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
  42 /**
  43  * SECTION:gunixoutputstream
  44  * @short_description: Streaming output operations for UNIX file descriptors
  45  * @include: gio/gunixoutputstream.h
  46  * @see_also: #GOutputStream
  47  *
  48  * #GUnixOutputStream implements #GOutputStream for writing to a
  49  * UNIX file descriptor, including asynchronous operations. The file
  50  * descriptor must be selectable, so it doesn't work with opened files.
  51  *
  52  * Note that <filename>&lt;gio/gunixoutputstream.h&gt;</filename> belongs
  53  * to the UNIX-specific GIO interfaces, thus you have to use the
  54  * <filename>gio-unix-2.0.pc</filename> pkg-config file when using it.
  55  */
  56
  57 enum {
  58   PROP_0,
  59   PROP_FD,
  60   PROP_CLOSE_FD
  61 };
  62
  63 static void g_unix_output_stream_pollable_iface_init (GPollableOutputStreamInterface *iface);
  64
  65 G_DEFINE_TYPE_WITH_CODE (GUnixOutputStream, g_unix_output_stream, G_TYPE_OUTPUT_STREAM,
  66                          G_IMPLEMENT_INTERFACE (G_TYPE_POLLABLE_OUTPUT_STREAM,
  67                                                 g_unix_output_stream_pollable_iface_init)
  68                          );
  69
  70 struct _GUnixOutputStreamPrivate {
  71   int fd;
  72   gboolean close_fd;
  73 };
  74
  75 static void     g_unix_output_stream_set_property (GObject              *object,
  76                                                    guint                 prop_id,
  77                                                    const GValue         *value,
  78                                                    GParamSpec           *pspec);
  79 static void     g_unix_output_stream_get_property (GObject              *object,
  80                                                    guint                 prop_id,
  81                                                    GValue               *value,
  82                                                    GParamSpec           *pspec);
  83 static gssize   g_unix_output_stream_write        (GOutputStream        *stream,
  84                                                    const void           *buffer,
  85                                                    gsize                 count,
  86                                                    GCancellable         *cancellable,
  87                                                    GError              **error);
  88 static gboolean g_unix_output_stream_close        (GOutputStream        *stream,
  89                                                    GCancellable         *cancellable,
  90                                                    GError              **error);
  91 static void     g_unix_output_stream_write_async  (GOutputStream        *stream,
  92                                                    const void           *buffer,
  93                                                    gsize                 count,
  94                                                    int                   io_priority,
  95                                                    GCancellable         *cancellable,
  96                                                    GAsyncReadyCallback   callback,
  97                                                    gpointer              data);
  98 static gssize   g_unix_output_stream_write_finish (GOutputStream        *stream,
  99                                                    GAsyncResult         *result,
 100                                                    GError              **error);
 101 static void     g_unix_output_stream_close_async  (GOutputStream        *stream,
 102                                                    int                   io_priority,
 103                                                    GCancellable         *cancellable,
 104                                                    GAsyncReadyCallback   callback,
 105                                                    gpointer              data);
 106 static gboolean g_unix_output_stream_close_finish (GOutputStream        *stream,
 107                                                    GAsyncResult         *result,
 108                                                    GError              **error);
 109
 110 static gboolean g_unix_output_stream_pollable_is_writable   (GPollableOutputStream *stream);
 111 static GSource *g_unix_output_stream_pollable_create_source (GPollableOutputStream *stream,
 112                                                              GCancellable         *cancellable);
 113
 114 static void
 115 g_unix_output_stream_finalize (GObject *object)
 116 {
 117   G_OBJECT_CLASS (g_unix_output_stream_parent_class)->finalize (object);
 118 }
 119
 120 static void
 121 g_unix_output_stream_class_init (GUnixOutputStreamClass *klass)
 122 {
 123   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 124   GOutputStreamClass *stream_class = G_OUTPUT_STREAM_CLASS (klass);
 125
 126   g_type_class_add_private (klass, sizeof (GUnixOutputStreamPrivate));
 127
 128   gobject_class->get_property = g_unix_output_stream_get_property;
 129   gobject_class->set_property = g_unix_output_stream_set_property;
 130   gobject_class->finalize = g_unix_output_stream_finalize;
 131
 132   stream_class->write_fn = g_unix_output_stream_write;
 133   stream_class->close_fn = g_unix_output_stream_close;
 134   stream_class->write_async = g_unix_output_stream_write_async;
 135   stream_class->write_finish = g_unix_output_stream_write_finish;
 136   stream_class->close_async = g_unix_output_stream_close_async;
 137   stream_class->close_finish = g_unix_output_stream_close_finish;
 138
 139    /**
 140    * GUnixOutputStream:fd:
 141    *
 142    * The file descriptor that the stream writes to.
 143    *
 144    * Since: 2.20
 145    */
 146   g_object_class_install_property (gobject_class,
 147                                    PROP_FD,
 148                                    g_param_spec_int ("fd",
 149                                                      P_("File descriptor"),
 150                                                      P_("The file descriptor to write to"),
 151                                                      G_MININT, G_MAXINT, -1,
 152                                                      G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
 153
 154   /**
 155    * GUnixOutputStream:close-fd:
 156    *
 157    * Whether to close the file descriptor when the stream is closed.
 158    *
 159    * Since: 2.20
 160    */
 161   g_object_class_install_property (gobject_class,
 162                                    PROP_CLOSE_FD,
 163                                    g_param_spec_boolean ("close-fd",
 164                                                          P_("Close file descriptor"),
 165                                                          P_("Whether to close the file descriptor when the stream is closed"),
 166                                                          TRUE,
 167                                                          G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
 168 }
 169
 170 static void
 171 g_unix_output_stream_pollable_iface_init (GPollableOutputStreamInterface *iface)
 172 {
 173   iface->is_writable = g_unix_output_stream_pollable_is_writable;
 174   iface->create_source = g_unix_output_stream_pollable_create_source;
 175 }
 176
 177 static void
 178 g_unix_output_stream_set_property (GObject         *object,
 179                                    guint            prop_id,
 180                                    const GValue    *value,
 181                                    GParamSpec      *pspec)
 182 {
 183   GUnixOutputStream *unix_stream;
 184
 185   unix_stream = G_UNIX_OUTPUT_STREAM (object);
 186
 187   switch (prop_id)
 188     {
 189     case PROP_FD:
 190       unix_stream->priv->fd = g_value_get_int (value);
 191       break;
 192     case PROP_CLOSE_FD:
 193       unix_stream->priv->close_fd = g_value_get_boolean (value);
 194       break;
 195     default:
 196       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 197       break;
 198     }
 199 }
 200
 201 static void
 202 g_unix_output_stream_get_property (GObject    *object,
 203                                    guint       prop_id,
 204                                    GValue     *value,
 205                                    GParamSpec *pspec)
 206 {
 207   GUnixOutputStream *unix_stream;
 208
 209   unix_stream = G_UNIX_OUTPUT_STREAM (object);
 210
 211   switch (prop_id)
 212     {
 213     case PROP_FD:
 214       g_value_set_int (value, unix_stream->priv->fd);
 215       break;
 216     case PROP_CLOSE_FD:
 217       g_value_set_boolean (value, unix_stream->priv->close_fd);
 218       break;
 219     default:
 220       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 221     }
 222 }
 223
 224 static void
 225 g_unix_output_stream_init (GUnixOutputStream *unix_stream)
 226 {
 227   unix_stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (unix_stream,
 228                                                    G_TYPE_UNIX_OUTPUT_STREAM,
 229                                                    GUnixOutputStreamPrivate);
 230
 231   unix_stream->priv->fd = -1;
 232   unix_stream->priv->close_fd = TRUE;
 233 }
 234
 235 /**
 236  * g_unix_output_stream_new:
 237  * @fd: a UNIX file descriptor
 238  * @close_fd: %TRUE to close the file descriptor when done
 239  *
 240  * Creates a new #GUnixOutputStream for the given @fd.
 241  *
 242  * If @close_fd, is %TRUE, the file descriptor will be closed when
 243  * the output stream is destroyed.
 244  *
 245  * Returns: a new #GOutputStream
 246  **/
 247 GOutputStream *
 248 g_unix_output_stream_new (gint     fd,
 249                           gboolean close_fd)
 250 {
 251   GUnixOutputStream *stream;
 252
 253   g_return_val_if_fail (fd != -1, NULL);
 254
 255   stream = g_object_new (G_TYPE_UNIX_OUTPUT_STREAM,
 256                          "fd", fd,
 257                          "close-fd", close_fd,
 258                          NULL);
 259
 260   return G_OUTPUT_STREAM (stream);
 261 }
 262
 263 /**
 264  * g_unix_output_stream_set_close_fd:
 265  * @stream: a #GUnixOutputStream
 266  * @close_fd: %TRUE to close the file descriptor when done
 267  *
 268  * Sets whether the file descriptor of @stream shall be closed
 269  * when the stream is closed.
 270  *
 271  * Since: 2.20
 272  */
 273 void
 274 g_unix_output_stream_set_close_fd (GUnixOutputStream *stream,
 275                                    gboolean           close_fd)
 276 {
 277   g_return_if_fail (G_IS_UNIX_OUTPUT_STREAM (stream));
 278
 279   close_fd = close_fd != FALSE;
 280   if (stream->priv->close_fd != close_fd)
 281     {
 282       stream->priv->close_fd = close_fd;
 283       g_object_notify (G_OBJECT (stream), "close-fd");
 284     }
 285 }
 286
 287 /**
 288  * g_unix_output_stream_get_close_fd:
 289  * @stream: a #GUnixOutputStream
 290  *
 291  * Returns whether the file descriptor of @stream will be
 292  * closed when the stream is closed.
 293  *
 294  * Return value: %TRUE if the file descriptor is closed when done
 295  *
 296  * Since: 2.20
 297  */
 298 gboolean
 299 g_unix_output_stream_get_close_fd (GUnixOutputStream *stream)
 300 {
 301   g_return_val_if_fail (G_IS_UNIX_OUTPUT_STREAM (stream), FALSE);
 302
 303   return stream->priv->close_fd;
 304 }
 305
 306 /**
 307  * g_unix_output_stream_get_fd:
 308  * @stream: a #GUnixOutputStream
 309  *
 310  * Return the UNIX file descriptor that the stream writes to.
 311  *
 312  * Return value: The file descriptor of @stream
 313  *
 314  * Since: 2.20
 315  */
 316 gint
 317 g_unix_output_stream_get_fd (GUnixOutputStream *stream)
 318 {
 319   g_return_val_if_fail (G_IS_UNIX_OUTPUT_STREAM (stream), -1);
 320
 321   return stream->priv->fd;
 322 }
 323
 324 static gssize
 325 g_unix_output_stream_write (GOutputStream  *stream,
 326                             const void     *buffer,
 327                             gsize           count,
 328                             GCancellable   *cancellable,
 329                             GError        **error)
 330 {
 331   GUnixOutputStream *unix_stream;
 332   gssize res;
 333   GPollFD poll_fds[2];
 334   int poll_ret;
 335
 336   unix_stream = G_UNIX_OUTPUT_STREAM (stream);
 337
 338   if (g_cancellable_make_pollfd (cancellable, &poll_fds[1]))
 339     {
 340       poll_fds[0].fd = unix_stream->priv->fd;
 341       poll_fds[0].events = G_IO_OUT;
 342       do
 343         poll_ret = g_poll (poll_fds, 2, -1);
 344       while (poll_ret == -1 && errno == EINTR);
 345       g_cancellable_release_fd (cancellable);
 346
 347       if (poll_ret == -1)
 348         {
 349           int errsv = errno;
 350
 351           g_set_error (error, G_IO_ERROR,
 352                        g_io_error_from_errno (errsv),
 353                        _("Error writing to unix: %s"),
 354                        g_strerror (errsv));
 355           return -1;
 356         }
 357     }
 358
 359   while (1)
 360     {
 361       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 362         return -1;
 363
 364       res = write (unix_stream->priv->fd, buffer, count);
 365       if (res == -1)
 366         {
 367           int errsv = errno;
 368
 369           if (errsv == EINTR)
 370             continue;
 371
 372           g_set_error (error, G_IO_ERROR,
 373                        g_io_error_from_errno (errsv),
 374                        _("Error writing to unix: %s"),
 375                        g_strerror (errsv));
 376         }
 377
 378       break;
 379     }
 380
 381   return res;
 382 }
 383
 384 static gboolean
 385 g_unix_output_stream_close (GOutputStream  *stream,
 386                             GCancellable   *cancellable,
 387                             GError        **error)
 388 {
 389   GUnixOutputStream *unix_stream;
 390   int res;
 391
 392   unix_stream = G_UNIX_OUTPUT_STREAM (stream);
 393
 394   if (!unix_stream->priv->close_fd)
 395     return TRUE;
 396
 397   while (1)
 398     {
 399       /* This might block during the close. Doesn't seem to be a way to avoid it though. */
 400       res = close (unix_stream->priv->fd);
 401       if (res == -1)
 402         {
 403           int errsv = errno;
 404
 405           g_set_error (error, G_IO_ERROR,
 406                        g_io_error_from_errno (errsv),
 407                        _("Error closing unix: %s"),
 408                        g_strerror (errsv));
 409         }
 410       break;
 411     }
 412
 413   return res != -1;
 414 }
 415
 416 typedef struct {
 417   gsize count;
 418   const void *buffer;
 419   GAsyncReadyCallback callback;
 420   gpointer user_data;
 421   GCancellable *cancellable;
 422   GUnixOutputStream *stream;
 423 } WriteAsyncData;
 424
 425 static gboolean
 426 write_async_cb (int             fd,
 427                 GIOCondition    condition,
 428                 WriteAsyncData *data)
 429 {
 430   GSimpleAsyncResult *simple;
 431   GError *error = NULL;
 432   gssize count_written;
 433
 434   while (1)
 435     {
 436       if (g_cancellable_set_error_if_cancelled (data->cancellable, &error))
 437         {
 438           count_written = -1;
 439           break;
 440         }
 441
 442       count_written = write (data->stream->priv->fd, data->buffer, data->count);
 443       if (count_written == -1)
 444         {
 445           int errsv = errno;
 446
 447           if (errsv == EINTR)
 448             continue;
 449
 450           g_set_error (&error, G_IO_ERROR,
 451                        g_io_error_from_errno (errsv),
 452                        _("Error writing to unix: %s"),
 453                        g_strerror (errsv));
 454         }
 455       break;
 456     }
 457
 458   simple = g_simple_async_result_new (G_OBJECT (data->stream),
 459                                       data->callback,
 460                                       data->user_data,
 461                                       g_unix_output_stream_write_async);
 462
 463   g_simple_async_result_set_op_res_gssize (simple, count_written);
 464
 465   if (count_written == -1)
 466     g_simple_async_result_take_error (simple, error);
 467
 468   /* Complete immediately, not in idle, since we're already in a mainloop callout */
 469   g_simple_async_result_complete (simple);
 470   g_object_unref (simple);
 471
 472   return FALSE;
 473 }
 474
 475 static void
 476 g_unix_output_stream_write_async (GOutputStream       *stream,
 477                                   const void          *buffer,
 478                                   gsize                count,
 479                                   int                  io_priority,
 480                                   GCancellable        *cancellable,
 481                                   GAsyncReadyCallback  callback,
 482                                   gpointer             user_data)
 483 {
 484   GSource *source;
 485   GUnixOutputStream *unix_stream;
 486   WriteAsyncData *data;
 487
 488   unix_stream = G_UNIX_OUTPUT_STREAM (stream);
 489
 490   data = g_new0 (WriteAsyncData, 1);
 491   data->count = count;
 492   data->buffer = buffer;
 493   data->callback = callback;
 494   data->user_data = user_data;
 495   data->cancellable = cancellable;
 496   data->stream = unix_stream;
 497
 498   source = _g_fd_source_new (unix_stream->priv->fd,
 499                              G_IO_OUT,
 500                              cancellable);
 501   g_source_set_name (source, "GUnixOutputStream");
 502
 503   g_source_set_callback (source, (GSourceFunc)write_async_cb, data, g_free);
 504   g_source_attach (source, g_main_context_get_thread_default ());
 505
 506   g_source_unref (source);
 507 }
 508
 509 static gssize
 510 g_unix_output_stream_write_finish (GOutputStream  *stream,
 511                                    GAsyncResult   *result,
 512                                    GError        **error)
 513 {
 514   GSimpleAsyncResult *simple;
 515   gssize nwritten;
 516
 517   simple = G_SIMPLE_ASYNC_RESULT (result);
 518   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_unix_output_stream_write_async);
 519
 520   nwritten = g_simple_async_result_get_op_res_gssize (simple);
 521   return nwritten;
 522 }
 523
 524 typedef struct {
 525   GOutputStream *stream;
 526   GAsyncReadyCallback callback;
 527   gpointer user_data;
 528 } CloseAsyncData;
 529
 530 static gboolean
 531 close_async_cb (CloseAsyncData *data)
 532 {
 533   GUnixOutputStream *unix_stream;
 534   GSimpleAsyncResult *simple;
 535   GError *error = NULL;
 536   gboolean result;
 537   int res;
 538
 539   unix_stream = G_UNIX_OUTPUT_STREAM (data->stream);
 540
 541   if (!unix_stream->priv->close_fd)
 542     {
 543       result = TRUE;
 544       goto out;
 545     }
 546
 547   while (1)
 548     {
 549       res = close (unix_stream->priv->fd);
 550       if (res == -1)
 551         {
 552           int errsv = errno;
 553
 554           g_set_error (&error, G_IO_ERROR,
 555                        g_io_error_from_errno (errsv),
 556                        _("Error closing unix: %s"),
 557                        g_strerror (errsv));
 558         }
 559       break;
 560     }
 561
 562   result = res != -1;
 563
 564  out:
 565   simple = g_simple_async_result_new (G_OBJECT (data->stream),
 566                                       data->callback,
 567                                       data->user_data,
 568                                       g_unix_output_stream_close_async);
 569
 570   if (!result)
 571     g_simple_async_result_take_error (simple, error);
 572
 573   /* Complete immediately, not in idle, since we're already in a mainloop callout */
 574   g_simple_async_result_complete (simple);
 575   g_object_unref (simple);
 576
 577   return FALSE;
 578 }
 579
 580 static void
 581 g_unix_output_stream_close_async (GOutputStream        *stream,
 582                                   int                  io_priority,
 583                                   GCancellable        *cancellable,
 584                                   GAsyncReadyCallback  callback,
 585                                   gpointer             user_data)
 586 {
 587   GSource *idle;
 588   CloseAsyncData *data;
 589
 590   data = g_new0 (CloseAsyncData, 1);
 591
 592   data->stream = stream;
 593   data->callback = callback;
 594   data->user_data = user_data;
 595
 596   idle = g_idle_source_new ();
 597   g_source_set_callback (idle, (GSourceFunc)close_async_cb, data, g_free);
 598   g_source_attach (idle, g_main_context_get_thread_default ());
 599   g_source_unref (idle);
 600 }
 601
 602 static gboolean
 603 g_unix_output_stream_close_finish (GOutputStream  *stream,
 604                                    GAsyncResult   *result,
 605                                    GError        **error)
 606 {
 607   /* Failures handled in generic close_finish code */
 608   return TRUE;
 609 }
 610
 611 static gboolean
 612 g_unix_output_stream_pollable_is_writable (GPollableOutputStream *stream)
 613 {
 614   GUnixOutputStream *unix_stream = G_UNIX_OUTPUT_STREAM (stream);
 615   GPollFD poll_fd;
 616   gint result;
 617
 618   poll_fd.fd = unix_stream->priv->fd;
 619   poll_fd.events = G_IO_OUT;
 620
 621   do
 622     result = g_poll (&poll_fd, 1, 0);
 623   while (result == -1 && errno == EINTR);
 624
 625   return poll_fd.revents != 0;
 626 }
 627
 628 static GSource *
 629 g_unix_output_stream_pollable_create_source (GPollableOutputStream *stream,
 630                                              GCancellable          *cancellable)
 631 {
 632   GUnixOutputStream *unix_stream = G_UNIX_OUTPUT_STREAM (stream);
 633   GSource *inner_source, *pollable_source;
 634
 635   pollable_source = g_pollable_source_new (G_OBJECT (stream));
 636
 637   inner_source = _g_fd_source_new (unix_stream->priv->fd, G_IO_OUT, cancellable);
 638   g_source_set_dummy_callback (inner_source);
 639   g_source_add_child_source (pollable_source, inner_source);
 640   g_source_unref (inner_source);
 641
 642   return pollable_source;
 643 }