lib/base/filepush.cpp

   1 #include <config.h>
   2 #include <lib/base/filepush.h>
   3 #include <lib/base/eerror.h>
   4 #include <errno.h>
   5 #include <fcntl.h>
   6
   7 eFilePushThread::eFilePushThread()
   8 {
   9         m_stop = 0;
  10         flush();
  11 }
  12
  13 static void signal_handler(int x)
  14 {
  15 }
  16
  17 void eFilePushThread::thread()
  18 {
  19         off_t dest_pos = 0;
  20         eDebug("FILEPUSH THREAD START");
  21                 // this is a race. FIXME.
  22
  23                 /* we set the signal to not restart syscalls, so we can detect our signal. */
  24         struct sigaction act;
  25         act.sa_handler = signal_handler; // no, SIG_IGN doesn't do it. we want to receive the -EINTR
  26         act.sa_flags = 0;
  27         sigaction(SIGUSR1, &act, 0);
  28
  29         dest_pos = lseek(m_fd_dest, 0, SEEK_CUR);
  30                 /* m_stop must be evaluated after each syscall. */
  31         while (!m_stop)
  32         {
  33                         /* first try flushing the bufptr */
  34                 if (m_buf_start != m_buf_end)
  35                 {
  36                                 // TODO: take care of boundaries.
  37                         int w = write(m_fd_dest, m_buffer + m_buf_start, m_buf_end - m_buf_start);
  38                         eDebug("wrote %d bytes", w);
  39                         if (w <= 0)
  40                         {
  41                                 if (errno == -EINTR)
  42                                         continue;
  43                                 eDebug("eFilePushThread *write error* - not yet handled");
  44                                 // ... we would stop the thread
  45                         }
  46
  47                                 /* this should flush all written pages to disk. */
  48                         posix_fadvise(m_fd_dest, dest_pos, w, POSIX_FADV_DONTNEED);
  49
  50                         dest_pos += w;
  51 //                      printf("FILEPUSH: wrote %d bytes\n", w);
  52                         m_buf_start += w;
  53                         continue;
  54                 }
  55
  56                         /* now fill our buffer. */
  57                 m_buf_start = 0;
  58                 m_buf_end = read(m_fd_source, m_buffer, sizeof(m_buffer));
  59                 if (m_buf_end < 0)
  60                 {
  61                         m_buf_end = 0;
  62                         if (errno == EINTR)
  63                                 continue;
  64                         eDebug("eFilePushThread *read error* - not yet handled");
  65                 }
  66                 if (m_buf_end == 0)
  67                 {
  68                         eDebug("FILEPUSH: end-of-file! (currently unhandled)");
  69                         if (!lseek(m_fd_source, 0, SEEK_SET))
  70                         {
  71                                 eDebug("(looping)");
  72                                 continue;
  73                         }
  74                         break;
  75                 }
  76 //              printf("FILEPUSH: read %d bytes\n", m_buf_end);
  77         }
  78
  79         eDebug("FILEPUSH THREAD STOP");
  80 }
  81
  82 void eFilePushThread::start(int fd_source, int fd_dest)
  83 {
  84         m_fd_source = fd_source;
  85         m_fd_dest = fd_dest;
  86         resume();
  87 }
  88
  89 void eFilePushThread::stop()
  90 {
  91         m_stop = 1;
  92         sendSignal(SIGUSR1);
  93         kill();
  94 }
  95
  96 void eFilePushThread::pause()
  97 {
  98         stop();
  99 }
 100
 101 void eFilePushThread::seek(int whence, off_t where)
 102 {
 103         ::lseek(m_fd_source, where, whence);
 104 }
 105
 106 void eFilePushThread::resume()
 107 {
 108         m_stop = 0;
 109         run();
 110 }
 111
 112 void eFilePushThread::flush()
 113 {
 114         m_buf_start = m_buf_end = 0;
 115 }
 116