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      1 /* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 2; tab-width: 8 -*- */
      2 
      3 /* inotify-helper.c - Gnome VFS Monitor based on inotify.
      4 
      5    Copyright (C) 2005 John McCutchan
      6 
      7    The Gnome Library is free software; you can redistribute it and/or
      8    modify it under the terms of the GNU Library General Public License as
      9    published by the Free Software Foundation; either version 2 of the
     10    License, or (at your option) any later version.
     11 
     12    The Gnome Library is distributed in the hope that it will be useful,
     13    but WITHOUT ANY WARRANTY; without even the implied warranty of
     14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     15    Library General Public License for more details.
     16 
     17    You should have received a copy of the GNU Library General Public
     18    License along with the Gnome Library; see the file COPYING.LIB.  If not,
     19    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
     20    Boston, MA 02111-1307, USA.
     21 
     22    Authors:
     23 		 John McCutchan <john (at) johnmccutchan.com>
     24 */
     25 
     26 #include "config.h"
     27 #include <glib.h>
     28 #include "inotify-missing.h"
     29 #include "inotify-path.h"
     30 
     31 #define SCAN_MISSING_TIME 4 /* 1/4 Hz */
     32 
     33 static gboolean im_debug_enabled = FALSE;
     34 #define IM_W if (im_debug_enabled) g_warning
     35 
     36 /* We put inotify_sub's that are missing on this list */
     37 static GList *missing_sub_list = NULL;
     38 static gboolean im_scan_missing (gpointer user_data);
     39 static gboolean scan_missing_running = FALSE;
     40 static void (*missing_cb)(inotify_sub *sub) = NULL;
     41 
     42 G_LOCK_EXTERN (inotify_lock);
     43 
     44 /* inotify_lock must be held before calling */
     45 void
     46 _im_startup (void (*callback)(inotify_sub *sub))
     47 {
     48   static gboolean initialized = FALSE;
     49 
     50   if (!initialized)
     51     {
     52       missing_cb = callback;
     53       initialized = TRUE;
     54     }
     55 }
     56 
     57 /* inotify_lock must be held before calling */
     58 void
     59 _im_add (inotify_sub *sub)
     60 {
     61   if (g_list_find (missing_sub_list, sub))
     62     {
     63       IM_W ("asked to add %s to missing list but it's already on the list!\n", sub->dirname);
     64       return;
     65     }
     66 
     67   IM_W ("adding %s to missing list\n", sub->dirname);
     68   missing_sub_list = g_list_prepend (missing_sub_list, sub);
     69 
     70   /* If the timeout is turned off, we turn it back on */
     71   if (!scan_missing_running)
     72     {
     73       scan_missing_running = TRUE;
     74       g_timeout_add_seconds (SCAN_MISSING_TIME, im_scan_missing, NULL);
     75     }
     76 }
     77 
     78 /* inotify_lock must be held before calling */
     79 void
     80 _im_rm (inotify_sub *sub)
     81 {
     82   GList *link;
     83 
     84   link = g_list_find (missing_sub_list, sub);
     85 
     86   if (!link)
     87     {
     88       IM_W ("asked to remove %s from missing list but it isn't on the list!\n", sub->dirname);
     89       return;
     90     }
     91 
     92   IM_W ("removing %s from missing list\n", sub->dirname);
     93 
     94   missing_sub_list = g_list_remove_link (missing_sub_list, link);
     95   g_list_free_1 (link);
     96 }
     97 
     98 /* Scans the list of missing subscriptions checking if they
     99  * are available yet.
    100  */
    101 static gboolean
    102 im_scan_missing (gpointer user_data)
    103 {
    104   GList *nolonger_missing = NULL;
    105   GList *l;
    106 
    107   G_LOCK (inotify_lock);
    108 
    109   IM_W ("scanning missing list with %d items\n", g_list_length (missing_sub_list));
    110   for (l = missing_sub_list; l; l = l->next)
    111     {
    112       inotify_sub *sub = l->data;
    113       gboolean not_m = FALSE;
    114 
    115       IM_W ("checking %p\n", sub);
    116       g_assert (sub);
    117       g_assert (sub->dirname);
    118       not_m = _ip_start_watching (sub);
    119 
    120       if (not_m)
    121 	{
    122 	  missing_cb (sub);
    123 	  IM_W ("removed %s from missing list\n", sub->dirname);
    124 	  /* We have to build a list of list nodes to remove from the
    125 	   * missing_sub_list. We do the removal outside of this loop.
    126 	   */
    127 	  nolonger_missing = g_list_prepend (nolonger_missing, l);
    128 	}
    129     }
    130 
    131   for (l = nolonger_missing; l ; l = l->next)
    132     {
    133       GList *llink = l->data;
    134       missing_sub_list = g_list_remove_link (missing_sub_list, llink);
    135       g_list_free_1 (llink);
    136     }
    137 
    138   g_list_free (nolonger_missing);
    139 
    140   /* If the missing list is now empty, we disable the timeout */
    141   if (missing_sub_list == NULL)
    142     {
    143       scan_missing_running = FALSE;
    144       G_UNLOCK (inotify_lock);
    145       return FALSE;
    146     }
    147   else
    148     {
    149       G_UNLOCK (inotify_lock);
    150       return TRUE;
    151     }
    152 }
    153 
    154 
    155 /* inotify_lock must be held */
    156 void
    157 _im_diag_dump (GIOChannel *ioc)
    158 {
    159   GList *l;
    160   g_io_channel_write_chars (ioc, "missing list:\n", -1, NULL, NULL);
    161   for (l = missing_sub_list; l; l = l->next)
    162     {
    163       inotify_sub *sub = l->data;
    164       g_io_channel_write_chars (ioc, sub->dirname, -1, NULL, NULL);
    165       g_io_channel_write_chars (ioc, "\n", -1, NULL, NULL);
    166     }
    167 }
    168