rename constants for clarity (#2048)

src/Microsoft.Azure.SignalR.Common/ServiceConnections/ServiceConnectionContainerBase.cs

@@ -26,6 +26,7 @@ internal abstract class ServiceConnectionContainerBase : IServiceConnectionConta
  private static readonly int MaxReconnectBackOffInternalInMilliseconds = 1000;
 
  private static readonly TimeSpan MessageWriteRetryDelay = TimeSpan.FromMilliseconds(200);
+
  private static readonly int MessageWriteMaxRetry = 3;
 
  // Give (interval * 3 + 1) delay when check value expire.
@@ -119,6 +120,7 @@ protected ServiceConnectionContainerBase(IServiceConnectionFactory serviceConnec
  Logger = logger ?? throw new ArgumentNullException(nameof(logger));
  ServiceConnectionFactory = serviceConnectionFactory;
  Endpoint = endpoint;
+
  // use globally unique AckHanlder if not specified
  // It is possible that the multiple MapHub calls the same hub, so that ack messages could be received by another instance of ServiceConnectionContainer
  // Use the ack handler singleton to allow ack message to be acked by another container instance
@@ -395,19 +397,15 @@ protected virtual ServiceConnectionStatus GetStatus()
  : ServiceConnectionStatus.Disconnected;
  }
 
- protected async Task WriteFinAsync(IServiceConnection c, GracefulShutdownMode mode)
- {
- var message = RuntimeServicePingMessage.GetFinPingMessage(mode);
- await c.WriteAsync(message);
- }
-
  protected async Task RemoveConnectionAsync(IServiceConnection c, GracefulShutdownMode mode)
  {
  var retry = 0;
  while (retry < MaxRetryRemoveSeverConnection)
  {
  using var source = new CancellationTokenSource();
- _ = WriteFinAsync(c, mode);
+
+ var message = RuntimeServicePingMessage.GetFinPingMessage(mode);
+ _ = c.WriteAsync(message);
 
  var task = await Task.WhenAny(c.ConnectionOfflineTask, Task.Delay(Constants.Periods.RemoveFromServiceTimeout, source.Token));
 

src/Microsoft.Azure.SignalR.Common/ServiceMessages/RuntimeServicePingMessages.cs

@@ -10,27 +10,38 @@ namespace Microsoft.Azure.SignalR;
 internal static class RuntimeServicePingMessage
 {
  private const string EchoKey = "echo";
+
  private const string OfflineKey = "offline";
+
  private const string TargetKey = "target";
+
  private const string StatusKey = "status";
+
  private const string ShutdownKey = "shutdown";
+
  private const string ServersKey = "servers";
+
  private const string ClientCountKey = "clientcount";
+
  private const string ServerCountKey = "servercount";
+
  private const string CapacityKey = "capacity";
+
  private const string DiagnosticLogsMessagingTypeKey = "d-m";
 
  private const string MessagingLogEnableValue = "1";
 
  private const string StatusActiveValue = "1";
+
  private const string StatusInactiveValue = "0";
 
- private const string ShutdownFinKeepAliveValue = "fin:2";
- private const string ShutdownFinMigratableValue = "fin:1";
  private const string ShutdownFinValue = "fin:0";
 
+ private const string ShutdownFinMigrateClientsValue = "fin:1";
+
+ private const string ShutdownFinWaitForClientsValue = "fin:2";
+
  private const string ShutdownFinAckValue = "finack";
- private const char ServerListSeparator = ';';
 
  private static readonly ServicePingMessage StatusActive =
  new ServicePingMessage { Messages = new[] { StatusKey, StatusActiveValue } };
@@ -41,11 +52,11 @@ internal static class RuntimeServicePingMessage
  private static readonly ServicePingMessage ShutdownFin =
  new ServicePingMessage { Messages = new[] { ShutdownKey, ShutdownFinValue } };
 
- private static readonly ServicePingMessage ShutdownFinMigratable =
- new ServicePingMessage { Messages = new[] { ShutdownKey, ShutdownFinMigratableValue } };
+ private static readonly ServicePingMessage ShutdownFinMigrateClients =
+ new ServicePingMessage { Messages = new[] { ShutdownKey, ShutdownFinMigrateClientsValue } };
 
- private static readonly ServicePingMessage ShutdownFinKeepAlive =
- new ServicePingMessage { Messages = new[] { ShutdownKey, ShutdownFinKeepAliveValue } };
+ private static readonly ServicePingMessage ShutdownFinWaitForClients =
+ new ServicePingMessage { Messages = new[] { ShutdownKey, ShutdownFinWaitForClientsValue } };
 
  private static readonly ServicePingMessage ShutdownFinAck =
  new ServicePingMessage { Messages = new[] { ShutdownKey, ShutdownFinAckValue } };
@@ -84,7 +95,6 @@ public static ServicePingMessage GetStatusPingMessage(bool isActive, int clientC
  ? new ServicePingMessage { Messages = new[] { StatusKey, StatusActiveValue, ClientCountKey, clientCount.ToString() } }
  : new ServicePingMessage { Messages = new[] { StatusKey, StatusInactiveValue, ClientCountKey, clientCount.ToString() } };
 
-
  public static bool TryGetStatus(this ServicePingMessage ping, out bool isActive)
  {
  if (!TryGetValue(ping, StatusKey, out var value))
@@ -150,8 +160,8 @@ public static ServicePingMessage GetFinPingMessage(GracefulShutdownMode mode = G
  {
  return mode switch
  {
- GracefulShutdownMode.WaitForClientsClose => ShutdownFinKeepAlive,
- GracefulShutdownMode.MigrateClients => ShutdownFinMigratable,
+ GracefulShutdownMode.WaitForClientsClose => ShutdownFinWaitForClients,
+ GracefulShutdownMode.MigrateClients => ShutdownFinMigrateClients,
  _ => ShutdownFin,
  };
  }
@@ -165,8 +175,8 @@ public static bool IsFin(this ServiceMessage serviceMessage) =>
  serviceMessage is ServicePingMessage ping && TryGetValue(ping, ShutdownKey, out var value) && (value switch
  {
  ShutdownFinValue => true,
- ShutdownFinMigratableValue => true,
- ShutdownFinKeepAliveValue => true,
+ ShutdownFinMigrateClientsValue => true,
+ ShutdownFinWaitForClientsValue => true,
  _ => false,
  });
 
@@ -185,7 +195,7 @@ internal static bool TryGetValue(ServicePingMessage pingMessage, string key, out
  return false;
  }
 
- for (int i = 0; i < pingMessage.Messages.Length - 1; i += 2)
+ for (var i = 0; i < pingMessage.Messages.Length - 1; i += 2)
  {
  if (pingMessage.Messages[i] == key)
  {
@@ -197,4 +207,4 @@ internal static bool TryGetValue(ServicePingMessage pingMessage, string key, out
  value = null;
  return false;
  }
-}
+}