client: Explain the exponential re-send delay

[tattlekey] / client / press.h

diff --git a/client/press.h b/client/press.h
index cd34b3df0b48aeb4189e8b9a0b393347121281f6..cd0f81d5a04f8eaaaae9cae052976dc6807b69ff 100644 (file)
--- a/client/press.h
+++ b/client/press.h
@@ -1,8 +1,26 @@
+/* tattlekey: A one-key UDP keyboard
+ * Copyright (C) 2023  Scott Worley <scottworley@scottworley.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
 #ifndef SENDS_H
 #define SENDS_H
 
 #include "pico/cyw43_arch.h"
 #include "pico/util/pheap.h"
+#include "pico/util/queue.h"
 
 typedef struct {
   uint32_t timestamp;
@@ -11,16 +29,32 @@ typedef struct {
 } press_t;
 
 typedef struct {
-  press_t *presses;
+  /* Queues of various sizes that hold presses.  There is one queue for each
+   * send_count. */
+  queue_t *presses;
+
+  /* Tracks when each queue will be next ready-to-send.  Empty queues are not in
+   * the heap. */
   pheap_t *sleeps_heap;
+
+  /* The companion-array for the heap. */
+  queue_t **sleeps;
+
 } press_pile_t;
 
 press_pile_t *create_press_pile();
 
-void create_press(press_pile_t *pp, uint32_t timestamp, u16_t seq);
+/* Adds this press to the pile.
+ * Copies the contents of `press`. */
+void add_press(press_pile_t *pp, press_t *press);
 
 /* When do we next need to send something (in seconds since boot)?
  * Returns -1 if there's nothing pending. */
 int32_t next_scheduled_send(press_pile_t *pp);
 
+/* Find a press ready for resend at or before `now`.
+ * Move it out of the press-pile `pp` and into into `press`.
+ * Or return false if there is no press due for re-send. */
+bool get_press_due_for_resend(press_pile_t *pp, uint32_t now, press_t *press);
+
 #endif