Adapt Mirror to use new SupportedCode from swarm

Part of sociomantic-tsunami#78.

src/dhtproto/client/request/internal/Mirror.d

@@ -163,6 +163,7 @@ private scope class MirrorHandler
     import swarm.neo.client.mixins.SuspendableRequestCore;
     import swarm.neo.request.RequestEventDispatcher;
     import swarm.neo.util.MessageFiber;
+    import swarm.neo.request.Command;
 
     import dhtproto.common.Mirror;
     import dhtproto.client.request.Mirror;
@@ -215,7 +216,7 @@ private scope class MirrorHandler
     {
         auto request = createSuspendableRequest!(Mirror)(this.conn, this.context,
             &this.connect, &this.disconnected, &this.fillPayload,
-            &this.handleStatusCode, &this.handle);
+            &this.handleSupportedCode, &this.handle);
         request.run();
     }
 
@@ -276,48 +277,51 @@ private scope class MirrorHandler
     /***************************************************************************
 
         HandleStatusCode policy, called from SuspendableRequestInitialiser
-        template to decide how to handle the status code received from the node.
+        template to decide how to handle the supported code received from the
+        node.
 
         Params:
-            status = status code received from the node in response to the
+            code = supported code received from the node in response to the
                 initial message
 
         Returns:
-            true to continue handling the request (OK status); false to abort
-            (error status)
+            true to continue handling the request (supported); false to abort
+            (unsupported)
 
     ***************************************************************************/
 
-    private bool handleStatusCode ( ubyte status )
+    private bool handleSupportedCode ( ubyte code )
     {
-        auto getall_status = cast(RequestStatusCode)status;
-
-        if ( Mirror.handleGlobalStatusCodes(getall_status, this.context,
-            this.conn.remote_address) )
-            return false; // Global code, e.g. request/version not supported
+        auto supported = cast(SupportedStatus)code;
+        if ( !Mirror.handleSupportedCodes(supported,
+            this.context, this.conn.remote_address) )
+        {
+            return false; // Request/version not supported
+        }
 
-        // Mirror-specific codes
-        with ( RequestStatusCode ) switch ( getall_status )
+        // Handle initial started/error message from node.
+        auto msg = conn.receiveValue!(MessageType)();
+        with ( MessageType ) switch ( msg )
         {
             case Started:
-                // Expected "request started" code
-                return true;
+                // Expected "request started" code. Continue handling request.
+                break;
 
             case Error:
-                // The node returned an error code. Notify the user and
-                // end the request.
+                // The node returned an error code. Notify the user and end the
+                // request.
                 Mirror.Notification n;
                 n.node_error = RequestNodeInfo(
                     this.context.request_id, conn.remote_address);
                 Mirror.notify(this.context.user_params, n);
                 return false;
 
             default:
-                // Treat unknown codes as internal errors.
+                // Treat unknown/unexpected codes as node errors.
                 goto case Error;
         }
 
-        assert(false);
+        return true;
     }
 
     /***************************************************************************

src/dhtproto/common/Mirror.d

@@ -14,24 +14,6 @@ module dhtproto.common.Mirror;
 
 import swarm.neo.request.Command;
 
-/*******************************************************************************
-
-    Status code enum. Sent from the node to the client.
-
-*******************************************************************************/
-
-public enum RequestStatusCode : StatusCode
-{
-    /// Invalid, default value
-    None,
-
-    /// Mirror started
-    Started,
-
-    /// Internal node error occurred
-    Error
-}
-
 /*******************************************************************************
 
     Message type enum. Each message sent between the client and the node as part
@@ -53,6 +35,8 @@ public enum MessageType : ubyte
                     // sent by the client to acknowledge the request finishing
 
     // Message types sent from the node to the client:
+    Started,        // Request handling beginning
+    Error,          // Internal node error occurred; request not being handled
     RecordChanged,  // Sent by the node when it sends a record value
     RecordDeleted,  // Sent by the node when it sends the key of a deleted record
     RecordRefreshBatch, // Sent by the node when it sends a batch of refreshed

src/dhtproto/node/neo/request/Mirror.d

@@ -383,7 +383,7 @@ public abstract scope class MirrorProtocol_v0
             ( RequestOnConnBase.EventDispatcher.Payload payload )
             {
                 payload.addConstant(ok
-                    ? RequestStatusCode.Started : RequestStatusCode.Error);
+                    ? MessageType.Started : MessageType.Error);
             }
         );
 

src/fakedht/neo/request/Mirror.d

@@ -45,16 +45,23 @@ public void handle ( Object shared_resources, RequestOnConn connection,
     Command.Version cmdver, Const!(void)[] msg_payload )
 {
     auto resources = new SharedResources;
+    auto ed = connection.event_dispatcher;
 
     switch ( cmdver )
     {
         case 0:
+            ed.send(
+                ( ed.Payload payload )
+                {
+                    payload.addConstant(SupportedStatus.RequestSupported);
+                }
+            );
+
             scope rq = new MirrorImpl_v0(resources);
             rq.handle(connection, msg_payload);
             break;
 
         default:
-            auto ed = connection.event_dispatcher;
             ed.send(
                 ( ed.Payload payload )
                 {