From eca3e9ded045e6139002a8dbb70fe25496b7de4f Mon Sep 17 00:00:00 2001
From: Tony Garnock-Jones <tonygarnockjones@gmail.com>
Date: Wed, 11 Jun 2014 16:03:22 -0400
Subject: [PATCH] Switch websocket driver to use send-ground-message.

---
 minimart/drivers/websocket.rkt | 74 ++++++++++++++++++++--------------
 1 file changed, 44 insertions(+), 30 deletions(-)

diff --git a/minimart/drivers/websocket.rkt b/minimart/drivers/websocket.rkt
index a723a4f..9c7a663 100644
--- a/minimart/drivers/websocket.rkt
+++ b/minimart/drivers/websocket.rkt
@@ -25,6 +25,12 @@
 (struct websocket-ssl-options (cert-file key-file) #:prefab)
 (struct websocket-message (from to body) #:prefab)
 
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Ground-level communication messages
+
+(struct websocket-accepted (id connection control-ch) #:prefab)
+(struct websocket-incoming-message (id message) #:prefab)
+
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; Driver
 
@@ -48,17 +54,28 @@
 	 (begin (when shutdown-procedure (shutdown-procedure))
 		(transition (struct-copy listener-state state [shutdown-procedure #f]) (quit)))
 	 #f)]
-    [(message (event _ (list (list c connection-shutdown-procedure))) 1 #f)
+    [(message (websocket-accepted id c control-ch) 1 #f)
      (transition state
-		 (spawn-connection (listener-state-server-addr state)
-				   c
-				   connection-shutdown-procedure))]
+		 (spawn-connection (listener-state-server-addr state) id c control-ch))]
     [_ #f]))
 
-(define ((connection-handler listener-ch) c dummy-state)
-  (define connection-ch (make-channel))
-  (channel-put listener-ch (list c (lambda () (channel-put connection-ch #t))))
-  (channel-get connection-ch)
+(define (connection-handler c dummy-state)
+  (define control-ch (make-channel))
+  (define c-input-port (ws-conn-base-ip c))
+  (define id (gensym 'ws))
+  (send-ground-message (websocket-accepted id c control-ch))
+  (let loop ((blocked? #t))
+    (sync (handle-evt control-ch
+		      (match-lambda
+		       ['unblock (loop #f)]
+		       ['quit (void)]))
+	  (if blocked?
+	      never-evt
+	      (handle-evt c-input-port
+			  (lambda (dummy)
+			    (define msg (ws-recv c #:payload-type 'text))
+			    (send-ground-message (websocket-incoming-message id msg))
+			    (loop (or blocked? (eof-object? msg))))))))
   (ws-close! c))
 
 (define (ssl-options->ssl-tcp@ ssl-options)
@@ -71,42 +88,38 @@
 
 (define (spawn-websocket-listener server-addr)
   (match-define (websocket-local-server port ssl-options) server-addr)
-  (define ch (make-channel))
   (define shutdown-procedure (ws-serve #:port port
 				       #:tcp@ (if ssl-options
 						  (ssl-options->ssl-tcp@ ssl-options)
 						  tcp@)
-				       (connection-handler ch)))
+				       connection-handler))
   (spawn websocket-listener
 	 (listener-state shutdown-procedure server-addr)
 	 (gestalt-union (pub (websocket-message ? server-addr ?) #:level 2)
-			(sub (event ch ?) #:meta-level 1))))
+			(sub (websocket-accepted ? ? ?) #:meta-level 1))))
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; Connection
 
-(struct connection-state (seen-peer? local-addr server-addr c [shutdown-procedure #:mutable])
-	#:transparent)
+(struct connection-state (seen-peer? local-addr server-addr c control-ch) #:transparent)
 
 (define (shutdown-connection state)
-  (when (connection-state-shutdown-procedure state)
-    ((connection-state-shutdown-procedure state))
-    (set-connection-state-shutdown-procedure! state #f))
-  (transition state (quit)))
+  (transition (match (connection-state-control-ch state)
+		[#f state]
+		[ch (channel-put ch 'quit)
+		    (struct-copy connection-state state [control-ch #f])])
+	      (quit)))
 
 (define (websocket-connection e state)
   (with-handlers [((lambda (exn) #t)
 		   (lambda (exn) (shutdown-connection state)))]
     (match e
-      [(message (event _ _) 1 #f)
-       (match-define (connection-state seen-peer? local-addr server-addr c _) state)
-       (and seen-peer?
-	    (let ((m (ws-recv c #:payload-type 'text)))
-	      (if (eof-object? m)
-		  (shutdown-connection state)
-		  (transition state (send (websocket-message local-addr
-							     server-addr
-							     m))))))]
+      [(message (websocket-incoming-message _ m) 1 #f)
+       (if (eof-object? m)
+	   (shutdown-connection state)
+	   (transition state (send (websocket-message (connection-state-local-addr state)
+						      (connection-state-server-addr state)
+						      m))))]
       [(message (websocket-message _ _ m) 0 #f)
        (ws-send! (connection-state-c state) m)
        #f]
@@ -115,16 +128,17 @@
 	[(and (connection-state-seen-peer? state) (gestalt-empty? g))
 	 (shutdown-connection state)]
 	[(and (not (connection-state-seen-peer? state)) (not (gestalt-empty? g)))
+	 (channel-put (connection-state-control-ch state) 'unblock)
 	 (transition (struct-copy connection-state state [seen-peer? #t]) '())]
 	[else
 	 #f])]
       [#f #f])))
 
-(define (spawn-connection server-addr c shutdown-procedure)
-  (define local-addr (websocket-remote-client (gensym 'ws)))
+(define (spawn-connection server-addr id c control-ch)
+  (define local-addr (websocket-remote-client id))
   (spawn websocket-connection
-	 (connection-state #f local-addr server-addr c shutdown-procedure)
+	 (connection-state #f local-addr server-addr c control-ch)
 	 (gestalt-union (pub (websocket-message local-addr server-addr ?))
 			(sub (websocket-message server-addr local-addr ?))
 			(sub (websocket-message server-addr local-addr ?) #:level 1)
-			(sub (event (ws-conn-base-ip c) ?) #:meta-level 1))))
+			(sub (websocket-incoming-message id ?) #:meta-level 1))))