implement ChannelMessage / ChannelMessageChannel to illustrate API;...

implement ChannelMessage / ChannelMessageChannel to illustrate API; PubSubGetAllCorrectOrder shows usage, although it doesn't work yet (order is wrong) - I need to implement sync enqueue

StackExchange.Redis.Tests/Booksleeve/PubSub.cs

@@ -75,8 +75,7 @@ private void TestMassivePublish(ISubscriber conn, string channel, string caption
             Assert.True(withFAF.ElapsedMilliseconds < withAsync.ElapsedMilliseconds, caption);
         }
 
-        // [FactLongRunning]
-        [Fact]
+        [FactLongRunning]
         public async Task PubSubGetAllAnyOrder()
         {
             using (var muxer = GetRemoteConnection(waitForOpen: true,
@@ -125,6 +124,66 @@ public async Task PubSubGetAllAnyOrder()
             }
         }
 
+        [FactLongRunning]
+        public async Task PubSubGetAllCorrectOrder()
+        {
+            using (var muxer = GetRemoteConnection(waitForOpen: true,
+                syncTimeout: 20000))
+            {
+                var sub = muxer.GetSubscriber();
+                RedisChannel channel = Me();
+                const int count = 500000;
+                var syncLock = new object();
+
+                var dataList = new List<int>(count);
+                var dataHash = new HashSet<int>();
+                var subChannel = await sub.SubscribeAsync(channel);
+
+                await sub.PingAsync();
+
+                async Task RunLoop()
+                {
+                    while (!subChannel.IsComplete)
+                    {
+                        var work = await subChannel.ReadAsync();
+                        int i = int.Parse(Encoding.UTF8.GetString(work.Value));
+                        lock (dataList)
+                        {
+                            dataList.Add(i);
+                            dataHash.Add(i);
+                            if (dataList.Count == count) break;
+                            if ((dataList.Count % 10) == 99) Output.WriteLine(dataList.Count.ToString());
+                        }
+                    }
+                    lock (syncLock)
+                    {
+                        Monitor.PulseAll(syncLock);
+                    }
+                }
+
+                lock (syncLock)
+                {
+                    Task.Run(RunLoop);
+                    for (int i = 0; i < count; i++)
+                    {
+                        sub.Publish(channel, i.ToString(), CommandFlags.FireAndForget);
+                    }
+                    sub.Ping();
+                    // subChannel.Unsubscribe();
+                    if (!Monitor.Wait(syncLock, 20000))
+                    {
+                        throw new TimeoutException("Items: " + dataList.Count);
+                    }
+                    for (int i = 0; i < count; i++)
+                    {
+                        Assert.Contains(i, dataHash);
+                        // Assert.Equal(i, data[i]);
+                    }
+                }
+            }
+        }
+
+
         [Fact]
         public void TestPublishWithSubscribers()
         {

StackExchange.Redis/StackExchange.Redis.csproj

@@ -25,5 +25,6 @@
   
   <ItemGroup>
     <PackageReference Include="Pipelines.Sockets.Unofficial" Version="0.2.1-alpha.58" />
+    <PackageReference Include="System.Threading.Channels" Version="4.5.0" />
   </ItemGroup>
 </Project>
\ No newline at end of file

StackExchange.Redis/StackExchange/Redis/ChannelMessage.cs

+using System;
+using System.Threading;
+using System.Threading.Channels;
+using System.Threading.Tasks;
+
+namespace StackExchange.Redis
+{
+    /// <summary>
+    /// Represents a message that is broadcast via pub/sub
+    /// </summary>
+    public readonly struct ChannelMessage
+    {
+        internal ChannelMessage(RedisChannel channel, RedisValue value)
+        {
+            Channel = channel;
+            Value = value;
+        }
+
+        /// <summary>
+        /// The channel that the message was broadcast to
+        /// </summary>
+        public RedisChannel Channel { get; }
+        /// <summary>
+        /// The value that was broadcast
+        /// </summary>
+        public RedisValue Value { get; }
+    }
+
+
+    /// <summary>
+    /// Represents a message queue of pub/sub notifications
+    /// </summary>
+    public sealed class ChannelMessageChannel
+    {
+        private readonly Channel<ChannelMessage> _channel;
+        private readonly RedisChannel _redisChannel;
+        private ISubscriber _parent;
+
+        /// <summary>
+        /// Indicates if all messages that will be received have been drained from this channel
+        /// </summary>
+        public bool IsComplete { get; private set; }
+
+        internal ChannelMessageChannel(RedisChannel redisChannel, ISubscriber parent)
+        {
+            _redisChannel = redisChannel;
+            _parent = parent;
+            _channel = Channel.CreateUnbounded<ChannelMessage>();
+            _channel.Reader.Completion.ContinueWith(
+                (t, state) => ((ChannelMessageChannel)state).IsComplete = true, this, TaskContinuationOptions.ExecuteSynchronously);
+        }
+        internal void Subscribe(CommandFlags flags) => _parent.Subscribe(_redisChannel, HandleMessage, flags);
+        internal Task SubscribeAsync(CommandFlags flags) => _parent.SubscribeAsync(_redisChannel, HandleMessage, flags);
+
+        private void HandleMessage(RedisChannel channel, RedisValue value)
+            =>  _channel.Writer.TryWrite(new ChannelMessage(channel, value));
+
+        /// <summary>
+        /// Consume a message from the channel
+        /// </summary>
+        public ValueTask<ChannelMessage> ReadAsync(CancellationToken cancellationToken = default)
+            => _channel.Reader.ReadAsync(cancellationToken);
+
+        internal void UnsubscribeImpl(Exception error = null, CommandFlags flags = CommandFlags.None)
+        {
+            var parent = _parent;
+            if (parent != null)
+            {
+                _parent.UnsubscribeAsync(_redisChannel, HandleMessage, flags);
+                _parent = null;
+                _channel.Writer.TryComplete(error);
+            }
+        }
+        internal async Task UnsubscribeAsyncImpl(Exception error = null, CommandFlags flags = CommandFlags.None)
+        {
+            var parent = _parent;
+            if (parent != null)
+            {
+                await _parent.UnsubscribeAsync(_redisChannel, HandleMessage, flags);
+                _parent = null;
+                _channel.Writer.TryComplete(error);
+            }
+        }
+
+        /// <summary>
+        /// Stop receiving messages on this channel
+        /// </summary>
+        public void Unsubscribe(CommandFlags flags = CommandFlags.None) => UnsubscribeImpl(null, flags);
+        /// <summary>
+        /// Stop receiving messages on this channel
+        /// </summary>
+        public Task UnsubscribeAsync(CommandFlags flags = CommandFlags.None) => UnsubscribeAsyncImpl(null, flags);
+    }
+}

StackExchange.Redis/StackExchange/Redis/Interfaces/ISubscriber.cs

-using System;
+using System;
 using System.Net;
+using System.Threading.Channels;
 using System.Threading.Tasks;
 
 namespace StackExchange.Redis
@@ -64,6 +65,16 @@ public interface ISubscriber : IRedis
         /// <remarks>https://redis.io/commands/psubscribe</remarks>
         void Subscribe(RedisChannel channel, Action<RedisChannel, RedisValue> handler, CommandFlags flags = CommandFlags.None);
 
+        /// <summary>
+        /// Subscribe to perform some operation when a change to the preferred/active node is broadcast, as a channel.
+        /// </summary>
+        /// <param name="channel">The redis channel to subscribe to.</param>
+        /// <param name="flags">The command flags to use.</param>
+        /// <returns>A channel that represents this source</returns>
+        /// <remarks>https://redis.io/commands/subscribe</remarks>
+        /// <remarks>https://redis.io/commands/psubscribe</remarks>
+        ChannelMessageChannel Subscribe(RedisChannel channel, CommandFlags flags = CommandFlags.None);
+
         /// <summary>
         /// Subscribe to perform some operation when a change to the preferred/active node is broadcast.
         /// </summary>
@@ -74,6 +85,16 @@ public interface ISubscriber : IRedis
         /// <remarks>https://redis.io/commands/psubscribe</remarks>
         Task SubscribeAsync(RedisChannel channel, Action<RedisChannel, RedisValue> handler, CommandFlags flags = CommandFlags.None);
 
+        /// <summary>
+        /// Subscribe to perform some operation when a change to the preferred/active node is broadcast, as a channel.
+        /// </summary>
+        /// <param name="channel">The redis channel to subscribe to.</param>
+        /// <param name="flags">The command flags to use.</param>
+        /// <returns>A channel that represents this source</returns>
+        /// <remarks>https://redis.io/commands/subscribe</remarks>
+        /// <remarks>https://redis.io/commands/psubscribe</remarks>
+        Task<ChannelMessageChannel> SubscribeAsync(RedisChannel channel, CommandFlags flags = CommandFlags.None);
+
         /// <summary>
         /// Inidicate to which redis server we are actively subscribed for a given channel; returns null if
         /// the channel is not actively subscribed
@@ -122,4 +143,4 @@ public interface ISubscriber : IRedis
         /// <remarks>https://redis.io/commands/punsubscribe</remarks>
         Task UnsubscribeAsync(RedisChannel channel, Action<RedisChannel, RedisValue> handler = null, CommandFlags flags = CommandFlags.None);
     }
-}
+}
\ No newline at end of file

StackExchange.Redis/StackExchange/Redis/RedisSubscriber.cs

@@ -287,12 +287,26 @@ public void Subscribe(RedisChannel channel, Action<RedisChannel, RedisValue> han
             if ((flags & CommandFlags.FireAndForget) == 0) Wait(task);
         }
 
+        public ChannelMessageChannel Subscribe(RedisChannel channel, CommandFlags flags = CommandFlags.None)
+        {
+            var c = new ChannelMessageChannel(channel, this);
+            c.Subscribe(flags);
+            return c;
+        }
+
         public Task SubscribeAsync(RedisChannel channel, Action<RedisChannel, RedisValue> handler, CommandFlags flags = CommandFlags.None)
         {
             if (channel.IsNullOrEmpty) throw new ArgumentNullException(nameof(channel));
             return multiplexer.AddSubscription(channel, handler, flags, asyncState);
         }
 
+        public async Task<ChannelMessageChannel> SubscribeAsync(RedisChannel channel, CommandFlags flags = CommandFlags.None)
+        {
+            var c = new ChannelMessageChannel(channel, this);
+            await c.SubscribeAsync(flags);
+            return c;
+        }
+
         public EndPoint SubscribedEndpoint(RedisChannel channel)
         {
             var server = multiplexer.GetSubscribedServer(channel);