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 #include "config.h"
  25 #include "gwin32directorymonitor.h"
  26 #include <windows.h>
  27
  28 G_DEFINE_TYPE_WITH_CODE (GWin32DirectoryMonitor,
  29                          g_win32_directory_monitor,
  30                          G_TYPE_LOCAL_DIRECTORY_MONITOR,
  31                          g_io_extension_point_implement (G_LOCAL_DIRECTORY_MONITOR_EXTENSION_POINT_NAME,
  32                                                          g_define_type_id,
  33                                                          "readdirectorychanges",
  34                                                          20))
  35
  36 struct _GWin32DirectoryMonitorPrivate {
  37   OVERLAPPED overlapped;
  38   DWORD buffer_allocated_bytes;
  39   gchar *file_notify_buffer;
  40   DWORD buffer_filled_bytes;
  41   HANDLE hDirectory;
  42   /* Needed in the APC where we only have this private struct */
  43   GFileMonitor *self;
  44 };
  45
  46 static void g_win32_directory_monitor_finalize (GObject *base);
  47 static gboolean g_win32_directory_monitor_cancel (GFileMonitor *base);
  48
  49 static GObject *g_win32_directory_monitor_constructor (GType                  type,
  50                                                        guint                  n_construct_properties,
  51                                                        GObjectConstructParam *construct_properties);
  52
  53 static gboolean
  54 g_win32_directory_monitor_is_supported (void)
  55 {
  56   return TRUE;
  57 }
  58
  59 static void
  60 g_win32_directory_monitor_finalize (GObject *base)
  61 {
  62   GWin32DirectoryMonitor *self;
  63   self = G_WIN32_DIRECTORY_MONITOR (base);
  64
  65   if (self->priv->hDirectory == INVALID_HANDLE_VALUE)
  66     {
  67       /* If we don't have a directory handle we can free
  68        * self->priv->file_notify_buffer and self->priv here. The
  69        * callback won't be called obviously any more (and presumably
  70        * never has been called).
  71        */
  72       g_free (self->priv->file_notify_buffer);
  73       self->priv->file_notify_buffer = NULL;
  74       g_free (self->priv);
  75     }
  76   else
  77     {
  78       /* If we have a directory handle, the OVERLAPPED struct is
  79        * passed once more to the callback as a result of the
  80        * CloseHandle() done in the cancel method, so self->priv has to
  81        * be kept around. The GWin32DirectoryMonitor object is
  82        * disappearing, so can't leave a pointer to it in
  83        * self->priv->self.
  84        */
  85       self->priv->self = NULL;
  86     }
  87
  88   if (G_OBJECT_CLASS (g_win32_directory_monitor_parent_class)->finalize)
  89     (*G_OBJECT_CLASS (g_win32_directory_monitor_parent_class)->finalize) (base);
  90 }
  91
  92 static gboolean
  93 g_win32_directory_monitor_cancel (GFileMonitor *base)
  94 {
  95   GWin32DirectoryMonitor *self;
  96   self = G_WIN32_DIRECTORY_MONITOR (base);
  97
  98   /* This triggers a last callback() with nBytes==0. */
  99
 100   /* Actually I am not so sure about that, it seems to trigger a last
 101    * callback allright, but the way to recognize that it is the final
 102    * one is not to check for nBytes==0, I think that was a
 103    * misunderstanding.
 104    */
 105   if (self->priv->hDirectory != INVALID_HANDLE_VALUE)
 106     CloseHandle (self->priv->hDirectory);
 107
 108   if (G_FILE_MONITOR_CLASS (g_win32_directory_monitor_parent_class)->cancel)
 109     (*G_FILE_MONITOR_CLASS (g_win32_directory_monitor_parent_class)->cancel) (base);
 110   return TRUE;
 111 }
 112
 113 static void CALLBACK
 114 g_win32_directory_monitor_callback (DWORD        error,
 115                                     DWORD        nBytes,
 116                                     LPOVERLAPPED lpOverlapped)
 117 {
 118   gulong offset;
 119   PFILE_NOTIFY_INFORMATION pfile_notify_walker;
 120   glong file_name_len;
 121   gchar *file_name;
 122   gchar *path;
 123   GFile *file;
 124   GWin32DirectoryMonitorPrivate *priv = (GWin32DirectoryMonitorPrivate *) lpOverlapped;
 125
 126   static GFileMonitorEvent events[] =
 127     {
 128       0,
 129       G_FILE_MONITOR_EVENT_CREATED, /* FILE_ACTION_ADDED            */
 130       G_FILE_MONITOR_EVENT_DELETED, /* FILE_ACTION_REMOVED          */
 131       G_FILE_MONITOR_EVENT_CHANGED, /* FILE_ACTION_MODIFIED         */
 132       G_FILE_MONITOR_EVENT_DELETED, /* FILE_ACTION_RENAMED_OLD_NAME */
 133       G_FILE_MONITOR_EVENT_CREATED, /* FILE_ACTION_RENAMED_NEW_NAME */
 134     };
 135
 136   /* If priv->self is NULL the GWin32DirectoryMonitor object has been destroyed. */
 137   if (priv->self == NULL ||
 138       g_file_monitor_is_cancelled (priv->self) ||
 139       priv->file_notify_buffer == NULL)
 140     {
 141       g_free (priv->file_notify_buffer);
 142       g_free (priv);
 143       return;
 144     }
 145
 146   offset = 0;
 147   do {
 148     pfile_notify_walker = (PFILE_NOTIFY_INFORMATION)(priv->file_notify_buffer + offset);
 149     if (pfile_notify_walker->Action > 0)
 150       {
 151         file_name = g_utf16_to_utf8 (pfile_notify_walker->FileName, pfile_notify_walker->FileNameLength / sizeof(WCHAR), NULL, &file_name_len, NULL);
 152         path = g_build_filename(G_LOCAL_DIRECTORY_MONITOR (priv->self)->dirname, file_name, NULL);
 153         file = g_file_new_for_path (path);
 154         g_file_monitor_emit_event (priv->self, file, NULL, events [pfile_notify_walker->Action]);
 155         g_object_unref (file);
 156         g_free (path);
 157         g_free (file_name);
 158       }
 159     offset += pfile_notify_walker->NextEntryOffset;
 160   } while (pfile_notify_walker->NextEntryOffset);
 161
 162   ReadDirectoryChangesW (priv->hDirectory,
 163                          (gpointer)priv->file_notify_buffer,
 164                          priv->buffer_allocated_bytes,
 165                          FALSE,
 166                          FILE_NOTIFY_CHANGE_FILE_NAME |
 167                          FILE_NOTIFY_CHANGE_DIR_NAME |
 168                          FILE_NOTIFY_CHANGE_ATTRIBUTES |
 169                          FILE_NOTIFY_CHANGE_SIZE,
 170                          &priv->buffer_filled_bytes,
 171                          &priv->overlapped,
 172                          g_win32_directory_monitor_callback);
 173 }
 174
 175 static GObject *
 176 g_win32_directory_monitor_constructor (GType                  type,
 177                                        guint                  n_construct_properties,
 178                                        GObjectConstructParam *construct_properties) {
 179   GObject *obj;
 180   GWin32DirectoryMonitorClass *klass;
 181   GObjectClass *parent_class;
 182   GWin32DirectoryMonitor *self;
 183   wchar_t *wdirname;
 184   gboolean result;
 185
 186   klass = G_WIN32_DIRECTORY_MONITOR_CLASS (g_type_class_peek (G_TYPE_WIN32_DIRECTORY_MONITOR));
 187   parent_class = G_OBJECT_CLASS (g_type_class_peek_parent (klass));
 188   obj = parent_class->constructor (type, n_construct_properties, construct_properties);
 189   self = G_WIN32_DIRECTORY_MONITOR (obj);
 190   wdirname = g_utf8_to_utf16 (G_LOCAL_DIRECTORY_MONITOR (obj)->dirname, -1, NULL, NULL, NULL);
 191
 192   self->priv->hDirectory = CreateFileW (wdirname,
 193                                         FILE_LIST_DIRECTORY,
 194                                         FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE,
 195
 196                                         NULL,
 197                                         OPEN_EXISTING,
 198                                         FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OVERLAPPED,
 199                                         NULL);
 200   g_free (wdirname);
 201   if (self->priv->hDirectory == INVALID_HANDLE_VALUE)
 202     {
 203       /* Ignore errors */
 204       return obj;
 205     }
 206
 207   result = ReadDirectoryChangesW (self->priv->hDirectory,
 208                                   (gpointer)self->priv->file_notify_buffer,
 209                                   self->priv->buffer_allocated_bytes,
 210                                   FALSE,
 211                                   FILE_NOTIFY_CHANGE_FILE_NAME |
 212                                   FILE_NOTIFY_CHANGE_DIR_NAME |
 213                                   FILE_NOTIFY_CHANGE_ATTRIBUTES |
 214                                   FILE_NOTIFY_CHANGE_SIZE,
 215                                   &self->priv->buffer_filled_bytes,
 216                                   &self->priv->overlapped,
 217                                   g_win32_directory_monitor_callback);
 218   /* Ignore errors */
 219
 220   return obj;
 221 }
 222
 223 static void
 224 g_win32_directory_monitor_class_init (GWin32DirectoryMonitorClass *klass)
 225 {
 226   g_win32_directory_monitor_parent_class = g_type_class_peek_parent (klass);
 227
 228   G_OBJECT_CLASS (klass)->constructor = g_win32_directory_monitor_constructor;
 229   G_OBJECT_CLASS (klass)->finalize = g_win32_directory_monitor_finalize;
 230   G_FILE_MONITOR_CLASS (klass)->cancel = g_win32_directory_monitor_cancel;
 231
 232   G_LOCAL_DIRECTORY_MONITOR_CLASS (klass)->mount_notify = FALSE;
 233   G_LOCAL_DIRECTORY_MONITOR_CLASS (klass)->is_supported = g_win32_directory_monitor_is_supported;
 234 }
 235
 236 static void
 237 g_win32_directory_monitor_init (GWin32DirectoryMonitor *self)
 238 {
 239   self->priv = (GWin32DirectoryMonitorPrivate*)g_new0 (GWin32DirectoryMonitorPrivate, 1);
 240   g_assert (self->priv != 0);
 241
 242   self->priv->buffer_allocated_bytes = 32768;
 243   self->priv->file_notify_buffer = g_new0 (gchar, self->priv->buffer_allocated_bytes);
 244   g_assert (self->priv->file_notify_buffer);
 245
 246   self->priv->self = G_FILE_MONITOR (self);
 247 }