From Jeff Morriss: avoid at least some N^2 behavior when changing the

time stamp format.

svn path=/trunk/; revision=9179

file.c

@@ -1,7 +1,7 @@
 /* file.c
  * File I/O routines
  *
- * $Id: file.c,v 1.326 2003/12/04 10:59:33 guy Exp $
+ * $Id: file.c,v 1.327 2003/12/06 04:05:02 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -1483,6 +1483,7 @@ change_time_formats(capture_file *cf)
   GTimeVal    start_time;
   gchar       status_str[100];
   int         first, last;
+  gboolean    sorted_by_frame_column;
 
   /* Are there any columns with time stamps in the "command-line-specified"
      format?
@@ -1511,6 +1512,27 @@ change_time_formats(capture_file *cf)
   /* Count of packets at which we've looked. */
   count = 0;
 
+  /*  If the rows are currently sorted by the frame column then we know
+   *  the row number of each packet: it's the row number of the previously
+   *  displayed packet + 1.
+   *
+   *  Otherwise, if the display is sorted by a different column then we have
+   *  to use the O(N) packet_list_find_row_from_data() (thus making the job
+   *  of changing the time display format O(N**2)).
+   *
+   *  (XXX - In fact it's still O(N**2) because gtk_clist_set_text() takes
+   *  the row number and walks that many elements down the clist to find
+   *  the appropriate element.)
+   */
+  sorted_by_frame_column = FALSE;
+  for (i = 0; i < cf->cinfo.num_cols; i++) {
+    if (cf->cinfo.col_fmt[i] == COL_NUMBER)
+    {
+      sorted_by_frame_column = (i == packet_list_get_sort_column());
+      break;
+    }
+  }
+
   stop_flag = FALSE;
   g_get_current_time(&start_time);
 
@@ -1518,7 +1540,7 @@ change_time_formats(capture_file *cf)
      is in a row of the summary list and, if so, whether there are
      any columns that show the time in the "command-line-specified"
      format and, if so, update that row. */
-  for (fdata = cf->plist; fdata != NULL; fdata = fdata->next) {
+  for (fdata = cf->plist, row = -1; fdata != NULL; fdata = fdata->next) {
     /* Update the progress bar, but do it only N_PROGBAR_UPDATES times;
        when we update it, we have to run the GTK+ main loop to get it
        to repaint what's pending, and doing so may involve an "ioctl()"
@@ -1558,7 +1580,20 @@ change_time_formats(capture_file *cf)
     count++;
 
     /* Find what row this packet is in. */
-    row = packet_list_find_row_from_data(fdata);
+    if (!sorted_by_frame_column) {
+      /* This function is O(N), so we try to avoid using it... */
+      row = packet_list_find_row_from_data(fdata);
+    } else {
+      /* ...which we do by maintaining a count of packets that are
+         being displayed (i.e., that have passed the display filter),
+         and using the current value of that count as the row number
+         (which is why we can only do it when the display is sorted
+         by the frame number). */
+      if (fdata->flags.passed_dfilter)
+	row++;
+      else
+	continue;
+    }
 
     if (row != -1) {
       /* This packet is in the summary list, on row "row". */

gtk/packet_list.c

@@ -1,7 +1,7 @@
 /* packet_list.c
  * packet list related functions   2002 Olivier Abad
  *
- * $Id: packet_list.c,v 1.5 2002/11/15 22:21:15 oabad Exp $
+ * $Id: packet_list.c,v 1.6 2003/12/06 04:05:02 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -173,3 +173,10 @@ packet_list_set_selected_row(gint row)
 
     gtk_clist_select_row(GTK_CLIST(packet_list), row, -1);
 }
+
+/* Return the column number that the clist is currently sorted by */
+gint
+packet_list_get_sort_column(void)
+{
+    return GTK_CLIST(packet_list)->sort_column;
+}

ui_util.h

@@ -1,13 +1,12 @@
 /* ui_util.h
  * Definitions for UI utility routines
  *
- * $Id: ui_util.h,v 1.12 2002/09/23 19:09:47 oabad Exp $
+ * $Id: ui_util.h,v 1.13 2003/12/06 04:05:02 guy Exp $
  *
  * Ethereal - Network traffic analyzer
- * By Gerald Combs <gerald@zing.org>
+ * By Gerald Combs <gerald@ethereal.com>
  * Copyright 1998 Gerald Combs
  *
- *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * as published by the Free Software Foundation; either version 2
@@ -49,6 +48,7 @@ void packet_list_set_text(gint, gint, const gchar *);
 void packet_list_set_cls_time_width(gint);
 gpointer packet_list_get_row_data(gint);
 void packet_list_set_selected_row(gint);
+gint packet_list_get_sort_column(void);
 
 /* create byte views in the main window */
 void add_main_byte_views(epan_dissect_t *edt);