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 "gfiledescriptorbased.h"
  40 #include "glibintl.h"
  41
  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 static void g_unix_output_stream_pollable_iface_init (GPollableOutputStreamInterface *iface);
  65 static void g_unix_output_stream_file_descriptor_based_iface_init (GFileDescriptorBasedIface *iface);
  66
  67 G_DEFINE_TYPE_WITH_CODE (GUnixOutputStream, g_unix_output_stream, G_TYPE_OUTPUT_STREAM,
  68                          G_IMPLEMENT_INTERFACE (G_TYPE_POLLABLE_OUTPUT_STREAM,
  69                                                 g_unix_output_stream_pollable_iface_init)
  70                          G_IMPLEMENT_INTERFACE (G_TYPE_FILE_DESCRIPTOR_BASED,
  71                                                 g_unix_output_stream_file_descriptor_based_iface_init)
  72                          )
  73
  74 struct _GUnixOutputStreamPrivate {
  75   int fd;
  76   gboolean close_fd;
  77 };
  78
  79 static void     g_unix_output_stream_set_property (GObject              *object,
  80                                                    guint                 prop_id,
  81                                                    const GValue         *value,
  82                                                    GParamSpec           *pspec);
  83 static void     g_unix_output_stream_get_property (GObject              *object,
  84                                                    guint                 prop_id,
  85                                                    GValue               *value,
  86                                                    GParamSpec           *pspec);
  87 static gssize   g_unix_output_stream_write        (GOutputStream        *stream,
  88                                                    const void           *buffer,
  89                                                    gsize                 count,
  90                                                    GCancellable         *cancellable,
  91                                                    GError              **error);
  92 static gboolean g_unix_output_stream_close        (GOutputStream        *stream,
  93                                                    GCancellable         *cancellable,
  94                                                    GError              **error);
  95 static void     g_unix_output_stream_write_async  (GOutputStream        *stream,
  96                                                    const void           *buffer,
  97                                                    gsize                 count,
  98                                                    int                   io_priority,
  99                                                    GCancellable         *cancellable,
 100                                                    GAsyncReadyCallback   callback,
 101                                                    gpointer              data);
 102 static gssize   g_unix_output_stream_write_finish (GOutputStream        *stream,
 103                                                    GAsyncResult         *result,
 104                                                    GError              **error);
 105 static void     g_unix_output_stream_close_async  (GOutputStream        *stream,
 106                                                    int                   io_priority,
 107                                                    GCancellable         *cancellable,
 108                                                    GAsyncReadyCallback   callback,
 109                                                    gpointer              data);
 110 static gboolean g_unix_output_stream_close_finish (GOutputStream        *stream,
 111                                                    GAsyncResult         *result,
 112                                                    GError              **error);
 113
 114 static gboolean g_unix_output_stream_pollable_is_writable   (GPollableOutputStream *stream);
 115 static GSource *g_unix_output_stream_pollable_create_source (GPollableOutputStream *stream,
 116                                                              GCancellable         *cancellable);
 117
 118 static void
 119 g_unix_output_stream_finalize (GObject *object)
 120 {
 121   G_OBJECT_CLASS (g_unix_output_stream_parent_class)->finalize (object);
 122 }
 123
 124 static void
 125 g_unix_output_stream_class_init (GUnixOutputStreamClass *klass)
 126 {
 127   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 128   GOutputStreamClass *stream_class = G_OUTPUT_STREAM_CLASS (klass);
 129
 130   g_type_class_add_private (klass, sizeof (GUnixOutputStreamPrivate));
 131
 132   gobject_class->get_property = g_unix_output_stream_get_property;
 133   gobject_class->set_property = g_unix_output_stream_set_property;
 134   gobject_class->finalize = g_unix_output_stream_finalize;
 135
 136   stream_class->write_fn = g_unix_output_stream_write;
 137   stream_class->close_fn = g_unix_output_stream_close;
 138   stream_class->write_async = g_unix_output_stream_write_async;
 139   stream_class->write_finish = g_unix_output_stream_write_finish;
 140   stream_class->close_async = g_unix_output_stream_close_async;
 141   stream_class->close_finish = g_unix_output_stream_close_finish;
 142
 143    /**
 144    * GUnixOutputStream:fd:
 145    *
 146    * The file descriptor that the stream writes to.
 147    *
 148    * Since: 2.20
 149    */
 150   g_object_class_install_property (gobject_class,
 151                                    PROP_FD,
 152                                    g_param_spec_int ("fd",
 153                                                      P_("File descriptor"),
 154                                                      P_("The file descriptor to write to"),
 155                                                      G_MININT, G_MAXINT, -1,
 156                                                      G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
 157
 158   /**
 159    * GUnixOutputStream:close-fd:
 160    *
 161    * Whether to close the file descriptor when the stream is closed.
 162    *
 163    * Since: 2.20
 164    */
 165   g_object_class_install_property (gobject_class,
 166                                    PROP_CLOSE_FD,
 167                                    g_param_spec_boolean ("close-fd",
 168                                                          P_("Close file descriptor"),
 169                                                          P_("Whether to close the file descriptor when the stream is closed"),
 170                                                          TRUE,
 171                                                          G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
 172 }
 173
 174 static void
 175 g_unix_output_stream_pollable_iface_init (GPollableOutputStreamInterface *iface)
 176 {
 177   iface->is_writable = g_unix_output_stream_pollable_is_writable;
 178   iface->create_source = g_unix_output_stream_pollable_create_source;
 179 }
 180
 181 static void
 182 g_unix_output_stream_file_descriptor_based_iface_init (GFileDescriptorBasedIface *iface)
 183 {
 184   iface->get_fd = (int (*) (GFileDescriptorBased *))g_unix_output_stream_get_fd;
 185 }
 186
 187 static void
 188 g_unix_output_stream_set_property (GObject         *object,
 189                                    guint            prop_id,
 190                                    const GValue    *value,
 191                                    GParamSpec      *pspec)
 192 {
 193   GUnixOutputStream *unix_stream;
 194
 195   unix_stream = G_UNIX_OUTPUT_STREAM (object);
 196
 197   switch (prop_id)
 198     {
 199     case PROP_FD:
 200       unix_stream->priv->fd = g_value_get_int (value);
 201       break;
 202     case PROP_CLOSE_FD:
 203       unix_stream->priv->close_fd = g_value_get_boolean (value);
 204       break;
 205     default:
 206       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 207       break;
 208     }
 209 }
 210
 211 static void
 212 g_unix_output_stream_get_property (GObject    *object,
 213                                    guint       prop_id,
 214                                    GValue     *value,
 215                                    GParamSpec *pspec)
 216 {
 217   GUnixOutputStream *unix_stream;
 218
 219   unix_stream = G_UNIX_OUTPUT_STREAM (object);
 220
 221   switch (prop_id)
 222     {
 223     case PROP_FD:
 224       g_value_set_int (value, unix_stream->priv->fd);
 225       break;
 226     case PROP_CLOSE_FD:
 227       g_value_set_boolean (value, unix_stream->priv->close_fd);
 228       break;
 229     default:
 230       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 231     }
 232 }
 233
 234 static void
 235 g_unix_output_stream_init (GUnixOutputStream *unix_stream)
 236 {
 237   unix_stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (unix_stream,
 238                                                    G_TYPE_UNIX_OUTPUT_STREAM,
 239                                                    GUnixOutputStreamPrivate);
 240
 241   unix_stream->priv->fd = -1;
 242   unix_stream->priv->close_fd = TRUE;
 243 }
 244
 245 /**
 246  * g_unix_output_stream_new:
 247  * @fd: a UNIX file descriptor
 248  * @close_fd: %TRUE to close the file descriptor when done
 249  *
 250  * Creates a new #GUnixOutputStream for the given @fd.
 251  *
 252  * If @close_fd, is %TRUE, the file descriptor will be closed when
 253  * the output stream is destroyed.
 254  *
 255  * Returns: a new #GOutputStream
 256  **/
 257 GOutputStream *
 258 g_unix_output_stream_new (gint     fd,
 259                           gboolean close_fd)
 260 {
 261   GUnixOutputStream *stream;
 262
 263   g_return_val_if_fail (fd != -1, NULL);
 264
 265   stream = g_object_new (G_TYPE_UNIX_OUTPUT_STREAM,
 266                          "fd", fd,
 267                          "close-fd", close_fd,
 268                          NULL);
 269
 270   return G_OUTPUT_STREAM (stream);
 271 }
 272
 273 /**
 274  * g_unix_output_stream_set_close_fd:
 275  * @stream: a #GUnixOutputStream
 276  * @close_fd: %TRUE to close the file descriptor when done
 277  *
 278  * Sets whether the file descriptor of @stream shall be closed
 279  * when the stream is closed.
 280  *
 281  * Since: 2.20
 282  */
 283 void
 284 g_unix_output_stream_set_close_fd (GUnixOutputStream *stream,
 285                                    gboolean           close_fd)
 286 {
 287   g_return_if_fail (G_IS_UNIX_OUTPUT_STREAM (stream));
 288
 289   close_fd = close_fd != FALSE;
 290   if (stream->priv->close_fd != close_fd)
 291     {
 292       stream->priv->close_fd = close_fd;
 293       g_object_notify (G_OBJECT (stream), "close-fd");
 294     }
 295 }
 296
 297 /**
 298  * g_unix_output_stream_get_close_fd:
 299  * @stream: a #GUnixOutputStream
 300  *
 301  * Returns whether the file descriptor of @stream will be
 302  * closed when the stream is closed.
 303  *
 304  * Return value: %TRUE if the file descriptor is closed when done
 305  *
 306  * Since: 2.20
 307  */
 308 gboolean
 309 g_unix_output_stream_get_close_fd (GUnixOutputStream *stream)
 310 {
 311   g_return_val_if_fail (G_IS_UNIX_OUTPUT_STREAM (stream), FALSE);
 312
 313   return stream->priv->close_fd;
 314 }
 315
 316 /**
 317  * g_unix_output_stream_get_fd:
 318  * @stream: a #GUnixOutputStream
 319  *
 320  * Return the UNIX file descriptor that the stream writes to.
 321  *
 322  * Return value: The file descriptor of @stream
 323  *
 324  * Since: 2.20
 325  */
 326 gint
 327 g_unix_output_stream_get_fd (GUnixOutputStream *stream)
 328 {
 329   g_return_val_if_fail (G_IS_UNIX_OUTPUT_STREAM (stream), -1);
 330
 331   return stream->priv->fd;
 332 }
 333
 334 static gssize
 335 g_unix_output_stream_write (GOutputStream  *stream,
 336                             const void     *buffer,
 337                             gsize           count,
 338                             GCancellable   *cancellable,
 339                             GError        **error)
 340 {
 341   GUnixOutputStream *unix_stream;
 342   gssize res;
 343   GPollFD poll_fds[2];
 344   int poll_ret;
 345
 346   unix_stream = G_UNIX_OUTPUT_STREAM (stream);
 347
 348   if (g_cancellable_make_pollfd (cancellable, &poll_fds[1]))
 349     {
 350       poll_fds[0].fd = unix_stream->priv->fd;
 351       poll_fds[0].events = G_IO_OUT;
 352       do
 353         poll_ret = g_poll (poll_fds, 2, -1);
 354       while (poll_ret == -1 && errno == EINTR);
 355       g_cancellable_release_fd (cancellable);
 356
 357       if (poll_ret == -1)
 358         {
 359           int errsv = errno;
 360
 361           g_set_error (error, G_IO_ERROR,
 362                        g_io_error_from_errno (errsv),
 363                        _("Error writing to unix: %s"),
 364                        g_strerror (errsv));
 365           return -1;
 366         }
 367     }
 368
 369   while (1)
 370     {
 371       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 372         return -1;
 373
 374       res = write (unix_stream->priv->fd, buffer, count);
 375       if (res == -1)
 376         {
 377           int errsv = errno;
 378
 379           if (errsv == EINTR)
 380             continue;
 381
 382           g_set_error (error, G_IO_ERROR,
 383                        g_io_error_from_errno (errsv),
 384                        _("Error writing to unix: %s"),
 385                        g_strerror (errsv));
 386         }
 387
 388       break;
 389     }
 390
 391   return res;
 392 }
 393
 394 static gboolean
 395 g_unix_output_stream_close (GOutputStream  *stream,
 396                             GCancellable   *cancellable,
 397                             GError        **error)
 398 {
 399   GUnixOutputStream *unix_stream;
 400   int res;
 401
 402   unix_stream = G_UNIX_OUTPUT_STREAM (stream);
 403
 404   if (!unix_stream->priv->close_fd)
 405     return TRUE;
 406
 407   while (1)
 408     {
 409       /* This might block during the close. Doesn't seem to be a way to avoid it though. */
 410       res = close (unix_stream->priv->fd);
 411       if (res == -1)
 412         {
 413           int errsv = errno;
 414
 415           g_set_error (error, G_IO_ERROR,
 416                        g_io_error_from_errno (errsv),
 417                        _("Error closing unix: %s"),
 418                        g_strerror (errsv));
 419         }
 420       break;
 421     }
 422
 423   return res != -1;
 424 }
 425
 426 typedef struct {
 427   gsize count;
 428   const void *buffer;
 429   GAsyncReadyCallback callback;
 430   gpointer user_data;
 431   GCancellable *cancellable;
 432   GUnixOutputStream *stream;
 433 } WriteAsyncData;
 434
 435 static gboolean
 436 write_async_cb (int             fd,
 437                 GIOCondition    condition,
 438                 WriteAsyncData *data)
 439 {
 440   GSimpleAsyncResult *simple;
 441   GError *error = NULL;
 442   gssize count_written;
 443
 444   while (1)
 445     {
 446       if (g_cancellable_set_error_if_cancelled (data->cancellable, &error))
 447         {
 448           count_written = -1;
 449           break;
 450         }
 451
 452       count_written = write (data->stream->priv->fd, data->buffer, data->count);
 453       if (count_written == -1)
 454         {
 455           int errsv = errno;
 456
 457           if (errsv == EINTR)
 458             continue;
 459
 460           g_set_error (&error, G_IO_ERROR,
 461                        g_io_error_from_errno (errsv),
 462                        _("Error writing to unix: %s"),
 463                        g_strerror (errsv));
 464         }
 465       break;
 466     }
 467
 468   simple = g_simple_async_result_new (G_OBJECT (data->stream),
 469                                       data->callback,
 470                                       data->user_data,
 471                                       g_unix_output_stream_write_async);
 472
 473   g_simple_async_result_set_op_res_gssize (simple, count_written);
 474
 475   if (count_written == -1)
 476     g_simple_async_result_take_error (simple, error);
 477
 478   /* Complete immediately, not in idle, since we're already in a mainloop callout */
 479   g_simple_async_result_complete (simple);
 480   g_object_unref (simple);
 481
 482   return FALSE;
 483 }
 484
 485 static void
 486 g_unix_output_stream_write_async (GOutputStream       *stream,
 487                                   const void          *buffer,
 488                                   gsize                count,
 489                                   int                  io_priority,
 490                                   GCancellable        *cancellable,
 491                                   GAsyncReadyCallback  callback,
 492                                   gpointer             user_data)
 493 {
 494   GSource *source;
 495   GUnixOutputStream *unix_stream;
 496   WriteAsyncData *data;
 497
 498   unix_stream = G_UNIX_OUTPUT_STREAM (stream);
 499
 500   data = g_new0 (WriteAsyncData, 1);
 501   data->count = count;
 502   data->buffer = buffer;
 503   data->callback = callback;
 504   data->user_data = user_data;
 505   data->cancellable = cancellable;
 506   data->stream = unix_stream;
 507
 508   source = _g_fd_source_new (unix_stream->priv->fd,
 509                              G_IO_OUT,
 510                              cancellable);
 511   g_source_set_name (source, "GUnixOutputStream");
 512
 513   g_source_set_callback (source, (GSourceFunc)write_async_cb, data, g_free);
 514   g_source_attach (source, g_main_context_get_thread_default ());
 515
 516   g_source_unref (source);
 517 }
 518
 519 static gssize
 520 g_unix_output_stream_write_finish (GOutputStream  *stream,
 521                                    GAsyncResult   *result,
 522                                    GError        **error)
 523 {
 524   GSimpleAsyncResult *simple;
 525   gssize nwritten;
 526
 527   simple = G_SIMPLE_ASYNC_RESULT (result);
 528   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_unix_output_stream_write_async);
 529
 530   nwritten = g_simple_async_result_get_op_res_gssize (simple);
 531   return nwritten;
 532 }
 533
 534 typedef struct {
 535   GOutputStream *stream;
 536   GAsyncReadyCallback callback;
 537   gpointer user_data;
 538 } CloseAsyncData;
 539
 540 static gboolean
 541 close_async_cb (CloseAsyncData *data)
 542 {
 543   GUnixOutputStream *unix_stream;
 544   GSimpleAsyncResult *simple;
 545   GError *error = NULL;
 546   gboolean result;
 547   int res;
 548
 549   unix_stream = G_UNIX_OUTPUT_STREAM (data->stream);
 550
 551   if (!unix_stream->priv->close_fd)
 552     {
 553       result = TRUE;
 554       goto out;
 555     }
 556
 557   while (1)
 558     {
 559       res = close (unix_stream->priv->fd);
 560       if (res == -1)
 561         {
 562           int errsv = errno;
 563
 564           g_set_error (&error, G_IO_ERROR,
 565                        g_io_error_from_errno (errsv),
 566                        _("Error closing unix: %s"),
 567                        g_strerror (errsv));
 568         }
 569       break;
 570     }
 571
 572   result = res != -1;
 573
 574  out:
 575   simple = g_simple_async_result_new (G_OBJECT (data->stream),
 576                                       data->callback,
 577                                       data->user_data,
 578                                       g_unix_output_stream_close_async);
 579
 580   if (!result)
 581     g_simple_async_result_take_error (simple, error);
 582
 583   /* Complete immediately, not in idle, since we're already in a mainloop callout */
 584   g_simple_async_result_complete (simple);
 585   g_object_unref (simple);
 586
 587   return FALSE;
 588 }
 589
 590 static void
 591 g_unix_output_stream_close_async (GOutputStream        *stream,
 592                                   int                  io_priority,
 593                                   GCancellable        *cancellable,
 594                                   GAsyncReadyCallback  callback,
 595                                   gpointer             user_data)
 596 {
 597   GSource *idle;
 598   CloseAsyncData *data;
 599
 600   data = g_new0 (CloseAsyncData, 1);
 601
 602   data->stream = stream;
 603   data->callback = callback;
 604   data->user_data = user_data;
 605
 606   idle = g_idle_source_new ();
 607   g_source_set_callback (idle, (GSourceFunc)close_async_cb, data, g_free);
 608   g_source_attach (idle, g_main_context_get_thread_default ());
 609   g_source_unref (idle);
 610 }
 611
 612 static gboolean
 613 g_unix_output_stream_close_finish (GOutputStream  *stream,
 614                                    GAsyncResult   *result,
 615                                    GError        **error)
 616 {
 617   /* Failures handled in generic close_finish code */
 618   return TRUE;
 619 }
 620
 621 static gboolean
 622 g_unix_output_stream_pollable_is_writable (GPollableOutputStream *stream)
 623 {
 624   GUnixOutputStream *unix_stream = G_UNIX_OUTPUT_STREAM (stream);
 625   GPollFD poll_fd;
 626   gint result;
 627
 628   poll_fd.fd = unix_stream->priv->fd;
 629   poll_fd.events = G_IO_OUT;
 630
 631   do
 632     result = g_poll (&poll_fd, 1, 0);
 633   while (result == -1 && errno == EINTR);
 634
 635   return poll_fd.revents != 0;
 636 }
 637
 638 static GSource *
 639 g_unix_output_stream_pollable_create_source (GPollableOutputStream *stream,
 640                                              GCancellable          *cancellable)
 641 {
 642   GUnixOutputStream *unix_stream = G_UNIX_OUTPUT_STREAM (stream);
 643   GSource *inner_source, *pollable_source;
 644
 645   pollable_source = g_pollable_source_new (G_OBJECT (stream));
 646
 647   inner_source = _g_fd_source_new (unix_stream->priv->fd, G_IO_OUT, cancellable);
 648   g_source_set_dummy_callback (inner_source);
 649   g_source_add_child_source (pollable_source, inner_source);
 650   g_source_unref (inner_source);
 651
 652   return pollable_source;
 653 }