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/*
Copyright (C) 2019, 2020 Leo Tenenbaum.
This file is part of toc. toc is distributed under version 3 of the GNU General Public License, without any warranty whatsoever.
You should have received a copy of the GNU General Public License along with toc. If not, see <https://www.gnu.org/licenses/>.
*/
static void *err_malloc(size_t bytes);
static void *err_calloc(size_t n, size_t sz);
static void *err_realloc(void *prev, size_t new_size);
#ifdef TOC_DEBUG
#define NO_ALLOCATOR 1 /* useful for debugging; valgrind (maybe) checks writing past the end of a malloc, but that won't work with an allocator */
#endif
/* number of bytes a page hold, not including the header */
#define PAGE_BYTES (16384 - sizeof(Page))
#define PAGE_MAX_ALIGNS (PAGE_BYTES / sizeof(MaxAlign))
static void allocr_create(Allocator *a) {
a->first = a->last = NULL;
}
static void *allocr_malloc(Allocator *a, size_t bytes) {
#if NO_ALLOCATOR
(void)a;
return err_malloc(bytes);
#else
if (bytes == 0)
return NULL;
if (a == NULL)
return err_malloc(bytes);
/* position in this page to return */
size_t pos = PAGE_MAX_ALIGNS;
if (a->last)
pos = a->last->used;
size_t max_aligns = (bytes + sizeof(MaxAlign) - 1) / sizeof(MaxAlign);
if (pos + max_aligns > PAGE_MAX_ALIGNS) {
/* make a new page for this data */
Page *page = err_malloc(sizeof *page + (bytes > PAGE_BYTES ? bytes : PAGE_BYTES));
page->next = NULL;
page->used = max_aligns;
if (a->last)
a->last->next = page;
else
a->first = page;
a->last = page;
return page->data;
} else {
a->last->used += max_aligns;
return &a->last->data[pos];
}
#endif
}
static void *allocr_calloc(Allocator *a, size_t n, size_t sz) {
#if NO_ALLOCATOR
a = NULL;
#endif
if (n == 0 || sz == 0) return NULL;
if (a == NULL) return err_calloc(n, sz);
/* OPTIM: use calloc */
size_t bytes = n * sz;
void *data = allocr_malloc(a, bytes);
memset(data, 0, bytes);
return data;
}
static void allocr_free(Allocator *a, void *data, size_t size) {
#if NO_ALLOCATOR
a = NULL;
#endif
if (a == NULL) {
free(data);
}
/* OPTIM */
(void)size;
}
/* OPTIM */
static void *allocr_realloc(Allocator *a, void *data, size_t old_size, size_t new_size) {
#if NO_ALLOCATOR
a = NULL;
#endif
if (new_size == 0) {
allocr_free(a, data, old_size);
return NULL;
}
if (a == NULL) return err_realloc(data, new_size);
void *ret = allocr_malloc(a, new_size);
memcpy(ret, data, old_size);
return ret;
}
static void allocr_free_all(Allocator *a) {
for (Page *page = a->first; page;) {
Page *next = page->next;
free(page);
page = next;
}
}
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