ms.c

   1 #include <stdint.h>
   2 #include <string.h>
   3 #include <stdlib.h>
   4 #include "dat.h"
   5
   6 void
   7 ms_init(ms a, ms_event_fn oninsert, ms_event_fn onremove)
   8 {
   9     a->used = a->cap = a->last = 0;
  10     a->items = NULL;
  11     a->oninsert = oninsert;
  12     a->onremove = onremove;
  13 }
  14
  15 static void
  16 grow(ms a)
  17 {
  18     void **nitems;
  19     size_t ncap = (a->cap << 1) ? : 1;
  20
  21     nitems = malloc(ncap * sizeof(void *));
  22     if (!nitems) return;
  23
  24     memcpy(nitems, a->items, a->used * sizeof(void *));
  25     free(a->items);
  26     a->items = nitems;
  27     a->cap = ncap;
  28 }
  29
  30 int
  31 ms_append(ms a, void *item)
  32 {
  33     if (a->used >= a->cap) grow(a);
  34     if (a->used >= a->cap) return 0;
  35
  36     a->items[a->used++] = item;
  37     if (a->oninsert) a->oninsert(a, item, a->used - 1);
  38     return 1;
  39 }
  40
  41 static int
  42 ms_delete(ms a, size_t i)
  43 {
  44     void *item;
  45
  46     if (i >= a->used) return 0;
  47     item = a->items[i];
  48     a->items[i] = a->items[--a->used];
  49
  50     /* it has already been removed now */
  51     if (a->onremove) a->onremove(a, item, i);
  52     return 1;
  53 }
  54
  55 void
  56 ms_clear(ms a)
  57 {
  58     while (ms_delete(a, 0));
  59     free(a->items);
  60     ms_init(a, a->oninsert, a->onremove);
  61 }
  62
  63 int
  64 ms_remove(ms a, void *item)
  65 {
  66     size_t i;
  67
  68     for (i = 0; i < a->used; i++) {
  69         if (a->items[i] == item) return ms_delete(a, i);
  70     }
  71     return 0;
  72 }
  73
  74 int
  75 ms_contains(ms a, void *item)
  76 {
  77     size_t i;
  78
  79     for (i = 0; i < a->used; i++) {
  80         if (a->items[i] == item) return 1;
  81     }
  82     return 0;
  83 }
  84
  85 void *
  86 ms_take(ms a)
  87 {
  88     void *item;
  89
  90     if (!a->used) return NULL;
  91
  92     a->last = a->last % a->used;
  93     item = a->items[a->last];
  94     ms_delete(a, a->last);
  95     ++a->last;
  96     return item;
  97 }