Subject: [bug#54836] [PATCH v3] http-client: Factor out open-connection*, rename variables.

From: Attila Lendvai <[email-masked]>
Date: Thu, 28 Apr 2022 12:22:34 +0200

This is an idempotent refactor.

* guix/http-client.scm (http-fetch): Introduce open-connection*. Rename some
variables to turn programmer mistakes into compile time errors.
---

v3: i have reordered the commits so that i can send this idempotent
refactor. i think this would be a useful addition to master. it makes
the code more defensive against future programmer mistakes, but
other than that it shouldn't change the semantics.

apply this as you see fit. the rest i'll do in the go importer's module.

 guix/http-client.scm | 66 ++++++++++++++++++++++----------------------
 1 file changed, 33 insertions(+), 33 deletions(-)

diff --git a/guix/http-client.scm b/guix/http-client.scm
index a367c41afa..6c61fd3d8e 100644
--- a/guix/http-client.scm
+++ b/guix/http-client.scm
@@ -100,15 +100,17 @@ (define* (http-fetch uri #:key port (text? #f) (buffered? #t)
 Write information about redirects to LOG-PORT.
 
 Raise an '&http-get-error' condition if downloading fails."
-  (define uri*
+  (define parsed-initial-uri
     (if (string? uri) (string->uri uri) uri))
 
-  (let loop ((uri uri*)
-             (port (or port (open-connection uri*
-                                             #:verify-certificate?
-                                             verify-certificate?
-                                             #:timeout timeout))))
-    (let ((headers (match (uri-userinfo uri)
+  (define (open-connection* uri)
+    (open-connection uri
+                     #:verify-certificate? verify-certificate?
+                     #:timeout timeout))
+
+  (let loop ((current-uri parsed-initial-uri)
+             (current-port (or port (open-connection parsed-initial-uri))))
+    (let ((headers (match (uri-userinfo current-uri)
                      ((? string? str)
                       (cons (cons 'Authorization
                                   (string-append "Basic "
@@ -116,10 +118,10 @@ (define uri*
                                                   (string->utf8 str))))
                             headers))
                      (_ headers))))
-      (unless (or buffered? (not (file-port? port)))
-        (setvbuf port 'none))
+      (unless (or buffered? (not (file-port? current-port)))
+        (setvbuf current-port 'none))
       (let*-values (((resp data)
-                     (http-get uri #:streaming? #t #:port port
+                     (http-get current-uri #:streaming? #t #:port current-port
                                #:keep-alive? keep-alive?
                                #:headers headers))
                     ((code)
@@ -132,36 +134,34 @@ (define uri*
             303                                   ; see other
             307                                   ; temporary redirection
             308)                                  ; permanent redirection
-           (let ((host (uri-host uri))
-                 (uri  (resolve-uri-reference (response-location resp) uri)))
+           (let ((host (uri-host current-uri))
+                 (new-uri (resolve-uri-reference (response-location resp)
+                                                 current-uri)))
              (if keep-alive?
                  (dump-port data (%make-void-port "w0")
                             (response-content-length resp))
-                 (close-port port))
+                 (close-port current-port))
              (format log-port (G_ "following redirection to `~a'...~%")
-                     (uri->string uri))
-             (loop uri
+                     (uri->string new-uri))
+             (loop new-uri
                    (or (and keep-alive?
-                            (or (not (uri-host uri))
-                                (string=? host (uri-host uri)))
-                            port)
-                       (open-connection uri
-                                        #:verify-certificate?
-                                        verify-certificate?
-                                        #:timeout timeout)))))
+                            (or (not (uri-host new-uri))
+                                (string=? host (uri-host new-uri)))
+                            current-port)
+                       (open-connection* new-uri)))))
           (else
            (raise (condition (&http-get-error
-                              (uri uri)
-                              (code code)
-                              (reason (response-reason-phrase resp))
-                              (headers (response-headers resp)))
-                             (&message
-                              (message
-                               (format
-                                #f
-                                (G_ "~a: HTTP download failed: ~a (~s)")
-                                (uri->string uri) code
-                                (response-reason-phrase resp))))))))))))
+                                  (uri current-uri)
+                                  (code code)
+                                  (reason (response-reason-phrase resp))
+                                  (headers (response-headers resp)))
+                                 (&message
+                                  (message
+                                   (format
+                                    #f
+                                    (G_ "~a: HTTP download failed: ~a (~s)")
+                                    (uri->string current-uri) code
+                                    (response-reason-phrase resp))))))))))))
 
 (define-syntax-rule (false-if-networking-error exp)
   "Return #f if EXP triggers a network related exception as can occur when
-- 
2.35.1