ACE/ace/OS_NS_sys_sendfile.cpp

   1 #include "ace/OS_NS_sys_sendfile.h"
   2 #include "ace/OS_NS_sys_mman.h"
   3
   4 #if defined (ACE_WIN32)
   5 # include "ace/OS_NS_sys_socket.h"
   6 #endif  /* ACE_WIN32 */
   7
   8 #include "ace/OS_NS_unistd.h"
   9
  10 #ifndef ACE_HAS_INLINED_OSCALLS
  11 # include "ace/OS_NS_sys_sendfile.inl"
  12 #endif  /* ACE_HAS_INLINED_OSCALLS */
  13
  14 #include "ace/Malloc_Base.h"
  15 #include "ace/OS_Memory.h"
  16 #include "ace/os_include/os_errno.h"
  17
  18 ACE_BEGIN_VERSIONED_NAMESPACE_DECL
  19
  20 #if defined ACE_HAS_SENDFILE && ACE_HAS_SENDFILE == 0
  21 ssize_t
  22 ACE_OS::sendfile_emulation (ACE_HANDLE out_fd,
  23                             ACE_HANDLE in_fd,
  24                             off_t *offset,
  25                             size_t count)
  26 {
  27   // @@ Is it possible to inline a call to ::TransmitFile() on
  28   //    MS Windows instead of emulating here?
  29
  30   // @@ We may want set up a signal lease (or oplock) if supported by
  31   //    the platform so that we don't get a bus error if the mmap()ed
  32   //    file is truncated.
  33   void *buf = ACE_OS::mmap (0, count, PROT_READ, MAP_SHARED, in_fd, *offset);
  34   const bool use_read = buf == MAP_FAILED && errno == ENODEV;
  35   ACE_OFF_T prev_pos;
  36
  37   if (use_read)
  38     {
  39 # ifdef ACE_HAS_ALLOC_HOOKS
  40       ACE_ALLOCATOR_RETURN (buf,
  41                             ACE_Allocator::instance ()->malloc (count), -1);
  42 # else
  43       ACE_NEW_RETURN (buf, char[count], -1);
  44 # endif
  45       prev_pos = ACE_OS::lseek (in_fd, 0, SEEK_CUR);
  46       if (ACE_OS::lseek (in_fd, *offset, SEEK_SET) == -1
  47           || ACE_OS::read (in_fd, buf, count) == -1)
  48         return -1;
  49     }
  50   else if (buf == MAP_FAILED)
  51     return -1;
  52
  53 #if defined (ACE_WIN32)
  54   ssize_t const r =
  55     ACE_OS::send (out_fd, static_cast<const char *> (buf), count);
  56 #else
  57   ssize_t const r = ACE_OS::write (out_fd, buf, count);
  58 #endif /* ACE_WIN32 */
  59
  60   if (use_read)
  61     {
  62       ACE_OS::lseek (in_fd, prev_pos, SEEK_SET);
  63 # ifdef ACE_HAS_ALLOC_HOOKS
  64       ACE_Allocator::instance ()->free (buf);
  65 # else
  66       delete[] static_cast<char *> (buf);
  67 # endif
  68     }
  69   else
  70     (void) ACE_OS::munmap (buf, count);
  71
  72   if (r > 0)
  73     *offset += static_cast<off_t> (r);
  74
  75   return r;
  76 }
  77 #endif  /* ACE_HAS_SENDFILE==0 */
  78
  79 ACE_END_VERSIONED_NAMESPACE_DECL