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 UNIX
  50  * file descriptor, including asynchronous operations. (If the file
  51  * descriptor refers to a socket or pipe, this will use poll() to do
  52  * asynchronous I/O. If it refers to a regular file, it will fall back
  53  * to doing asynchronous I/O in another thread.)
  54  *
  55  * Note that <filename>&lt;gio/gunixoutputstream.h&gt;</filename> belongs
  56  * to the UNIX-specific GIO interfaces, thus you have to use the
  57  * <filename>gio-unix-2.0.pc</filename> pkg-config file when using it.
  58  */
  59
  60 enum {
  61   PROP_0,
  62   PROP_FD,
  63   PROP_CLOSE_FD
  64 };
  65
  66 static void g_unix_output_stream_pollable_iface_init (GPollableOutputStreamInterface *iface);
  67 static void g_unix_output_stream_file_descriptor_based_iface_init (GFileDescriptorBasedIface *iface);
  68
  69 G_DEFINE_TYPE_WITH_CODE (GUnixOutputStream, g_unix_output_stream, G_TYPE_OUTPUT_STREAM,
  70                          G_IMPLEMENT_INTERFACE (G_TYPE_POLLABLE_OUTPUT_STREAM,
  71                                                 g_unix_output_stream_pollable_iface_init)
  72                          G_IMPLEMENT_INTERFACE (G_TYPE_FILE_DESCRIPTOR_BASED,
  73                                                 g_unix_output_stream_file_descriptor_based_iface_init)
  74                          )
  75
  76 struct _GUnixOutputStreamPrivate {
  77   int fd;
  78   guint close_fd : 1;
  79   guint is_pipe_or_socket : 1;
  80 };
  81
  82 static void     g_unix_output_stream_set_property (GObject              *object,
  83                                                    guint                 prop_id,
  84                                                    const GValue         *value,
  85                                                    GParamSpec           *pspec);
  86 static void     g_unix_output_stream_get_property (GObject              *object,
  87                                                    guint                 prop_id,
  88                                                    GValue               *value,
  89                                                    GParamSpec           *pspec);
  90 static gssize   g_unix_output_stream_write        (GOutputStream        *stream,
  91                                                    const void           *buffer,
  92                                                    gsize                 count,
  93                                                    GCancellable         *cancellable,
  94                                                    GError              **error);
  95 static gboolean g_unix_output_stream_close        (GOutputStream        *stream,
  96                                                    GCancellable         *cancellable,
  97                                                    GError              **error);
  98 static void     g_unix_output_stream_write_async  (GOutputStream        *stream,
  99                                                    const void           *buffer,
 100                                                    gsize                 count,
 101                                                    int                   io_priority,
 102                                                    GCancellable         *cancellable,
 103                                                    GAsyncReadyCallback   callback,
 104                                                    gpointer              data);
 105 static gssize   g_unix_output_stream_write_finish (GOutputStream        *stream,
 106                                                    GAsyncResult         *result,
 107                                                    GError              **error);
 108 static void     g_unix_output_stream_close_async  (GOutputStream        *stream,
 109                                                    int                   io_priority,
 110                                                    GCancellable         *cancellable,
 111                                                    GAsyncReadyCallback   callback,
 112                                                    gpointer              data);
 113 static gboolean g_unix_output_stream_close_finish (GOutputStream        *stream,
 114                                                    GAsyncResult         *result,
 115                                                    GError              **error);
 116
 117 static gboolean g_unix_output_stream_pollable_is_writable   (GPollableOutputStream *stream);
 118 static GSource *g_unix_output_stream_pollable_create_source (GPollableOutputStream *stream,
 119                                                              GCancellable         *cancellable);
 120
 121 static void
 122 g_unix_output_stream_finalize (GObject *object)
 123 {
 124   G_OBJECT_CLASS (g_unix_output_stream_parent_class)->finalize (object);
 125 }
 126
 127 static void
 128 g_unix_output_stream_class_init (GUnixOutputStreamClass *klass)
 129 {
 130   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 131   GOutputStreamClass *stream_class = G_OUTPUT_STREAM_CLASS (klass);
 132
 133   g_type_class_add_private (klass, sizeof (GUnixOutputStreamPrivate));
 134
 135   gobject_class->get_property = g_unix_output_stream_get_property;
 136   gobject_class->set_property = g_unix_output_stream_set_property;
 137   gobject_class->finalize = g_unix_output_stream_finalize;
 138
 139   stream_class->write_fn = g_unix_output_stream_write;
 140   stream_class->close_fn = g_unix_output_stream_close;
 141   stream_class->write_async = g_unix_output_stream_write_async;
 142   stream_class->write_finish = g_unix_output_stream_write_finish;
 143   stream_class->close_async = g_unix_output_stream_close_async;
 144   stream_class->close_finish = g_unix_output_stream_close_finish;
 145
 146    /**
 147    * GUnixOutputStream:fd:
 148    *
 149    * The file descriptor that the stream writes to.
 150    *
 151    * Since: 2.20
 152    */
 153   g_object_class_install_property (gobject_class,
 154                                    PROP_FD,
 155                                    g_param_spec_int ("fd",
 156                                                      P_("File descriptor"),
 157                                                      P_("The file descriptor to write to"),
 158                                                      G_MININT, G_MAXINT, -1,
 159                                                      G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
 160
 161   /**
 162    * GUnixOutputStream:close-fd:
 163    *
 164    * Whether to close the file descriptor when the stream is closed.
 165    *
 166    * Since: 2.20
 167    */
 168   g_object_class_install_property (gobject_class,
 169                                    PROP_CLOSE_FD,
 170                                    g_param_spec_boolean ("close-fd",
 171                                                          P_("Close file descriptor"),
 172                                                          P_("Whether to close the file descriptor when the stream is closed"),
 173                                                          TRUE,
 174                                                          G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
 175 }
 176
 177 static void
 178 g_unix_output_stream_pollable_iface_init (GPollableOutputStreamInterface *iface)
 179 {
 180   iface->is_writable = g_unix_output_stream_pollable_is_writable;
 181   iface->create_source = g_unix_output_stream_pollable_create_source;
 182 }
 183
 184 static void
 185 g_unix_output_stream_file_descriptor_based_iface_init (GFileDescriptorBasedIface *iface)
 186 {
 187   iface->get_fd = (int (*) (GFileDescriptorBased *))g_unix_output_stream_get_fd;
 188 }
 189
 190 static void
 191 g_unix_output_stream_set_property (GObject         *object,
 192                                    guint            prop_id,
 193                                    const GValue    *value,
 194                                    GParamSpec      *pspec)
 195 {
 196   GUnixOutputStream *unix_stream;
 197
 198   unix_stream = G_UNIX_OUTPUT_STREAM (object);
 199
 200   switch (prop_id)
 201     {
 202     case PROP_FD:
 203       unix_stream->priv->fd = g_value_get_int (value);
 204       if (lseek (unix_stream->priv->fd, 0, SEEK_CUR) == -1 && errno == ESPIPE)
 205         unix_stream->priv->is_pipe_or_socket = TRUE;
 206       else
 207         unix_stream->priv->is_pipe_or_socket = FALSE;
 208       break;
 209     case PROP_CLOSE_FD:
 210       unix_stream->priv->close_fd = g_value_get_boolean (value);
 211       break;
 212     default:
 213       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 214       break;
 215     }
 216 }
 217
 218 static void
 219 g_unix_output_stream_get_property (GObject    *object,
 220                                    guint       prop_id,
 221                                    GValue     *value,
 222                                    GParamSpec *pspec)
 223 {
 224   GUnixOutputStream *unix_stream;
 225
 226   unix_stream = G_UNIX_OUTPUT_STREAM (object);
 227
 228   switch (prop_id)
 229     {
 230     case PROP_FD:
 231       g_value_set_int (value, unix_stream->priv->fd);
 232       break;
 233     case PROP_CLOSE_FD:
 234       g_value_set_boolean (value, unix_stream->priv->close_fd);
 235       break;
 236     default:
 237       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 238     }
 239 }
 240
 241 static void
 242 g_unix_output_stream_init (GUnixOutputStream *unix_stream)
 243 {
 244   unix_stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (unix_stream,
 245                                                    G_TYPE_UNIX_OUTPUT_STREAM,
 246                                                    GUnixOutputStreamPrivate);
 247
 248   unix_stream->priv->fd = -1;
 249   unix_stream->priv->close_fd = TRUE;
 250 }
 251
 252 /**
 253  * g_unix_output_stream_new:
 254  * @fd: a UNIX file descriptor
 255  * @close_fd: %TRUE to close the file descriptor when done
 256  *
 257  * Creates a new #GUnixOutputStream for the given @fd.
 258  *
 259  * If @close_fd, is %TRUE, the file descriptor will be closed when
 260  * the output stream is destroyed.
 261  *
 262  * Returns: a new #GOutputStream
 263  **/
 264 GOutputStream *
 265 g_unix_output_stream_new (gint     fd,
 266                           gboolean close_fd)
 267 {
 268   GUnixOutputStream *stream;
 269
 270   g_return_val_if_fail (fd != -1, NULL);
 271
 272   stream = g_object_new (G_TYPE_UNIX_OUTPUT_STREAM,
 273                          "fd", fd,
 274                          "close-fd", close_fd,
 275                          NULL);
 276
 277   return G_OUTPUT_STREAM (stream);
 278 }
 279
 280 /**
 281  * g_unix_output_stream_set_close_fd:
 282  * @stream: a #GUnixOutputStream
 283  * @close_fd: %TRUE to close the file descriptor when done
 284  *
 285  * Sets whether the file descriptor of @stream shall be closed
 286  * when the stream is closed.
 287  *
 288  * Since: 2.20
 289  */
 290 void
 291 g_unix_output_stream_set_close_fd (GUnixOutputStream *stream,
 292                                    gboolean           close_fd)
 293 {
 294   g_return_if_fail (G_IS_UNIX_OUTPUT_STREAM (stream));
 295
 296   close_fd = close_fd != FALSE;
 297   if (stream->priv->close_fd != close_fd)
 298     {
 299       stream->priv->close_fd = close_fd;
 300       g_object_notify (G_OBJECT (stream), "close-fd");
 301     }
 302 }
 303
 304 /**
 305  * g_unix_output_stream_get_close_fd:
 306  * @stream: a #GUnixOutputStream
 307  *
 308  * Returns whether the file descriptor of @stream will be
 309  * closed when the stream is closed.
 310  *
 311  * Return value: %TRUE if the file descriptor is closed when done
 312  *
 313  * Since: 2.20
 314  */
 315 gboolean
 316 g_unix_output_stream_get_close_fd (GUnixOutputStream *stream)
 317 {
 318   g_return_val_if_fail (G_IS_UNIX_OUTPUT_STREAM (stream), FALSE);
 319
 320   return stream->priv->close_fd;
 321 }
 322
 323 /**
 324  * g_unix_output_stream_get_fd:
 325  * @stream: a #GUnixOutputStream
 326  *
 327  * Return the UNIX file descriptor that the stream writes to.
 328  *
 329  * Return value: The file descriptor of @stream
 330  *
 331  * Since: 2.20
 332  */
 333 gint
 334 g_unix_output_stream_get_fd (GUnixOutputStream *stream)
 335 {
 336   g_return_val_if_fail (G_IS_UNIX_OUTPUT_STREAM (stream), -1);
 337
 338   return stream->priv->fd;
 339 }
 340
 341 static gssize
 342 g_unix_output_stream_write (GOutputStream  *stream,
 343                             const void     *buffer,
 344                             gsize           count,
 345                             GCancellable   *cancellable,
 346                             GError        **error)
 347 {
 348   GUnixOutputStream *unix_stream;
 349   gssize res;
 350   GPollFD poll_fds[2];
 351   int poll_ret;
 352
 353   unix_stream = G_UNIX_OUTPUT_STREAM (stream);
 354
 355   if (unix_stream->priv->is_pipe_or_socket &&
 356       g_cancellable_make_pollfd (cancellable, &poll_fds[1]))
 357     {
 358       poll_fds[0].fd = unix_stream->priv->fd;
 359       poll_fds[0].events = G_IO_OUT;
 360       do
 361         poll_ret = g_poll (poll_fds, 2, -1);
 362       while (poll_ret == -1 && errno == EINTR);
 363       g_cancellable_release_fd (cancellable);
 364
 365       if (poll_ret == -1)
 366         {
 367           int errsv = errno;
 368
 369           g_set_error (error, G_IO_ERROR,
 370                        g_io_error_from_errno (errsv),
 371                        _("Error writing to unix: %s"),
 372                        g_strerror (errsv));
 373           return -1;
 374         }
 375     }
 376
 377   while (1)
 378     {
 379       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 380         return -1;
 381
 382       res = write (unix_stream->priv->fd, buffer, count);
 383       if (res == -1)
 384         {
 385           int errsv = errno;
 386
 387           if (errsv == EINTR)
 388             continue;
 389
 390           g_set_error (error, G_IO_ERROR,
 391                        g_io_error_from_errno (errsv),
 392                        _("Error writing to unix: %s"),
 393                        g_strerror (errsv));
 394         }
 395
 396       break;
 397     }
 398
 399   return res;
 400 }
 401
 402 static gboolean
 403 g_unix_output_stream_close (GOutputStream  *stream,
 404                             GCancellable   *cancellable,
 405                             GError        **error)
 406 {
 407   GUnixOutputStream *unix_stream;
 408   int res;
 409
 410   unix_stream = G_UNIX_OUTPUT_STREAM (stream);
 411
 412   if (!unix_stream->priv->close_fd)
 413     return TRUE;
 414
 415   while (1)
 416     {
 417       /* This might block during the close. Doesn't seem to be a way to avoid it though. */
 418       res = close (unix_stream->priv->fd);
 419       if (res == -1)
 420         {
 421           int errsv = errno;
 422
 423           g_set_error (error, G_IO_ERROR,
 424                        g_io_error_from_errno (errsv),
 425                        _("Error closing unix: %s"),
 426                        g_strerror (errsv));
 427         }
 428       break;
 429     }
 430
 431   return res != -1;
 432 }
 433
 434 typedef struct {
 435   gsize count;
 436   const void *buffer;
 437   GAsyncReadyCallback callback;
 438   gpointer user_data;
 439   GCancellable *cancellable;
 440   GUnixOutputStream *stream;
 441 } WriteAsyncData;
 442
 443 static gboolean
 444 write_async_cb (int             fd,
 445                 GIOCondition    condition,
 446                 WriteAsyncData *data)
 447 {
 448   GSimpleAsyncResult *simple;
 449   GError *error = NULL;
 450   gssize count_written;
 451
 452   while (1)
 453     {
 454       if (g_cancellable_set_error_if_cancelled (data->cancellable, &error))
 455         {
 456           count_written = -1;
 457           break;
 458         }
 459
 460       count_written = write (data->stream->priv->fd, data->buffer, data->count);
 461       if (count_written == -1)
 462         {
 463           int errsv = errno;
 464
 465           if (errsv == EINTR)
 466             continue;
 467
 468           g_set_error (&error, G_IO_ERROR,
 469                        g_io_error_from_errno (errsv),
 470                        _("Error writing to unix: %s"),
 471                        g_strerror (errsv));
 472         }
 473       break;
 474     }
 475
 476   simple = g_simple_async_result_new (G_OBJECT (data->stream),
 477                                       data->callback,
 478                                       data->user_data,
 479                                       g_unix_output_stream_write_async);
 480
 481   g_simple_async_result_set_op_res_gssize (simple, count_written);
 482
 483   if (count_written == -1)
 484     g_simple_async_result_take_error (simple, error);
 485
 486   /* Complete immediately, not in idle, since we're already in a mainloop callout */
 487   g_simple_async_result_complete (simple);
 488   g_object_unref (simple);
 489
 490   return FALSE;
 491 }
 492
 493 static void
 494 g_unix_output_stream_write_async (GOutputStream       *stream,
 495                                   const void          *buffer,
 496                                   gsize                count,
 497                                   int                  io_priority,
 498                                   GCancellable        *cancellable,
 499                                   GAsyncReadyCallback  callback,
 500                                   gpointer             user_data)
 501 {
 502   GSource *source;
 503   GUnixOutputStream *unix_stream;
 504   WriteAsyncData *data;
 505
 506   unix_stream = G_UNIX_OUTPUT_STREAM (stream);
 507
 508   if (!unix_stream->priv->is_pipe_or_socket)
 509     {
 510       G_OUTPUT_STREAM_CLASS (g_unix_output_stream_parent_class)->
 511         write_async (stream, buffer, count, io_priority,
 512                      cancellable, callback, user_data);
 513       return;
 514     }
 515
 516   data = g_new0 (WriteAsyncData, 1);
 517   data->count = count;
 518   data->buffer = buffer;
 519   data->callback = callback;
 520   data->user_data = user_data;
 521   data->cancellable = cancellable;
 522   data->stream = unix_stream;
 523
 524   source = _g_fd_source_new (unix_stream->priv->fd,
 525                              G_IO_OUT,
 526                              cancellable);
 527   g_source_set_name (source, "GUnixOutputStream");
 528
 529   g_source_set_callback (source, (GSourceFunc)write_async_cb, data, g_free);
 530   g_source_attach (source, g_main_context_get_thread_default ());
 531
 532   g_source_unref (source);
 533 }
 534
 535 static gssize
 536 g_unix_output_stream_write_finish (GOutputStream  *stream,
 537                                    GAsyncResult   *result,
 538                                    GError        **error)
 539 {
 540   GUnixOutputStream *unix_stream = G_UNIX_OUTPUT_STREAM (stream);
 541   GSimpleAsyncResult *simple;
 542   gssize nwritten;
 543
 544   if (!unix_stream->priv->is_pipe_or_socket)
 545     {
 546       return G_OUTPUT_STREAM_CLASS (g_unix_output_stream_parent_class)->
 547         write_finish (stream, result, error);
 548     }
 549
 550   simple = G_SIMPLE_ASYNC_RESULT (result);
 551   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_unix_output_stream_write_async);
 552
 553   nwritten = g_simple_async_result_get_op_res_gssize (simple);
 554   return nwritten;
 555 }
 556
 557 typedef struct {
 558   GOutputStream *stream;
 559   GAsyncReadyCallback callback;
 560   gpointer user_data;
 561 } CloseAsyncData;
 562
 563 static gboolean
 564 close_async_cb (CloseAsyncData *data)
 565 {
 566   GUnixOutputStream *unix_stream;
 567   GSimpleAsyncResult *simple;
 568   GError *error = NULL;
 569   gboolean result;
 570   int res;
 571
 572   unix_stream = G_UNIX_OUTPUT_STREAM (data->stream);
 573
 574   if (!unix_stream->priv->close_fd)
 575     {
 576       result = TRUE;
 577       goto out;
 578     }
 579
 580   while (1)
 581     {
 582       res = close (unix_stream->priv->fd);
 583       if (res == -1)
 584         {
 585           int errsv = errno;
 586
 587           g_set_error (&error, G_IO_ERROR,
 588                        g_io_error_from_errno (errsv),
 589                        _("Error closing unix: %s"),
 590                        g_strerror (errsv));
 591         }
 592       break;
 593     }
 594
 595   result = res != -1;
 596
 597  out:
 598   simple = g_simple_async_result_new (G_OBJECT (data->stream),
 599                                       data->callback,
 600                                       data->user_data,
 601                                       g_unix_output_stream_close_async);
 602
 603   if (!result)
 604     g_simple_async_result_take_error (simple, error);
 605
 606   /* Complete immediately, not in idle, since we're already in a mainloop callout */
 607   g_simple_async_result_complete (simple);
 608   g_object_unref (simple);
 609
 610   return FALSE;
 611 }
 612
 613 static void
 614 g_unix_output_stream_close_async (GOutputStream        *stream,
 615                                   int                  io_priority,
 616                                   GCancellable        *cancellable,
 617                                   GAsyncReadyCallback  callback,
 618                                   gpointer             user_data)
 619 {
 620   GSource *idle;
 621   CloseAsyncData *data;
 622
 623   data = g_new0 (CloseAsyncData, 1);
 624
 625   data->stream = stream;
 626   data->callback = callback;
 627   data->user_data = user_data;
 628
 629   idle = g_idle_source_new ();
 630   g_source_set_callback (idle, (GSourceFunc)close_async_cb, data, g_free);
 631   g_source_attach (idle, g_main_context_get_thread_default ());
 632   g_source_unref (idle);
 633 }
 634
 635 static gboolean
 636 g_unix_output_stream_close_finish (GOutputStream  *stream,
 637                                    GAsyncResult   *result,
 638                                    GError        **error)
 639 {
 640   /* Failures handled in generic close_finish code */
 641   return TRUE;
 642 }
 643
 644 static gboolean
 645 g_unix_output_stream_pollable_is_writable (GPollableOutputStream *stream)
 646 {
 647   GUnixOutputStream *unix_stream = G_UNIX_OUTPUT_STREAM (stream);
 648   GPollFD poll_fd;
 649   gint result;
 650
 651   poll_fd.fd = unix_stream->priv->fd;
 652   poll_fd.events = G_IO_OUT;
 653
 654   do
 655     result = g_poll (&poll_fd, 1, 0);
 656   while (result == -1 && errno == EINTR);
 657
 658   return poll_fd.revents != 0;
 659 }
 660
 661 static GSource *
 662 g_unix_output_stream_pollable_create_source (GPollableOutputStream *stream,
 663                                              GCancellable          *cancellable)
 664 {
 665   GUnixOutputStream *unix_stream = G_UNIX_OUTPUT_STREAM (stream);
 666   GSource *inner_source, *pollable_source;
 667
 668   pollable_source = g_pollable_source_new (G_OBJECT (stream));
 669
 670   inner_source = _g_fd_source_new (unix_stream->priv->fd, G_IO_OUT, cancellable);
 671   g_source_set_dummy_callback (inner_source);
 672   g_source_add_child_source (pollable_source, inner_source);
 673   g_source_unref (inner_source);
 674
 675   return pollable_source;
 676 }