cosmopolitan/libc/stdio/fputcfb.c

53 lines
2.4 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/stdio/internal.h"
#include "libc/stdio/stdio.h"
static noinline int slowpath(int c, FILE *f) {
if (f->beg < f->size) {
c &= 0xff;
f->buf[f->beg++] = c;
if (f->beg == f->size) {
if (f->writer) {
if (f->writer(f) == -1) return -1;
} else if (f->beg == f->size) {
f->beg = 0;
}
}
return c;
} else {
return __fseteof(f);
}
}
/**
* Writes byte to stream.
*
* @return c (as unsigned char) if written or -1 w/ errno
*/
noinstrument int fputcfb(int c, FILE *f) {
if (f->beg + 1 < f->size) {
c &= 0xff;
f->buf[f->beg++] = c;
return c;
} else {
return slowpath(c, f);
}
}