From bd111aa4470d07ac9ab46902ff45a98c471de3a0 Mon Sep 17 00:00:00 2001
From: Tony Garnock-Jones <tonygarnockjones@gmail.com>
Date: Wed, 10 Aug 2016 12:46:41 -0400
Subject: [PATCH] More fine-grained control over things to rerender without
 restarting

---
 src/main.rkt    |  2 +-
 src/signals.rkt | 19 +++++++++++++++----
 src/site.rkt    | 16 ++++++++++------
 3 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/src/main.rkt b/src/main.rkt
index d4b7028..32d2dc5 100644
--- a/src/main.rkt
+++ b/src/main.rkt
@@ -8,7 +8,7 @@
 (define (main [config (hash)])
   (make-persistent-state '*config* (lambda () config))
   (void (make-reloadable-entry-point 'refresh-packages! "packages.rkt"))
-  (void (make-reloadable-entry-point 'rerender-all! "site.rkt"))
+  (void (make-reloadable-entry-point 'rerender! "site.rkt"))
   (start-service #:port (hash-ref config 'port (lambda ()
                                                  (let ((port-str (getenv "SITE_PORT")))
                                                    (if port-str (string->number port-str) 7443))))
diff --git a/src/signals.rkt b/src/signals.rkt
index a2a2e57..2970b1e 100644
--- a/src/signals.rkt
+++ b/src/signals.rkt
@@ -4,14 +4,20 @@
 (provide poll-signal
 	 start-restart-signal-watcher)
 
+(require (only-in racket/file file->string))
 (require reloadable)
 (require "daemon.rkt")
 
 (define (poll-signal signal-file-name message handler)
   (when (file-exists? signal-file-name)
-    (log-info message)
+    (define contents (file->string signal-file-name))
+    (if (string=? contents "")
+        (log-info "~a" message)
+        (log-info "~a: ~a" message contents))
     (delete-file signal-file-name)
-    (handler)))
+    (if (procedure-arity-includes? handler 1)
+        (handler contents)
+        (handler))))
 
 (define (start-restart-signal-watcher)
   (daemon-thread
@@ -37,7 +43,12 @@
                      (lookup-reloadable-entry-point 'refresh-packages! "packages.rkt")))
        (poll-signal "../signals/.rerender"
                     "Static rerender request received"
-                    (reloadable-entry-point->procedure
-                     (lookup-reloadable-entry-point 'rerender-all! "site.rkt")))
+                    (lambda (request-body)
+                      (define items-to-rerender (read (open-input-string request-body)))
+                      ((reloadable-entry-point->procedure
+                        (lookup-reloadable-entry-point 'rerender! "site.rkt"))
+                       (if (eof-object? items-to-rerender)
+                           #f
+                           items-to-rerender))))
        (sleep 0.5)
        (loop)))))
diff --git a/src/site.rkt b/src/site.rkt
index 755a096..5b213c0 100644
--- a/src/site.rkt
+++ b/src/site.rkt
@@ -2,7 +2,7 @@
 
 (provide request-handler
          on-continuation-expiry
-         rerender-all!)
+         rerender!)
 
 (require racket/runtime-path)
 (require racket/set)
@@ -1421,8 +1421,8 @@
                    (hash))))))
   (set-package-external-information! package-name external-information))
 
-(define (rerender-all!)
-  (thread-send (package-change-handler-thread) 'rerender-all!))
+(define (rerender! items-to-rerender)
+  (thread-send (package-change-handler-thread) (list 'rerender! items-to-rerender)))
 
 (define (internal:rerender-not-found!)
   ;; TODO: general-purpose error page instead.
@@ -1457,9 +1457,13 @@
                                  (internal:rerender-not-found!)
                                  (package-change-handler index-rerender-needed?
                                                          pending-completions)]
-                                ['rerender-all!
-                                 (log-info "rerender-all!")
-                                 (for ((p (all-package-names)))
+                                [(list 'rerender! items-to-rerender)
+                                 (log-info "rerender! ~v" items-to-rerender)
+                                 (define packages-to-rerender
+                                   (if items-to-rerender
+                                       (filter symbol? items-to-rerender)
+                                       (all-package-names)))
+                                 (for ((p packages-to-rerender))
                                    (update-external-package-information! p)
                                    (static-render! #:mime-type "text/html"
                                                    relative-named-url