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 #ifndef PAGE_SIZE
   8 #warning "your C library sucks."
   9 #define PAGE_SIZE 4096
  10 #endif
  11
  12 sblist* sblist_new(size_t itemsize, size_t blockitems) {
  13         sblist* ret = (sblist*) malloc(sizeof(sblist));
  14         sblist_init(ret, itemsize, blockitems);
  15         return ret;
  16 }
  17
  18 static void sblist_clear(sblist* l) {
  19         l->items = NULL;
  20         l->capa = 0;
  21         l->count = 0;
  22 }
  23
  24 void sblist_init(sblist* l, size_t itemsize, size_t blockitems) {
  25         if(l) {
  26                 l->blockitems = blockitems ? blockitems : PAGE_SIZE / itemsize;
  27                 l->itemsize = itemsize;
  28                 sblist_clear(l);
  29         }
  30 }
  31
  32 void sblist_free_items(sblist* l) {
  33         if(l) {
  34                 if(l->items) free(l->items);
  35                 sblist_clear(l);
  36         }
  37 }
  38
  39 void sblist_free(sblist* l) {
  40         if(l) {
  41                 sblist_free_items(l);
  42                 free(l);
  43         }
  44 }
  45
  46 char* sblist_item_from_index(sblist* l, size_t idx) {
  47         return l->items + (idx * l->itemsize);
  48 }
  49
  50 void* sblist_get(sblist* l, size_t item) {
  51         if(item < l->count) return (void*) sblist_item_from_index(l, item);
  52         return NULL;
  53 }
  54
  55 int sblist_set(sblist* l, void* item, size_t pos) {
  56         if(pos >= l->count) return 0;
  57         memcpy(sblist_item_from_index(l, pos), item, l->itemsize);
  58         return 1;
  59 }
  60
  61 int sblist_grow_if_needed(sblist* l) {
  62         char* temp;
  63         if(l->count == l->capa) {
  64                 temp = realloc(l->items, (l->capa + l->blockitems) * l->itemsize);
  65                 if(!temp) return 0;
  66                 l->capa += l->blockitems;
  67                 l->items = temp;
  68         }
  69         return 1;
  70 }
  71
  72 int sblist_add(sblist* l, void* item) {
  73         if(!sblist_grow_if_needed(l)) return 0;
  74         l->count++;
  75         return sblist_set(l, item, l->count - 1);
  76 }