gio/gwin32inputstream.c

   1 /* GIO - GLib Input, Output and Streaming Library
   2  *
   3  * Copyright (C) 2006-2010 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: Alexander Larsson <alexl@redhat.com>
  19  * Author: Tor Lillqvist <tml@iki.fi>
  20  */
  21
  22 #include "config.h"
  23
  24 #include <windows.h>
  25
  26 #include <io.h>
  27
  28 #include <glib.h>
  29 #include "gioerror.h"
  30 #include "gwin32inputstream.h"
  31 #include "giowin32-priv.h"
  32 #include "gcancellable.h"
  33 #include "gasynchelper.h"
  34 #include "glibintl.h"
  35
  36 /**
  37  * SECTION:gwin32inputstream
  38  * @short_description: Streaming input operations for Windows file handles
  39  * @include: gio/gwin32inputstream.h
  40  * @see_also: #GInputStream
  41  *
  42  * #GWin32InputStream implements #GInputStream for reading from a
  43  * Windows file handle.
  44  *
  45  * Note that `<gio/gwin32inputstream.h>` belongs to the Windows-specific GIO
  46  * interfaces, thus you have to use the `gio-windows-2.0.pc` pkg-config file
  47  * when using it.
  48  */
  49
  50 struct _GWin32InputStreamPrivate {
  51   HANDLE handle;
  52   gboolean close_handle;
  53   gint fd;
  54 };
  55
  56 enum {
  57   PROP_0,
  58   PROP_HANDLE,
  59   PROP_CLOSE_HANDLE,
  60   LAST_PROP
  61 };
  62
  63 static GParamSpec *props[LAST_PROP];
  64
  65 G_DEFINE_TYPE_WITH_PRIVATE (GWin32InputStream, g_win32_input_stream, G_TYPE_INPUT_STREAM)
  66
  67 static void
  68 g_win32_input_stream_set_property (GObject         *object,
  69                                    guint            prop_id,
  70                                    const GValue    *value,
  71                                    GParamSpec      *pspec)
  72 {
  73   GWin32InputStream *win32_stream;
  74
  75   win32_stream = G_WIN32_INPUT_STREAM (object);
  76
  77   switch (prop_id)
  78     {
  79     case PROP_HANDLE:
  80       win32_stream->priv->handle = g_value_get_pointer (value);
  81       break;
  82     case PROP_CLOSE_HANDLE:
  83       win32_stream->priv->close_handle = g_value_get_boolean (value);
  84       break;
  85     default:
  86       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
  87       break;
  88     }
  89 }
  90
  91 static void
  92 g_win32_input_stream_get_property (GObject    *object,
  93                                    guint       prop_id,
  94                                    GValue     *value,
  95                                    GParamSpec *pspec)
  96 {
  97   GWin32InputStream *win32_stream;
  98
  99   win32_stream = G_WIN32_INPUT_STREAM (object);
 100
 101   switch (prop_id)
 102     {
 103     case PROP_HANDLE:
 104       g_value_set_pointer (value, win32_stream->priv->handle);
 105       break;
 106     case PROP_CLOSE_HANDLE:
 107       g_value_set_boolean (value, win32_stream->priv->close_handle);
 108       break;
 109     default:
 110       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 111     }
 112 }
 113
 114 static gssize
 115 g_win32_input_stream_read (GInputStream  *stream,
 116                            void          *buffer,
 117                            gsize          count,
 118                            GCancellable  *cancellable,
 119                            GError       **error)
 120 {
 121   GWin32InputStream *win32_stream;
 122   BOOL res;
 123   DWORD nbytes, nread;
 124   OVERLAPPED overlap = { 0, };
 125   gssize retval = -1;
 126
 127   win32_stream = G_WIN32_INPUT_STREAM (stream);
 128
 129   if (g_cancellable_set_error_if_cancelled (cancellable, error))
 130     return -1;
 131
 132   if (count > G_MAXINT)
 133     nbytes = G_MAXINT;
 134   else
 135     nbytes = count;
 136
 137   overlap.hEvent = CreateEvent (NULL, FALSE, FALSE, NULL);
 138   g_return_val_if_fail (overlap.hEvent != NULL, -1);
 139
 140   res = ReadFile (win32_stream->priv->handle, buffer, nbytes, &nread, &overlap);
 141   if (res)
 142     retval = nread;
 143   else
 144     {
 145       int errsv = GetLastError ();
 146
 147       if (errsv == ERROR_IO_PENDING &&
 148           _g_win32_overlap_wait_result (win32_stream->priv->handle,
 149                                         &overlap, &nread, cancellable))
 150         {
 151           retval = nread;
 152           goto end;
 153         }
 154
 155       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 156         goto end;
 157
 158       errsv = GetLastError ();
 159       if (errsv == ERROR_MORE_DATA)
 160         {
 161           /* If a named pipe is being read in message mode and the
 162            * next message is longer than the nNumberOfBytesToRead
 163            * parameter specifies, ReadFile returns FALSE and
 164            * GetLastError returns ERROR_MORE_DATA */
 165           retval = nread;
 166           goto end;
 167         }
 168       else if (errsv == ERROR_HANDLE_EOF ||
 169                errsv == ERROR_BROKEN_PIPE)
 170         {
 171           /* TODO: the other end of a pipe may call the WriteFile
 172            * function with nNumberOfBytesToWrite set to zero. In this
 173            * case, it's not possible for the caller to know if it's
 174            * broken pipe or a read of 0. Perhaps we should add a
 175            * is_broken flag for this win32 case.. */
 176           retval = 0;
 177         }
 178       else
 179         {
 180           gchar *emsg;
 181
 182           emsg = g_win32_error_message (errsv);
 183           g_set_error (error, G_IO_ERROR,
 184                        g_io_error_from_win32_error (errsv),
 185                        _("Error reading from handle: %s"),
 186                        emsg);
 187           g_free (emsg);
 188         }
 189     }
 190
 191 end:
 192   CloseHandle (overlap.hEvent);
 193   return retval;
 194 }
 195
 196 static gboolean
 197 g_win32_input_stream_close (GInputStream  *stream,
 198                            GCancellable  *cancellable,
 199                            GError       **error)
 200 {
 201   GWin32InputStream *win32_stream;
 202   BOOL res;
 203
 204   win32_stream = G_WIN32_INPUT_STREAM (stream);
 205
 206   if (!win32_stream->priv->close_handle)
 207     return TRUE;
 208
 209   if (win32_stream->priv->fd != -1)
 210     {
 211       if (close (win32_stream->priv->fd) < 0)
 212         {
 213           int errsv = errno;
 214
 215           g_set_error (error, G_IO_ERROR,
 216                        g_io_error_from_errno (errsv),
 217                        _("Error closing file descriptor: %s"),
 218                        g_strerror (errsv));
 219           return FALSE;
 220         }
 221     }
 222   else
 223     {
 224       res = CloseHandle (win32_stream->priv->handle);
 225       if (!res)
 226         {
 227           int errsv = GetLastError ();
 228           gchar *emsg = g_win32_error_message (errsv);
 229
 230           g_set_error (error, G_IO_ERROR,
 231                        g_io_error_from_win32_error (errsv),
 232                        _("Error closing handle: %s"),
 233                        emsg);
 234           g_free (emsg);
 235           return FALSE;
 236         }
 237     }
 238
 239   return TRUE;
 240 }
 241
 242 static void
 243 g_win32_input_stream_class_init (GWin32InputStreamClass *klass)
 244 {
 245   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 246   GInputStreamClass *stream_class = G_INPUT_STREAM_CLASS (klass);
 247
 248   gobject_class->get_property = g_win32_input_stream_get_property;
 249   gobject_class->set_property = g_win32_input_stream_set_property;
 250
 251   stream_class->read_fn = g_win32_input_stream_read;
 252   stream_class->close_fn = g_win32_input_stream_close;
 253
 254   /**
 255    * GWin32InputStream:handle:
 256    *
 257    * The handle that the stream reads from.
 258    *
 259    * Since: 2.26
 260    */
 261   props[PROP_HANDLE] =
 262     g_param_spec_pointer ("handle",
 263                           P_("File handle"),
 264                           P_("The file handle to read from"),
 265                           G_PARAM_READABLE |
 266                           G_PARAM_WRITABLE |
 267                           G_PARAM_CONSTRUCT_ONLY |
 268                           G_PARAM_STATIC_STRINGS);
 269
 270   /**
 271    * GWin32InputStream:close-handle:
 272    *
 273    * Whether to close the file handle when the stream is closed.
 274    *
 275    * Since: 2.26
 276    */
 277   props[PROP_CLOSE_HANDLE] =
 278     g_param_spec_boolean ("close-handle",
 279                           P_("Close file handle"),
 280                           P_("Whether to close the file handle when the stream is closed"),
 281                           TRUE,
 282                           G_PARAM_READABLE |
 283                           G_PARAM_WRITABLE |
 284                           G_PARAM_STATIC_STRINGS);
 285
 286   g_object_class_install_properties (gobject_class, LAST_PROP, props);
 287 }
 288
 289 static void
 290 g_win32_input_stream_init (GWin32InputStream *win32_stream)
 291 {
 292   win32_stream->priv = g_win32_input_stream_get_instance_private (win32_stream);
 293   win32_stream->priv->handle = NULL;
 294   win32_stream->priv->close_handle = TRUE;
 295   win32_stream->priv->fd = -1;
 296 }
 297
 298 /**
 299  * g_win32_input_stream_new:
 300  * @handle: a Win32 file handle
 301  * @close_handle: %TRUE to close the handle when done
 302  *
 303  * Creates a new #GWin32InputStream for the given @handle.
 304  *
 305  * If @close_handle is %TRUE, the handle will be closed
 306  * when the stream is closed.
 307  *
 308  * Note that "handle" here means a Win32 HANDLE, not a "file descriptor"
 309  * as used in the Windows C libraries.
 310  *
 311  * Returns: a new #GWin32InputStream
 312  **/
 313 GInputStream *
 314 g_win32_input_stream_new (void     *handle,
 315                           gboolean close_handle)
 316 {
 317   GWin32InputStream *stream;
 318
 319   g_return_val_if_fail (handle != NULL, NULL);
 320
 321   stream = g_object_new (G_TYPE_WIN32_INPUT_STREAM,
 322                          "handle", handle,
 323                          "close-handle", close_handle,
 324                          NULL);
 325
 326   return G_INPUT_STREAM (stream);
 327 }
 328
 329 /**
 330  * g_win32_input_stream_set_close_handle:
 331  * @stream: a #GWin32InputStream
 332  * @close_handle: %TRUE to close the handle when done
 333  *
 334  * Sets whether the handle of @stream shall be closed
 335  * when the stream is closed.
 336  *
 337  * Since: 2.26
 338  */
 339 void
 340 g_win32_input_stream_set_close_handle (GWin32InputStream *stream,
 341                                        gboolean          close_handle)
 342 {
 343   g_return_if_fail (G_IS_WIN32_INPUT_STREAM (stream));
 344
 345   close_handle = close_handle != FALSE;
 346   if (stream->priv->close_handle != close_handle)
 347     {
 348       stream->priv->close_handle = close_handle;
 349       g_object_notify (G_OBJECT (stream), "close-handle");
 350     }
 351 }
 352
 353 /**
 354  * g_win32_input_stream_get_close_handle:
 355  * @stream: a #GWin32InputStream
 356  *
 357  * Returns whether the handle of @stream will be
 358  * closed when the stream is closed.
 359  *
 360  * Returns: %TRUE if the handle is closed when done
 361  *
 362  * Since: 2.26
 363  */
 364 gboolean
 365 g_win32_input_stream_get_close_handle (GWin32InputStream *stream)
 366 {
 367   g_return_val_if_fail (G_IS_WIN32_INPUT_STREAM (stream), FALSE);
 368
 369   return stream->priv->close_handle;
 370 }
 371
 372 /**
 373  * g_win32_input_stream_get_handle:
 374  * @stream: a #GWin32InputStream
 375  *
 376  * Return the Windows file handle that the stream reads from.
 377  *
 378  * Returns: The file handle of @stream
 379  *
 380  * Since: 2.26
 381  */
 382 void *
 383 g_win32_input_stream_get_handle (GWin32InputStream *stream)
 384 {
 385   g_return_val_if_fail (G_IS_WIN32_INPUT_STREAM (stream), NULL);
 386
 387   return stream->priv->handle;
 388 }
 389
 390 GInputStream *
 391 g_win32_input_stream_new_from_fd (gint      fd,
 392                                   gboolean  close_fd)
 393 {
 394   GWin32InputStream *win32_stream;
 395
 396   win32_stream = G_WIN32_INPUT_STREAM (g_win32_input_stream_new ((HANDLE) _get_osfhandle (fd), close_fd));
 397   win32_stream->priv->fd = fd;
 398
 399   return (GInputStream*)win32_stream;
 400 }