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, see <http://www.gnu.org/licenses/>.
  17  *
  18  * Author: Vlad Grecescu <b100dian@gmail.com>
  19  *
  20  */
  21
  22 #include "config.h"
  23 #include "gwin32directorymonitor.h"
  24 #include <windows.h>
  25
  26 G_DEFINE_TYPE_WITH_CODE (GWin32DirectoryMonitor,
  27                          g_win32_directory_monitor,
  28                          G_TYPE_LOCAL_DIRECTORY_MONITOR,
  29                          g_io_extension_point_implement (G_LOCAL_DIRECTORY_MONITOR_EXTENSION_POINT_NAME,
  30                                                          g_define_type_id,
  31                                                          "readdirectorychanges",
  32                                                          20))
  33
  34 struct _GWin32DirectoryMonitorPrivate {
  35   OVERLAPPED overlapped;
  36   DWORD buffer_allocated_bytes;
  37   gchar *file_notify_buffer;
  38   DWORD buffer_filled_bytes;
  39   HANDLE hDirectory;
  40   /* Needed in the APC where we only have this private struct */
  41   GFileMonitor *self;
  42 };
  43
  44 static void g_win32_directory_monitor_finalize (GObject *base);
  45 static gboolean g_win32_directory_monitor_cancel (GFileMonitor *base);
  46
  47 static GObject *g_win32_directory_monitor_constructor (GType                  type,
  48                                                        guint                  n_construct_properties,
  49                                                        GObjectConstructParam *construct_properties);
  50
  51 static gboolean
  52 g_win32_directory_monitor_is_supported (void)
  53 {
  54   return TRUE;
  55 }
  56
  57 static void
  58 g_win32_directory_monitor_finalize (GObject *base)
  59 {
  60   GWin32DirectoryMonitor *self;
  61   self = G_WIN32_DIRECTORY_MONITOR (base);
  62
  63   if (self->priv->hDirectory == INVALID_HANDLE_VALUE)
  64     {
  65       /* If we don't have a directory handle we can free
  66        * self->priv->file_notify_buffer and self->priv here. The
  67        * callback won't be called obviously any more (and presumably
  68        * never has been called).
  69        */
  70       g_free (self->priv->file_notify_buffer);
  71       self->priv->file_notify_buffer = NULL;
  72       g_free (self->priv);
  73     }
  74   else
  75     {
  76       /* If we have a directory handle, the OVERLAPPED struct is
  77        * passed once more to the callback as a result of the
  78        * CloseHandle() done in the cancel method, so self->priv has to
  79        * be kept around. The GWin32DirectoryMonitor object is
  80        * disappearing, so can't leave a pointer to it in
  81        * self->priv->self.
  82        */
  83       self->priv->self = NULL;
  84     }
  85
  86   if (G_OBJECT_CLASS (g_win32_directory_monitor_parent_class)->finalize)
  87     (*G_OBJECT_CLASS (g_win32_directory_monitor_parent_class)->finalize) (base);
  88 }
  89
  90 static gboolean
  91 g_win32_directory_monitor_cancel (GFileMonitor *base)
  92 {
  93   GWin32DirectoryMonitor *self;
  94   self = G_WIN32_DIRECTORY_MONITOR (base);
  95
  96   /* This triggers a last callback() with nBytes==0. */
  97
  98   /* Actually I am not so sure about that, it seems to trigger a last
  99    * callback allright, but the way to recognize that it is the final
 100    * one is not to check for nBytes==0, I think that was a
 101    * misunderstanding.
 102    */
 103   if (self->priv->hDirectory != INVALID_HANDLE_VALUE)
 104     CloseHandle (self->priv->hDirectory);
 105
 106   if (G_FILE_MONITOR_CLASS (g_win32_directory_monitor_parent_class)->cancel)
 107     (*G_FILE_MONITOR_CLASS (g_win32_directory_monitor_parent_class)->cancel) (base);
 108   return TRUE;
 109 }
 110
 111 static void CALLBACK
 112 g_win32_directory_monitor_callback (DWORD        error,
 113                                     DWORD        nBytes,
 114                                     LPOVERLAPPED lpOverlapped)
 115 {
 116   gulong offset;
 117   PFILE_NOTIFY_INFORMATION pfile_notify_walker;
 118   glong file_name_len;
 119   gchar *file_name;
 120   gchar *path;
 121   GFile *file;
 122   GWin32DirectoryMonitorPrivate *priv = (GWin32DirectoryMonitorPrivate *) lpOverlapped;
 123
 124   static GFileMonitorEvent events[] =
 125     {
 126       0,
 127       G_FILE_MONITOR_EVENT_CREATED, /* FILE_ACTION_ADDED            */
 128       G_FILE_MONITOR_EVENT_DELETED, /* FILE_ACTION_REMOVED          */
 129       G_FILE_MONITOR_EVENT_CHANGED, /* FILE_ACTION_MODIFIED         */
 130       G_FILE_MONITOR_EVENT_DELETED, /* FILE_ACTION_RENAMED_OLD_NAME */
 131       G_FILE_MONITOR_EVENT_CREATED, /* FILE_ACTION_RENAMED_NEW_NAME */
 132     };
 133
 134   /* If priv->self is NULL the GWin32DirectoryMonitor object has been destroyed. */
 135   if (priv->self == NULL ||
 136       g_file_monitor_is_cancelled (priv->self) ||
 137       priv->file_notify_buffer == NULL)
 138     {
 139       g_free (priv->file_notify_buffer);
 140       g_free (priv);
 141       return;
 142     }
 143
 144   offset = 0;
 145   do {
 146     pfile_notify_walker = (PFILE_NOTIFY_INFORMATION)(priv->file_notify_buffer + offset);
 147     if (pfile_notify_walker->Action > 0)
 148       {
 149         file_name = g_utf16_to_utf8 (pfile_notify_walker->FileName, pfile_notify_walker->FileNameLength / sizeof(WCHAR), NULL, &file_name_len, NULL);
 150         path = g_build_filename(G_LOCAL_DIRECTORY_MONITOR (priv->self)->dirname, file_name, NULL);
 151         file = g_file_new_for_path (path);
 152         g_file_monitor_emit_event (priv->self, file, NULL, events [pfile_notify_walker->Action]);
 153         g_object_unref (file);
 154         g_free (path);
 155         g_free (file_name);
 156       }
 157     offset += pfile_notify_walker->NextEntryOffset;
 158   } while (pfile_notify_walker->NextEntryOffset);
 159
 160   ReadDirectoryChangesW (priv->hDirectory,
 161                          (gpointer)priv->file_notify_buffer,
 162                          priv->buffer_allocated_bytes,
 163                          FALSE,
 164                          FILE_NOTIFY_CHANGE_FILE_NAME |
 165                          FILE_NOTIFY_CHANGE_DIR_NAME |
 166                          FILE_NOTIFY_CHANGE_ATTRIBUTES |
 167                          FILE_NOTIFY_CHANGE_SIZE,
 168                          &priv->buffer_filled_bytes,
 169                          &priv->overlapped,
 170                          g_win32_directory_monitor_callback);
 171 }
 172
 173 static GObject *
 174 g_win32_directory_monitor_constructor (GType                  type,
 175                                        guint                  n_construct_properties,
 176                                        GObjectConstructParam *construct_properties) {
 177   GObject *obj;
 178   GWin32DirectoryMonitorClass *klass;
 179   GObjectClass *parent_class;
 180   GWin32DirectoryMonitor *self;
 181   wchar_t *wdirname;
 182
 183   klass = G_WIN32_DIRECTORY_MONITOR_CLASS (g_type_class_peek (G_TYPE_WIN32_DIRECTORY_MONITOR));
 184   parent_class = G_OBJECT_CLASS (g_type_class_peek_parent (klass));
 185   obj = parent_class->constructor (type, n_construct_properties, construct_properties);
 186   self = G_WIN32_DIRECTORY_MONITOR (obj);
 187   wdirname = g_utf8_to_utf16 (G_LOCAL_DIRECTORY_MONITOR (obj)->dirname, -1, NULL, NULL, NULL);
 188
 189   self->priv->hDirectory = CreateFileW (wdirname,
 190                                         FILE_LIST_DIRECTORY,
 191                                         FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE,
 192
 193                                         NULL,
 194                                         OPEN_EXISTING,
 195                                         FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OVERLAPPED,
 196                                         NULL);
 197   g_free (wdirname);
 198   if (self->priv->hDirectory == INVALID_HANDLE_VALUE)
 199     {
 200       /* Ignore errors */
 201       return obj;
 202     }
 203
 204   ReadDirectoryChangesW (self->priv->hDirectory,
 205                          (gpointer)self->priv->file_notify_buffer,
 206                          self->priv->buffer_allocated_bytes,
 207                          FALSE,
 208                          FILE_NOTIFY_CHANGE_FILE_NAME |
 209                          FILE_NOTIFY_CHANGE_DIR_NAME |
 210                          FILE_NOTIFY_CHANGE_ATTRIBUTES |
 211                          FILE_NOTIFY_CHANGE_SIZE,
 212                          &self->priv->buffer_filled_bytes,
 213                          &self->priv->overlapped,
 214                          g_win32_directory_monitor_callback);
 215   /* Ignore errors */
 216
 217   return obj;
 218 }
 219
 220 static void
 221 g_win32_directory_monitor_class_init (GWin32DirectoryMonitorClass *klass)
 222 {
 223   g_win32_directory_monitor_parent_class = g_type_class_peek_parent (klass);
 224
 225   G_OBJECT_CLASS (klass)->constructor = g_win32_directory_monitor_constructor;
 226   G_OBJECT_CLASS (klass)->finalize = g_win32_directory_monitor_finalize;
 227   G_FILE_MONITOR_CLASS (klass)->cancel = g_win32_directory_monitor_cancel;
 228
 229   G_LOCAL_DIRECTORY_MONITOR_CLASS (klass)->mount_notify = FALSE;
 230   G_LOCAL_DIRECTORY_MONITOR_CLASS (klass)->is_supported = g_win32_directory_monitor_is_supported;
 231 }
 232
 233 static void
 234 g_win32_directory_monitor_init (GWin32DirectoryMonitor *self)
 235 {
 236   self->priv = (GWin32DirectoryMonitorPrivate*)g_new0 (GWin32DirectoryMonitorPrivate, 1);
 237   g_assert (self->priv != 0);
 238
 239   self->priv->buffer_allocated_bytes = 32768;
 240   self->priv->file_notify_buffer = g_new0 (gchar, self->priv->buffer_allocated_bytes);
 241   g_assert (self->priv->file_notify_buffer);
 242
 243   self->priv->self = G_FILE_MONITOR (self);
 244 }