cosmopolitan/libc/stdio/fflush.c

107 lines
3.7 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 │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program is distributed in the hope that it will be useful, but │
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/alg/arraylist.internal.h"
#include "libc/bits/bits.h"
#include "libc/bits/pushpop.h"
#include "libc/calls/calls.h"
#include "libc/macros.h"
#include "libc/mem/mem.h"
#include "libc/runtime/runtime.h"
#include "libc/stdio/internal.h"
#include "libc/stdio/stdio.h"
#include "libc/sysv/consts/o.h"
struct StdioFlushHandles {
size_t i, n;
FILE **p;
};
struct StdioFlush {
struct StdioFlushHandles handles;
FILE *handles_initmem[8];
};
static struct StdioFlush g_fflush;
/**
* Blocks until data from stream buffer is written out.
*
* @param f is the stream handle
* @return number of bytes written or -1 on error
*/
int fflush(FILE *f) {
size_t i;
int res, wrote;
res = 0;
if (!f) {
for (i = g_fflush.handles.i; i; --i) {
if ((f = g_fflush.handles.p[i - 1])) {
if ((wrote = fflush(f)) != -1) {
res += wrote;
} else {
res = -1;
break;
}
}
}
} else if (f->fd != -1) {
while (!f->state && f->beg && !f->end) {
if ((wrote = __fwritebuf(f)) != -1) {
res += wrote;
}
}
} else if (f->beg && f->beg < f->size) {
f->buf[f->beg] = 0;
}
return res;
}
textstartup int _fflushregister(FILE *f) {
size_t i;
struct StdioFlush *sf;
sf = &g_fflush;
sf = sf;
if (!sf->handles.p) {
sf->handles.p = &sf->handles_initmem[0];
pushmov(&sf->handles.n, ARRAYLEN(sf->handles_initmem));
__cxa_atexit(fflush, NULL, NULL);
}
for (i = sf->handles.i; i; --i) {
if (!sf->handles.p[i - 1]) {
sf->handles.p[i - 1] = f;
return 0;
}
}
return append(&sf->handles, &f);
}
void _fflushunregister(FILE *f) {
size_t i;
struct StdioFlush *sf;
sf = &g_fflush;
sf = pushpop(sf);
for (i = sf->handles.i; i; --i) {
if (sf->handles.p[i - 1] == f) {
pushmov(&sf->handles.p[i - 1], NULL);
return;
}
}
}