Fix Issue/314

core/State/InMemory/InMemoryWindowStore.cs

@@ -12,6 +12,7 @@
 using Streamiz.Kafka.Net.Metrics;
 using Streamiz.Kafka.Net.Metrics.Internal;
 using Streamiz.Kafka.Net.State.Helper;
+using Streamiz.Kafka.Net.State.InMemory.Internal;
 
 namespace Streamiz.Kafka.Net.State.InMemory
 {
@@ -260,7 +261,8 @@ public Windowed<Bytes> PeekNextKey()
 
     #endregion
 
-    internal class InMemoryWindowStore : IWindowStore<Bytes, byte[]>
+    internal class 
+        InMemoryWindowStore : IWindowStore<Bytes, byte[]>
     {
         private readonly TimeSpan retention;
         private readonly long size;
@@ -272,8 +274,7 @@ internal class InMemoryWindowStore : IWindowStore<Bytes, byte[]>
         private int seqnum = 0;
 
         private readonly ConcurrentDictionary<long, ConcurrentDictionary<Bytes, byte[]>> map = new();
-
-        private readonly ISet<InMemoryWindowStoreEnumeratorWrapper> openIterators = new HashSet<InMemoryWindowStoreEnumeratorWrapper>();
+        private readonly ConcurrentSet<InMemoryWindowStoreEnumeratorWrapper> openIterators = new();
 
         private readonly ILogger logger = Logger.GetLogger(typeof(InMemoryWindowStore));
 
@@ -309,8 +310,9 @@ public void Close()
             if (openIterators.Count != 0)
             {
                 logger.LogWarning("Closing {OpenIteratorCount} open iterators for store {Name}", openIterators.Count, Name);
-                for (int i = 0; i< openIterators.Count; ++i)
-                    openIterators.ElementAt(i).Close();
+                foreach(var iterator in openIterators)
+                    iterator.Close();
+                openIterators.Clear();
             }
 
             map.Clear();

core/State/InMemory/Internal/ConcurrentHashSet.cs

@@ -0,0 +1,71 @@
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+
+namespace Streamiz.Kafka.Net.State.InMemory.Internal
+{
+    internal class ConcurrentSet<T>
+    {
+        private readonly ConcurrentDictionary<T, byte> _dictionary = new();
+
+        /// <summary>
+        /// Returns an enumerator that iterates through the collection.
+        /// </summary>
+        /// <returns>
+        /// A <see cref="T:System.Collections.Generic.IEnumerator`1"/> that can be used to iterate through the collection.
+        /// </returns>
+        public IEnumerator<T> GetEnumerator()
+        {
+            return _dictionary.Keys.GetEnumerator();
+        }
+
+        /// <summary>
+        /// Removes the first occurrence of a specific object from the <see cref="T:System.Collections.Generic.ICollection`1"/>.
+        /// </summary>
+        /// <returns>
+        /// true if <paramref name="item"/> was successfully removed from the <see cref="T:System.Collections.Generic.ICollection`1"/>; otherwise, false. This method also returns false if <paramref name="item"/> is not found in the original <see cref="T:System.Collections.Generic.ICollection`1"/>.
+        /// </returns>
+        /// <param name="item">The object to remove from the <see cref="T:System.Collections.Generic.ICollection`1"/>.</param><exception cref="T:System.NotSupportedException">The <see cref="T:System.Collections.Generic.ICollection`1"/> is read-only.</exception>
+        public bool Remove(T item)
+        {
+            return TryRemove(item);
+        }
+
+        /// <summary>
+        /// Gets the number of elements in the set.
+        /// </summary>
+        public int Count => _dictionary.Count;
+
+        /// <summary>
+        /// Adds an element to the current set and returns a value to indicate if the element was successfully added. 
+        /// </summary>
+        /// <returns>
+        /// true if the element is added to the set; false if the element is already in the set.
+        /// </returns>
+        /// <param name="item">The element to add to the set.</param>
+        public bool Add(T item)
+        {
+            return TryAdd(item);
+        }
+
+        public void Clear()
+        {
+            _dictionary.Clear();
+        }
+
+        public bool Contains(T item)
+        {
+            return _dictionary.ContainsKey(item);
+        }
+
+        private bool TryAdd(T item)
+        {
+            return _dictionary.TryAdd(item, default);
+        }
+
+        private bool TryRemove(T item)
+        {
+            return _dictionary.TryRemove(item, out _);
+        }
+    }
+
+}

environment/datagen_connector.json

@@ -0,0 +1,14 @@
+{
+  "name": "datagen-users",
+  "config": {
+    "connector.class": "io.confluent.kafka.connect.datagen.DatagenConnector",
+    "kafka.topic": "users",
+    "quickstart": "users",
+    "key.converter": "org.apache.kafka.connect.storage.StringConverter",
+    "value.converter": "org.apache.kafka.connect.json.JsonConverter",
+    "value.converter.schemas.enable": "false",
+    "max.interval": 1000,
+    "iterations": 10000000,
+    "tasks.max": "1"
+  }
+}

environment/docker-compose-with-connect.yml

@@ -2,7 +2,7 @@
 version: '2'
 services:
   zookeeper:
-    image: confluentinc/cp-zookeeper:7.4.0
+    image: confluentinc/cp-zookeeper:7.6.1
     hostname: zookeeper
     container_name: zookeeper
     ports:
@@ -13,7 +13,7 @@ services:
       KAFKA_OPTS: "-Dzookeeper.4lw.commands.whitelist=*"
 
   broker:
-    image: confluentinc/cp-server:7.4.0
+    image: confluentinc/cp-server:7.6.1
     hostname: broker
     container_name: broker
     depends_on:
@@ -42,7 +42,7 @@ services:
       CONFLUENT_SUPPORT_CUSTOMER_ID: 'anonymous'
 
   schema-registry:
-    image: confluentinc/cp-schema-registry:7.4.0
+    image: confluentinc/cp-schema-registry:7.6.1
     hostname: schema-registry
     container_name: schema-registry
     depends_on:
@@ -55,7 +55,7 @@ services:
       SCHEMA_REGISTRY_LISTENERS: http://0.0.0.0:8081
 
   connect:
-    image: cnfldemos/kafka-connect-datagen:0.6.0-7.3.0
+    image: cnfldemos/kafka-connect-datagen:0.6.4-7.6.0
     container_name: connect
     depends_on:
       - broker

samples/sample-stream/Program.cs

@@ -14,7 +14,7 @@ namespace sample_stream
 {
     public static class Program
     {
-        public static async Task Main(string[] args)
+        public static async Task Main2(string[] args)
         {
             var config = new StreamConfig<StringSerDes, StringSerDes>{
                 ApplicationId = $"test-app",

samples/sample-stream/Reproducer314.cs

@@ -0,0 +1,75 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using Confluent.Kafka;
+using Streamiz.Kafka.Net;
+using Streamiz.Kafka.Net.SerDes;
+using Streamiz.Kafka.Net.State;
+using Streamiz.Kafka.Net.Stream;
+using Streamiz.Kafka.Net.Table;
+
+namespace sample_stream;
+
+public class Reproducer314
+{
+    public static async Task Main(string[] args)
+    {
+        Console.WriteLine("Hello Streams");
+
+        var config = new StreamConfig<StringSerDes, StringSerDes>
+        {
+            ApplicationId = $"test-windowedtable-bis",
+            BootstrapServers = "localhost:9092",
+            AutoOffsetReset = AutoOffsetReset.Earliest
+        };
+
+        var builder = CreateWindowedStore();
+        var t = builder.Build();
+        var windowedTableStream = new KafkaStream(t, config);
+
+        await windowedTableStream.StartAsync();
+
+        // wait for the store to be restored and ready
+        Thread.Sleep(10000);
+
+        GetValueFromWindowedStore(windowedTableStream, DateTime.UtcNow.AddHours(-1), new CancellationToken());
+
+        Console.WriteLine("Finished");
+    }
+
+    private static void GetValueFromWindowedStore(KafkaStream windowedTableStream, DateTime startUtcForWindowLookup, CancellationToken cancellationToken)
+    {
+        var windowedStore = windowedTableStream.Store(StoreQueryParameters.FromNameAndType("store", QueryableStoreTypes.WindowStore<string, int>()));
+
+        while (!cancellationToken.IsCancellationRequested)
+        {
+            var records = windowedStore.FetchAll(startUtcForWindowLookup, DateTime.UtcNow).ToList();
+
+            if (records.Count > 0)
+            {
+                foreach (var item in records)
+                {
+                    Console.WriteLine($"Value from windowed store : KEY = {item.Key} VALUE = {item.Value}");
+                }
+
+                startUtcForWindowLookup = DateTime.UtcNow;
+            }
+        }
+    }
+
+    private static StreamBuilder CreateWindowedStore()
+    {
+        var builder = new StreamBuilder();
+
+        builder
+            .Stream<string, string>("users")
+            .GroupByKey()
+            .WindowedBy(TumblingWindowOptions.Of(60000))
+            .Aggregate(
+                () => 0,
+                (k, v, agg) => Math.Max(v.Length, agg),
+                InMemoryWindows.As<string, int>("store").WithValueSerdes<Int32SerDes>());
+
+        return builder;
+    }
+}

test/Streamiz.Kafka.Net.Tests/Private/ConcurrentSetTests.cs

@@ -0,0 +1,93 @@
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using NUnit.Framework;
+using Streamiz.Kafka.Net.State.InMemory.Internal;
+
+namespace Streamiz.Kafka.Net.Tests.Private;
+
+public class ConcurrentSetTests
+{
+    private ConcurrentSet<string> concurrentSet;
+
+    [SetUp]
+    public void Init()
+    {
+        concurrentSet = new();
+    }
+
+    [TearDown]
+    public void Dispose()
+    {
+        concurrentSet.Clear();
+    }
+
+    [TestCase(1000)]
+    public void ConcurrencyAdded(int numberTasks)
+    {
+        var taskList = new List<Task>();
+        for (int i = 0; i < numberTasks; i++)
+        {
+            taskList.Add(Task.Factory.StartNew((Object obj) =>
+            {
+                concurrentSet.Add(Guid.NewGuid().ToString());
+            }, null));
+        }
+        Task.WaitAll(taskList.ToArray());
+        Assert.AreEqual(numberTasks, concurrentSet.Count);
+    }
+
+    [TestCase(1000)]
+    public void ConcurrencyRemoved(int numberTasks)
+    {
+        for (int i = 0; i < numberTasks; i++)
+            concurrentSet.Add(i.ToString());
+
+        var taskList = new List<Task>();
+        for (int i = 0; i < numberTasks; i++)
+        {
+            taskList.Add(Task.Factory.StartNew((Object obj) =>
+            {
+                concurrentSet.Remove(obj.ToString());
+            }, i));
+        }
+
+        Task.WaitAll(taskList.ToArray());
+        Assert.AreEqual(0, concurrentSet.Count);
+    }
+
+    [TestCase(10000)]
+    public void ConcurrencyAddedAndForeach(int numberTasks)
+    {
+        var taskList = new List<Task>();
+        for (int i = 0; i < numberTasks; i++)
+        {
+            taskList.Add(Task.Factory.StartNew((Object obj) =>
+            {
+                concurrentSet.Add(Guid.NewGuid().ToString());
+                foreach (var c in concurrentSet)
+                    ;
+            }, null));
+        }
+        Task.WaitAll(taskList.ToArray());
+        Assert.AreEqual(numberTasks, concurrentSet.Count);
+    }
+
+    [TestCase(10000)]
+    public void ConcurrencyAddedAndContains(int numberTasks)
+    {
+        var taskList = new List<Task>();
+        for (int i = 0; i < numberTasks; i++)
+        {
+            taskList.Add(Task.Factory.StartNew((Object obj) =>
+            {
+                var guid = Guid.NewGuid().ToString();
+                concurrentSet.Add(guid);
+                Assert.IsTrue(concurrentSet.Contains(guid));
+            }, null));
+        }
+        Task.WaitAll(taskList.ToArray());
+        Assert.AreEqual(numberTasks, concurrentSet.Count);
+    }
+
+}