From 9f431462db9ea0140c3a1ec16eeddfd1a3cb19f8 Mon Sep 17 00:00:00 2001
From: Christopher Baines <mail@cbaines.net>
Date: Thu, 19 Jun 2025 09:40:01 +0100
Subject: [PATCH] Improve render procedures

---
 guix-data-service/web/render.scm | 49 +++++++++++++++++++-------------
 1 file changed, 29 insertions(+), 20 deletions(-)

diff --git a/guix-data-service/web/render.scm b/guix-data-service/web/render.scm
index 3e2cf79..95c5a48 100644
--- a/guix-data-service/web/render.scm
+++ b/guix-data-service/web/render.scm
@@ -26,6 +26,7 @@
   #:use-module (ice-9 ftw)
   #:use-module (ice-9 iconv)
   #:use-module (ice-9 binary-ports)
+  #:use-module (ice-9 textual-ports)
   #:use-module (web request)
   #:use-module (web response)
   #:use-module (web uri)
@@ -147,15 +148,15 @@
                            '((content-type . (text/html
                                               (charset . "utf-8")))
                              (vary . (accept)))))
-        (if stream?
-            (lambda (port)
-              (set-port-encoding! port "utf-8")
-              (setvbuf port 'block (expt 2 20))
-              (sxml->html sxml port))
-            (call-with-encoded-output-string
-             "utf-8"
+        (and
+         sxml
+         (if stream?
              (lambda (port)
-               (sxml->html sxml port))))))
+               (sxml->html sxml port))
+             (call-with-encoded-output-string
+              "utf-8"
+              (lambda (port)
+                (sxml->html sxml port)))))))
 
 (define* (render-json json #:key (extra-headers '())
                       (code 200)
@@ -166,27 +167,35 @@
                            '((content-type . (application/json
                                               (charset . "utf-8")))
                              (vary . (accept)))))
-        (if stream?
-            (lambda (port)
-              (setvbuf port 'block (expt 2 16))
-              (scm->json json port #:unicode #t))
-            (call-with-encoded-output-string
-             "utf-8"
+
+        (and
+         json
+         (if stream?
              (lambda (port)
-               (scm->json json port #:unicode #t))))))
+               (scm->json json port #:unicode #t))
+             (call-with-encoded-output-string
+              "utf-8"
+              (lambda (port)
+                (scm->json json port)))))))
 
 (define* (render-text text #:key (extra-headers '())
-                      (code 200))
+                      (code 200)
+                      stream?)
   (list (build-response
          #:code code
          #:headers (append extra-headers
                            '((content-type . (text/plain
                                               (charset . "utf-8")))
                              (vary . (accept)))))
-        (call-with-encoded-output-string
-         "utf-8"
-         (lambda (port)
-           (display text port)))))
+        (and
+         text
+         (if stream?
+             (lambda (port)
+               (put-string port text))
+             (call-with-encoded-output-string
+              "utf-8"
+              (lambda (port)
+                (display text port)))))))
 
 (define (not-found uri)
   (list (build-response #:code 404)