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#include "__stdio.h" // for __FILE, _IO_ERR
#include "stddef.h" // for NULL
#include <atomic.h> // for LIBC_UNLOCK, LIBC_LOCK
#include <errno.h> // for errno, EOVERFLOW, EBADF, EINVAL, EIO
#include <fcntl.h> // for O_ACCMODE, O_RDONLY
#include <stdio.h> // for fflush, fwrite, BUFSIZ, FILE, _IOFBF, _IOLBF
#include <string.h> // for memcpy, memchr
#include <unistd.h> // for size_t, ssize_t, write
char __stdout_buffer[BUFSIZ];
void (*__stdio_cleanup)(void);
size_t fwrite(const void *restrict ptr, size_t size, size_t nitems,
FILE *restrict stream)
{
size_t total_bytes;
size_t written = 0;
const char *data = (const char *)ptr;
if (ptr == NULL || stream == NULL || size == 0) {
if (size == 0) {
return nitems;
}
errno = EINVAL;
return 0;
}
if (__FILE(stream)->fd == -1 && __FILE(stream)->buf != NULL) {
if (__builtin_mul_overflow(size, nitems, &total_bytes)) {
errno = EOVERFLOW;
return 0;
}
size_t space_left =
__FILE(stream)->buf_size > __FILE(stream)->buf_len ?
__FILE(stream)->buf_size -
__FILE(stream)->buf_len - 1 :
0;
if (space_left == 0) {
return 0;
}
size_t to_copy = total_bytes < space_left ? total_bytes :
space_left;
if (to_copy > 0) {
memcpy(__FILE(stream)->buf + __FILE(stream)->buf_len,
data, to_copy);
__FILE(stream)->buf_len += to_copy;
}
return to_copy == total_bytes ? nitems : to_copy / size;
}
if (__builtin_mul_overflow(size, nitems, &total_bytes)) {
errno = EOVERFLOW;
return 0;
}
if ((__FILE(stream)->flags & O_ACCMODE) == O_RDONLY) {
errno = EBADF;
return 0;
}
if (__FILE(stream)->flags & _IO_ERR) {
errno = EIO;
return 0;
}
LIBC_LOCK(__FILE(stream)->lock);
if (__FILE(stream)->type == _IONBF) {
ssize_t result = write(__FILE(stream)->fd, data, total_bytes);
LIBC_UNLOCK(__FILE(stream)->lock);
if (result < 0) {
__FILE(stream)->flags |= _IO_ERR;
return 0;
}
return result == (ssize_t)total_bytes ? nitems : result / size;
}
size_t remaining = total_bytes;
while (remaining > 0) {
size_t space_available =
__FILE(stream)->buf_size - __FILE(stream)->buf_len;
if (space_available == 0) {
LIBC_UNLOCK(__FILE(stream)->lock);
if (fflush(stream) != 0) {
return written / size;
}
space_available = __FILE(stream)->buf_size;
}
size_t to_copy = remaining < space_available ? remaining :
space_available;
memcpy(__FILE(stream)->buf + __FILE(stream)->buf_len,
data + written, to_copy);
__FILE(stream)->buf_len += to_copy;
written += to_copy;
remaining -= to_copy;
if (__FILE(stream)->type == _IOLBF) {
char *newline_pos = memchr(
__FILE(stream)->buf + __FILE(stream)->buf_len -
to_copy,
'\n', to_copy);
if (newline_pos != NULL) {
LIBC_UNLOCK(__FILE(stream)->lock);
if (fflush(stream) != 0) {
return written / size;
}
}
}
else if (__FILE(stream)->type == _IOFBF &&
__FILE(stream)->buf_len == __FILE(stream)->buf_size) {
LIBC_UNLOCK(__FILE(stream)->lock);
if (fflush(stream) != 0) {
return written / size;
}
}
}
LIBC_UNLOCK(__FILE(stream)->lock);
return written == total_bytes ? nitems : written / size;
}
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