aboutsummaryrefslogtreecommitdiff
path: root/array.c
blob: 7120899a2ab656d9966c348d004174f145671f97 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "array.h"


array_info* array_new_(size_t item_size, size_t size) {
	// find capacity
	size_t cap = 8;
	if (size > cap) {
		cap = size;

		// round up to next power of 2
		cap--;
		cap |= cap >> 1;
		cap |= cap >> 2;
		cap |= cap >> 4;
		cap |= cap >> 8;
		cap |= cap >> 16;
		cap++;
	}

	// make array
    array_info* info = calloc(1, sizeof(array_info) + item_size * cap);
	info->size = size;
    info->capacity = cap;
    return info;
}

void* array_add_(void* array, size_t item_size) {
    array_info* info = NULL;
    if (!array) {
        info = array_new_(item_size, 0);
    }
    else {
        info = ((array_info*)array) - 1;
    }
    if (info->size == info->capacity) {
        info->capacity <<= 1;
        info = realloc(info, sizeof(array_info) + (info->capacity * item_size));
    }
    info->size++;
    return &(info[1]);
}

void array_print(void* array) {
    array_info* info = &((array_info*)array)[-1];
    printf( "size: %lu\n"
           "capacity: %lu\n"
           "array: %p\n",
           info->size,
           info->capacity,
           info->array);
}

void array_pop(void* array) {
    array_info* info = &((array_info*)array)[-1];
    if (info->size)
        info->size--;
}