lib/base/filepush.cpp

   1 #include <lib/base/filepush.h>
   2 #include <lib/base/eerror.h>
   3 #include <errno.h>
   4 #include <fcntl.h>
   5
   6 eFilePushThread::eFilePushThread()
   7 {
   8         m_stop = 0;
   9         m_buf_start = m_buf_end = 0;
  10 }
  11
  12 static void signal_handler(int x)
  13 {
  14 }
  15
  16 void eFilePushThread::thread()
  17 {
  18         off_t dest_pos = 0;
  19         eDebug("FILEPUSH THREAD START");
  20                 // this is a race. FIXME.
  21
  22                 /* we set the signal to not restart syscalls, so we can detect our signal. */
  23         struct sigaction act;
  24         act.sa_handler = signal_handler; // no, SIG_IGN doesn't do it. we want to receive the -EINTR
  25         act.sa_flags = 0;
  26         sigaction(SIGUSR1, &act, 0);
  27
  28         dest_pos = lseek(m_fd_dest, 0, SEEK_CUR);
  29                 /* m_stop must be evaluated after each syscall. */
  30         while (!m_stop)
  31         {
  32                         /* first try flushing the bufptr */
  33                 if (m_buf_start != m_buf_end)
  34                 {
  35                                 // TODO: take care of boundaries.
  36                         int w = write(m_fd_dest, m_buffer + m_buf_start, m_buf_end - m_buf_start);
  37                         eDebug("wrote %d bytes", w);
  38                         if (w <= 0)
  39                         {
  40                                 if (errno == -EINTR)
  41                                         continue;
  42                                 eDebug("eFilePushThread *write error* - not yet handled");
  43                                 // ... we would stop the thread
  44                         }
  45
  46                                 /* this should flush all written pages to disk. */
  47                         posix_fadvise(m_fd_dest, dest_pos, w, POSIX_FADV_DONTNEED);
  48
  49                         dest_pos += w;
  50 //                      printf("FILEPUSH: wrote %d bytes\n", w);
  51                         m_buf_start += w;
  52                         continue;
  53                 }
  54
  55                         /* now fill our buffer. */
  56                 m_buf_start = 0;
  57                 m_buf_end = read(m_fd_source, m_buffer, sizeof(m_buffer));
  58                 if (m_buf_end < 0)
  59                 {
  60                         m_buf_end = 0;
  61                         if (errno == EINTR)
  62                                 continue;
  63                         eDebug("eFilePushThread *read error* - not yet handled");
  64                 }
  65                 if (m_buf_end == 0)
  66                 {
  67                         eDebug("FILEPUSH: end-of-file! (currently unhandled)");
  68                         if (!lseek(m_fd_source, 0, SEEK_SET))
  69                         {
  70                                 eDebug("(looping)");
  71                                 continue;
  72                         }
  73                         break;
  74                 }
  75 //              printf("FILEPUSH: read %d bytes\n", m_buf_end);
  76         }
  77
  78         eDebug("FILEPUSH THREAD STOP");
  79 }
  80
  81 void eFilePushThread::start(int fd_source, int fd_dest)
  82 {
  83         m_fd_source = fd_source;
  84         m_fd_dest = fd_dest;
  85         resume();
  86 }
  87
  88 void eFilePushThread::stop()
  89 {
  90         m_stop = 1;
  91         sendSignal(SIGUSR1);
  92         kill();
  93 }
  94
  95 void eFilePushThread::pause()
  96 {
  97         stop();
  98 }
  99
 100 void eFilePushThread::seek(off_t where)
 101 {
 102         ::lseek(m_fd_source, where, SEEK_SET);
 103 }
 104
 105 void eFilePushThread::resume()
 106 {
 107         m_stop = 0;
 108         run();
 109 }