Cleanup: RedisSubscriber

StackExchange.Redis/StackExchange/Redis/RedisSubscriber.cs

@@ -6,7 +6,7 @@
 
 namespace StackExchange.Redis
 {
-    partial class ConnectionMultiplexer
+    public partial class ConnectionMultiplexer
     {
         private readonly Dictionary<RedisChannel, Subscription> subscriptions = new Dictionary<RedisChannel, Subscription>();
 
@@ -33,8 +33,7 @@ internal Task AddSubscription(RedisChannel channel, Action<RedisChannel, RedisVa
             {
                 lock (subscriptions)
                 {
-                    Subscription sub;
-                    if (subscriptions.TryGetValue(channel, out sub))
+                    if (subscriptions.TryGetValue(channel, out Subscription sub))
                     {
                         sub.Add(handler);
                     }
@@ -45,7 +44,6 @@ internal Task AddSubscription(RedisChannel channel, Action<RedisChannel, RedisVa
                         var task = sub.SubscribeToServer(this, channel, flags, asyncState, false);
                         if (task != null) return task;
                     }
-
                 }
             }
             return CompletedTask<bool>.Default(asyncState);
@@ -57,8 +55,7 @@ internal ServerEndPoint GetSubscribedServer(RedisChannel channel)
             {
                 lock (subscriptions)
                 {
-                    Subscription sub;
-                    if (subscriptions.TryGetValue(channel, out sub))
+                    if (subscriptions.TryGetValue(channel, out Subscription sub))
                     {
                         return sub.GetOwner();
                     }
@@ -72,8 +69,7 @@ internal void OnMessage(RedisChannel subscription, RedisChannel channel, RedisVa
             ICompletable completable = null;
             lock (subscriptions)
             {
-                Subscription sub;
-                if (subscriptions.TryGetValue(subscription, out sub))
+                if (subscriptions.TryGetValue(subscription, out Subscription sub))
                 {
                     completable = sub.ForInvoke(channel, payload);
                 }
@@ -101,17 +97,13 @@ internal Task RemoveSubscription(RedisChannel channel, Action<RedisChannel, Redi
         {
             lock (subscriptions)
             {
-                Subscription sub;
-                if (subscriptions.TryGetValue(channel, out sub))
-                {
-                    if (sub.Remove(handler))
+                if (subscriptions.TryGetValue(channel, out Subscription sub) && sub.Remove(handler))
                 {
                     subscriptions.Remove(channel);
                     var task = sub.UnsubscribeFromServer(channel, flags, asyncState, false);
                     if (task != null) return task;
                 }
             }
-            }
             return CompletedTask<bool>.Default(asyncState);
         }
 
@@ -133,11 +125,9 @@ internal bool SubscriberConnected(RedisChannel channel = default(RedisChannel))
             if (server != null) return server.IsConnected;
 
             server = SelectServer(-1, RedisCommand.SUBSCRIBE, CommandFlags.DemandMaster, default(RedisKey));
-            return server != null && server.IsConnected;
+            return server?.IsConnected == true;
         }
 
-
-
         internal long ValidateSubscriptions()
         {
             lock (subscriptions)
@@ -156,14 +146,10 @@ private sealed class Subscription
             private Action<RedisChannel, RedisValue> handler;
             private ServerEndPoint owner;
 
-            public Subscription(Action<RedisChannel, RedisValue> value)
-            {
-                handler = value;
-            }
-            public void Add(Action<RedisChannel, RedisValue> value)
-            {
-                handler += value;
-            }
+            public Subscription(Action<RedisChannel, RedisValue> value) => handler = value;
+
+            public void Add(Action<RedisChannel, RedisValue> value) => handler += value;
+
             public ICompletable ForInvoke(RedisChannel channel, RedisValue message)
             {
                 var tmp = handler;
@@ -182,6 +168,7 @@ public bool Remove(Action<RedisChannel, RedisValue> value)
                     return (handler -= value) == null;
                 }
             }
+
             public Task SubscribeToServer(ConnectionMultiplexer multiplexer, RedisChannel channel, CommandFlags flags, object asyncState, bool internalCall)
             {
                 var cmd = channel.IsPatternBased ? RedisCommand.PSUBSCRIBE : RedisCommand.SUBSCRIBE;
@@ -205,10 +192,8 @@ public Task UnsubscribeFromServer(RedisChannel channel, CommandFlags flags, obje
                 return oldOwner.QueueDirectAsync(msg, ResultProcessor.TrackSubscriptions, asyncState);
             }
 
-            internal ServerEndPoint GetOwner()
-            {
-                return Interlocked.CompareExchange(ref owner, null, null);
-            }
+            internal ServerEndPoint GetOwner() => Interlocked.CompareExchange(ref owner, null, null);
+
             internal void Resubscribe(RedisChannel channel, ServerEndPoint server)
             {
                 if (server != null && Interlocked.CompareExchange(ref owner, server, server) == server)
@@ -232,17 +217,12 @@ internal bool Validate(ConnectionMultiplexer multiplexer, RedisChannel channel)
                     }
                     oldOwner = null;
                 }
-                if (oldOwner == null)
-                {
-                    if (SubscribeToServer(multiplexer, channel, CommandFlags.FireAndForget, null, true) != null)
+                if (oldOwner == null && SubscribeToServer(multiplexer, channel, CommandFlags.FireAndForget, null, true) != null)
                 {
                     changed = true;
                 }
-                }
                 return changed;
             }
-
-
         }
     }
 
@@ -309,12 +289,10 @@ public void Subscribe(RedisChannel channel, Action<RedisChannel, RedisValue> han
 
         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 EndPoint SubscribedEndpoint(RedisChannel channel)
         {
             var server = multiplexer.GetSubscribedServer(channel);