From c56943e6e12da3bd98dd7824a5901bac42da348f Mon Sep 17 00:00:00 2001
From: Daniel Barlow <dan@telent.net>
Date: Mon, 30 Jun 2025 20:30:23 +0100
Subject: [PATCH] use cqueues for gnss socket

This is to avoid a weird bug in the previous glib iochannel
implementation, where the socket was randomly being closed
after about a minute run time. But it's also less code, so
that's OK
---
 pkgs/maps/Makefile |  2 +-
 pkgs/maps/main.fnl | 64 ++++++++++++++++++++--------------------------
 2 files changed, 29 insertions(+), 37 deletions(-)

diff --git a/pkgs/maps/Makefile b/pkgs/maps/Makefile
index c220aa6..ca7f206 100644
--- a/pkgs/maps/Makefile
+++ b/pkgs/maps/Makefile
@@ -12,7 +12,7 @@ $(NAME): $(patsubst %.fnl,%.lua,$(MODULES)) Makefile
 	chmod +x $@
 
 run:
-	( fennel fake-nmea.fnl commute.nmea /tmp/gnss & ) ; sleep 1; fennel -e '((. (require :main) :run) "/tmp/gnss")'
+	fennel -e '((. (require :main) :run) "/tmp/gnss")'
 
 test:
 	fennel run-tests.fnl $(MODULES)
diff --git a/pkgs/maps/main.fnl b/pkgs/maps/main.fnl
index 67a6e76..18a98b6 100644
--- a/pkgs/maps/main.fnl
+++ b/pkgs/maps/main.fnl
@@ -2,6 +2,7 @@
 (local { : fdopen } (require :posix.stdio))
 (local ptime (require :posix.time))
 (local cqueues (require :cqueues))
+(local socket (require :cqueues.socket))
 
 (local nmea (require :nmea))
 (local tiles (require :tiles))
@@ -452,32 +453,29 @@ label.readout {
       (> b c) c
       b))
 
-(fn read-gnss [socket]
-  (each [l #(socket:read "l")]
-    ; (print "gnss" l)
-    (if (not (= l ""))
-        (let [message (nmea.parse l)]
-          (case message
-            { : lat : lon : utc}
+(fn read-gnss-sentence [l]
+  (if (not (= l ""))
+      (let [message (nmea.parse l)]
+        (case message
+          { : lat : lon : utc}
+          (update-app-state
+           {
+            : lat : lon
+            :time-of-day
+            (let [(h m s) (string.match utc "(..)(..)(..)")]
+              (+ s (* m 60) (* h 60 60)))
+            }
+           )
+          { : speed-knots }
+          (update-app-state { :speed (* speed-knots knot-in-m-s) }))
+        (when message.bearing-true
+          (let [c1 message.bearing-true
+                c2 (. app-state.courses 1)
+                c3 (. app-state.courses 2)]
             (update-app-state
-             {
-              : lat : lon
-              :time-of-day
-              (let [(h m s) (string.match utc "(..)(..)(..)")]
-                (+ s (* m 60) (* h 60 60)))
-              }
-             )
-            { : speed-knots }
-            (update-app-state { :speed (* speed-knots knot-in-m-s) }))
-          (when message.bearing-true
-            (let [c1 message.bearing-true
-                  c2 (. app-state.courses 1)
-                  c3 (. app-state.courses 2)]
-              (update-app-state
-               { :course (clamp c1 c2 c3)
-                 :courses [c1 c2 c3]
-                 }))))))
-  true)
+             { :course (clamp c1 c2 c3)
+               :courses [c1 c2 c3]
+               }))))))
 
 (fn collect-profile []
   (GLib.timeout_add
@@ -488,17 +486,11 @@ label.readout {
   (profile.start 0))
 
 (fn watch-gnss-socket [socket-path]
-  (let [gnss-socket
-        (let [addr (Gio.UnixSocketAddress {
-                                           :path socket-path
-                                           })]
-          (: (Gio.SocketClient) :connect addr nil))
-        sock (gnss-socket:get_socket)
-        fd (sock:get_fd)
-        events [ GLib.IOCondition.IN GLib.IOCondition.HUP]
-        channel (GLib.IOChannel.unix_new fd)
-        handle (fdopen fd :r)]
-    (GLib.io_add_watch channel 0 events #(read-gnss handle))))
+  (let [sock (socket.connect { :path socket-path :unlink true })]
+    (cq:wrap
+     #(each [l (sock:lines "*L")]
+        (read-gnss-sentence l)))))
+
 
 (fn run [gnss-socket]
   (watch-gnss-socket (or gnss-socket "/var/run/gnss-share.sock"))