compat_sendfile.h

   1 /*
   2  * Copyright (C) 2012-2020 all contributors <cmogstored-public@yhbt.net>
   3  * License: GPL-3.0+ <https://www.gnu.org/licenses/gpl-3.0.txt>
   4  */
   5 #ifndef HAVE_SENDFILE
   6 static ssize_t compat_sendfile(int sockfd, int filefd, off_t *off, size_t count)
   7 {
   8         size_t max_pread;
   9         void *buf = mog_fsbuf_get(&max_pread);
  10         ssize_t r;
  11         ssize_t w;
  12
  13         max_pread = MIN(max_pread, count);
  14         do {
  15                 r = off ? pread(filefd, buf, max_pread, *off) :
  16                         read(filefd, buf, max_pread);
  17         } while (r < 0 && errno == EINTR);
  18
  19         if (r <= 0)
  20                 return r;
  21
  22         w = write(sockfd, buf, r);
  23         if (w > 0 && off)
  24                 *off += w;
  25         return w;
  26 }
  27 # define sendfile(out_fd, in_fd, offset, count) \
  28          compat_sendfile((out_fd),(in_fd),(offset),(count))
  29 #endif