gio/win32/gwin32directorymonitor.c

   1 /* GIO - GLib Input, Output and Streaming Library
   2  *
   3  * Copyright (C) 2006-2007 Red Hat, Inc.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General
  16  * Public License along with this library; if not, write to the
  17  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  18  * Boston, MA 02111-1307, USA.
  19  *
  20  * Author: Vlad Grecescu <b100dian@gmail.com>
  21  *
  22  */
  23
  24 #define _WIN32_WINNT 0x0400
  25
  26 #include "config.h"
  27 #include "gwin32directorymonitor.h"
  28 #include <windows.h>
  29
  30 G_DEFINE_TYPE_WITH_CODE (GWin32DirectoryMonitor,
  31                          g_win32_directory_monitor,
  32                          G_TYPE_LOCAL_DIRECTORY_MONITOR,
  33                          g_io_extension_point_implement (G_LOCAL_DIRECTORY_MONITOR_EXTENSION_POINT_NAME,
  34                                                          g_define_type_id,
  35                                                          "readdirectorychanges",
  36                                                          20))
  37
  38 struct _GWin32DirectoryMonitorPrivate {
  39   OVERLAPPED overlapped;
  40   DWORD buffer_allocated_bytes;
  41   gchar *file_notify_buffer;
  42   DWORD buffer_filled_bytes;
  43   HANDLE hDirectory;
  44   /* Needed in the APC where we only have this private struct */
  45   GFileMonitor *self;
  46 };
  47
  48 static void g_win32_directory_monitor_finalize (GObject *base);
  49 static gboolean g_win32_directory_monitor_cancel (GFileMonitor *base);
  50
  51 static GObject *g_win32_directory_monitor_constructor (GType                  type,
  52                                                        guint                  n_construct_properties,
  53                                                        GObjectConstructParam *construct_properties);
  54
  55 static gboolean
  56 g_win32_directory_monitor_is_supported (void)
  57 {
  58   return TRUE;
  59 }
  60
  61 static void
  62 g_win32_directory_monitor_finalize (GObject *base)
  63 {
  64   GWin32DirectoryMonitor *self;
  65   self = G_WIN32_DIRECTORY_MONITOR (base);
  66
  67   if (self->priv->hDirectory == INVALID_HANDLE_VALUE)
  68     {
  69       /* If we don't have a directory handle we can free
  70        * self->priv->file_notify_buffer and self->priv here. The
  71        * callback won't be called obviously any more (and presumably
  72        * never has been called).
  73        */
  74       g_free (self->priv->file_notify_buffer);
  75       self->priv->file_notify_buffer = NULL;
  76       g_free (self->priv);
  77     }
  78   else
  79     {
  80       /* If we have a directory handle, the OVERLAPPED struct is
  81        * passed once more to the callback as a result of the
  82        * CloseHandle() done in the cancel method, so self->priv has to
  83        * be kept around. The GWin32DirectoryMonitor object is
  84        * disappearing, so can't leave a pointer to it in
  85        * self->priv->self.
  86        */
  87       self->priv->self = NULL;
  88     }
  89
  90   if (G_OBJECT_CLASS (g_win32_directory_monitor_parent_class)->finalize)
  91     (*G_OBJECT_CLASS (g_win32_directory_monitor_parent_class)->finalize) (base);
  92 }
  93
  94 static gboolean
  95 g_win32_directory_monitor_cancel (GFileMonitor *base)
  96 {
  97   GWin32DirectoryMonitor *self;
  98   self = G_WIN32_DIRECTORY_MONITOR (base);
  99
 100   /* This triggers a last callback() with nBytes==0. */
 101
 102   /* Actually I am not so sure about that, it seems to trigger a last
 103    * callback allright, but the way to recognize that it is the final
 104    * one is not to check for nBytes==0, I think that was a
 105    * misunderstanding.
 106    */
 107   if (self->priv->hDirectory != INVALID_HANDLE_VALUE)
 108     CloseHandle (self->priv->hDirectory);
 109
 110   if (G_FILE_MONITOR_CLASS (g_win32_directory_monitor_parent_class)->cancel)
 111     (*G_FILE_MONITOR_CLASS (g_win32_directory_monitor_parent_class)->cancel) (base);
 112   return TRUE;
 113 }
 114
 115 static void CALLBACK
 116 g_win32_directory_monitor_callback (DWORD        error,
 117                                     DWORD        nBytes,
 118                                     LPOVERLAPPED lpOverlapped)
 119 {
 120   gulong offset;
 121   PFILE_NOTIFY_INFORMATION pfile_notify_walker;
 122   glong file_name_len;
 123   gchar *file_name;
 124   gchar *path;
 125   GFile *file;
 126   GWin32DirectoryMonitorPrivate *priv = (GWin32DirectoryMonitorPrivate *) lpOverlapped;
 127
 128   static GFileMonitorEvent events[] =
 129     {
 130       0,
 131       G_FILE_MONITOR_EVENT_CREATED, /* FILE_ACTION_ADDED            */
 132       G_FILE_MONITOR_EVENT_DELETED, /* FILE_ACTION_REMOVED          */
 133       G_FILE_MONITOR_EVENT_CHANGED, /* FILE_ACTION_MODIFIED         */
 134       G_FILE_MONITOR_EVENT_DELETED, /* FILE_ACTION_RENAMED_OLD_NAME */
 135       G_FILE_MONITOR_EVENT_CREATED, /* FILE_ACTION_RENAMED_NEW_NAME */
 136     };
 137
 138   /* If priv->self is NULL the GWin32DirectoryMonitor object has been destroyed. */
 139   if (priv->self == NULL ||
 140       g_file_monitor_is_cancelled (priv->self) ||
 141       priv->file_notify_buffer == NULL)
 142     {
 143       g_free (priv->file_notify_buffer);
 144       g_free (priv);
 145       return;
 146     }
 147
 148   offset = 0;
 149   do {
 150     pfile_notify_walker = (PFILE_NOTIFY_INFORMATION)(priv->file_notify_buffer + offset);
 151     if (pfile_notify_walker->Action > 0)
 152       {
 153         file_name = g_utf16_to_utf8 (pfile_notify_walker->FileName, pfile_notify_walker->FileNameLength / sizeof(WCHAR), NULL, &file_name_len, NULL);
 154         path = g_build_filename(G_LOCAL_DIRECTORY_MONITOR (priv->self)->dirname, file_name, NULL);
 155         file = g_file_new_for_path (path);
 156         g_file_monitor_emit_event (priv->self, file, NULL, events [pfile_notify_walker->Action]);
 157         g_object_unref (file);
 158         g_free (path);
 159         g_free (file_name);
 160       }
 161     offset += pfile_notify_walker->NextEntryOffset;
 162   } while (pfile_notify_walker->NextEntryOffset);
 163
 164   ReadDirectoryChangesW (priv->hDirectory,
 165                          (gpointer)priv->file_notify_buffer,
 166                          priv->buffer_allocated_bytes,
 167                          FALSE,
 168                          FILE_NOTIFY_CHANGE_FILE_NAME |
 169                          FILE_NOTIFY_CHANGE_DIR_NAME |
 170                          FILE_NOTIFY_CHANGE_ATTRIBUTES |
 171                          FILE_NOTIFY_CHANGE_SIZE,
 172                          &priv->buffer_filled_bytes,
 173                          &priv->overlapped,
 174                          g_win32_directory_monitor_callback);
 175 }
 176
 177 static GObject *
 178 g_win32_directory_monitor_constructor (GType                  type,
 179                                        guint                  n_construct_properties,
 180                                        GObjectConstructParam *construct_properties) {
 181   GObject *obj;
 182   GWin32DirectoryMonitorClass *klass;
 183   GObjectClass *parent_class;
 184   GWin32DirectoryMonitor *self;
 185   wchar_t *wdirname;
 186   gboolean result;
 187
 188   klass = G_WIN32_DIRECTORY_MONITOR_CLASS (g_type_class_peek (G_TYPE_WIN32_DIRECTORY_MONITOR));
 189   parent_class = G_OBJECT_CLASS (g_type_class_peek_parent (klass));
 190   obj = parent_class->constructor (type, n_construct_properties, construct_properties);
 191   self = G_WIN32_DIRECTORY_MONITOR (obj);
 192   wdirname = g_utf8_to_utf16 (G_LOCAL_DIRECTORY_MONITOR (obj)->dirname, -1, NULL, NULL, NULL);
 193
 194   self->priv->hDirectory = CreateFileW (wdirname,
 195                                         FILE_LIST_DIRECTORY,
 196                                         FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE,
 197
 198                                         NULL,
 199                                         OPEN_EXISTING,
 200                                         FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OVERLAPPED,
 201                                         NULL);
 202   g_free (wdirname);
 203   if (self->priv->hDirectory == INVALID_HANDLE_VALUE)
 204     {
 205       /* Ignore errors */
 206       return obj;
 207     }
 208
 209   result = ReadDirectoryChangesW (self->priv->hDirectory,
 210                                   (gpointer)self->priv->file_notify_buffer,
 211                                   self->priv->buffer_allocated_bytes,
 212                                   FALSE,
 213                                   FILE_NOTIFY_CHANGE_FILE_NAME |
 214                                   FILE_NOTIFY_CHANGE_DIR_NAME |
 215                                   FILE_NOTIFY_CHANGE_ATTRIBUTES |
 216                                   FILE_NOTIFY_CHANGE_SIZE,
 217                                   &self->priv->buffer_filled_bytes,
 218                                   &self->priv->overlapped,
 219                                   g_win32_directory_monitor_callback);
 220   /* Ignore errors */
 221
 222   return obj;
 223 }
 224
 225 static void
 226 g_win32_directory_monitor_class_init (GWin32DirectoryMonitorClass *klass)
 227 {
 228   g_win32_directory_monitor_parent_class = g_type_class_peek_parent (klass);
 229
 230   G_OBJECT_CLASS (klass)->constructor = g_win32_directory_monitor_constructor;
 231   G_OBJECT_CLASS (klass)->finalize = g_win32_directory_monitor_finalize;
 232   G_FILE_MONITOR_CLASS (klass)->cancel = g_win32_directory_monitor_cancel;
 233
 234   G_LOCAL_DIRECTORY_MONITOR_CLASS (klass)->mount_notify = FALSE;
 235   G_LOCAL_DIRECTORY_MONITOR_CLASS (klass)->is_supported = g_win32_directory_monitor_is_supported;
 236 }
 237
 238 static void
 239 g_win32_directory_monitor_init (GWin32DirectoryMonitor *self)
 240 {
 241   self->priv = (GWin32DirectoryMonitorPrivate*)g_new0 (GWin32DirectoryMonitorPrivate, 1);
 242   g_assert (self->priv != 0);
 243
 244   self->priv->buffer_allocated_bytes = 32768;
 245   self->priv->file_notify_buffer = g_new0 (gchar, self->priv->buffer_allocated_bytes);
 246   g_assert (self->priv->file_notify_buffer);
 247
 248   self->priv->self = G_FILE_MONITOR (self);
 249 }