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