gio/gunixinputstream.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 "gsimpleasyncresult.h"
  36 #include "gunixinputstream.h"
  37 #include "gcancellable.h"
  38 #include "gasynchelper.h"
  39 #include "glibintl.h"
  40
  41
  42 /**
  43  * SECTION:gunixinputstream
  44  * @short_description: Streaming input operations for UNIX file descriptors
  45  * @include: gio/gunixinputstream.h
  46  * @see_also: #GInputStream
  47  *
  48  * #GUnixInputStream implements #GInputStream for reading from 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/gunixinputstream.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 (GUnixInputStream, g_unix_input_stream, G_TYPE_INPUT_STREAM);
  64
  65 struct _GUnixInputStreamPrivate {
  66   int fd;
  67   gboolean close_fd;
  68 };
  69
  70 static void     g_unix_input_stream_set_property (GObject              *object,
  71                                                   guint                 prop_id,
  72                                                   const GValue         *value,
  73                                                   GParamSpec           *pspec);
  74 static void     g_unix_input_stream_get_property (GObject              *object,
  75                                                   guint                 prop_id,
  76                                                   GValue               *value,
  77                                                   GParamSpec           *pspec);
  78 static gssize   g_unix_input_stream_read         (GInputStream         *stream,
  79                                                   void                 *buffer,
  80                                                   gsize                 count,
  81                                                   GCancellable         *cancellable,
  82                                                   GError              **error);
  83 static gboolean g_unix_input_stream_close        (GInputStream         *stream,
  84                                                   GCancellable         *cancellable,
  85                                                   GError              **error);
  86 static void     g_unix_input_stream_read_async   (GInputStream         *stream,
  87                                                   void                 *buffer,
  88                                                   gsize                 count,
  89                                                   int                   io_priority,
  90                                                   GCancellable         *cancellable,
  91                                                   GAsyncReadyCallback   callback,
  92                                                   gpointer              data);
  93 static gssize   g_unix_input_stream_read_finish  (GInputStream         *stream,
  94                                                   GAsyncResult         *result,
  95                                                   GError              **error);
  96 static void     g_unix_input_stream_skip_async   (GInputStream         *stream,
  97                                                   gsize                 count,
  98                                                   int                   io_priority,
  99                                                   GCancellable         *cancellable,
 100                                                   GAsyncReadyCallback   callback,
 101                                                   gpointer              data);
 102 static gssize   g_unix_input_stream_skip_finish  (GInputStream         *stream,
 103                                                   GAsyncResult         *result,
 104                                                   GError              **error);
 105 static void     g_unix_input_stream_close_async  (GInputStream         *stream,
 106                                                   int                   io_priority,
 107                                                   GCancellable         *cancellable,
 108                                                   GAsyncReadyCallback   callback,
 109                                                   gpointer              data);
 110 static gboolean g_unix_input_stream_close_finish (GInputStream         *stream,
 111                                                   GAsyncResult         *result,
 112                                                   GError              **error);
 113
 114
 115 static void
 116 g_unix_input_stream_finalize (GObject *object)
 117 {
 118   G_OBJECT_CLASS (g_unix_input_stream_parent_class)->finalize (object);
 119 }
 120
 121 static void
 122 g_unix_input_stream_class_init (GUnixInputStreamClass *klass)
 123 {
 124   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 125   GInputStreamClass *stream_class = G_INPUT_STREAM_CLASS (klass);
 126
 127   g_type_class_add_private (klass, sizeof (GUnixInputStreamPrivate));
 128
 129   gobject_class->get_property = g_unix_input_stream_get_property;
 130   gobject_class->set_property = g_unix_input_stream_set_property;
 131   gobject_class->finalize = g_unix_input_stream_finalize;
 132
 133   stream_class->read_fn = g_unix_input_stream_read;
 134   stream_class->close_fn = g_unix_input_stream_close;
 135   stream_class->read_async = g_unix_input_stream_read_async;
 136   stream_class->read_finish = g_unix_input_stream_read_finish;
 137   if (0)
 138     {
 139       /* TODO: Implement instead of using fallbacks */
 140       stream_class->skip_async = g_unix_input_stream_skip_async;
 141       stream_class->skip_finish = g_unix_input_stream_skip_finish;
 142     }
 143   stream_class->close_async = g_unix_input_stream_close_async;
 144   stream_class->close_finish = g_unix_input_stream_close_finish;
 145
 146   /**
 147    * GUnixInputStream:fd:
 148    *
 149    * The file descriptor that the stream reads from.
 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 read from"),
 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    * GUnixInputStream: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_input_stream_set_property (GObject         *object,
 179                                   guint            prop_id,
 180                                   const GValue    *value,
 181                                   GParamSpec      *pspec)
 182 {
 183   GUnixInputStream *unix_stream;
 184
 185   unix_stream = G_UNIX_INPUT_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_input_stream_get_property (GObject    *object,
 203                                   guint       prop_id,
 204                                   GValue     *value,
 205                                   GParamSpec *pspec)
 206 {
 207   GUnixInputStream *unix_stream;
 208
 209   unix_stream = G_UNIX_INPUT_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_input_stream_init (GUnixInputStream *unix_stream)
 226 {
 227   unix_stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (unix_stream,
 228                                                    G_TYPE_UNIX_INPUT_STREAM,
 229                                                    GUnixInputStreamPrivate);
 230
 231   unix_stream->priv->fd = -1;
 232   unix_stream->priv->close_fd = TRUE;
 233 }
 234
 235 /**
 236  * g_unix_input_stream_new:
 237  * @fd: a UNIX file descriptor
 238  * @close_fd: %TRUE to close the file descriptor when done
 239  *
 240  * Creates a new #GUnixInputStream for the given @fd.
 241  *
 242  * If @close_fd is %TRUE, the file descriptor will be closed
 243  * when the stream is closed.
 244  *
 245  * Returns: a new #GUnixInputStream
 246  **/
 247 GInputStream *
 248 g_unix_input_stream_new (gint     fd,
 249                          gboolean close_fd)
 250 {
 251   GUnixInputStream *stream;
 252
 253   g_return_val_if_fail (fd != -1, NULL);
 254
 255   stream = g_object_new (G_TYPE_UNIX_INPUT_STREAM,
 256                          "fd", fd,
 257                          "close-fd", close_fd,
 258                          NULL);
 259
 260   return G_INPUT_STREAM (stream);
 261 }
 262
 263 /**
 264  * g_unix_input_stream_set_close_fd:
 265  * @stream: a #GUnixInputStream
 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_input_stream_set_close_fd (GUnixInputStream *stream,
 275                                   gboolean          close_fd)
 276 {
 277   g_return_if_fail (G_IS_UNIX_INPUT_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_input_stream_get_close_fd:
 289  * @stream: a #GUnixInputStream
 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_input_stream_get_close_fd (GUnixInputStream *stream)
 300 {
 301   g_return_val_if_fail (G_IS_UNIX_INPUT_STREAM (stream), FALSE);
 302
 303   return stream->priv->close_fd;
 304 }
 305
 306 /**
 307  * g_unix_input_stream_get_fd:
 308  * @stream: a #GUnixInputStream
 309  *
 310  * Return the UNIX file descriptor that the stream reads from.
 311  *
 312  * Return value: The file descriptor of @stream
 313  *
 314  * Since: 2.20
 315  */
 316 gint
 317 g_unix_input_stream_get_fd (GUnixInputStream *stream)
 318 {
 319   g_return_val_if_fail (G_IS_UNIX_INPUT_STREAM (stream), -1);
 320
 321   return stream->priv->fd;
 322 }
 323
 324 static gssize
 325 g_unix_input_stream_read (GInputStream  *stream,
 326                           void          *buffer,
 327                           gsize          count,
 328                           GCancellable  *cancellable,
 329                           GError       **error)
 330 {
 331   GUnixInputStream *unix_stream;
 332   gssize res;
 333   GPollFD poll_fds[2];
 334   int poll_ret;
 335
 336   unix_stream = G_UNIX_INPUT_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_IN;
 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 reading from 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       res = read (unix_stream->priv->fd, buffer, count);
 364       if (res == -1)
 365         {
 366           int errsv = errno;
 367
 368           if (errsv == EINTR)
 369             continue;
 370
 371           g_set_error (error, G_IO_ERROR,
 372                        g_io_error_from_errno (errsv),
 373                        _("Error reading from unix: %s"),
 374                        g_strerror (errsv));
 375         }
 376
 377       break;
 378     }
 379
 380   return res;
 381 }
 382
 383 static gboolean
 384 g_unix_input_stream_close (GInputStream  *stream,
 385                            GCancellable  *cancellable,
 386                            GError       **error)
 387 {
 388   GUnixInputStream *unix_stream;
 389   int res;
 390
 391   unix_stream = G_UNIX_INPUT_STREAM (stream);
 392
 393   if (!unix_stream->priv->close_fd)
 394     return TRUE;
 395
 396   while (1)
 397     {
 398       /* This might block during the close. Doesn't seem to be a way to avoid it though. */
 399       res = close (unix_stream->priv->fd);
 400       if (res == -1)
 401         {
 402           int errsv = errno;
 403
 404           g_set_error (error, G_IO_ERROR,
 405                        g_io_error_from_errno (errsv),
 406                        _("Error closing unix: %s"),
 407                        g_strerror (errsv));
 408         }
 409       break;
 410     }
 411
 412   return res != -1;
 413 }
 414
 415 typedef struct {
 416   gsize count;
 417   void *buffer;
 418   GAsyncReadyCallback callback;
 419   gpointer user_data;
 420   GCancellable *cancellable;
 421   GUnixInputStream *stream;
 422 } ReadAsyncData;
 423
 424 static gboolean
 425 read_async_cb (ReadAsyncData *data,
 426                GIOCondition   condition,
 427                int            fd)
 428 {
 429   GSimpleAsyncResult *simple;
 430   GError *error = NULL;
 431   gssize count_read;
 432
 433   /* We know that we can read from fd once without blocking */
 434   while (1)
 435     {
 436       if (g_cancellable_set_error_if_cancelled (data->cancellable, &error))
 437         {
 438           count_read = -1;
 439           break;
 440         }
 441       count_read = read (data->stream->priv->fd, data->buffer, data->count);
 442       if (count_read == -1)
 443         {
 444           int errsv = errno;
 445
 446           if (errsv == EINTR)
 447             continue;
 448
 449           g_set_error (&error, G_IO_ERROR,
 450                        g_io_error_from_errno (errsv),
 451                        _("Error reading from unix: %s"),
 452                        g_strerror (errsv));
 453         }
 454       break;
 455     }
 456
 457   simple = g_simple_async_result_new (G_OBJECT (data->stream),
 458                                       data->callback,
 459                                       data->user_data,
 460                                       g_unix_input_stream_read_async);
 461
 462   g_simple_async_result_set_op_res_gssize (simple, count_read);
 463
 464   if (count_read == -1)
 465     {
 466       g_simple_async_result_set_from_error (simple, error);
 467       g_error_free (error);
 468     }
 469
 470   /* Complete immediately, not in idle, since we're already in a mainloop callout */
 471   g_simple_async_result_complete (simple);
 472   g_object_unref (simple);
 473
 474   return FALSE;
 475 }
 476
 477 static void
 478 g_unix_input_stream_read_async (GInputStream        *stream,
 479                                 void                *buffer,
 480                                 gsize                count,
 481                                 int                  io_priority,
 482                                 GCancellable        *cancellable,
 483                                 GAsyncReadyCallback  callback,
 484                                 gpointer             user_data)
 485 {
 486   GSource *source;
 487   GUnixInputStream *unix_stream;
 488   ReadAsyncData *data;
 489
 490   unix_stream = G_UNIX_INPUT_STREAM (stream);
 491
 492   data = g_new0 (ReadAsyncData, 1);
 493   data->count = count;
 494   data->buffer = buffer;
 495   data->callback = callback;
 496   data->user_data = user_data;
 497   data->cancellable = cancellable;
 498   data->stream = unix_stream;
 499
 500   source = _g_fd_source_new (unix_stream->priv->fd,
 501                              G_IO_IN,
 502                              cancellable);
 503
 504   g_source_set_callback (source, (GSourceFunc)read_async_cb, data, g_free);
 505   g_source_attach (source, g_main_context_get_thread_default ());
 506
 507   g_source_unref (source);
 508 }
 509
 510 static gssize
 511 g_unix_input_stream_read_finish (GInputStream  *stream,
 512                                  GAsyncResult  *result,
 513                                  GError       **error)
 514 {
 515   GSimpleAsyncResult *simple;
 516   gssize nread;
 517
 518   simple = G_SIMPLE_ASYNC_RESULT (result);
 519   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_unix_input_stream_read_async);
 520
 521   nread = g_simple_async_result_get_op_res_gssize (simple);
 522   return nread;
 523 }
 524
 525 static void
 526 g_unix_input_stream_skip_async (GInputStream        *stream,
 527                                 gsize                count,
 528                                 int                  io_priority,
 529                                 GCancellable        *cancellable,
 530                                 GAsyncReadyCallback  callback,
 531                                 gpointer             data)
 532 {
 533   g_warn_if_reached ();
 534   /* TODO: Not implemented */
 535 }
 536
 537 static gssize
 538 g_unix_input_stream_skip_finish  (GInputStream  *stream,
 539                                   GAsyncResult  *result,
 540                                   GError       **error)
 541 {
 542   g_warn_if_reached ();
 543   return 0;
 544   /* TODO: Not implemented */
 545 }
 546
 547
 548 typedef struct {
 549   GInputStream *stream;
 550   GAsyncReadyCallback callback;
 551   gpointer user_data;
 552 } CloseAsyncData;
 553
 554 static void
 555 close_async_data_free (gpointer _data)
 556 {
 557   CloseAsyncData *data = _data;
 558
 559   g_free (data);
 560 }
 561
 562 static gboolean
 563 close_async_cb (CloseAsyncData *data)
 564 {
 565   GUnixInputStream *unix_stream;
 566   GSimpleAsyncResult *simple;
 567   GError *error = NULL;
 568   gboolean result;
 569   int res;
 570
 571   unix_stream = G_UNIX_INPUT_STREAM (data->stream);
 572
 573   if (!unix_stream->priv->close_fd)
 574     {
 575       result = TRUE;
 576       goto out;
 577     }
 578
 579   while (1)
 580     {
 581       res = close (unix_stream->priv->fd);
 582       if (res == -1)
 583         {
 584           int errsv = errno;
 585
 586           g_set_error (&error, G_IO_ERROR,
 587                        g_io_error_from_errno (errsv),
 588                        _("Error closing unix: %s"),
 589                        g_strerror (errsv));
 590         }
 591       break;
 592     }
 593
 594   result = res != -1;
 595
 596  out:
 597   simple = g_simple_async_result_new (G_OBJECT (data->stream),
 598                                       data->callback,
 599                                       data->user_data,
 600                                       g_unix_input_stream_close_async);
 601
 602   if (!result)
 603     {
 604       g_simple_async_result_set_from_error (simple, error);
 605       g_error_free (error);
 606     }
 607
 608   /* Complete immediately, not in idle, since we're already in a mainloop callout */
 609   g_simple_async_result_complete (simple);
 610   g_object_unref (simple);
 611
 612   return FALSE;
 613 }
 614
 615 static void
 616 g_unix_input_stream_close_async (GInputStream        *stream,
 617                                  int                  io_priority,
 618                                  GCancellable        *cancellable,
 619                                  GAsyncReadyCallback  callback,
 620                                  gpointer             user_data)
 621 {
 622   GSource *idle;
 623   CloseAsyncData *data;
 624
 625   data = g_new0 (CloseAsyncData, 1);
 626
 627   data->stream = stream;
 628   data->callback = callback;
 629   data->user_data = user_data;
 630
 631   idle = g_idle_source_new ();
 632   g_source_set_callback (idle, (GSourceFunc)close_async_cb, data, close_async_data_free);
 633   g_source_attach (idle, g_main_context_get_thread_default ());
 634   g_source_unref (idle);
 635 }
 636
 637 static gboolean
 638 g_unix_input_stream_close_finish (GInputStream  *stream,
 639                                   GAsyncResult  *result,
 640                                   GError       **error)
 641 {
 642   /* Failures handled in generic close_finish code */
 643   return TRUE;
 644 }