cosmopolitan/libc/runtime/grow.c

67 lines
3.0 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=8 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/assert.h"
#include "libc/bits/bits.h"
#include "libc/bits/weaken.h"
#include "libc/fmt/conv.h"
#include "libc/macros.h"
#include "libc/mem/mem.h"
#include "libc/runtime/runtime.h"
#include "libc/str/str.h"
#include "libc/sysv/errfuns.h"
/* TODO(jart): DELETE */
#define GUARANTEE_TERMINATOR 1
#define INITIAL_CAPACITY (32 - GUARANTEE_TERMINATOR)
/**
* Grows array.
* @deprecated favor realloc
*/
bool __grow(void *pp, size_t *capacity, size_t itemsize, size_t extra) {
void **p, *p1, *p2;
size_t n1, n2;
size_t t1, t2;
extra += GUARANTEE_TERMINATOR;
p = (void **)pp;
assert(itemsize);
assert((*p && *capacity) || (!*p && !*capacity));
assert(!isheap(*p) || ((intptr_t)*p & 15) == 0);
p1 = isheap(*p) ? *p : NULL;
p2 = NULL;
n1 = *capacity;
n2 = (*p ? n1 + (n1 >> 1) : MAX(4, INITIAL_CAPACITY / itemsize)) + extra;
if (!__builtin_mul_overflow(n1, itemsize, &t1) &&
!__builtin_mul_overflow(n2, itemsize, &t2)) {
if (weaken(realloc) && (p2 = weaken(realloc)(p1, ROUNDUP(t2, 32)))) {
if (!p1 && *p) memcpy(p2, *p, t1);
memset((char *)p2 + t1, 0, t2 - t1);
*capacity = n2;
*p = p2;
return true;
} else {
enomem();
}
} else {
eoverflow();
}
return false;
}