Load cups into easysw/current.

[thirdparty/cups.git] / backend / runloop.c

diff --git a/backend/runloop.c b/backend/runloop.c
index fd0bb8f0499ac6b5b71518dd7bcbafa1e5678841..647c794889a39e1c060d5a184e25d09078025c1e 100644 (file)
--- a/backend/runloop.c
+++ b/backend/runloop.c
@@ -1,7 +1,7 @@
 /*
- * "$Id: runloop.c 6498 2007-04-30 21:40:33Z mike $"
+ * "$Id: runloop.c 6591 2007-06-21 20:35:28Z mike $"
  *
- *   Common run loop API for the Common UNIX Printing System (CUPS).
+ *   Common run loop APIs for the Common UNIX Printing System (CUPS).
  *
  *   Copyright 2006-2007 by Easy Software Products, all rights reserved.
  *
@@ -25,7 +25,8 @@
  *
  * Contents:
  *
- *   backendRunLoop() - Read and write print and back-channel data.
+ *   backendDrainOutput() - Drain pending print data to the device.
+ *   backendRunLoop()     - Read and write print and back-channel data.
  */
 
 /*
@@ -40,6 +41,109 @@
 #endif /* __hpux */
 
 
+/*
+ * 'backendDrainOutput()' - Drain pending print data to the device.
+ */
+
+int                                    /* O - 0 on success, -1 on error */
+backendDrainOutput(int print_fd,       /* I - Print file descriptor */
+                   int device_fd)      /* I - Device file descriptor */
+{
+  int          nfds;                   /* Maximum file descriptor value + 1 */
+  fd_set       input;                  /* Input set for reading */
+  ssize_t      print_bytes,            /* Print bytes read */
+               bytes;                  /* Bytes written */
+  char         print_buffer[8192],     /* Print data buffer */
+               *print_ptr;             /* Pointer into print data buffer */
+  struct timeval timeout;              /* Timeout for read... */
+
+
+  fprintf(stderr, "DEBUG: backendDrainOutput(print_fd=%d, device_fd=%d)\n",
+          print_fd, device_fd);
+
+ /*
+  * Figure out the maximum file descriptor value to use with select()...
+  */
+
+  nfds = (print_fd > device_fd ? print_fd : device_fd) + 1;
+
+ /*
+  * Now loop until we are out of data from print_fd...
+  */
+
+  for (;;)
+  {
+   /*
+    * Use select() to determine whether we have data to copy around...
+    */
+
+    FD_ZERO(&input);
+    FD_SET(print_fd, &input);
+
+    timeout.tv_sec  = 0;
+    timeout.tv_usec = 0;
+
+    if (select(nfds, &input, NULL, NULL, &timeout) < 0)
+      return (-1);
+
+    if (!FD_ISSET(print_fd, &input))
+      return (0);
+
+    if ((print_bytes = read(print_fd, print_buffer,
+                           sizeof(print_buffer))) < 0)
+    {
+     /*
+      * Read error - bail if we don't see EAGAIN or EINTR...
+      */
+
+      if (errno != EAGAIN || errno != EINTR)
+      {
+       perror("ERROR: Unable to read print data");
+       return (-1);
+      }
+
+      print_bytes = 0;
+    }
+    else if (print_bytes == 0)
+    {
+     /*
+      * End of file, return...
+      */
+
+      return (0);
+    }
+
+    fprintf(stderr, "DEBUG: Read %d bytes of print data...\n",
+           (int)print_bytes);
+
+    for (print_ptr = print_buffer; print_bytes > 0;)
+    {
+      if ((bytes = write(device_fd, print_ptr, print_bytes)) < 0)
+      {
+       /*
+        * Write error - bail if we don't see an error we can retry...
+       */
+
+        if (errno != ENOSPC && errno != ENXIO && errno != EAGAIN &&
+           errno != EINTR && errno != ENOTTY)
+       {
+         fprintf(stderr, _("ERROR: Unable to write print data: %s\n"),
+                 strerror(errno));
+         return (-1);
+       }
+      }
+      else
+      {
+        fprintf(stderr, "DEBUG: Wrote %d bytes of print data...\n", (int)bytes);
+
+        print_bytes -= bytes;
+       print_ptr   += bytes;
+      }
+    }
+  }
+}
+
+
 /*
  * 'backendRunLoop()' - Read and write print and back-channel data.
  */
@@ -69,8 +173,9 @@ backendRunLoop(
 
 
   fprintf(stderr,
-          "DEBUG: backendRunLoop(print_fd=%d, device_fd=%d, use_bc=%d)\n",
-          print_fd, device_fd, use_bc);
+          "DEBUG: backendRunLoop(print_fd=%d, device_fd=%d, use_bc=%d, "
+         "side_cb=%p)\n",
+          print_fd, device_fd, use_bc, side_cb);
 
  /*
   * If we are printing data from a print driver on stdin, ignore SIGTERM
@@ -278,5 +383,5 @@ backendRunLoop(
 
 
 /*
- * End of "$Id: runloop.c 6498 2007-04-30 21:40:33Z mike $".
+ * End of "$Id: runloop.c 6591 2007-06-21 20:35:28Z mike $".
  */