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 "giomodule.h"
  29 #include <windows.h>
  30
  31 G_DEFINE_TYPE_WITH_CODE (GWin32DirectoryMonitor,
  32                          g_win32_directory_monitor,
  33                          G_TYPE_LOCAL_DIRECTORY_MONITOR,
  34                          g_io_extension_point_implement (G_LOCAL_DIRECTORY_MONITOR_EXTENSION_POINT_NAME,
  35                                                          g_define_type_id,
  36                                                          "readdirectorychanges",
  37                                                          20))
  38
  39 struct _GWin32DirectoryMonitorPrivate {
  40   OVERLAPPED overlapped;
  41   DWORD buffer_allocated_bytes;
  42   gchar *file_notify_buffer;
  43   DWORD buffer_filled_bytes;
  44   HANDLE hDirectory;
  45   /* Needed in the APC where we only have this private struct */
  46   GFileMonitor *self;
  47 };
  48
  49 static void g_win32_directory_monitor_finalize (GObject *base);
  50 static gboolean g_win32_directory_monitor_cancel (GFileMonitor *base);
  51
  52 static GObject *g_win32_directory_monitor_constructor (GType                  type,
  53                                                        guint                  n_construct_properties,
  54                                                        GObjectConstructParam *construct_properties);
  55
  56 static gboolean
  57 g_win32_directory_monitor_is_supported (void)
  58 {
  59   return TRUE;
  60 }
  61
  62 static void
  63 g_win32_directory_monitor_finalize (GObject *base)
  64 {
  65   GWin32DirectoryMonitor *self;
  66   self = G_WIN32_DIRECTORY_MONITOR (base);
  67
  68   if (self->priv->hDirectory == INVALID_HANDLE_VALUE)
  69     {
  70       /* If we don't have a directory handle we can free
  71        * self->priv->file_notify_buffer and self->priv here. The
  72        * callback won't be called obviously any more (and presumably
  73        * never has been called).
  74        */
  75       g_free (self->priv->file_notify_buffer);
  76       self->priv->file_notify_buffer = NULL;
  77       g_free (self->priv);
  78     }
  79   else
  80     {
  81       /* If we have a directory handle, the OVERLAPPED struct is
  82        * passed once more to the callback as a result of the
  83        * CloseHandle() done in the cancel method, so self->priv has to
  84        * be kept around. The GWin32DirectoryMonitor object is
  85        * disappearing, so can't leave a pointer to it in
  86        * self->priv->self.
  87        */
  88       self->priv->self = NULL;
  89     }
  90
  91   if (G_OBJECT_CLASS (g_win32_directory_monitor_parent_class)->finalize)
  92     (*G_OBJECT_CLASS (g_win32_directory_monitor_parent_class)->finalize) (base);
  93 }
  94
  95 static gboolean
  96 g_win32_directory_monitor_cancel (GFileMonitor *base)
  97 {
  98   GWin32DirectoryMonitor *self;
  99   self = G_WIN32_DIRECTORY_MONITOR (base);
 100
 101   /* This triggers a last callback() with nBytes==0. */
 102
 103   /* Actually I am not so sure about that, it seems to trigger a last
 104    * callback allright, but the way to recognize that it is the final
 105    * one is not to check for nBytes==0, I think that was a
 106    * misunderstanding.
 107    */
 108   if (self->priv->hDirectory != INVALID_HANDLE_VALUE)
 109     CloseHandle (self->priv->hDirectory);
 110
 111   if (G_FILE_MONITOR_CLASS (g_win32_directory_monitor_parent_class)->cancel)
 112     (*G_FILE_MONITOR_CLASS (g_win32_directory_monitor_parent_class)->cancel) (base);
 113   return TRUE;
 114 }
 115
 116 static void CALLBACK
 117 g_win32_directory_monitor_callback (DWORD        error,
 118                                     DWORD        nBytes,
 119                                     LPOVERLAPPED lpOverlapped)
 120 {
 121   gulong offset;
 122   PFILE_NOTIFY_INFORMATION pfile_notify_walker;
 123   glong file_name_len;
 124   gchar *file_name;
 125   gchar *path;
 126   GFile *file;
 127   GWin32DirectoryMonitorPrivate *priv = (GWin32DirectoryMonitorPrivate *) lpOverlapped;
 128
 129   static GFileMonitorEvent events[] =
 130     {
 131       0,
 132       G_FILE_MONITOR_EVENT_CREATED, /* FILE_ACTION_ADDED            */
 133       G_FILE_MONITOR_EVENT_DELETED, /* FILE_ACTION_REMOVED          */
 134       G_FILE_MONITOR_EVENT_CHANGED, /* FILE_ACTION_MODIFIED         */
 135       G_FILE_MONITOR_EVENT_DELETED, /* FILE_ACTION_RENAMED_OLD_NAME */
 136       G_FILE_MONITOR_EVENT_CREATED, /* FILE_ACTION_RENAMED_NEW_NAME */
 137     };
 138
 139   /* If priv->self is NULL the GWin32DirectoryMonitor object has been destroyed. */
 140   if (priv->self == NULL ||
 141       g_file_monitor_is_cancelled (priv->self) ||
 142       priv->file_notify_buffer == NULL)
 143     {
 144       g_free (priv->file_notify_buffer);
 145       g_free (priv);
 146       return;
 147     }
 148
 149   offset = 0;
 150   do {
 151     pfile_notify_walker = (PFILE_NOTIFY_INFORMATION)(priv->file_notify_buffer + offset);
 152     if (pfile_notify_walker->Action > 0)
 153       {
 154         file_name = g_utf16_to_utf8 (pfile_notify_walker->FileName, pfile_notify_walker->FileNameLength / sizeof(WCHAR), NULL, &file_name_len, NULL);
 155         path = g_build_filename(G_LOCAL_DIRECTORY_MONITOR (priv->self)->dirname, file_name, NULL);
 156         file = g_file_new_for_path (path);
 157         g_file_monitor_emit_event (priv->self, file, NULL, events [pfile_notify_walker->Action]);
 158         g_object_unref (file);
 159         g_free (path);
 160         g_free (file_name);
 161       }
 162     offset += pfile_notify_walker->NextEntryOffset;
 163   } while (pfile_notify_walker->NextEntryOffset);
 164
 165   ReadDirectoryChangesW (priv->hDirectory,
 166                          (gpointer)priv->file_notify_buffer,
 167                          priv->buffer_allocated_bytes,
 168                          FALSE,
 169                          FILE_NOTIFY_CHANGE_FILE_NAME |
 170                          FILE_NOTIFY_CHANGE_DIR_NAME |
 171                          FILE_NOTIFY_CHANGE_ATTRIBUTES |
 172                          FILE_NOTIFY_CHANGE_SIZE,
 173                          &priv->buffer_filled_bytes,
 174                          &priv->overlapped,
 175                          g_win32_directory_monitor_callback);
 176 }
 177
 178 static GObject *
 179 g_win32_directory_monitor_constructor (GType                  type,
 180                                        guint                  n_construct_properties,
 181                                        GObjectConstructParam *construct_properties) {
 182   GObject *obj;
 183   GWin32DirectoryMonitorClass *klass;
 184   GObjectClass *parent_class;
 185   GWin32DirectoryMonitor *self;
 186   wchar_t *wdirname;
 187   gboolean result;
 188
 189   klass = G_WIN32_DIRECTORY_MONITOR_CLASS (g_type_class_peek (G_TYPE_WIN32_DIRECTORY_MONITOR));
 190   parent_class = G_OBJECT_CLASS (g_type_class_peek_parent (klass));
 191   obj = parent_class->constructor (type, n_construct_properties, construct_properties);
 192   self = G_WIN32_DIRECTORY_MONITOR (obj);
 193   wdirname = g_utf8_to_utf16 (G_LOCAL_DIRECTORY_MONITOR (obj)->dirname, -1, NULL, NULL, NULL);
 194
 195   self->priv->hDirectory = CreateFileW (wdirname,
 196                                         FILE_LIST_DIRECTORY,
 197                                         FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE,
 198
 199                                         NULL,
 200                                         OPEN_EXISTING,
 201                                         FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OVERLAPPED,
 202                                         NULL);
 203   g_free (wdirname);
 204   if (self->priv->hDirectory == INVALID_HANDLE_VALUE)
 205     {
 206       /* Ignore errors */
 207       return obj;
 208     }
 209
 210   result = ReadDirectoryChangesW (self->priv->hDirectory,
 211                                   (gpointer)self->priv->file_notify_buffer,
 212                                   self->priv->buffer_allocated_bytes,
 213                                   FALSE,
 214                                   FILE_NOTIFY_CHANGE_FILE_NAME |
 215                                   FILE_NOTIFY_CHANGE_DIR_NAME |
 216                                   FILE_NOTIFY_CHANGE_ATTRIBUTES |
 217                                   FILE_NOTIFY_CHANGE_SIZE,
 218                                   &self->priv->buffer_filled_bytes,
 219                                   &self->priv->overlapped,
 220                                   g_win32_directory_monitor_callback);
 221   /* Ignore errors */
 222
 223   return obj;
 224 }
 225
 226 static void
 227 g_win32_directory_monitor_class_init (GWin32DirectoryMonitorClass *klass)
 228 {
 229   g_win32_directory_monitor_parent_class = g_type_class_peek_parent (klass);
 230
 231   G_OBJECT_CLASS (klass)->constructor = g_win32_directory_monitor_constructor;
 232   G_OBJECT_CLASS (klass)->finalize = g_win32_directory_monitor_finalize;
 233   G_FILE_MONITOR_CLASS (klass)->cancel = g_win32_directory_monitor_cancel;
 234
 235   G_LOCAL_DIRECTORY_MONITOR_CLASS (klass)->mount_notify = FALSE;
 236   G_LOCAL_DIRECTORY_MONITOR_CLASS (klass)->is_supported = g_win32_directory_monitor_is_supported;
 237 }
 238
 239 static void
 240 g_win32_directory_monitor_init (GWin32DirectoryMonitor *self)
 241 {
 242   self->priv = (GWin32DirectoryMonitorPrivate*)g_new0 (GWin32DirectoryMonitorPrivate, 1);
 243   g_assert (self->priv != 0);
 244
 245   self->priv->buffer_allocated_bytes = 32768;
 246   self->priv->file_notify_buffer = g_new0 (gchar, self->priv->buffer_allocated_bytes);
 247   g_assert (self->priv->file_notify_buffer);
 248
 249   self->priv->self = G_FILE_MONITOR (self);
 250 }