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 struct _GWin32InputStreamPrivate {
  60   HANDLE handle;
  61   gboolean close_handle;
  62 };
  63
  64 G_DEFINE_TYPE_WITH_PRIVATE (GWin32InputStream, g_win32_input_stream, G_TYPE_INPUT_STREAM)
  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_class_init (GWin32InputStreamClass *klass)
  85 {
  86   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
  87   GInputStreamClass *stream_class = G_INPUT_STREAM_CLASS (klass);
  88
  89   gobject_class->get_property = g_win32_input_stream_get_property;
  90   gobject_class->set_property = g_win32_input_stream_set_property;
  91
  92   stream_class->read_fn = g_win32_input_stream_read;
  93   stream_class->close_fn = g_win32_input_stream_close;
  94
  95   /**
  96    * GWin32InputStream:handle:
  97    *
  98    * The handle that the stream reads from.
  99    *
 100    * Since: 2.26
 101    */
 102   g_object_class_install_property (gobject_class,
 103                                    PROP_HANDLE,
 104                                    g_param_spec_pointer ("handle",
 105                                                          P_("File handle"),
 106                                                          P_("The file handle to read from"),
 107                                                          G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
 108
 109   /**
 110    * GWin32InputStream:close-handle:
 111    *
 112    * Whether to close the file handle when the stream is closed.
 113    *
 114    * Since: 2.26
 115    */
 116   g_object_class_install_property (gobject_class,
 117                                    PROP_CLOSE_HANDLE,
 118                                    g_param_spec_boolean ("close-handle",
 119                                                          P_("Close file handle"),
 120                                                          P_("Whether to close the file handle when the stream is closed"),
 121                                                          TRUE,
 122                                                          G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
 123 }
 124
 125 static void
 126 g_win32_input_stream_set_property (GObject         *object,
 127                                    guint            prop_id,
 128                                    const GValue    *value,
 129                                    GParamSpec      *pspec)
 130 {
 131   GWin32InputStream *win32_stream;
 132
 133   win32_stream = G_WIN32_INPUT_STREAM (object);
 134
 135   switch (prop_id)
 136     {
 137     case PROP_HANDLE:
 138       win32_stream->priv->handle = g_value_get_pointer (value);
 139       break;
 140     case PROP_CLOSE_HANDLE:
 141       win32_stream->priv->close_handle = g_value_get_boolean (value);
 142       break;
 143     default:
 144       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 145       break;
 146     }
 147 }
 148
 149 static void
 150 g_win32_input_stream_get_property (GObject    *object,
 151                                    guint       prop_id,
 152                                    GValue     *value,
 153                                    GParamSpec *pspec)
 154 {
 155   GWin32InputStream *win32_stream;
 156
 157   win32_stream = G_WIN32_INPUT_STREAM (object);
 158
 159   switch (prop_id)
 160     {
 161     case PROP_HANDLE:
 162       g_value_set_pointer (value, win32_stream->priv->handle);
 163       break;
 164     case PROP_CLOSE_HANDLE:
 165       g_value_set_boolean (value, win32_stream->priv->close_handle);
 166       break;
 167     default:
 168       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 169     }
 170 }
 171
 172 static void
 173 g_win32_input_stream_init (GWin32InputStream *win32_stream)
 174 {
 175   win32_stream->priv = g_win32_input_stream_get_instance_private (win32_stream);
 176   win32_stream->priv->handle = NULL;
 177   win32_stream->priv->close_handle = TRUE;
 178 }
 179
 180 /**
 181  * g_win32_input_stream_new:
 182  * @handle: a Win32 file handle
 183  * @close_handle: %TRUE to close the handle when done
 184  *
 185  * Creates a new #GWin32InputStream for the given @handle.
 186  *
 187  * If @close_handle is %TRUE, the handle will be closed
 188  * when the stream is closed.
 189  *
 190  * Note that "handle" here means a Win32 HANDLE, not a "file descriptor"
 191  * as used in the Windows C libraries.
 192  *
 193  * Returns: a new #GWin32InputStream
 194  **/
 195 GInputStream *
 196 g_win32_input_stream_new (void     *handle,
 197                           gboolean close_handle)
 198 {
 199   GWin32InputStream *stream;
 200
 201   g_return_val_if_fail (handle != NULL, NULL);
 202
 203   stream = g_object_new (G_TYPE_WIN32_INPUT_STREAM,
 204                          "handle", handle,
 205                          "close-handle", close_handle,
 206                          NULL);
 207
 208   return G_INPUT_STREAM (stream);
 209 }
 210
 211 /**
 212  * g_win32_input_stream_set_close_handle:
 213  * @stream: a #GWin32InputStream
 214  * @close_handle: %TRUE to close the handle when done
 215  *
 216  * Sets whether the handle of @stream shall be closed
 217  * when the stream is closed.
 218  *
 219  * Since: 2.26
 220  */
 221 void
 222 g_win32_input_stream_set_close_handle (GWin32InputStream *stream,
 223                                        gboolean          close_handle)
 224 {
 225   g_return_if_fail (G_IS_WIN32_INPUT_STREAM (stream));
 226
 227   close_handle = close_handle != FALSE;
 228   if (stream->priv->close_handle != close_handle)
 229     {
 230       stream->priv->close_handle = close_handle;
 231       g_object_notify (G_OBJECT (stream), "close-handle");
 232     }
 233 }
 234
 235 /**
 236  * g_win32_input_stream_get_close_handle:
 237  * @stream: a #GWin32InputStream
 238  *
 239  * Returns whether the handle of @stream will be
 240  * closed when the stream is closed.
 241  *
 242  * Return value: %TRUE if the handle is closed when done
 243  *
 244  * Since: 2.26
 245  */
 246 gboolean
 247 g_win32_input_stream_get_close_handle (GWin32InputStream *stream)
 248 {
 249   g_return_val_if_fail (G_IS_WIN32_INPUT_STREAM (stream), FALSE);
 250
 251   return stream->priv->close_handle;
 252 }
 253
 254 /**
 255  * g_win32_input_stream_get_handle:
 256  * @stream: a #GWin32InputStream
 257  *
 258  * Return the Windows file handle that the stream reads from.
 259  *
 260  * Return value: The file handle of @stream
 261  *
 262  * Since: 2.26
 263  */
 264 void *
 265 g_win32_input_stream_get_handle (GWin32InputStream *stream)
 266 {
 267   g_return_val_if_fail (G_IS_WIN32_INPUT_STREAM (stream), NULL);
 268
 269   return stream->priv->handle;
 270 }
 271
 272 static gssize
 273 g_win32_input_stream_read (GInputStream  *stream,
 274                            void          *buffer,
 275                            gsize          count,
 276                            GCancellable  *cancellable,
 277                            GError       **error)
 278 {
 279   GWin32InputStream *win32_stream;
 280   BOOL res;
 281   DWORD nbytes, nread;
 282   OVERLAPPED overlap = { 0, };
 283   gssize retval = -1;
 284
 285   win32_stream = G_WIN32_INPUT_STREAM (stream);
 286
 287   if (g_cancellable_set_error_if_cancelled (cancellable, error))
 288     return -1;
 289
 290   if (count > G_MAXINT)
 291     nbytes = G_MAXINT;
 292   else
 293     nbytes = count;
 294
 295   overlap.hEvent = CreateEvent (NULL, FALSE, FALSE, NULL);
 296   g_return_val_if_fail (overlap.hEvent != NULL, -1);
 297
 298   res = ReadFile (win32_stream->priv->handle, buffer, nbytes, &nread, &overlap);
 299   if (res)
 300     retval = nread;
 301   else
 302     {
 303       int errsv = GetLastError ();
 304
 305       if (errsv == ERROR_IO_PENDING &&
 306           _g_win32_overlap_wait_result (win32_stream->priv->handle,
 307                                         &overlap, &nread, cancellable))
 308         {
 309           retval = nread;
 310           goto end;
 311         }
 312
 313       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 314         goto end;
 315
 316       errsv = GetLastError ();
 317       if (errsv == ERROR_MORE_DATA)
 318         {
 319           /* If a named pipe is being read in message mode and the
 320            * next message is longer than the nNumberOfBytesToRead
 321            * parameter specifies, ReadFile returns FALSE and
 322            * GetLastError returns ERROR_MORE_DATA */
 323           retval = nread;
 324           goto end;
 325         }
 326       else if (errsv == ERROR_HANDLE_EOF ||
 327                errsv == ERROR_BROKEN_PIPE)
 328         {
 329           /* TODO: the other end of a pipe may call the WriteFile
 330            * function with nNumberOfBytesToWrite set to zero. In this
 331            * case, it's not possible for the caller to know if it's
 332            * broken pipe or a read of 0. Perhaps we should add a
 333            * is_broken flag for this win32 case.. */
 334           retval = 0;
 335         }
 336       else
 337         {
 338           gchar *emsg;
 339
 340           emsg = g_win32_error_message (errsv);
 341           g_set_error (error, G_IO_ERROR,
 342                        g_io_error_from_win32_error (errsv),
 343                        _("Error reading from handle: %s"),
 344                        emsg);
 345           g_free (emsg);
 346         }
 347     }
 348
 349 end:
 350   CloseHandle (overlap.hEvent);
 351   return retval;
 352 }
 353
 354 static gboolean
 355 g_win32_input_stream_close (GInputStream  *stream,
 356                            GCancellable  *cancellable,
 357                            GError       **error)
 358 {
 359   GWin32InputStream *win32_stream;
 360   BOOL res;
 361
 362   win32_stream = G_WIN32_INPUT_STREAM (stream);
 363
 364   if (!win32_stream->priv->close_handle)
 365     return TRUE;
 366
 367   res = CloseHandle (win32_stream->priv->handle);
 368   if (!res)
 369     {
 370       int errsv = GetLastError ();
 371       gchar *emsg = g_win32_error_message (errsv);
 372
 373       g_set_error (error, G_IO_ERROR,
 374                    g_io_error_from_win32_error (errsv),
 375                    _("Error closing handle: %s"),
 376                    emsg);
 377       g_free (emsg);
 378       return FALSE;
 379     }
 380
 381   return TRUE;
 382 }