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

   1 #include "press.h"
   2 #include "blink.h"
   3 #include "config.h"
   4
   5 static uint32_t press_next_send(press_t *s) {
   6   return s->timestamp + (1 << s->send_count) - 1;
   7 }
   8
   9 static uint32_t press_queue_next_send(queue_t *q) {
  10   press_t press;
  11   return queue_try_peek(q, &press) ? press_next_send(&press) : UINT32_MAX;
  12 }
  13
  14 static bool next_send_less_than(void *user_data, pheap_node_id_t a,
  15                                 pheap_node_id_t b) {
  16   queue_t **sleeps = (queue_t **)user_data;
  17   return press_queue_next_send(sleeps[a]) < press_queue_next_send(sleeps[b]);
  18 }
  19
  20 static void *xcalloc(size_t nmemb, size_t size) {
  21   void *p = calloc(nmemb, size);
  22   if (p == NULL)
  23     signal_error_by_blinking();
  24   return p;
  25 }
  26
  27 press_pile_t *create_press_pile() {
  28   press_pile_t *pp = (press_pile_t *)xcalloc(1, sizeof(press_pile_t));
  29   pp->presses = (queue_t *)xcalloc(config_resend_count, sizeof(queue_t));
  30   pp->sleeps = (queue_t **)xcalloc(config_resend_count, sizeof(queue_t *));
  31   for (int i = 0; i < config_resend_count; i++) {
  32     const uint paranoid_safety_fudge = 10;
  33     uint element_count = paranoid_safety_fudge + (1 << i);
  34     element_count = MAX(element_count, config_minimum_queue_size);
  35     element_count = MIN(element_count, config_maximum_queue_size);
  36     queue_init(&pp->presses[i], sizeof(press_t), element_count);
  37   }
  38   pp->sleeps_heap =
  39       ph_create(config_resend_count, next_send_less_than, pp->sleeps);
  40   if (pp->sleeps_heap == NULL)
  41     signal_error_by_blinking();
  42   return pp;
  43 }
  44
  45 void add_press(press_pile_t *pp, press_t *press) {
  46   int sc = press->send_count;
  47   if (sc >= config_resend_count)
  48     signal_error_by_blinking();
  49   bool was_empty = queue_is_empty(&pp->presses[sc]);
  50   /* No error check; blithely continue if the queue was full. */
  51   queue_try_add(&pp->presses[sc], press);
  52   if (was_empty) {
  53     pheap_node_id_t i = ph_new_node(pp->sleeps_heap);
  54     pp->sleeps[i] = &pp->presses[sc];
  55     ph_insert_node(pp->sleeps_heap, i);
  56   }
  57 }
  58
  59 int32_t next_scheduled_send(press_pile_t *pp) {
  60   pheap_node_id_t i = ph_peek_head(pp->sleeps_heap);
  61   if (i == 0)
  62     return -1;
  63   return press_queue_next_send(pp->sleeps[i]);
  64 }
  65
  66 bool get_press_due_for_resend(press_pile_t *pp, uint32_t now, press_t *press) {
  67   pheap_node_id_t i = ph_peek_head(pp->sleeps_heap);
  68   if (i == 0 || press_queue_next_send(pp->sleeps[i]) > now)
  69     return false;
  70   if (!queue_try_remove(pp->sleeps[i], press))
  71     signal_error_by_blinking();
  72   bool became_empty = queue_is_empty(pp->sleeps[i]);
  73   if (ph_remove_head(pp->sleeps_heap, became_empty) != i)
  74     signal_error_by_blinking();
  75   if (became_empty) {
  76     pp->sleeps[i] = NULL;
  77   } else {
  78     ph_insert_node(pp->sleeps_heap, i);
  79   }
  80   return true;
  81 }