Ruby

#if defined __linux__ && defined __NR_copy_file_range

# define USE_COPY_FILE_RANGE

#endif

#ifdef USE_COPY_FILE_RANGE

static ssize_t

simple_copy_file_range(int in_fd, off_t *in_offset, int out_fd, off_t *out_offset, size_t count, unsigned int flags)

{

return syscall(__NR_copy_file_range, in_fd, in_offset, out_fd, out_offset, count, flags);

}

static int

nogvl_copy_file_range(struct copy_stream_struct *stp)

{

struct stat src_stat, dst_stat;

ssize_t ss;

int ret;

off_t copy_length, src_offset, *src_offset_ptr;

ret = fstat(stp->src_fd, &src_stat);

if (ret == -1) {

stp->syserr = "fstat";

stp->error_no = errno;

return -1;

}

if (!S_ISREG(src_stat.st_mode))

return 0;

ret = fstat(stp->dst_fd, &dst_stat);

if (ret == -1) {

stp->syserr = "fstat";

stp->error_no = errno;

return -1;

}

src_offset = stp->src_offset;

if (src_offset != (off_t)-1) {

src_offset_ptr = &src_offset;

}

else {

src_offset_ptr = NULL; /* if src_offset_ptr is NULL, then bytes are read from in_fd starting from the file offset */

}

copy_length = stp->copy_length;

if (copy_length == (off_t)-1) {

if (src_offset == (off_t)-1) {

off_t current_offset;

errno = 0;

current_offset = lseek(stp->src_fd, 0, SEEK_CUR);

if (current_offset == (off_t)-1 && errno) {

stp->syserr = "lseek";

stp->error_no = errno;

return -1;

}

copy_length = src_stat.st_size - current_offset;

}

else {

copy_length = src_stat.st_size - src_offset;

}

}

retry_copy_file_range:

# if SIZEOF_OFF_T > SIZEOF_SIZE_T

/* we are limited by the 32-bit ssize_t return value on 32-bit */

ss = (copy_length > (off_t)SSIZE_MAX) ? SSIZE_MAX : (ssize_t)copy_length;

# else

ss = (ssize_t)copy_length;

# endif

ss = simple_copy_file_range(stp->src_fd, src_offset_ptr, stp->dst_fd, NULL, ss, 0);

if (0 < ss) {

stp->total += ss;

copy_length -= ss;

if (0 < copy_length) {

goto retry_copy_file_range;

}

}

if (ss == -1) {

if (maygvl_copy_stream_continue_p(0, stp)) {

goto retry_copy_file_range;

}

switch (errno) {

case EINVAL:

#ifdef ENOSYS

case ENOSYS:

#endif

#ifdef EXDEV

case EXDEV: /* in_fd and out_fd are not on the same filesystem */

#endif

return 0;

case EAGAIN:

#if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN

case EWOULDBLOCK:

#endif

if (nogvl_copy_stream_wait_write(stp) == -1)

return -1;

goto retry_copy_file_range;

}

stp->syserr = "copy_file_range";

stp->error_no = errno;

return -1;

}

return 1;

}

#endif

#ifdef USE_COPY_FILE_RANGE

ret = nogvl_copy_file_range(stp);

if (ret != 0)

goto finish; /* error or success */

#endif