force-output of a prepend-stream

%Testing: aserve/test/t-aserve.cl

The prepend-stream is a stream defined in AllegroServe.
In this change we cause a force-output of a prepend-stream
to pass the data in the prepend-stream's buffer to the underlying
stream and then do a force-output of the underlying stream.
As the prepend-stream is used when sending a response back to
the client this allows a function handling an http request
to send the response back in pieces and have those pieces available
to the client as soon as they are computed.

Change-Id: I92c1d65a479ef7e9ab4945a009bf0a343c99120c
Reviewed-on: https://gerrit.franz.com:9080/9692
Reviewed-by: John Foderaro <jkf@franz.com>
Reviewed-by: Kevin Layer <layer@franz.com>
Tested-by: Kevin Layer <layer@franz.com>

main.cl

@@ -21,7 +21,7 @@
 #+ignore
 (check-smp-consistency)
 
-(defparameter *aserve-version* '(1 3 55))
+(defparameter *aserve-version* '(1 3 56))
 
 (eval-when (eval load)
     (require :sock)

packages.cl

@@ -5,8 +5,9 @@
 ;; See the file LICENSE for the full license governing this code.
 
 #+(version= 10 1)
-(sys:defpatch "aserve" 7
-  "v7: 1.3.55: Add and export a more full set of http response codes;
+(sys:defpatch "aserve" 8
+  "v8: 1.3.56: force-output of a prepend-stream supported
+v7: 1.3.55: Add and export a more full set of http response codes;
 v6: 1.3.54: Use Allegro's built-in base64 routines when available;
 v5: 1.3.53: Add :no-keep-alive strategy;
 v4: 1.3.52: optimize compilation for speed;
@@ -17,8 +18,9 @@ v1: 1.3.49: speed up read-sock-line."
   :post-loadable t)
 
 #+(version= 10 0)
-(sys:defpatch "aserve" 18
-  "v18: 1.3.55: Add and export a more full set of http response codes;
+(sys:defpatch "aserve" 19
+  "v19: 1.3.56: force-output of a prepend-stream supported
+v18: 1.3.55: Add and export a more full set of http response codes;
 v17: 1.3.54: Use Allegro's built-in base64 routines when available;
 v16: 1.3.53: Add :no-keep-alive strategy;
 v15: 1.3.52: optimize compilation for speed;

publish.cl

@@ -2986,10 +2986,15 @@
 	    (write-full-vector content output-handle))
 
     (if* (> end start) 
-       then (write-full-vector (or buffer (slot-value p 'excl::buffer))
+       then (prog1 (write-full-vector (or buffer (slot-value p 'excl::buffer))
 			       output-handle
 			       :start start
 			       :end end)
+              ;; this will cause a force-output of the prepend-stream
+              ;; to also force-output the underlying stream.
+              ;; We'll also force-output when the buffer fills up
+              ;; and that's not a bad thing to do and it is unavoidable.
+              (force-output output-handle))
        else start)))
 
 

test/t-aserve.cl

@@ -346,6 +346,9 @@
 	(stop-proxy-running)
 	))
 
+    ;; independent test of a stream used in aserve
+    (test-force-output-prepend-stream)
+
     (if* (and ssl (errorset (as-require :ssl)))
        then (test-aserve-extra-ssl))
     )
@@ -2922,7 +2925,36 @@ Returns a vector."
       (test t seen-error-3)
       (and *wserver* (shutdown)))))
 
+
+(defun test-force-output-prepend-stream ()
+  ;; the prepend-stream is defined in aserve
+  ;; we test here that force-output of such 
+  ;; a stream will force-output the underlying
+  ;; stream
+  (let* ((passive (socket:make-socket :connect :passive))
+         (sender (socket:make-socket :remote-host "127.0.0.1"
+                                     :remote-port
+                                     (socket:local-port passive)))
+         (receiver (socket:accept-connection passive))
+         (prepend (net.aserve::make-instance-prepend-stream+content+output-handle
+                   "" ; no content
+                   sender)))
+    (unwind-protect 
+        (progn
+          (write-byte 1 prepend)
+          (force-output prepend)
+
+          (mp::with-timeout (10 (test nil "force-output of prepend-stream didn't work"))
+
+            ;; read-byte will return immediately if the force-output
+            ;; was successful
+            (test 1 (read-byte receiver))))
 
+      (close passive)
+      (close sender)
+      (close receiver))))
+
+
 
 
 ;; (net.aserve::debug-on :xmit)