gio/inotify/inotify-helper.c

   1 /* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 2; tab-width: 8 -*- */
   2
   3 /* inotify-helper.c - GVFS Monitor based on inotify.
   4
   5    Copyright (C) 2007 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 <errno.h>
  28 #include <time.h>
  29 #include <string.h>
  30 #include <sys/ioctl.h>
  31 /* Just include the local header to stop all the pain */
  32 #include <sys/inotify.h>
  33 #include <gio/glocalfile.h>
  34 #include <gio/gfilemonitor.h>
  35 #include <gio/gfile.h>
  36 #include "inotify-helper.h"
  37 #include "inotify-missing.h"
  38 #include "inotify-path.h"
  39 #include "inotify-diag.h"
  40
  41 #include "gioalias.h"
  42
  43
  44 static gboolean ih_debug_enabled = FALSE;
  45 #define IH_W if (ih_debug_enabled) g_warning
  46
  47 static void ih_event_callback (ik_event_t *event, inotify_sub *sub);
  48 static void ih_not_missing_callback (inotify_sub *sub);
  49
  50 /* We share this lock with inotify-kernel.c and inotify-missing.c
  51  *
  52  * inotify-kernel.c takes the lock when it reads events from
  53  * the kernel and when it processes those events
  54  *
  55  * inotify-missing.c takes the lock when it is scanning the missing
  56  * list.
  57  *
  58  * We take the lock in all public functions
  59  */
  60 G_GNUC_INTERNAL G_LOCK_DEFINE (inotify_lock);
  61
  62 static GFileMonitorEvent ih_mask_to_EventFlags (guint32 mask);
  63
  64 /**
  65  * _ih_startup:
  66  *
  67  * Initializes the inotify backend.  This must be called before
  68  * any other functions in this module.
  69  *
  70  * Return value: #TRUE if initialization succeeded, #FALSE otherwise
  71  */
  72 gboolean
  73 _ih_startup (void)
  74 {
  75   static gboolean initialized = FALSE;
  76   static gboolean result = FALSE;
  77
  78   G_LOCK (inotify_lock);
  79
  80   if (initialized == TRUE)
  81     {
  82       G_UNLOCK (inotify_lock);
  83       return result;
  84     }
  85
  86   result = _ip_startup (ih_event_callback);
  87   if (!result)
  88     {
  89       g_warning ("Could not initialize inotify\n");
  90       G_UNLOCK (inotify_lock);
  91       return FALSE;
  92     }
  93   _im_startup (ih_not_missing_callback);
  94   _id_startup ();
  95
  96   IH_W ("started gvfs inotify backend\n");
  97
  98   initialized = TRUE;
  99
 100   G_UNLOCK (inotify_lock);
 101
 102   return TRUE;
 103 }
 104
 105 /**
 106  * Adds a subscription to be monitored.
 107  */
 108 gboolean
 109 _ih_sub_add (inotify_sub *sub)
 110 {
 111   G_LOCK (inotify_lock);
 112
 113   if (!_ip_start_watching (sub))
 114     _im_add (sub);
 115
 116   G_UNLOCK (inotify_lock);
 117   return TRUE;
 118 }
 119
 120 /**
 121  * Cancels a subscription which was being monitored.
 122  */
 123 gboolean
 124 _ih_sub_cancel (inotify_sub *sub)
 125 {
 126   G_LOCK (inotify_lock);
 127
 128   if (!sub->cancelled)
 129     {
 130       IH_W ("cancelling %s\n", sub->dirname);
 131       sub->cancelled = TRUE;
 132       _im_rm (sub);
 133       _ip_stop_watching (sub);
 134     }
 135
 136   G_UNLOCK (inotify_lock);
 137
 138   return TRUE;
 139 }
 140
 141
 142 static void
 143 ih_event_callback (ik_event_t  *event,
 144                    inotify_sub *sub)
 145 {
 146   gchar *fullpath;
 147   GFileMonitorEvent eflags;
 148   GFile* parent;
 149   GFile* child;
 150
 151   eflags = ih_mask_to_EventFlags (event->mask);
 152   parent = g_file_new_for_path (sub->dirname);
 153   if (event->name)
 154     fullpath = g_strdup_printf ("%s/%s", sub->dirname, event->name);
 155   else
 156     fullpath = g_strdup_printf ("%s/", sub->dirname);
 157
 158   child = g_file_new_for_path (fullpath);
 159   g_free (fullpath);
 160
 161   g_file_monitor_emit_event (G_FILE_MONITOR (sub->user_data),
 162                              child, NULL, eflags);
 163
 164   g_object_unref (child);
 165   g_object_unref (parent);
 166 }
 167
 168 static void
 169 ih_not_missing_callback (inotify_sub *sub)
 170 {
 171   gchar *fullpath;
 172   GFileMonitorEvent eflags;
 173   guint32 mask;
 174   GFile* parent;
 175   GFile* child;
 176
 177   parent = g_file_new_for_path (sub->dirname);
 178
 179   if (sub->filename)
 180     {
 181       fullpath = g_strdup_printf ("%s/%s", sub->dirname, sub->filename);
 182       g_warning ("Missing callback called fullpath = %s\n", fullpath);
 183       if (!g_file_test (fullpath, G_FILE_TEST_EXISTS))
 184         {
 185           g_free (fullpath);
 186           return;
 187         }
 188       mask = IN_CREATE;
 189     }
 190   else
 191     {
 192       fullpath = g_strdup_printf ("%s", sub->dirname);
 193       mask = IN_CREATE|IN_ISDIR;
 194     }
 195
 196   eflags = ih_mask_to_EventFlags (mask);
 197   child = g_file_new_for_path (fullpath);
 198   g_free (fullpath);
 199
 200   g_file_monitor_emit_event (G_FILE_MONITOR (sub->user_data),
 201                              child, NULL, eflags);
 202
 203   g_object_unref (child);
 204   g_object_unref (parent);
 205 }
 206
 207 /* Transforms a inotify event to a GVFS event. */
 208 static GFileMonitorEvent
 209 ih_mask_to_EventFlags (guint32 mask)
 210 {
 211   mask &= ~IN_ISDIR;
 212   switch (mask)
 213     {
 214     case IN_MODIFY:
 215       return G_FILE_MONITOR_EVENT_CHANGED;
 216     case IN_CLOSE_WRITE:
 217       return G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT;
 218     case IN_ATTRIB:
 219       return G_FILE_MONITOR_EVENT_ATTRIBUTE_CHANGED;
 220     case IN_MOVE_SELF:
 221     case IN_MOVED_FROM:
 222     case IN_DELETE:
 223     case IN_DELETE_SELF:
 224       return G_FILE_MONITOR_EVENT_DELETED;
 225     case IN_CREATE:
 226     case IN_MOVED_TO:
 227       return G_FILE_MONITOR_EVENT_CREATED;
 228     case IN_UNMOUNT:
 229       return G_FILE_MONITOR_EVENT_UNMOUNTED;
 230     case IN_Q_OVERFLOW:
 231     case IN_OPEN:
 232     case IN_CLOSE_NOWRITE:
 233     case IN_ACCESS:
 234     case IN_IGNORED:
 235     default:
 236       return -1;
 237     }
 238 }