git.scottworley.com Git - tattlekey/blob - client/press.c

   1 /* tattlekey: A one-key UDP keyboard
   2  * Copyright (C) 2023  Scott Worley <scottworley@scottworley.com>
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "press.h"
  19 #include "blink.h"
  20 #include "config.h"
  21
  22 static uint32_t press_next_send(press_t *s) {
  23   return s->timestamp + (1 << s->send_count) - 1;
  24 }
  25
  26 static uint32_t press_queue_next_send(queue_t *q) {
  27   press_t press;
  28   return queue_try_peek(q, &press) ? press_next_send(&press) : UINT32_MAX;
  29 }
  30
  31 static bool next_send_less_than(void *user_data, pheap_node_id_t a,
  32                                 pheap_node_id_t b) {
  33   queue_t **sleeps = (queue_t **)user_data;
  34   return press_queue_next_send(sleeps[a]) < press_queue_next_send(sleeps[b]);
  35 }
  36
  37 static void *xcalloc(size_t nmemb, size_t size) {
  38   void *p = calloc(nmemb, size);
  39   if (p == NULL)
  40     signal_error_by_blinking();
  41   return p;
  42 }
  43
  44 press_pile_t *create_press_pile() {
  45   press_pile_t *pp = (press_pile_t *)xcalloc(1, sizeof(press_pile_t));
  46   pp->presses = (queue_t *)xcalloc(config_resend_count, sizeof(queue_t));
  47   pp->sleeps = (queue_t **)xcalloc(config_resend_count, sizeof(queue_t *));
  48   for (uint i = 0; i < config_resend_count; i++) {
  49     const uint paranoid_safety_fudge = 10;
  50     uint element_count = paranoid_safety_fudge + (1 << i);
  51     element_count = MAX(element_count, config_minimum_queue_size);
  52     element_count = MIN(element_count, config_maximum_queue_size);
  53     queue_init(&pp->presses[i], sizeof(press_t), element_count);
  54   }
  55   pp->sleeps_heap =
  56       ph_create(config_resend_count, next_send_less_than, pp->sleeps);
  57   if (pp->sleeps_heap == NULL)
  58     signal_error_by_blinking();
  59   return pp;
  60 }
  61
  62 void add_press(press_pile_t *pp, press_t *press) {
  63   u16_t sc = press->send_count;
  64   if (sc >= config_resend_count)
  65     signal_error_by_blinking();
  66   bool was_empty = queue_is_empty(&pp->presses[sc]);
  67   /* No error check; blithely continue if the queue was full. */
  68   queue_try_add(&pp->presses[sc], press);
  69   if (was_empty) {
  70     pheap_node_id_t i = ph_new_node(pp->sleeps_heap);
  71     pp->sleeps[i] = &pp->presses[sc];
  72     ph_insert_node(pp->sleeps_heap, i);
  73   }
  74 }
  75
  76 int32_t next_scheduled_send(press_pile_t *pp) {
  77   pheap_node_id_t i = ph_peek_head(pp->sleeps_heap);
  78   if (i == 0)
  79     return -1;
  80   return press_queue_next_send(pp->sleeps[i]);
  81 }
  82
  83 bool get_press_due_for_resend(press_pile_t *pp, uint32_t now, press_t *press) {
  84   pheap_node_id_t i = ph_peek_head(pp->sleeps_heap);
  85   if (i == 0 || press_queue_next_send(pp->sleeps[i]) > now)
  86     return false;
  87   if (!queue_try_remove(pp->sleeps[i], press))
  88     signal_error_by_blinking();
  89   bool became_empty = queue_is_empty(pp->sleeps[i]);
  90   if (ph_remove_head(pp->sleeps_heap, became_empty) != i)
  91     signal_error_by_blinking();
  92   if (became_empty) {
  93     pp->sleeps[i] = NULL;
  94   } else {
  95     ph_insert_node(pp->sleeps_heap, i);
  96   }
  97   return true;
  98 }