Pushing missing changes

1 files changed, 223 insertions, 0 deletions

diff --git a/MediaBrowser.Common/Kernel/BasePeriodicWebSocketListener.cs b/MediaBrowser.Common/Kernel/BasePeriodicWebSocketListener.cs
new file mode 100644
index 000000000..7db1ca36b
--- /dev/null
+++ b/MediaBrowser.Common/Kernel/BasePeriodicWebSocketListener.cs
@@ -0,0 +1,223 @@
+using MediaBrowser.Common.Logging;
+using MediaBrowser.Common.Net;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net.WebSockets;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace MediaBrowser.Common.Kernel
+{
+    /// <summary>
+    /// Starts sending data over a web socket periodically when a message is received, and then stops when a corresponding stop message is received
+    /// </summary>
+    /// <typeparam name="TKernelType">The type of the T kernel type.</typeparam>
+    /// <typeparam name="TReturnDataType">The type of the T return data type.</typeparam>
+    /// <typeparam name="TStateType">The type of the T state type.</typeparam>
+    public abstract class BasePeriodicWebSocketListener<TKernelType, TReturnDataType, TStateType> : BaseWebSocketListener<TKernelType>
+        where TKernelType : IKernel
+        where TStateType : class, new()
+    {
+        /// <summary>
+        /// The _active connections
+        /// </summary>
+        protected readonly List<Tuple<WebSocketConnection, CancellationTokenSource, Timer, TStateType, SemaphoreSlim>> ActiveConnections =
+            new List<Tuple<WebSocketConnection, CancellationTokenSource, Timer, TStateType, SemaphoreSlim>>();
+
+        /// <summary>
+        /// Gets the name.
+        /// </summary>
+        /// <value>The name.</value>
+        protected abstract string Name { get; }
+
+        /// <summary>
+        /// Gets the data to send.
+        /// </summary>
+        /// <param name="state">The state.</param>
+        /// <returns>Task{`1}.</returns>
+        protected abstract Task<TReturnDataType> GetDataToSend(TStateType state);
+
+        /// <summary>
+        /// Processes the message internal.
+        /// </summary>
+        /// <param name="message">The message.</param>
+        /// <returns>Task.</returns>
+        protected override Task ProcessMessageInternal(WebSocketMessageInfo message)
+        {
+            if (message.MessageType.Equals(Name + "Start", StringComparison.OrdinalIgnoreCase))
+            {
+                Start(message);
+            }
+
+            if (message.MessageType.Equals(Name + "Stop", StringComparison.OrdinalIgnoreCase))
+            {
+                Stop(message);
+            }
+
+            return NullTaskResult;
+        }
+
+        /// <summary>
+        /// Starts sending messages over a web socket
+        /// </summary>
+        /// <param name="message">The message.</param>
+        private void Start(WebSocketMessageInfo message)
+        {
+            var vals = message.Data.Split(',');
+
+            var dueTimeMs = long.Parse(vals[0]);
+            var periodMs = long.Parse(vals[1]);
+
+            var cancellationTokenSource = new CancellationTokenSource();
+
+            Logger.LogInfo("{1} Begin transmitting over websocket to {0}", message.Connection.RemoteEndPoint, GetType().Name);
+
+            var timer = new Timer(TimerCallback, message.Connection, Timeout.Infinite, Timeout.Infinite);
+
+            var state = new TStateType();
+
+            var semaphore = new SemaphoreSlim(1, 1);
+
+            lock (ActiveConnections)
+            {
+                ActiveConnections.Add(new Tuple<WebSocketConnection, CancellationTokenSource, Timer, TStateType, SemaphoreSlim>(message.Connection, cancellationTokenSource, timer, state, semaphore));
+            }
+
+            timer.Change(TimeSpan.FromMilliseconds(dueTimeMs), TimeSpan.FromMilliseconds(periodMs));
+        }
+
+        /// <summary>
+        /// Timers the callback.
+        /// </summary>
+        /// <param name="state">The state.</param>
+        private async void TimerCallback(object state)
+        {
+            var connection = (WebSocketConnection)state;
+
+            Tuple<WebSocketConnection, CancellationTokenSource, Timer, TStateType, SemaphoreSlim> tuple;
+
+            lock (ActiveConnections)
+            {
+                tuple = ActiveConnections.FirstOrDefault(c => c.Item1 == connection);
+            }
+
+            if (tuple == null)
+            {
+                return;
+            }
+
+            if (connection.State != WebSocketState.Open || tuple.Item2.IsCancellationRequested)
+            {
+                DisposeConnection(tuple);
+                return;
+            }
+
+            try
+            {
+                await tuple.Item5.WaitAsync(tuple.Item2.Token).ConfigureAwait(false);
+
+                var data = await GetDataToSend(tuple.Item4).ConfigureAwait(false);
+
+                await connection.SendAsync(new WebSocketMessage<TReturnDataType>
+                {
+                    MessageType = Name,
+                    Data = data
+
+                }, tuple.Item2.Token).ConfigureAwait(false);
+            }
+            catch (OperationCanceledException)
+            {
+                if (tuple.Item2.IsCancellationRequested)
+                {
+                    DisposeConnection(tuple);
+                }
+            }
+            catch (Exception ex)
+            {
+                Logger.LogException("Error sending web socket message {0}", ex, Name);
+                DisposeConnection(tuple);
+            }
+            finally
+            {
+                tuple.Item5.Release();
+            }
+        }
+
+        /// <summary>
+        /// Stops sending messages over a web socket
+        /// </summary>
+        /// <param name="message">The message.</param>
+        private void Stop(WebSocketMessageInfo message)
+        {
+            lock (ActiveConnections)
+            {
+                var connection = ActiveConnections.FirstOrDefault(c => c.Item1 == message.Connection);
+
+                if (connection != null)
+                {
+                    DisposeConnection(connection);
+                }
+            }
+        }
+
+        /// <summary>
+        /// Disposes the connection.
+        /// </summary>
+        /// <param name="connection">The connection.</param>
+        private void DisposeConnection(Tuple<WebSocketConnection, CancellationTokenSource, Timer, TStateType, SemaphoreSlim> connection)
+        {
+            Logger.LogInfo("{1} stop transmitting over websocket to {0}", connection.Item1.RemoteEndPoint, GetType().Name);
+
+            try
+            {
+                connection.Item3.Dispose();
+            }
+            catch (ObjectDisposedException)
+            {
+
+            }
+
+            try
+            {
+                connection.Item2.Cancel();
+                connection.Item2.Dispose();
+            }
+            catch (ObjectDisposedException)
+            {
+                
+            }
+
+            try
+            {
+                connection.Item5.Dispose();
+            }
+            catch (ObjectDisposedException)
+            {
+
+            }
+            
+            ActiveConnections.Remove(connection);
+        }
+
+        /// <summary>
+        /// Releases unmanaged and - optionally - managed resources.
+        /// </summary>
+        /// <param name="dispose"><c>true</c> to release both managed and unmanaged resources; <c>false</c> to release only unmanaged resources.</param>
+        protected override void Dispose(bool dispose)
+        {
+            if (dispose)
+            {
+                lock (ActiveConnections)
+                {
+                    foreach (var connection in ActiveConnections.ToList())
+                    {
+                        DisposeConnection(connection);
+                    }
+                }
+            }
+
+            base.Dispose(dispose);
+        }
+    }
+}