sblist.c

   1 #undef _POSIX_C_SOURCE
   2 #define _POSIX_C_SOURCE 200809L
   3 #include "sblist.h"
   4 #include <limits.h>
   5 #include <stdlib.h>
   6 #include <string.h>
   7 #define MY_PAGE_SIZE 4096
   8
   9 sblist* sblist_new(size_t itemsize, size_t blockitems) {
  10         sblist* ret = (sblist*) malloc(sizeof(sblist));
  11         sblist_init(ret, itemsize, blockitems);
  12         return ret;
  13 }
  14
  15 static void sblist_clear(sblist* l) {
  16         l->items = NULL;
  17         l->capa = 0;
  18         l->count = 0;
  19 }
  20
  21 void sblist_init(sblist* l, size_t itemsize, size_t blockitems) {
  22         if(l) {
  23                 l->blockitems = blockitems ? blockitems : MY_PAGE_SIZE / itemsize;
  24                 l->itemsize = itemsize;
  25                 sblist_clear(l);
  26         }
  27 }
  28
  29 void sblist_free_items(sblist* l) {
  30         if(l) {
  31                 if(l->items) free(l->items);
  32                 sblist_clear(l);
  33         }
  34 }
  35
  36 void sblist_free(sblist* l) {
  37         if(l) {
  38                 sblist_free_items(l);
  39                 free(l);
  40         }
  41 }
  42
  43 char* sblist_item_from_index(sblist* l, size_t idx) {
  44         return l->items + (idx * l->itemsize);
  45 }
  46
  47 void* sblist_get(sblist* l, size_t item) {
  48         if(item < l->count) return (void*) sblist_item_from_index(l, item);
  49         return NULL;
  50 }
  51
  52 int sblist_set(sblist* l, void* item, size_t pos) {
  53         if(pos >= l->count) return 0;
  54         memcpy(sblist_item_from_index(l, pos), item, l->itemsize);
  55         return 1;
  56 }
  57
  58 int sblist_grow_if_needed(sblist* l) {
  59         char* temp;
  60         if(l->count == l->capa) {
  61                 temp = realloc(l->items, (l->capa + l->blockitems) * l->itemsize);
  62                 if(!temp) return 0;
  63                 l->capa += l->blockitems;
  64                 l->items = temp;
  65         }
  66         return 1;
  67 }
  68
  69 int sblist_add(sblist* l, void* item) {
  70         if(!sblist_grow_if_needed(l)) return 0;
  71         l->count++;
  72         return sblist_set(l, item, l->count - 1);
  73 }