gio/inotify/inotify-missing.c

   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@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 }