Files
mars-libowfat/buffer/buffer_putflush.c
leitner b7b8a0efc1 gcc 15 and C23 force some union trickery on buffer.h :-(
add a few buffer_init*_forread variants to pretend we have type safety
  make sure buffer_init_staticcontents handles flushing attempts
2025-04-22 09:32:03 +00:00

65 lines
1.7 KiB
C

#ifndef __MINGW32__
#include <sys/types.h>
#include <sys/uio.h>
#include <errno.h>
#include <unistd.h>
#endif
#include "buffer.h"
#ifndef __unlikely
#ifdef __GNUC__
#define __unlikely(x) __builtin_expect((x),0)
#else
#define __unlikely(x) (x)
#endif
#endif
extern ssize_t buffer_stubborn(ssize_t (*op)(int fd,const char* buf,size_t len,void* cookie),int fd,const char* buf, size_t len,void* cookie);
int buffer_putflush(buffer* b,const char* x,size_t len) {
/* Since we know we are going to flush anyway, let's see if we can
* optimize a bit */
if (!b->p) { /* if the buffer is empty, just call buffer_stubborn directly */
ssize_t r = buffer_stubborn(b->op.wopc,b->fd,x,len,b);
if (r == -1 && errno==ENOENT) {
// tried to flush on buffer_init_staticcontents, ignore
} else {
if (r <= 0 || (size_t)r == len) return r; // common case
// partial write
x+=r;
len-=r;
// fall through
}
}
#ifndef __MINGW32__
if (b->op.wop==write && len>sizeof(struct iovec)*2) {
struct iovec v[2];
ssize_t w;
size_t cl=b->p+len;
v[0].iov_base=b->x;
v[0].iov_len=b->p;
v[1].iov_base=(char*)x;
v[1].iov_len=len;
while ((w=writev(b->fd,v,2))<0) {
if (errno == EINTR) continue;
return -1;
}
if (__unlikely((size_t)w!=cl)) {
/* partial write. ugh. */
if ((size_t)w<v[0].iov_len) {
if (buffer_stubborn(b->op.wopc,b->fd,v[0].iov_base+w,v[0].iov_len-w,b) ||
buffer_stubborn(b->op.wopc,b->fd,v[1].iov_base,v[0].iov_len,b)) return -1;
} else {
w-=v[0].iov_len;
return buffer_stubborn(b->op.wopc,b->fd,v[1].iov_base+w,v[1].iov_len-w,b);
}
}
b->p=0;
return 0;
}
#endif
if (buffer_put(b,x,len)<0) return -1;
if (buffer_flush(b)<0) return -1;
return 0;
}