TEST OF REVIEW

src/DotJEM.Json.Index2.Management/IJsonIndexManager.cs

@@ -128,11 +128,6 @@ public async Task ResetIndexAsync()
     {
         await jsonDocumentSource.StopAsync().ConfigureAwait(false);
         index.Storage.Delete();
-        //TODO: Force a commit after delete to see if that helps?
-        using (var lease = index.WriterManager.Lease())
-        {
-            lease.Value.Commit();
-        }
         await jsonDocumentSource.ResetAsync().ConfigureAwait(false);
         await jsonDocumentSource.StartAsync().ConfigureAwait(false);
     }

src/DotJEM.Json.Index2.Management/Snapshots/IJsonIndexSnapshotManager.cs

@@ -6,6 +6,7 @@
 using DotJEM.Json.Index2.Snapshots;
 using DotJEM.ObservableExtensions.InfoStreams;
 using DotJEM.Web.Scheduler;
+using Lucene.Net.Search;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
 
@@ -41,6 +42,8 @@ public class JsonIndexSnapshotManager : IJsonIndexSnapshotManager
 {
     private readonly IJsonIndex index;
     private readonly ISnapshotStrategy strategy;
+    //TODO: This binds us to a concrete idea (even though this is an interface).
+    //      instead it would be preferred if we could provide an abstraction for what is needed.
     private readonly IWebTaskScheduler scheduler;
     private readonly IInfoStream<JsonIndexSnapshotManager> infoStream = new InfoStream<JsonIndexSnapshotManager>();
 

src/DotJEM.Json.Index2.Management/Writer/IJsonIndexWriter.cs

@@ -7,6 +7,7 @@
 using DotJEM.Json.Index2.Documents;
 using DotJEM.Json.Index2.Documents.Info;
 using DotJEM.Json.Index2.IO;
+using DotJEM.Json.Index2.Leases;
 using DotJEM.ObservableExtensions.InfoStreams;
 using Lucene.Net.Index;
 using Newtonsoft.Json.Linq;

src/DotJEM.Json.Index2.Snapshots/IndexSnapshotHandler.cs

@@ -5,6 +5,7 @@
 using System.Text.RegularExpressions;
 using System.Threading.Tasks;
 using DotJEM.Json.Index2.IO;
+using DotJEM.Json.Index2.Leases;
 using DotJEM.Json.Index2.Snapshots.Streams;
 using Lucene.Net.Index;
 using Lucene.Net.Store;

src/DotJEM.Json.Index2/IO/JsonIndexWriter.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using DotJEM.Json.Index2.Documents;
+using DotJEM.Json.Index2.Leases;
 using DotJEM.Json.Index2.Util;
 using Lucene.Net.Documents;
 using Lucene.Net.Index;

src/DotJEM.Json.Index2/IO/JsonIndexWriterManager.cs

@@ -4,25 +4,24 @@
 using System.Diagnostics;
 using System.Linq;
 using System.Threading;
+using System.Threading.Tasks;
 using DotJEM.Json.Index2.Configuration;
+using DotJEM.Json.Index2.Leases;
 using DotJEM.Json.Index2.Util;
 using Lucene.Net.Analysis;
 using Lucene.Net.Index;
+using Lucene.Net.Search;
 
 namespace DotJEM.Json.Index2.IO;
 
 public interface IIndexWriterManager : IDisposable
 {
     event EventHandler<EventArgs> OnClose;
+
     ILease<IndexWriter> Lease();
     void Close();
 }
 
-public interface ILease<out T> : IDisposable
-{
-    T Value { get; }
-    bool IsExpired { get; }
-}
 
 public class IndexWriterManager : Disposable, IIndexWriterManager
 {
@@ -31,8 +30,9 @@ public class IndexWriterManager : Disposable, IIndexWriterManager
     private readonly IJsonIndex index;
     private volatile IndexWriter writer;
     private readonly object writerPadLock = new();
-    private readonly object leasesPadLock = new();
+    private readonly LeaseManager<IndexWriter> leaseManager = new();
 
+    //TODO: With leases, this should not be needed.
     public event EventHandler<EventArgs> OnClose;
 
     private IndexWriter Writer
@@ -47,40 +47,13 @@ private IndexWriter Writer
                 if (writer != null)
                     return writer;
 
-                try
-                {
-                    return writer = Open(index);
-                }
-                catch (Exception e)
-                {
-                    Debug.WriteLine("ACTIVE LEASES: " +leases.Count);
-                    throw;
-                }
+                return writer = Open(index);
             }
         }
     }
 
-    private readonly List<TimeLimitedIndexWriterLease> leases = new List<TimeLimitedIndexWriterLease>();
-
-    public ILease<IndexWriter> Lease()
-    {
-        //TODO: Optimizied collection for this.
-        TimeLimitedIndexWriterLease lease = new(this, OnReturned);
-        lock (leasesPadLock)
-        {
-            leases.Add(lease);
-        }
-        return lease;
-    }
-
-    private void OnReturned(TimeLimitedIndexWriterLease lease)
-    {
-        lock (leasesPadLock)
-        {
-            leases.Remove(lease);
-        }
-    }
 
+    public ILease<IndexWriter> Lease() => leaseManager.Create(Writer, TimeSpan.FromSeconds(3));
 
     public IndexWriterManager(IJsonIndex index)
     {
@@ -89,7 +62,6 @@ public IndexWriterManager(IJsonIndex index)
 
     private static IndexWriter Open(IJsonIndex index)
     {
-        Debug.WriteLine("OPEN WRITER");
         IndexWriterConfig config = new(index.Configuration.Version, index.Configuration.Analyzer);
         config.RAMBufferSizeMB = DEFAULT_RAM_BUFFER_SIZE_MB;
         config.OpenMode = OpenMode.CREATE_OR_APPEND;
@@ -103,28 +75,15 @@ public void Close()
         if (writer == null)
             return;
 
-        lock (leasesPadLock)
+        lock (writerPadLock)
         {
-            TimeLimitedIndexWriterLease[] leasesCopy = leases.ToArray();
-
-            Debug.WriteLine("ACTIVE LEASES: " + leasesCopy.Length);
-            leases.Clear();
-            foreach (TimeLimitedIndexWriterLease lease in leasesCopy)
-            {
-                if (!lease.IsExpired)
-                    lease.Wait();
-                lease.Dispose();
-            }
-
-            lock (writerPadLock)
-            {
-                if (writer == null)
-                    return;
+            leaseManager.RecallAll();
+            if (writer == null)
+                return;
 
-                writer.Dispose();
-                writer = null;
-                RaiseOnClose();
-            }
+            writer.Dispose();
+            writer = null;
+            RaiseOnClose();
         }
     }
 
@@ -140,63 +99,4 @@ protected virtual void RaiseOnClose()
     {
         OnClose?.Invoke(this, EventArgs.Empty);
     }
-
-    private class TimeLimitedIndexWriterLease : Disposable, ILease<IndexWriter>
-    {
-        private readonly DateTime leaseTime = DateTime.Now;
-        private readonly Action<TimeLimitedIndexWriterLease> onReturned;
-        private readonly IndexWriterManager manager;
-        public AutoResetEvent Handle { get; } = new(false);
-
-        public IndexWriter Value
-        {
-            get
-            {
-                if (IsDisposed)
-                {
-                    throw new ObjectDisposedException("Index writer lease has been returned or is expired.");
-                }
-
-                if (IsExpired)
-                {
-                    throw new LeaseExpiredException("Index writer lease has been returned or is expired.");
-                }
-                return manager.Writer;
-            }
-        }
-
-        public bool IsExpired => (DateTime.Now - leaseTime > TimeSpan.FromSeconds(5)) || IsDisposed;
-
-        public TimeLimitedIndexWriterLease(IndexWriterManager manager, Action<TimeLimitedIndexWriterLease> onReturned)
-        {
-            this.onReturned = onReturned;
-            this.manager = manager;
-        }
-
-        protected override void Dispose(bool disposing)
-        {
-            Handle.Set();
-            onReturned(this);
-        }
-
-        public void Wait()
-        {
-            if (IsExpired)
-                return;
-
-            Handle.WaitOne(TimeSpan.FromSeconds(6) - (DateTime.Now - leaseTime));
-        }
-    }
-
 }
-
-public class LeaseExpiredException : Exception
-{
-    public LeaseExpiredException(string message) : base(message)
-    {
-    }
-
-    public LeaseExpiredException(string message, Exception innerException) : base(message, innerException)
-    {
-    }
-}

src/DotJEM.Json.Index2/Leases/Lease.cs

@@ -0,0 +1,18 @@
+using System;
+
+namespace DotJEM.Json.Index2.Leases;
+
+public interface ILease<out T> : IDisposable
+{
+    event EventHandler<EventArgs> Terminated; 
+
+    T Value { get; }
+    bool IsExpired { get; }
+    bool TryRenew();
+}
+
+
+public interface ILessor<out T>
+{
+    ILease<T> Lease();
+}