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, write to the
  17  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  18  * Boston, MA 02111-1307, USA.
  19  *
  20  * Author: Alexander Larsson <alexl@redhat.com>
  21  * Author: Tor Lillqvist <tml@iki.fi>
  22  */
  23
  24 #include "config.h"
  25
  26 #include <windows.h>
  27
  28 #include <io.h>
  29
  30 #include <glib.h>
  31 #include "gioerror.h"
  32 #include "gsimpleasyncresult.h"
  33 #include "gwin32inputstream.h"
  34 #include "gcancellable.h"
  35 #include "gasynchelper.h"
  36 #include "glibintl.h"
  37
  38
  39 /**
  40  * SECTION:gwin32inputstream
  41  * @short_description: Streaming input operations for Windows file handles
  42  * @include: gio/gwin32inputstream.h
  43  * @see_also: #GInputStream
  44  *
  45  * #GWin32InputStream implements #GInputStream for reading from a
  46  * Windows file handle.
  47  *
  48  * Note that <filename>&lt;gio/gwin32inputstream.h&gt;</filename> belongs
  49  * to the Windows-specific GIO interfaces, thus you have to use the
  50  * <filename>gio-windows-2.0.pc</filename> pkg-config file when using it.
  51  */
  52
  53 enum {
  54   PROP_0,
  55   PROP_HANDLE,
  56   PROP_CLOSE_HANDLE
  57 };
  58
  59 G_DEFINE_TYPE (GWin32InputStream, g_win32_input_stream, G_TYPE_INPUT_STREAM);
  60
  61 struct _GWin32InputStreamPrivate {
  62   HANDLE handle;
  63   gboolean close_handle;
  64 };
  65
  66 static void     g_win32_input_stream_set_property (GObject              *object,
  67                                                    guint                 prop_id,
  68                                                    const GValue         *value,
  69                                                    GParamSpec           *pspec);
  70 static void     g_win32_input_stream_get_property (GObject              *object,
  71                                                    guint                 prop_id,
  72                                                    GValue               *value,
  73                                                    GParamSpec           *pspec);
  74 static gssize   g_win32_input_stream_read         (GInputStream         *stream,
  75                                                    void                 *buffer,
  76                                                    gsize                 count,
  77                                                    GCancellable         *cancellable,
  78                                                    GError              **error);
  79 static gboolean g_win32_input_stream_close        (GInputStream         *stream,
  80                                                    GCancellable         *cancellable,
  81                                                    GError              **error);
  82
  83 static void
  84 g_win32_input_stream_finalize (GObject *object)
  85 {
  86   G_OBJECT_CLASS (g_win32_input_stream_parent_class)->finalize (object);
  87 }
  88
  89 static void
  90 g_win32_input_stream_class_init (GWin32InputStreamClass *klass)
  91 {
  92   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
  93   GInputStreamClass *stream_class = G_INPUT_STREAM_CLASS (klass);
  94
  95   g_type_class_add_private (klass, sizeof (GWin32InputStreamPrivate));
  96
  97   gobject_class->get_property = g_win32_input_stream_get_property;
  98   gobject_class->set_property = g_win32_input_stream_set_property;
  99   gobject_class->finalize = g_win32_input_stream_finalize;
 100
 101   stream_class->read_fn = g_win32_input_stream_read;
 102   stream_class->close_fn = g_win32_input_stream_close;
 103
 104   /**
 105    * GWin32InputStream:handle:
 106    *
 107    * The handle that the stream reads from.
 108    *
 109    * Since: 2.26
 110    */
 111   g_object_class_install_property (gobject_class,
 112                                    PROP_HANDLE,
 113                                    g_param_spec_pointer ("handle",
 114                                                          P_("File handle"),
 115                                                          P_("The file handle to read from"),
 116                                                          G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
 117
 118   /**
 119    * GWin32InputStream:close-handle:
 120    *
 121    * Whether to close the file handle when the stream is closed.
 122    *
 123    * Since: 2.26
 124    */
 125   g_object_class_install_property (gobject_class,
 126                                    PROP_CLOSE_HANDLE,
 127                                    g_param_spec_boolean ("close-handle",
 128                                                          P_("Close file handle"),
 129                                                          P_("Whether to close the file handle when the stream is closed"),
 130                                                          TRUE,
 131                                                          G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
 132 }
 133
 134 static void
 135 g_win32_input_stream_set_property (GObject         *object,
 136                                    guint            prop_id,
 137                                    const GValue    *value,
 138                                    GParamSpec      *pspec)
 139 {
 140   GWin32InputStream *win32_stream;
 141
 142   win32_stream = G_WIN32_INPUT_STREAM (object);
 143
 144   switch (prop_id)
 145     {
 146     case PROP_HANDLE:
 147       win32_stream->priv->handle = g_value_get_pointer (value);
 148       break;
 149     case PROP_CLOSE_HANDLE:
 150       win32_stream->priv->close_handle = g_value_get_boolean (value);
 151       break;
 152     default:
 153       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 154       break;
 155     }
 156 }
 157
 158 static void
 159 g_win32_input_stream_get_property (GObject    *object,
 160                                    guint       prop_id,
 161                                    GValue     *value,
 162                                    GParamSpec *pspec)
 163 {
 164   GWin32InputStream *win32_stream;
 165
 166   win32_stream = G_WIN32_INPUT_STREAM (object);
 167
 168   switch (prop_id)
 169     {
 170     case PROP_HANDLE:
 171       g_value_set_pointer (value, win32_stream->priv->handle);
 172       break;
 173     case PROP_CLOSE_HANDLE:
 174       g_value_set_boolean (value, win32_stream->priv->close_handle);
 175       break;
 176     default:
 177       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 178     }
 179 }
 180
 181 static void
 182 g_win32_input_stream_init (GWin32InputStream *win32_stream)
 183 {
 184   win32_stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (win32_stream,
 185                                                     G_TYPE_WIN32_INPUT_STREAM,
 186                                                     GWin32InputStreamPrivate);
 187
 188   win32_stream->priv->handle = NULL;
 189   win32_stream->priv->close_handle = TRUE;
 190 }
 191
 192 /**
 193  * g_win32_input_stream_new:
 194  * @handle: a Win32 file handle
 195  * @close_handle: %TRUE to close the handle when done
 196  *
 197  * Creates a new #GWin32InputStream for the given @handle.
 198  *
 199  * If @close_handle is %TRUE, the handle will be closed
 200  * when the stream is closed.
 201  *
 202  * Note that "handle" here means a Win32 HANDLE, not a "file descriptor"
 203  * as used in the Windows C libraries.
 204  *
 205  * Returns: a new #GWin32InputStream
 206  **/
 207 GInputStream *
 208 g_win32_input_stream_new (void     *handle,
 209                           gboolean close_handle)
 210 {
 211   GWin32InputStream *stream;
 212
 213   g_return_val_if_fail (handle != NULL, NULL);
 214
 215   stream = g_object_new (G_TYPE_WIN32_INPUT_STREAM,
 216                          "handle", handle,
 217                          "close-handle", close_handle,
 218                          NULL);
 219
 220   return G_INPUT_STREAM (stream);
 221 }
 222
 223 /**
 224  * g_win32_input_stream_set_close_handle:
 225  * @stream: a #GWin32InputStream
 226  * @close_handle: %TRUE to close the handle when done
 227  *
 228  * Sets whether the handle of @stream shall be closed
 229  * when the stream is closed.
 230  *
 231  * Since: 2.26
 232  */
 233 void
 234 g_win32_input_stream_set_close_handle (GWin32InputStream *stream,
 235                                        gboolean          close_handle)
 236 {
 237   g_return_if_fail (G_IS_WIN32_INPUT_STREAM (stream));
 238
 239   close_handle = close_handle != FALSE;
 240   if (stream->priv->close_handle != close_handle)
 241     {
 242       stream->priv->close_handle = close_handle;
 243       g_object_notify (G_OBJECT (stream), "close-handle");
 244     }
 245 }
 246
 247 /**
 248  * g_win32_input_stream_get_close_handle:
 249  * @stream: a #GWin32InputStream
 250  *
 251  * Returns whether the handle of @stream will be
 252  * closed when the stream is closed.
 253  *
 254  * Return value: %TRUE if the handle is closed when done
 255  *
 256  * Since: 2.26
 257  */
 258 gboolean
 259 g_win32_input_stream_get_close_handle (GWin32InputStream *stream)
 260 {
 261   g_return_val_if_fail (G_IS_WIN32_INPUT_STREAM (stream), FALSE);
 262
 263   return stream->priv->close_handle;
 264 }
 265
 266 /**
 267  * g_win32_input_stream_get_handle:
 268  * @stream: a #GWin32InputStream
 269  *
 270  * Return the Windows file handle that the stream reads from.
 271  *
 272  * Return value: The file handle of @stream
 273  *
 274  * Since: 2.26
 275  */
 276 void *
 277 g_win32_input_stream_get_handle (GWin32InputStream *stream)
 278 {
 279   g_return_val_if_fail (G_IS_WIN32_INPUT_STREAM (stream), NULL);
 280
 281   return stream->priv->handle;
 282 }
 283
 284 static gssize
 285 g_win32_input_stream_read (GInputStream  *stream,
 286                            void          *buffer,
 287                            gsize          count,
 288                            GCancellable  *cancellable,
 289                            GError       **error)
 290 {
 291   GWin32InputStream *win32_stream;
 292   BOOL res;
 293   DWORD nbytes, nread;
 294   OVERLAPPED overlap = { 0, };
 295   gssize retval = -1;
 296
 297   win32_stream = G_WIN32_INPUT_STREAM (stream);
 298
 299   if (g_cancellable_set_error_if_cancelled (cancellable, error))
 300     return -1;
 301
 302   if (count > G_MAXINT)
 303     nbytes = G_MAXINT;
 304   else
 305     nbytes = count;
 306
 307   overlap.hEvent = CreateEvent (NULL, FALSE, FALSE, NULL);
 308   g_return_val_if_fail (overlap.hEvent != NULL, -1);
 309
 310   res = ReadFile (win32_stream->priv->handle, buffer, nbytes, &nread, &overlap);
 311   if (res)
 312     retval = nread;
 313   else
 314     {
 315       int errsv = GetLastError ();
 316
 317       if (errsv == ERROR_IO_PENDING &&
 318           _g_win32_overlap_wait_result (win32_stream->priv->handle,
 319                                         &overlap, &nread, cancellable))
 320         {
 321           retval = nread;
 322           goto end;
 323         }
 324
 325       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 326         goto end;
 327
 328       errsv = GetLastError ();
 329       if (errsv == ERROR_MORE_DATA)
 330         {
 331           /* If a named pipe is being read in message mode and the
 332            * next message is longer than the nNumberOfBytesToRead
 333            * parameter specifies, ReadFile returns FALSE and
 334            * GetLastError returns ERROR_MORE_DATA */
 335           retval = nread;
 336           goto end;
 337         }
 338       else if (errsv == ERROR_HANDLE_EOF ||
 339                errsv == ERROR_BROKEN_PIPE)
 340         {
 341           /* TODO: the other end of a pipe may call the WriteFile
 342            * function with nNumberOfBytesToWrite set to zero. In this
 343            * case, it's not possible for the caller to know if it's
 344            * broken pipe or a read of 0. Perhaps we should add a
 345            * is_broken flag for this win32 case.. */
 346           retval = 0;
 347         }
 348       else
 349         {
 350           gchar *emsg;
 351
 352           emsg = g_win32_error_message (errsv);
 353           g_set_error (error, G_IO_ERROR,
 354                        g_io_error_from_win32_error (errsv),
 355                        _("Error reading from handle: %s"),
 356                        emsg);
 357           g_free (emsg);
 358         }
 359     }
 360
 361 end:
 362   CloseHandle (overlap.hEvent);
 363   return retval;
 364 }
 365
 366 static gboolean
 367 g_win32_input_stream_close (GInputStream  *stream,
 368                            GCancellable  *cancellable,
 369                            GError       **error)
 370 {
 371   GWin32InputStream *win32_stream;
 372   BOOL res;
 373
 374   win32_stream = G_WIN32_INPUT_STREAM (stream);
 375
 376   if (!win32_stream->priv->close_handle)
 377     return TRUE;
 378
 379   res = CloseHandle (win32_stream->priv->handle);
 380   if (!res)
 381     {
 382       int errsv = GetLastError ();
 383       gchar *emsg = g_win32_error_message (errsv);
 384
 385       g_set_error (error, G_IO_ERROR,
 386                    g_io_error_from_win32_error (errsv),
 387                    _("Error closing handle: %s"),
 388                    emsg);
 389       g_free (emsg);
 390       return FALSE;
 391     }
 392
 393   return TRUE;
 394 }