text: /* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 2; tab-width: 8 -*- */
  
  /* inotify-helper.c - Gnome VFS Monitor based on inotify.
  
     Copyright (C) 2005 John McCutchan
  
     The Gnome Library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public License as
     published by the Free Software Foundation; either version 2 of the
     License, or (at your option) any later version.
  
     The Gnome Library is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     Library General Public License for more details.
  
     You should have received a copy of the GNU Library General Public
     License along with the Gnome Library; see the file COPYING.LIB.  If not,
     write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
     Boston, MA 02111-1307, USA.
  
     Authors: 
  		 John McCutchan <john@johnmccutchan.com>
  */
  
  #include "config.h"
  #include <glib.h>
  #include "inotify-missing.h"
  #include "inotify-path.h"
  
  #define SCAN_MISSING_TIME 4 /* 1/4 Hz */
  
  static gboolean im_debug_enabled = FALSE;
  #define IM_W if (im_debug_enabled) g_warning
  
  /* We put inotify_sub's that are missing on this list */
  static GList *missing_sub_list = NULL;
  static gboolean im_scan_missing (gpointer user_data);
  static gboolean scan_missing_running = FALSE;
  static void (*missing_cb)(inotify_sub *sub) = NULL;
  
  G_LOCK_EXTERN (inotify_lock);
  
  /* inotify_lock must be held before calling */
  void
  _im_startup (void (*callback)(inotify_sub *sub))
  {
    static gboolean initialized = FALSE;
    
    if (!initialized)
      {
        missing_cb = callback;
        initialized = TRUE;
      }
  }
  
  /* inotify_lock must be held before calling */
  void
  _im_add (inotify_sub *sub)
  {
    if (g_list_find (missing_sub_list, sub))
      {
        IM_W ("asked to add %s to missing list but it's already on the list!\n", sub->dirname);
        return;
      }
  
    IM_W ("adding %s to missing list\n", sub->dirname);
    missing_sub_list = g_list_prepend (missing_sub_list, sub);
  
    /* If the timeout is turned off, we turn it back on */
    if (!scan_missing_running)
      {
        scan_missing_running = TRUE;
        g_timeout_add_seconds (SCAN_MISSING_TIME, im_scan_missing, NULL);
      }
  }
  
  /* inotify_lock must be held before calling */
  void
  _im_rm (inotify_sub *sub)
  {
    GList *link;
    
    link = g_list_find (missing_sub_list, sub);
  
    if (!link)
      {
        IM_W ("asked to remove %s from missing list but it isn't on the list!\n", sub->dirname);
        return;
      }
  
    IM_W ("removing %s from missing list\n", sub->dirname);
  
    missing_sub_list = g_list_remove_link (missing_sub_list, link);
    g_list_free_1 (link);
  }
  
  /* Scans the list of missing subscriptions checking if they
   * are available yet.
   */
  static gboolean
  im_scan_missing (gpointer user_data)
  {
    GList *nolonger_missing = NULL;
    GList *l;
    
    G_LOCK (inotify_lock);
    
    IM_W ("scanning missing list with %d items\n", g_list_length (missing_sub_list));
    for (l = missing_sub_list; l; l = l->next)
      {
        inotify_sub *sub = l->data;
        gboolean not_m = FALSE;
        
        IM_W ("checking %p\n", sub);
        g_assert (sub);
        g_assert (sub->dirname);
        not_m = _ip_start_watching (sub);
  
        if (not_m)
  	{
  	  missing_cb (sub);
  	  IM_W ("removed %s from missing list\n", sub->dirname);
  	  /* We have to build a list of list nodes to remove from the
  	   * missing_sub_list. We do the removal outside of this loop.
  	   */
  	  nolonger_missing = g_list_prepend (nolonger_missing, l);
  	} 
      }
  
    for (l = nolonger_missing; l ; l = l->next)
      {
        GList *llink = l->data;
        missing_sub_list = g_list_remove_link (missing_sub_list, llink);
        g_list_free_1 (llink);
      }
  
    g_list_free (nolonger_missing);
    
    /* If the missing list is now empty, we disable the timeout */
    if (missing_sub_list == NULL)
      {
        scan_missing_running = FALSE;
        G_UNLOCK (inotify_lock);
        return FALSE;
      }
    else
      {
        G_UNLOCK (inotify_lock);
        return TRUE;
      }
  }
  
  
  /* inotify_lock must be held */
  void
  _im_diag_dump (GIOChannel *ioc)
  {
    GList *l;
    g_io_channel_write_chars (ioc, "missing list:\n", -1, NULL, NULL);
    for (l = missing_sub_list; l; l = l->next)
      {
        inotify_sub *sub = l->data;
        g_io_channel_write_chars (ioc, sub->dirname, -1, NULL, NULL);
        g_io_channel_write_chars (ioc, "\n", -1, NULL, NULL);
      }
  }
  