsureAuthorized(command);
             FireExecutingEvent(command);
 
@@ -153,7 +157,11 @@ public object Execute(Command command)
                 command.Timestamp = DateTime.Now;
                 bool exceptionThrown = false;
                 _executionTimer.Restart();
-                ulong lastEntryId = PersistIfJournaling(command);
+
+                ulong lastEntryId = (_config.PersistenceMode == PersistenceMode.Journaling)
+                    ? _journalAppender.Append(command)
+                    : 0;
+
                 try
                 {
                     _capturedEvents.Clear();
@@ -195,21 +203,6 @@ private void FireExecutingEvent(Command command)
         }
 
 
-        private ulong PersistIfJournaling(Command command)
-        {
-            return _config.PersistenceMode == PersistenceMode.Journaling
-                ? _journalAppender.Append(command)
-                : 0;
-        }
-
-        private void HandleSnapshotPersistence()
-        {
-            if (_config.PersistenceMode == PersistenceMode.SnapshotPerTransaction)
-            {
-                CreateSnapshot();
-            }
-        }
-
         private void EnsureAuthorized(object securable)
         {
             var principal = Thread.CurrentPrincipal;
@@ -266,6 +259,7 @@ private void Dispose(bool disposing)
             if (_isDisposed) return;
             if (disposing)
             {
+                _journalAppender.Dispose();
                 //todo: bad dependency, use events instead
                 Core.Config.Engines.Remove(this);
                 if (_config.SnapshotBehavior == SnapshotBehavior.OnShutdown) CreateSnapshot();
@@ -289,7 +283,7 @@ public void Close()
             Dispose(true); 
         }
 
-        private void EnsureRunning()
+        private void EnsureNotDisposed()
         {
             if (_isDisposed) throw new ObjectDisposedException(GetType().FullName);
         }

src/OrigoDB.Core/Journaling/IJournalWriter.cs

@@ -2,9 +2,13 @@
 
 namespace OrigoDB.Core
 {
+    /// <summary>
+    /// Journal writers write JournalEntry objects to the journal
+    /// </summary>
 	public interface IJournalWriter : IDisposable
     {
         void Write(JournalEntry item);
-    	void Close();
+
+        void Close();
     }
 }

src/OrigoDB.Core/Journaling/JournalAppender.cs

@@ -8,7 +8,7 @@ namespace OrigoDB.Core
     /// Wraps objects in JournalEntry and sends to an underlying writer.
     /// Responsible for maintaining the sequence number.
     /// </summary>
-    public class JournalAppender
+    public class JournalAppender : IDisposable
     {
         readonly IJournalWriter _writer;
         private ulong _nextEntryId;
@@ -88,5 +88,10 @@ public static JournalAppender Create(ulong nextEntryId, IJournalWriter writer)
         {
             return new JournalAppender(nextEntryId, writer);
         }
+
+        public void Dispose()
+        {
+            _writer.Dispose();
+        }
     }
 }

src/OrigoDB.Core/Model.cs

@@ -1,6 +1,4 @@
 using System;
-using System.Runtime.InteropServices;
-using System.Security.Cryptography.X509Certificates;
 
 namespace OrigoDB.Core
 {

src/OrigoDB.Core/OrigoDB.Core.csproj

@@ -87,6 +87,10 @@
     <Compile Include="Events\IEvent.cs" />
     <Compile Include="Events\IHandleEvents.cs" />
     <Compile Include="Events\ISelectEvents.cs" />
+    <Compile Include="Storage\Rollover\CompositeRolloverStrategy.cs" />
+    <Compile Include="Storage\Rollover\MaxBytesRolloverStrategy.cs" />
+    <Compile Include="Storage\Rollover\MaxEntriesRolloverStrategy.cs" />
+    <Compile Include="Storage\Rollover\ScheduledRolloverStrategy.cs" />
     <Compile Include="Utilities\Utils.Converters.cs" />
     <Compile Include="Journaling\JournalAppender.cs" />
     <Compile Include="Journaling\ModelCreated.cs" />
@@ -99,7 +103,7 @@
     <Compile Include="Storage\FileSnapshot.cs" />
     <Compile Include="Storage\FileSnapshotStore.cs" />
     <Compile Include="Storage\FormatterExtensions.cs" />
-    <Compile Include="Storage\Initialized.cs" />
+    <Compile Include="Storage\Initializable.cs" />
     <Compile Include="Storage\InMemorySnapshotStore.cs" />
     <Compile Include="Storage\ISnapshotStore.cs" />
     <Compile Include="Storage\ModelLoader.cs" />
@@ -158,7 +162,7 @@
     <Compile Include="Utilities\Disposable[T].cs" />
     <Compile Include="Linq\CachingLinqCompiler.cs" />
     <Compile Include="Linq\CompiledLinqExtensions.cs" />
-    <Compile Include="Storage\RolloverStrategy.cs" />
+    <Compile Include="Storage\Rollover\RolloverStrategy.cs" />
     <Compile Include="Proxy\ModelProxy.cs" />
     <Compile Include="Proxy\ProxyMethodAttribute.cs" />
     <Compile Include="Proxy\ProxyCommand.cs" />

src/OrigoDB.Core/Storage/CommandStore.cs

@@ -8,18 +8,42 @@
 namespace OrigoDB.Core.Storage
 {
 
-    public abstract class CommandStore : Initialized, ICommandStore
+    /// <summary>
+    /// Base class with common behavior for CommandStore implementations
+    /// </summary>
+    public abstract class CommandStore : Initializable, ICommandStore
     {
         protected static ILogger _log = LogProvider.Factory.GetLoggerForCallingType();
 
         protected EngineConfiguration _config;
         protected IFormatter _formatter;
 
-
-        protected abstract IJournalWriter CreateStoreSpecificJournalWriter();
-        public abstract IEnumerable<JournalEntry> GetJournalEntriesFrom(ulong entryId);
-        public abstract IEnumerable<JournalEntry> GetJournalEntriesBeforeOrAt(DateTime pointInTime);
+        /// <summary>
+        /// Read the sequence of entries with id greater than or equal to a given entryId
+        /// </summary>
+        protected abstract IEnumerable<JournalEntry> GetJournalEntriesFromImpl(ulong entryId);
+
+
+        /// <summary>
+        /// Get an append-only stream for writing journal entries
+        /// </summary>
         public abstract Stream CreateJournalWriterStream(ulong firstEntryId = 1);
+
+        /// <summary>
+        /// Override if necessary
+        /// </summary>
+        /// <param name="pointInTime"></param>
+        /// <returns></returns>
+        public virtual IEnumerable<JournalEntry> GetJournalEntriesBeforeOrAt(DateTime pointInTime)
+        {
+            return GetJournalEntriesFrom(0).TakeWhile(e => e.Created <= pointInTime);
+        }
+
+
+        protected virtual IJournalWriter CreateStoreSpecificJournalWriter()
+        {
+            return new StreamJournalWriter(_config, CreateJournalWriterStream);
+        }
 
 
         protected CommandStore(EngineConfiguration config)
@@ -28,16 +52,28 @@ protected CommandStore(EngineConfiguration config)
         }
 
 
-
-        public virtual IEnumerable<JournalEntry> GetJournalEntries()
+        public IEnumerable<JournalEntry> GetJournalEntriesFrom(ulong entryId)
         {
-            return GetJournalEntriesFrom(0);
+            bool firstEntry = true;
+            foreach (var entry in GetJournalEntriesFromImpl(entryId))
+            {
+                if (firstEntry && entry.Id > entryId && entryId > 0)
+                {
+                    string msg = String.Format("requested journal entry missing [{0}]", entryId);
+                    throw new InvalidOperationException(msg);
+                }
+                firstEntry = false;
+                yield return entry;
+            }
         }
 
-
-        public JournalAppender CreateAppender(ulong nextRevision)
+        /// <summary>
+        /// Iterate all the entries in the journal
+        /// </summary>
+        /// <returns></returns>
+        public virtual IEnumerable<JournalEntry> GetJournalEntries()
         {
-            return new JournalAppender(nextRevision, CreateJournalWriter(nextRevision));
+            return GetJournalEntriesFrom(0);
         }
 
         public virtual IJournalWriter CreateJournalWriter(ulong lastEntryId)
@@ -54,31 +90,37 @@ public override void Initialize()
             base.Initialize();
         }
 
-        public bool IsEmpty
+        /// <summary>
+        /// True if the journal is empty
+        /// </summary>
+        public virtual bool IsEmpty
         {
             get
             {
                 return !GetJournalEntries().Any();
             }
         }
 
+        /// <summary>
+        /// Throw an exception unless the journal is empty
+        /// </summary>
         protected void AssertEmpty()
         {
-            if (!IsEmpty) throw new InvalidOperationException("Store must be empty");
+            if (!IsEmpty) throw new InvalidOperationException("Journal must be empty");
         }
 
         /// <summary>
-        /// Get commands beginning from a specific entry id (inclusive)
+        /// Get commited commands beginning from a specific entry id (inclusive)
         /// </summary>
         public IEnumerable<JournalEntry<Command>> CommandEntriesFrom(ulong entryId)
         {
-            return CommittedCommandEntries(() => GetJournalEntriesFrom(entryId));
+            return CommittedCommandEntries(() => GetJournalEntriesFromImpl(entryId));
         }
 
         /// <summary>
-        /// Get non rolled back commands from a point in time
+        /// Get committed commands from a point in time
         /// </summary>
-        public IEnumerable<JournalEntry<Command>> CommandEntriesFrom(DateTime pointInTime)
+        public IEnumerable<JournalEntry<Command>> CommandEntriesBeforeOrAt(DateTime pointInTime)
         {
             return CommittedCommandEntries(() => GetJournalEntriesBeforeOrAt(pointInTime));
         }
@@ -112,26 +154,5 @@ public IEnumerable<JournalEntry<Command>> CommandEntries()
         {
             return CommandEntriesFrom(1);
         }
-        //public virtual void Create<T>() where T : Model, new()
-        //{
-        //    AssertEmpty();
-        //    Create(typeof(T));
-        //}
-
-        //public virtual void Create(Type modelType)
-        //{
-        //    AssertEmpty();
-        //    var writer = CreateJournalWriter(0);
-        //    var appender = new JournalAppender(1, writer);
-        //    appender.AppendModelCreated(modelType);
-        //    writer.Close();
-        //}
-
-        //public virtual void Create(Model model)
-        //{
-        //    AssertEmpty();
-        //    WriteSnapshotImpl(model, 0);
-        //}
-
     }
 }