cosmopolitan/libc/stdio/appendd.c
Jōshin e16a7d8f3b
flip et / noet in modelines
`et` means `expandtab`.

```sh
rg 'vi: .* :vi' -l -0 | \
  xargs -0 sed -i '' 's/vi: \(.*\) et\(.*\)  :vi/vi: \1 xoet\2:vi/'
rg 'vi: .*  :vi' -l -0 | \
  xargs -0 sed -i '' 's/vi: \(.*\)noet\(.*\):vi/vi: \1et\2  :vi/'
rg 'vi: .*  :vi' -l -0 | \
  xargs -0 sed -i '' 's/vi: \(.*\)xoet\(.*\):vi/vi: \1noet\2:vi/'
```
2023-12-07 22:17:11 -05:00

71 lines
3 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2021 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/dce.h"
#include "libc/macros.internal.h"
#include "libc/mem/mem.h"
#include "libc/stdio/append.h"
#include "libc/str/str.h"
#define W sizeof(size_t)
/**
* Appends data to buffer, e.g.
*
* char *b = 0;
* appendd(&b, "hello", 5);
* free(b);
*
* The resulting buffer is guaranteed to be NUL-terminated, i.e.
* `!b[appendz(b).i]` will be the case.
*
* @param s may contain nul characters and may be null if `l` is zero
* @param l is byte length of `s`
* @return bytes appended (always `l`) or -1 if `ENOMEM`
* @see appendz(b).i to get buffer length
* @note 20% faster than appends()
*/
ssize_t appendd(char **b, const void *s, size_t l) {
char *p;
size_t n;
struct appendz z;
z = appendz((p = *b));
n = ROUNDUP(z.i + l + 1, 8) + W;
if (n > z.n) {
if (!z.n) z.n = W * 2;
while (n > z.n) z.n += z.n >> 1;
z.n = ROUNDUP(z.n, W);
if ((p = realloc(p, z.n))) {
z.n = malloc_usable_size(p);
unassert(!(z.n & (W - 1)));
*b = p;
} else {
return -1;
}
}
if (l) {
*(char *)mempcpy(p + z.i, s, l) = 0;
} else {
p[z.i] = 0;
}
z.i += l;
if (!IsTiny() && W == 8) z.i |= (size_t)APPEND_COOKIE << 48;
*(size_t *)(p + z.n - W) = z.i;
return l;
}