gio/gunixoutputstream.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, 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  */
  22
  23 #include "config.h"
  24
  25 #include <sys/types.h>
  26 #include <sys/stat.h>
  27 #include <unistd.h>
  28 #include <errno.h>
  29 #include <stdio.h>
  30 #include <fcntl.h>
  31
  32 #include <glib.h>
  33 #include <glib/gstdio.h>
  34 #include "gioerror.h"
  35 #include "gunixoutputstream.h"
  36 #include "gcancellable.h"
  37 #include "gsimpleasyncresult.h"
  38 #include "gasynchelper.h"
  39 #include "glibintl.h"
  40
  41 #include "gioalias.h"
  42
  43 /**
  44  * SECTION:gunixoutputstream
  45  * @short_description: Streaming output operations for Unix file descriptors
  46  * @include: gio/gunixoutputstream.h
  47  * @see_also: #GOutputStream
  48  *
  49  * #GUnixOutputStream implements #GOutputStream for writing to a
  50  * unix file descriptor, including asynchronous operations. The file
  51  * descriptor must be selectable, so it doesn't work with opened files.
  52  *
  53  * Note that <filename>&lt;gio/gunixoutputstream.h&gt;</filename> belongs
  54  * to the UNIX-specific GIO interfaces, thus you have to use the
  55  * <filename>gio-unix-2.0.pc</filename> pkg-config file when using it.
  56  */
  57
  58 enum {
  59   PROP_0,
  60   PROP_FD,
  61   PROP_CLOSE_FD
  62 };
  63
  64 G_DEFINE_TYPE (GUnixOutputStream, g_unix_output_stream, G_TYPE_OUTPUT_STREAM);
  65
  66
  67 struct _GUnixOutputStreamPrivate {
  68   int fd;
  69   gboolean close_fd;
  70 };
  71
  72 static void     g_unix_output_stream_set_property (GObject              *object,
  73                                                    guint                 prop_id,
  74                                                    const GValue         *value,
  75                                                    GParamSpec           *pspec);
  76 static void     g_unix_output_stream_get_property (GObject              *object,
  77                                                    guint                 prop_id,
  78                                                    GValue               *value,
  79                                                    GParamSpec           *pspec);
  80 static gssize   g_unix_output_stream_write        (GOutputStream        *stream,
  81                                                    const void           *buffer,
  82                                                    gsize                 count,
  83                                                    GCancellable         *cancellable,
  84                                                    GError              **error);
  85 static gboolean g_unix_output_stream_close        (GOutputStream        *stream,
  86                                                    GCancellable         *cancellable,
  87                                                    GError              **error);
  88 static void     g_unix_output_stream_write_async  (GOutputStream        *stream,
  89                                                    const void           *buffer,
  90                                                    gsize                 count,
  91                                                    int                   io_priority,
  92                                                    GCancellable         *cancellable,
  93                                                    GAsyncReadyCallback   callback,
  94                                                    gpointer              data);
  95 static gssize   g_unix_output_stream_write_finish (GOutputStream        *stream,
  96                                                    GAsyncResult         *result,
  97                                                    GError              **error);
  98 static void     g_unix_output_stream_close_async  (GOutputStream        *stream,
  99                                                    int                   io_priority,
 100                                                    GCancellable         *cancellable,
 101                                                    GAsyncReadyCallback   callback,
 102                                                    gpointer              data);
 103 static gboolean g_unix_output_stream_close_finish (GOutputStream        *stream,
 104                                                    GAsyncResult         *result,
 105                                                    GError              **error);
 106
 107
 108 static void
 109 g_unix_output_stream_finalize (GObject *object)
 110 {
 111   GUnixOutputStream *stream;
 112
 113   stream = G_UNIX_OUTPUT_STREAM (object);
 114
 115   G_OBJECT_CLASS (g_unix_output_stream_parent_class)->finalize (object);
 116 }
 117
 118 static void
 119 g_unix_output_stream_class_init (GUnixOutputStreamClass *klass)
 120 {
 121   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 122   GOutputStreamClass *stream_class = G_OUTPUT_STREAM_CLASS (klass);
 123
 124   g_type_class_add_private (klass, sizeof (GUnixOutputStreamPrivate));
 125
 126   gobject_class->get_property = g_unix_output_stream_get_property;
 127   gobject_class->set_property = g_unix_output_stream_set_property;
 128   gobject_class->finalize = g_unix_output_stream_finalize;
 129
 130   stream_class->write_fn = g_unix_output_stream_write;
 131   stream_class->close_fn = g_unix_output_stream_close;
 132   stream_class->write_async = g_unix_output_stream_write_async;
 133   stream_class->write_finish = g_unix_output_stream_write_finish;
 134   stream_class->close_async = g_unix_output_stream_close_async;
 135   stream_class->close_finish = g_unix_output_stream_close_finish;
 136
 137    /**
 138    * GUnixOutputStream:fd:
 139    *
 140    * The file descriptor that the stream writes to.
 141    *
 142    * Since: 2.20
 143    */
 144   g_object_class_install_property (gobject_class,
 145                                    PROP_FD,
 146                                    g_param_spec_int ("fd",
 147                                                      P_("File descriptor"),
 148                                                      P_("The file descriptor to write to"),
 149                                                      G_MININT, G_MAXINT, -1,
 150                                                      G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
 151
 152   /**
 153    * GUnixOutputStream:close-fd:
 154    *
 155    * Whether to close the file descriptor when the stream is closed.
 156    *
 157    * Since: 2.20
 158    */
 159   g_object_class_install_property (gobject_class,
 160                                    PROP_CLOSE_FD,
 161                                    g_param_spec_boolean ("close-fd",
 162                                                          P_("Close file descriptor"),
 163                                                          P_("Whether to close the file descriptor when the stream is closed"),
 164                                                          TRUE,
 165                                                          G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
 166 }
 167
 168 static void
 169 g_unix_output_stream_set_property (GObject         *object,
 170                                    guint            prop_id,
 171                                    const GValue    *value,
 172                                    GParamSpec      *pspec)
 173 {
 174   GUnixOutputStream *unix_stream;
 175
 176   unix_stream = G_UNIX_OUTPUT_STREAM (object);
 177
 178   switch (prop_id)
 179     {
 180     case PROP_FD:
 181       unix_stream->priv->fd = g_value_get_int (value);
 182       break;
 183     case PROP_CLOSE_FD:
 184       unix_stream->priv->close_fd = g_value_get_boolean (value);
 185       break;
 186     default:
 187       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 188       break;
 189     }
 190 }
 191
 192 static void
 193 g_unix_output_stream_get_property (GObject    *object,
 194                                    guint       prop_id,
 195                                    GValue     *value,
 196                                    GParamSpec *pspec)
 197 {
 198   GUnixOutputStream *unix_stream;
 199
 200   unix_stream = G_UNIX_OUTPUT_STREAM (object);
 201
 202   switch (prop_id)
 203     {
 204     case PROP_FD:
 205       g_value_set_int (value, unix_stream->priv->fd);
 206       break;
 207     case PROP_CLOSE_FD:
 208       g_value_set_boolean (value, unix_stream->priv->close_fd);
 209       break;
 210     default:
 211       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 212     }
 213 }
 214
 215 static void
 216 g_unix_output_stream_init (GUnixOutputStream *unix_stream)
 217 {
 218   unix_stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (unix_stream,
 219                                                    G_TYPE_UNIX_OUTPUT_STREAM,
 220                                                    GUnixOutputStreamPrivate);
 221
 222   unix_stream->priv->fd = -1;
 223   unix_stream->priv->close_fd = TRUE;
 224 }
 225
 226 /**
 227  * g_unix_output_stream_new:
 228  * @fd: a UNIX file descriptor
 229  * @close_fd: %TRUE to close the file descriptor when done
 230  *
 231  * Creates a new #GUnixOutputStream for the given @fd.
 232  *
 233  * If @close_fd, is %TRUE, the file descriptor will be closed when
 234  * the output stream is destroyed.
 235  *
 236  * Returns: a new #GOutputStream
 237  **/
 238 GOutputStream *
 239 g_unix_output_stream_new (gint     fd,
 240                           gboolean close_fd)
 241 {
 242   GUnixOutputStream *stream;
 243
 244   g_return_val_if_fail (fd != -1, NULL);
 245
 246   stream = g_object_new (G_TYPE_UNIX_OUTPUT_STREAM,
 247                          "fd", fd,
 248                          "close-fd", close_fd,
 249                          NULL);
 250
 251   return G_OUTPUT_STREAM (stream);
 252 }
 253
 254 /**
 255  * g_unix_output_stream_set_close_fd:
 256  * @stream: a #GUnixOutputStream
 257  * @close_fd: %TRUE to close the file descriptor when done
 258  *
 259  * Sets whether the file descriptor of @stream shall be closed
 260  * when the stream is closed.
 261  *
 262  * Since: 2.20
 263  */
 264 void
 265 g_unix_output_stream_set_close_fd (GUnixOutputStream *stream,
 266                                    gboolean           close_fd)
 267 {
 268   g_return_if_fail (G_IS_UNIX_OUTPUT_STREAM (stream));
 269
 270   close_fd = close_fd != FALSE;
 271   if (stream->priv->close_fd != close_fd)
 272     {
 273       stream->priv->close_fd = close_fd;
 274       g_object_notify (G_OBJECT (stream), "close-fd");
 275     }
 276 }
 277
 278 /**
 279  * g_unix_output_stream_get_close_fd:
 280  * @stream: a #GUnixOutputStream
 281  *
 282  * Returns whether the file descriptor of @stream will be
 283  * closed when the stream is closed.
 284  *
 285  * Return value: %TRUE if the file descriptor is closed when done
 286  *
 287  * Since: 2.20
 288  */
 289 gboolean
 290 g_unix_output_stream_get_close_fd (GUnixOutputStream *stream)
 291 {
 292   g_return_val_if_fail (G_IS_UNIX_OUTPUT_STREAM (stream), FALSE);
 293
 294   return stream->priv->close_fd;
 295 }
 296
 297 /**
 298  * g_unix_output_stream_get_fd:
 299  * @stream: a #GUnixOutputStream
 300  *
 301  * Return the UNIX file descriptor that the stream writes to.
 302  *
 303  * Return value: The file descriptor of @stream
 304  *
 305  * Since: 2.20
 306  */
 307 gint
 308 g_unix_output_stream_get_fd (GUnixOutputStream *stream)
 309 {
 310   g_return_val_if_fail (G_IS_UNIX_OUTPUT_STREAM (stream), -1);
 311
 312   return stream->priv->fd;
 313 }
 314
 315 static gssize
 316 g_unix_output_stream_write (GOutputStream  *stream,
 317                             const void     *buffer,
 318                             gsize           count,
 319                             GCancellable   *cancellable,
 320                             GError        **error)
 321 {
 322   GUnixOutputStream *unix_stream;
 323   gssize res;
 324   GPollFD poll_fds[2];
 325   int poll_ret;
 326
 327   unix_stream = G_UNIX_OUTPUT_STREAM (stream);
 328
 329   if (g_cancellable_make_pollfd (cancellable, &poll_fds[1]))
 330     {
 331       poll_fds[0].fd = unix_stream->priv->fd;
 332       poll_fds[0].events = G_IO_OUT;
 333       do
 334         poll_ret = g_poll (poll_fds, 2, -1);
 335       while (poll_ret == -1 && errno == EINTR);
 336
 337       if (poll_ret == -1)
 338         {
 339           int errsv = errno;
 340
 341           g_set_error (error, G_IO_ERROR,
 342                        g_io_error_from_errno (errsv),
 343                        _("Error writing to unix: %s"),
 344                        g_strerror (errsv));
 345           return -1;
 346         }
 347     }
 348
 349   while (1)
 350     {
 351       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 352         return -1;
 353
 354       res = write (unix_stream->priv->fd, buffer, count);
 355       if (res == -1)
 356         {
 357           int errsv = errno;
 358
 359           if (errsv == EINTR)
 360             continue;
 361
 362           g_set_error (error, G_IO_ERROR,
 363                        g_io_error_from_errno (errsv),
 364                        _("Error writing to unix: %s"),
 365                        g_strerror (errsv));
 366         }
 367
 368       break;
 369     }
 370
 371   return res;
 372 }
 373
 374 static gboolean
 375 g_unix_output_stream_close (GOutputStream  *stream,
 376                             GCancellable   *cancellable,
 377                             GError        **error)
 378 {
 379   GUnixOutputStream *unix_stream;
 380   int res;
 381
 382   unix_stream = G_UNIX_OUTPUT_STREAM (stream);
 383
 384   if (!unix_stream->priv->close_fd)
 385     return TRUE;
 386
 387   while (1)
 388     {
 389       /* This might block during the close. Doesn't seem to be a way to avoid it though. */
 390       res = close (unix_stream->priv->fd);
 391       if (res == -1)
 392         {
 393           int errsv = errno;
 394
 395           g_set_error (error, G_IO_ERROR,
 396                        g_io_error_from_errno (errsv),
 397                        _("Error closing unix: %s"),
 398                        g_strerror (errsv));
 399         }
 400       break;
 401     }
 402
 403   return res != -1;
 404 }
 405
 406 typedef struct {
 407   gsize count;
 408   const void *buffer;
 409   GAsyncReadyCallback callback;
 410   gpointer user_data;
 411   GCancellable *cancellable;
 412   GUnixOutputStream *stream;
 413 } WriteAsyncData;
 414
 415 static gboolean
 416 write_async_cb (WriteAsyncData *data,
 417                 GIOCondition    condition,
 418                 int             fd)
 419 {
 420   GSimpleAsyncResult *simple;
 421   GError *error = NULL;
 422   gssize count_written;
 423
 424   while (1)
 425     {
 426       if (g_cancellable_set_error_if_cancelled (data->cancellable, &error))
 427         {
 428           count_written = -1;
 429           break;
 430         }
 431
 432       count_written = write (data->stream->priv->fd, data->buffer, data->count);
 433       if (count_written == -1)
 434         {
 435           int errsv = errno;
 436
 437           if (errsv == EINTR)
 438             continue;
 439
 440           g_set_error (&error, G_IO_ERROR,
 441                        g_io_error_from_errno (errsv),
 442                        _("Error reading from unix: %s"),
 443                        g_strerror (errsv));
 444         }
 445       break;
 446     }
 447
 448   simple = g_simple_async_result_new (G_OBJECT (data->stream),
 449                                       data->callback,
 450                                       data->user_data,
 451                                       g_unix_output_stream_write_async);
 452
 453   g_simple_async_result_set_op_res_gssize (simple, count_written);
 454
 455   if (count_written == -1)
 456     {
 457       g_simple_async_result_set_from_error (simple, error);
 458       g_error_free (error);
 459     }
 460
 461   /* Complete immediately, not in idle, since we're already in a mainloop callout */
 462   g_simple_async_result_complete (simple);
 463   g_object_unref (simple);
 464
 465   return FALSE;
 466 }
 467
 468 static void
 469 g_unix_output_stream_write_async (GOutputStream       *stream,
 470                                   const void          *buffer,
 471                                   gsize                count,
 472                                   int                  io_priority,
 473                                   GCancellable        *cancellable,
 474                                   GAsyncReadyCallback  callback,
 475                                   gpointer             user_data)
 476 {
 477   GSource *source;
 478   GUnixOutputStream *unix_stream;
 479   WriteAsyncData *data;
 480
 481   unix_stream = G_UNIX_OUTPUT_STREAM (stream);
 482
 483   data = g_new0 (WriteAsyncData, 1);
 484   data->count = count;
 485   data->buffer = buffer;
 486   data->callback = callback;
 487   data->user_data = user_data;
 488   data->cancellable = cancellable;
 489   data->stream = unix_stream;
 490
 491   source = _g_fd_source_new (unix_stream->priv->fd,
 492                              G_IO_OUT,
 493                              cancellable);
 494
 495   g_source_set_callback (source, (GSourceFunc)write_async_cb, data, g_free);
 496   g_source_attach (source, g_main_context_get_thread_default ());
 497
 498   g_source_unref (source);
 499 }
 500
 501 static gssize
 502 g_unix_output_stream_write_finish (GOutputStream  *stream,
 503                                    GAsyncResult   *result,
 504                                    GError        **error)
 505 {
 506   GSimpleAsyncResult *simple;
 507   gssize nwritten;
 508
 509   simple = G_SIMPLE_ASYNC_RESULT (result);
 510   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_unix_output_stream_write_async);
 511
 512   nwritten = g_simple_async_result_get_op_res_gssize (simple);
 513   return nwritten;
 514 }
 515
 516 typedef struct {
 517   GOutputStream *stream;
 518   GAsyncReadyCallback callback;
 519   gpointer user_data;
 520 } CloseAsyncData;
 521
 522 static gboolean
 523 close_async_cb (CloseAsyncData *data)
 524 {
 525   GUnixOutputStream *unix_stream;
 526   GSimpleAsyncResult *simple;
 527   GError *error = NULL;
 528   gboolean result;
 529   int res;
 530
 531   unix_stream = G_UNIX_OUTPUT_STREAM (data->stream);
 532
 533   if (!unix_stream->priv->close_fd)
 534     {
 535       result = TRUE;
 536       goto out;
 537     }
 538
 539   while (1)
 540     {
 541       res = close (unix_stream->priv->fd);
 542       if (res == -1)
 543         {
 544           int errsv = errno;
 545
 546           g_set_error (&error, G_IO_ERROR,
 547                        g_io_error_from_errno (errsv),
 548                        _("Error closing unix: %s"),
 549                        g_strerror (errsv));
 550         }
 551       break;
 552     }
 553
 554   result = res != -1;
 555
 556  out:
 557   simple = g_simple_async_result_new (G_OBJECT (data->stream),
 558                                       data->callback,
 559                                       data->user_data,
 560                                       g_unix_output_stream_close_async);
 561
 562   if (!result)
 563     {
 564       g_simple_async_result_set_from_error (simple, error);
 565       g_error_free (error);
 566     }
 567
 568   /* Complete immediately, not in idle, since we're already in a mainloop callout */
 569   g_simple_async_result_complete (simple);
 570   g_object_unref (simple);
 571
 572   return FALSE;
 573 }
 574
 575 static void
 576 g_unix_output_stream_close_async (GOutputStream        *stream,
 577                                   int                  io_priority,
 578                                   GCancellable        *cancellable,
 579                                   GAsyncReadyCallback  callback,
 580                                   gpointer             user_data)
 581 {
 582   GSource *idle;
 583   CloseAsyncData *data;
 584
 585   data = g_new0 (CloseAsyncData, 1);
 586
 587   data->stream = stream;
 588   data->callback = callback;
 589   data->user_data = user_data;
 590
 591   idle = g_idle_source_new ();
 592   g_source_set_callback (idle, (GSourceFunc)close_async_cb, data, g_free);
 593   g_source_attach (idle, g_main_context_get_thread_default ());
 594   g_source_unref (idle);
 595 }
 596
 597 static gboolean
 598 g_unix_output_stream_close_finish (GOutputStream  *stream,
 599                                    GAsyncResult   *result,
 600                                    GError        **error)
 601 {
 602   /* Failures handled in generic close_finish code */
 603   return TRUE;
 604 }
 605
 606 #define __G_UNIX_OUTPUT_STREAM_C__
 607 #include "gioaliasdef.c"