gio/win32/gwin32fsmonitorutils.c

   1 /* GIO - GLib Input, Output and Streaming Library
   2  *
   3  * Copyright (C) 2006-2007 Red Hat, Inc.
   4  * Copyright (C) 2015 Chun-wei Fan
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General
  17  * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  *
  19  * Author: Vlad Grecescu <b100dian@gmail.com>
  20  * Author: Chun-wei Fan <fanc999@yahoo.com.tw>
  21  *
  22  */
  23
  24 #include "config.h"
  25
  26 #include "gwin32fsmonitorutils.h"
  27 #include "gio/gfile.h"
  28
  29 #include <windows.h>
  30
  31 #define MAX_PATH_LONG 32767 /* Support Paths longer than MAX_PATH (260) characters */
  32
  33 static gboolean
  34 g_win32_fs_monitor_handle_event (GWin32FSMonitorPrivate   *monitor,
  35                                  const gchar              *filename,
  36                                  PFILE_NOTIFY_INFORMATION  pfni)
  37 {
  38   GFileMonitorEvent fme;
  39   PFILE_NOTIFY_INFORMATION pfni_next;
  40   WIN32_FILE_ATTRIBUTE_DATA attrib_data = {0, };
  41   gchar *renamed_file = NULL;
  42
  43   switch (pfni->Action)
  44     {
  45     case FILE_ACTION_ADDED:
  46       fme = G_FILE_MONITOR_EVENT_CREATED;
  47       break;
  48
  49     case FILE_ACTION_REMOVED:
  50       fme = G_FILE_MONITOR_EVENT_DELETED;
  51       break;
  52
  53     case FILE_ACTION_MODIFIED:
  54       {
  55         gboolean success_attribs = GetFileAttributesExW (monitor->wfullpath_with_long_prefix,
  56                                                          GetFileExInfoStandard,
  57                                                          &attrib_data);
  58
  59         if (monitor->file_attribs != INVALID_FILE_ATTRIBUTES &&
  60             success_attribs &&
  61             attrib_data.dwFileAttributes != monitor->file_attribs)
  62           fme = G_FILE_MONITOR_EVENT_ATTRIBUTE_CHANGED;
  63         else
  64           fme = G_FILE_MONITOR_EVENT_CHANGED;
  65
  66         monitor->file_attribs = attrib_data.dwFileAttributes;
  67       }
  68       break;
  69
  70     case FILE_ACTION_RENAMED_OLD_NAME:
  71       if (pfni->NextEntryOffset != 0)
  72         {
  73           /* If the file was renamed in the same directory, we would get a
  74            * FILE_ACTION_RENAMED_NEW_NAME action in the next FILE_NOTIFY_INFORMATION
  75            * structure.
  76            */
  77           glong file_name_len = 0;
  78
  79           pfni_next = (PFILE_NOTIFY_INFORMATION) ((BYTE*)pfni + pfni->NextEntryOffset);
  80           renamed_file = g_utf16_to_utf8 (pfni_next->FileName, pfni_next->FileNameLength / sizeof(WCHAR), NULL, &file_name_len, NULL);
  81           if (pfni_next->Action == FILE_ACTION_RENAMED_NEW_NAME)
  82            fme = G_FILE_MONITOR_EVENT_RENAMED;
  83           else
  84            fme = G_FILE_MONITOR_EVENT_MOVED_OUT;
  85         }
  86       else
  87         fme = G_FILE_MONITOR_EVENT_MOVED_OUT;
  88       break;
  89
  90     case FILE_ACTION_RENAMED_NEW_NAME:
  91       if (monitor->pfni_prev != NULL &&
  92           monitor->pfni_prev->Action == FILE_ACTION_RENAMED_OLD_NAME)
  93         {
  94           /* don't bother sending events, was already sent (rename) */
  95           fme = -1;
  96         }
  97       else
  98         fme = G_FILE_MONITOR_EVENT_MOVED_IN;
  99       break;
 100
 101     default:
 102       /* The possible Windows actions are all above, so shouldn't get here */
 103       g_assert_not_reached ();
 104       break;
 105     }
 106
 107   if (fme != -1)
 108     return g_file_monitor_source_handle_event (monitor->fms,
 109                                                fme,
 110                                                filename,
 111                                                renamed_file,
 112                                                NULL,
 113                                                g_get_monotonic_time ());
 114   else
 115     return FALSE;
 116 }
 117
 118
 119 static void CALLBACK
 120 g_win32_fs_monitor_callback (DWORD        error,
 121                              DWORD        nBytes,
 122                              LPOVERLAPPED lpOverlapped)
 123 {
 124   gulong offset;
 125   PFILE_NOTIFY_INFORMATION pfile_notify_walker;
 126   GWin32FSMonitorPrivate *monitor = (GWin32FSMonitorPrivate *) lpOverlapped;
 127
 128   DWORD notify_filter = monitor->isfile ?
 129                         (FILE_NOTIFY_CHANGE_FILE_NAME |
 130                          FILE_NOTIFY_CHANGE_ATTRIBUTES |
 131                          FILE_NOTIFY_CHANGE_SIZE) :
 132                         (FILE_NOTIFY_CHANGE_FILE_NAME |
 133                          FILE_NOTIFY_CHANGE_DIR_NAME |
 134                          FILE_NOTIFY_CHANGE_ATTRIBUTES |
 135                          FILE_NOTIFY_CHANGE_SIZE);
 136
 137   /* If monitor->self is NULL the GWin32FileMonitor object has been destroyed. */
 138   if (monitor->self == NULL ||
 139       g_file_monitor_is_cancelled (monitor->self) ||
 140       monitor->file_notify_buffer == NULL)
 141     {
 142       g_free (monitor->file_notify_buffer);
 143       g_free (monitor);
 144       return;
 145     }
 146
 147   offset = 0;
 148
 149   do
 150     {
 151       pfile_notify_walker = (PFILE_NOTIFY_INFORMATION)((BYTE *)monitor->file_notify_buffer + offset);
 152       if (pfile_notify_walker->Action > 0)
 153         {
 154           glong file_name_len;
 155           gchar *changed_file;
 156
 157           changed_file = g_utf16_to_utf8 (pfile_notify_walker->FileName,
 158                                           pfile_notify_walker->FileNameLength / sizeof(WCHAR),
 159                                           NULL, &file_name_len, NULL);
 160
 161           if (monitor->isfile)
 162             {
 163               gint long_filename_length = wcslen (monitor->wfilename_long);
 164               gint short_filename_length = wcslen (monitor->wfilename_short);
 165               enum GWin32FileMonitorFileAlias alias_state;
 166
 167               /* If monitoring a file, check that the changed file
 168               * in the directory matches the file that is to be monitored
 169               * We need to check both the long and short file names for the same file.
 170               *
 171               * We need to send in the name of the monitored file, not its long (or short) variant,
 172               * if they exist.
 173               */
 174
 175               if (_wcsnicmp (pfile_notify_walker->FileName,
 176                              monitor->wfilename_long,
 177                              long_filename_length) == 0)
 178                 {
 179                   if (_wcsnicmp (pfile_notify_walker->FileName,
 180                                  monitor->wfilename_short,
 181                                  short_filename_length) == 0)
 182                     {
 183                       alias_state = G_WIN32_FILE_MONITOR_NO_ALIAS;
 184                     }
 185                   else
 186                     alias_state = G_WIN32_FILE_MONITOR_LONG_FILENAME;
 187                 }
 188               else if (_wcsnicmp (pfile_notify_walker->FileName,
 189                                   monitor->wfilename_short,
 190                                   short_filename_length) == 0)
 191                 {
 192                   alias_state = G_WIN32_FILE_MONITOR_SHORT_FILENAME;
 193                 }
 194               else
 195                 alias_state = G_WIN32_FILE_MONITOR_NO_MATCH_FOUND;
 196
 197               if (alias_state != G_WIN32_FILE_MONITOR_NO_MATCH_FOUND)
 198                 {
 199                   wchar_t *monitored_file_w;
 200                   gchar *monitored_file;
 201
 202                   switch (alias_state)
 203                     {
 204                     case G_WIN32_FILE_MONITOR_NO_ALIAS:
 205                       monitored_file = g_strdup (changed_file);
 206                       break;
 207                     case G_WIN32_FILE_MONITOR_LONG_FILENAME:
 208                     case G_WIN32_FILE_MONITOR_SHORT_FILENAME:
 209                       monitored_file_w = wcsrchr (monitor->wfullpath_with_long_prefix, L'\\');
 210                       monitored_file = g_utf16_to_utf8 (monitored_file_w + 1, -1, NULL, NULL, NULL);
 211                       break;
 212                     default:
 213                       g_assert_not_reached ();
 214                       break;
 215                     }
 216
 217                   g_win32_fs_monitor_handle_event (monitor, monitored_file, pfile_notify_walker);
 218                   g_free (monitored_file);
 219                 }
 220             }
 221           else
 222             g_win32_fs_monitor_handle_event (monitor, changed_file, pfile_notify_walker);
 223
 224           g_free (changed_file);
 225         }
 226
 227       monitor->pfni_prev = pfile_notify_walker;
 228       offset += pfile_notify_walker->NextEntryOffset;
 229     }
 230   while (pfile_notify_walker->NextEntryOffset);
 231
 232   ReadDirectoryChangesW (monitor->hDirectory,
 233                          monitor->file_notify_buffer,
 234                          monitor->buffer_allocated_bytes,
 235                          FALSE,
 236                          notify_filter,
 237                          &monitor->buffer_filled_bytes,
 238                          &monitor->overlapped,
 239                          g_win32_fs_monitor_callback);
 240 }
 241
 242 void
 243 g_win32_fs_monitor_init (GWin32FSMonitorPrivate *monitor,
 244                          const gchar *dirname,
 245                          const gchar *filename,
 246                          gboolean isfile)
 247 {
 248   wchar_t *wdirname_with_long_prefix = NULL;
 249   const gchar LONGPFX[] = "\\\\?\\";
 250   gchar *fullpath_with_long_prefix, *dirname_with_long_prefix;
 251   DWORD notify_filter = isfile ?
 252                         (FILE_NOTIFY_CHANGE_FILE_NAME |
 253                          FILE_NOTIFY_CHANGE_ATTRIBUTES |
 254                          FILE_NOTIFY_CHANGE_SIZE) :
 255                         (FILE_NOTIFY_CHANGE_FILE_NAME |
 256                          FILE_NOTIFY_CHANGE_DIR_NAME |
 257                          FILE_NOTIFY_CHANGE_ATTRIBUTES |
 258                          FILE_NOTIFY_CHANGE_SIZE);
 259
 260   gboolean success_attribs;
 261   WIN32_FILE_ATTRIBUTE_DATA attrib_data = {0, };
 262
 263
 264   if (dirname != NULL)
 265     {
 266       dirname_with_long_prefix = g_strconcat (LONGPFX, dirname, NULL);
 267       wdirname_with_long_prefix = g_utf8_to_utf16 (dirname_with_long_prefix, -1, NULL, NULL, NULL);
 268
 269       if (isfile)
 270         {
 271           gchar *fullpath;
 272           wchar_t wlongname[MAX_PATH_LONG];
 273           wchar_t wshortname[MAX_PATH_LONG];
 274           wchar_t *wfullpath, *wbasename_long, *wbasename_short;
 275
 276           fullpath = g_build_filename (dirname, filename, NULL);
 277           fullpath_with_long_prefix = g_strconcat (LONGPFX, fullpath, NULL);
 278
 279           wfullpath = g_utf8_to_utf16 (fullpath, -1, NULL, NULL, NULL);
 280
 281           monitor->wfullpath_with_long_prefix =
 282             g_utf8_to_utf16 (fullpath_with_long_prefix, -1, NULL, NULL, NULL);
 283
 284           /* ReadDirectoryChangesW() can return the normal filename or the
 285            * "8.3" format filename, so we need to keep track of both these names
 286            * so that we can check against them later when it returns
 287            */
 288           if (GetLongPathNameW (monitor->wfullpath_with_long_prefix, wlongname, MAX_PATH_LONG) == 0)
 289             {
 290               wbasename_long = wcsrchr (monitor->wfullpath_with_long_prefix, L'\\');
 291               monitor->wfilename_long = wbasename_long != NULL ?
 292                                         wcsdup (wbasename_long + 1) :
 293                                         wcsdup (wfullpath);
 294             }
 295           else
 296             {
 297               wbasename_long = wcsrchr (wlongname, L'\\');
 298               monitor->wfilename_long = wbasename_long != NULL ?
 299                                         wcsdup (wbasename_long + 1) :
 300                                         wcsdup (wlongname);
 301
 302             }
 303
 304           if (GetShortPathNameW (monitor->wfullpath_with_long_prefix, wshortname, MAX_PATH_LONG) == 0)
 305             {
 306               wbasename_short = wcsrchr (monitor->wfullpath_with_long_prefix, L'\\');
 307               monitor->wfilename_short = wbasename_short != NULL ?
 308                                          wcsdup (wbasename_short + 1) :
 309                                          wcsdup (wfullpath);
 310             }
 311           else
 312             {
 313               wbasename_short = wcsrchr (wshortname, L'\\');
 314               monitor->wfilename_short = wbasename_short != NULL ?
 315                                          wcsdup (wbasename_short + 1) :
 316                                          wcsdup (wshortname);
 317             }
 318
 319           g_free (fullpath);
 320         }
 321       else
 322         {
 323           monitor->wfilename_short = NULL;
 324           monitor->wfilename_long = NULL;
 325           monitor->wfullpath_with_long_prefix = g_utf8_to_utf16 (dirname_with_long_prefix, -1, NULL, NULL, NULL);
 326         }
 327
 328       monitor->isfile = isfile;
 329     }
 330   else
 331     {
 332       dirname_with_long_prefix = g_strconcat (LONGPFX, filename, NULL);
 333       monitor->wfullpath_with_long_prefix = g_utf8_to_utf16 (dirname_with_long_prefix, -1, NULL, NULL, NULL);
 334       monitor->wfilename_long = NULL;
 335       monitor->wfilename_short = NULL;
 336       monitor->isfile = FALSE;
 337     }
 338
 339   success_attribs = GetFileAttributesExW (monitor->wfullpath_with_long_prefix,
 340                                           GetFileExInfoStandard,
 341                                           &attrib_data);
 342   if (success_attribs)
 343     monitor->file_attribs = attrib_data.dwFileAttributes; /* Store up original attributes */
 344   else
 345     monitor->file_attribs = INVALID_FILE_ATTRIBUTES;
 346   monitor->pfni_prev = NULL;
 347   monitor->hDirectory = CreateFileW (wdirname_with_long_prefix != NULL ? wdirname_with_long_prefix : monitor->wfullpath_with_long_prefix,
 348                                      FILE_GENERIC_READ | FILE_GENERIC_WRITE,
 349                                      FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE,
 350                                      NULL,
 351                                      OPEN_EXISTING,
 352                                      FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OVERLAPPED,
 353                                      NULL);
 354
 355   g_free (wdirname_with_long_prefix);
 356   g_free (dirname_with_long_prefix);
 357
 358   if (monitor->hDirectory != INVALID_HANDLE_VALUE)
 359     {
 360       ReadDirectoryChangesW (monitor->hDirectory,
 361                              monitor->file_notify_buffer,
 362                              monitor->buffer_allocated_bytes,
 363                              FALSE,
 364                              notify_filter,
 365                              &monitor->buffer_filled_bytes,
 366                              &monitor->overlapped,
 367                              g_win32_fs_monitor_callback);
 368     }
 369 }
 370
 371 GWin32FSMonitorPrivate *
 372 g_win32_fs_monitor_create (gboolean isfile)
 373 {
 374   GWin32FSMonitorPrivate *monitor = g_new0 (GWin32FSMonitorPrivate, 1);
 375
 376   monitor->buffer_allocated_bytes = 32784;
 377   monitor->file_notify_buffer = g_new0 (FILE_NOTIFY_INFORMATION, monitor->buffer_allocated_bytes);
 378
 379   return monitor;
 380 }
 381
 382 void
 383 g_win32_fs_monitor_finalize (GWin32FSMonitorPrivate *monitor)
 384 {
 385   g_free (monitor->wfullpath_with_long_prefix);
 386   g_free (monitor->wfilename_long);
 387   g_free (monitor->wfilename_short);
 388
 389   if (monitor->hDirectory == INVALID_HANDLE_VALUE)
 390     {
 391       /* If we don't have a directory handle we can free
 392        * monitor->file_notify_buffer and monitor here. The
 393        * callback won't be called obviously any more (and presumably
 394        * never has been called).
 395        */
 396       g_free (monitor->file_notify_buffer);
 397       monitor->file_notify_buffer = NULL;
 398       g_free (monitor);
 399     }
 400   else
 401     {
 402       /* If we have a directory handle, the OVERLAPPED struct is
 403        * passed once more to the callback as a result of the
 404        * CloseHandle() done in the cancel method, so monitor has to
 405        * be kept around. The GWin32DirectoryMonitor object is
 406        * disappearing, so can't leave a pointer to it in
 407        * monitor->self.
 408        */
 409       monitor->self = NULL;
 410     }
 411 }
 412
 413 void
 414 g_win32_fs_monitor_close_handle (GWin32FSMonitorPrivate *monitor)
 415 {
 416   /* This triggers a last callback() with nBytes==0. */
 417
 418   /* Actually I am not so sure about that, it seems to trigger a last
 419    * callback allright, but the way to recognize that it is the final
 420    * one is not to check for nBytes==0, I think that was a
 421    * misunderstanding.
 422    */
 423   if (monitor->hDirectory != INVALID_HANDLE_VALUE)
 424     CloseHandle (monitor->hDirectory);
 425 }