From: Scott Worley <scottworley@scottworley.com>
Date: Tue, 10 Oct 2023 08:14:15 +0000 (-0700)
Subject: client: Make the queue size bounds configurable
X-Git-Tag: v0.1.0~29
X-Git-Url: http://git.scottworley.com/tattlekey/commitdiff_plain/a36c278f05a806c9ced1a96b04eae0e6b9d8a5d5?ds=sidebyside

client: Make the queue size bounds configurable
---

diff --git a/client/config.c b/client/config.c
index 8a31cf5..0e1a86d 100644
--- a/client/config.c
+++ b/client/config.c
@@ -24,3 +24,18 @@ u32_t config_minimum_seconds_between_button_presses = 1;
 
 /* Send each report multiple times. */
 uint config_resend_count = 5;
+
+/* These control the size of the per-send-count press queues.
+When the button is pressed more than config_maximum_queue_size times
+within the resend interval, some presses will be reported fewer
+than config_resend_count times. This is usually fine because it's
+the old, longest-delayed, most-redundant reports that get dropped;
+fresh, timely reports of new button presses will not get anywhere near
+config_resend_count in a resend interval because the early resend internals
+are so short.  */
+uint config_maximum_queue_size = 512;
+
+/* This is paranoia about unanticipated delays.  Setting this to zero
+would probably be fine, but imposing a minimum queue size is an easy
+safety measure. */
+uint config_minimum_queue_size = 32;
diff --git a/client/config.h b/client/config.h
index 744e586..23f04d5 100644
--- a/client/config.h
+++ b/client/config.h
@@ -28,4 +28,19 @@ extern u32_t config_minimum_seconds_between_button_presses;
 /* Send each report multiple times. */
 extern uint config_resend_count;
 
+/* These control the size of the per-send-count press queues.
+When the button is pressed more than config_maximum_queue_size times
+within the resend interval, some presses will be reported fewer
+than config_resend_count times. This is usually fine because it's
+the old, longest-delyed, most-redundant reports that get dropped;
+fresh, timely reports of new button presses will not get anywhere near
+config_resend_count in a resend interval because the early resend interals
+are so short.  */
+extern uint config_maximum_queue_size;
+
+/* This is paranoia about unanticipated delays.  Setting this to zero
+would pobably be fine, but imposing a minimum queue size is an easy
+safety measure. */
+extern uint config_minimum_queue_size;
+
 #endif
diff --git a/client/press.c b/client/press.c
index cec1709..6c46ae9 100644
--- a/client/press.c
+++ b/client/press.c
@@ -29,9 +29,10 @@ press_pile_t *create_press_pile() {
   pp->presses = (queue_t *)xcalloc(config_resend_count, sizeof(queue_t));
   pp->sleeps = (queue_t **)xcalloc(config_resend_count, sizeof(queue_t *));
   for (int i = 0; i < config_resend_count; i++) {
-    uint element_count = 1 << i;
-    element_count = MAX(element_count, 32);
-    element_count = MIN(element_count, 512);
+    const uint paranoid_safety_fudge = 10;
+    uint element_count = paranoid_safety_fudge + (1 << i);
+    element_count = MAX(element_count, config_minimum_queue_size);
+    element_count = MIN(element_count, config_maximum_queue_size);
     queue_init(&pp->presses[i], sizeof(press_t), element_count);
   }
   pp->sleeps_heap =