cosmopolitan/tool/build/lib/iovs.c

53 lines
2.6 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 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/str/str.h"
#include "tool/build/lib/iovs.h"
/**
* Appends memory region to i/o vector builder.
*/
int AppendIovs(struct Iovs *ib, void *base, size_t len) {
unsigned i, n;
struct iovec *p;
if (len) {
p = ib->p;
i = ib->i;
n = ib->n;
if (i && (intptr_t)base == (intptr_t)p[i - 1].iov_base + p[i - 1].iov_len) {
p[i - 1].iov_len += len;
} else {
if (__builtin_expect(i == n, 0)) {
n += n >> 1;
if (p == ib->init) {
if (!(p = malloc(sizeof(struct iovec) * n))) return -1;
memcpy(p, ib->init, sizeof(ib->init));
} else {
if (!(p = realloc(p, sizeof(struct iovec) * n))) return -1;
}
ib->p = p;
ib->n = n;
}
p[i].iov_base = base;
p[i].iov_len = len;
++ib->i;
}
}
return 0;
}