From 6b6aef2192769ce12a2962b02d103a019f4bc9c6 Mon Sep 17 00:00:00 2001
From: NalaGinrut <NalaGinrut@gmail.com>
Date: Sun, 11 Mar 2012 23:02:07 +0800
Subject: [PATCH] read-response-body should return received data in any break

---
 module/web/response.scm |   52 +++++++++++++++++++++++++++++++++++++++-------
 1 files changed, 44 insertions(+), 8 deletions(-)

diff --git a/module/web/response.scm b/module/web/response.scm
index 07e1245..e3ea0a6 100644
--- a/module/web/response.scm
+++ b/module/web/response.scm
@@ -21,6 +21,7 @@
 
 (define-module (web response)
   #:use-module (rnrs bytevectors)
+  #:autoload (rnrs) (call-with-port)
   #:use-module (ice-9 binary-ports)
   #:use-module (ice-9 rdelim)
   #:use-module (srfi srfi-9)
@@ -38,6 +39,8 @@
 
             response-must-not-include-body?
             read-response-body
+            output-received-response-body
+            throw-from-response-body-break
             write-response-body
 
             ;; General headers
@@ -224,16 +227,49 @@ This is true for some response types, like those with code 304."
       (= (response-code r) 204)
       (= (response-code r) 304)))
 
-(define (read-response-body r)
+(define* (read-response-body r #:key (block 4096))
   "Reads the response body from @var{r}, as a bytevector.  Returns
 @code{#f} if there was no response body."
-  (let ((nbytes (response-content-length r)))
-    (and nbytes
-         (let ((bv (get-bytevector-n (response-port r) nbytes)))
-           (if (= (bytevector-length bv) nbytes)
-               bv
-               (bad-response "EOF while reading response body: ~a bytes of ~a"
-                            (bytevector-length bv) nbytes))))))
+  (let* ((nbytes (response-content-length r))
+         (bv (and nbytes (make-bytevector nbytes)))
+         (start 0))
+    (catch #t
+           (lambda ()
+             (let lp((buf (get-bytevector-n (response-port r) block)))
+                 (if (eof-object? buf)
+                     bv
+                     (let ((len (bytevector-length buf)))
+                       (cond
+                        ((<= len block)
+                         (bytevector-copy! buf 0 bv start len)
+                         (set! start (+ start len))
+                         (lp (get-bytevector-n (response-port r) block)))
+                        (else
+                         (bad-response "EOF while reading response body: ~a bytes of ~a"
+                                       start nbytes)))))))
+             (lambda (k . e)
+               (let ((received (call-with-port 
+                                (open-bytevector-input-port bv) 
+                                (lambda (port)
+                                  (get-bytevector-n port start)))))
+                 (throw k `(,@e (body ,@received))) ;; return the received data
+                 )))))
+
+;; output the received data if there is, or do nothing
+(define (output-received-response-body e port)
+  (let ((received (assoc-ref (cadr e) 'body)))
+    (if received
+        (begin
+          (put-bytevector port received) 
+          (force-output port)))))
+   
+;; Exceptional information contains the received bytevector added from the
+;; read-response-body if any exception had been caught.
+;; If received data ware huge(it always does), it'd be a trouble during the tracing.
+;; This helper function could get rid of the received data from exceptional info,
+;; and re-throw it.
+(define (throw-from-response-body-break e)
+  (throw (car e) (list-head (cdr e) (1- (length (cdr e))))))
 
 (define (write-response-body r bv)
   "Write @var{bv}, a bytevector, to the port corresponding to the HTTP
-- 
1.7.0.4