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 "gfiledescriptorbased.h"
  40 #include "glibintl.h"
  41
  42
  43 /**
  44  * SECTION:gunixinputstream
  45  * @short_description: Streaming input operations for UNIX file descriptors
  46  * @include: gio/gunixinputstream.h
  47  * @see_also: #GInputStream
  48  *
  49  * #GUnixInputStream implements #GInputStream for reading from 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/gunixinputstream.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 struct _GUnixInputStreamPrivate {
  67   int fd;
  68   guint close_fd : 1;
  69   guint is_pipe_or_socket : 1;
  70 };
  71
  72 static void g_unix_input_stream_pollable_iface_init (GPollableInputStreamInterface *iface);
  73 static void g_unix_input_stream_file_descriptor_based_iface_init (GFileDescriptorBasedIface *iface);
  74
  75 G_DEFINE_TYPE_WITH_CODE (GUnixInputStream, g_unix_input_stream, G_TYPE_INPUT_STREAM,
  76                          G_ADD_PRIVATE (GUnixInputStream)
  77                          G_IMPLEMENT_INTERFACE (G_TYPE_POLLABLE_INPUT_STREAM,
  78                                                 g_unix_input_stream_pollable_iface_init)
  79                          G_IMPLEMENT_INTERFACE (G_TYPE_FILE_DESCRIPTOR_BASED,
  80                                                 g_unix_input_stream_file_descriptor_based_iface_init)
  81                          )
  82
  83 static void     g_unix_input_stream_set_property (GObject              *object,
  84                                                   guint                 prop_id,
  85                                                   const GValue         *value,
  86                                                   GParamSpec           *pspec);
  87 static void     g_unix_input_stream_get_property (GObject              *object,
  88                                                   guint                 prop_id,
  89                                                   GValue               *value,
  90                                                   GParamSpec           *pspec);
  91 static gssize   g_unix_input_stream_read         (GInputStream         *stream,
  92                                                   void                 *buffer,
  93                                                   gsize                 count,
  94                                                   GCancellable         *cancellable,
  95                                                   GError              **error);
  96 static gboolean g_unix_input_stream_close        (GInputStream         *stream,
  97                                                   GCancellable         *cancellable,
  98                                                   GError              **error);
  99 static void     g_unix_input_stream_skip_async   (GInputStream         *stream,
 100                                                   gsize                 count,
 101                                                   int                   io_priority,
 102                                                   GCancellable         *cancellable,
 103                                                   GAsyncReadyCallback   callback,
 104                                                   gpointer              data);
 105 static gssize   g_unix_input_stream_skip_finish  (GInputStream         *stream,
 106                                                   GAsyncResult         *result,
 107                                                   GError              **error);
 108 static void     g_unix_input_stream_close_async  (GInputStream         *stream,
 109                                                   int                   io_priority,
 110                                                   GCancellable         *cancellable,
 111                                                   GAsyncReadyCallback   callback,
 112                                                   gpointer              data);
 113 static gboolean g_unix_input_stream_close_finish (GInputStream         *stream,
 114                                                   GAsyncResult         *result,
 115                                                   GError              **error);
 116
 117 static gboolean g_unix_input_stream_pollable_can_poll      (GPollableInputStream *stream);
 118 static gboolean g_unix_input_stream_pollable_is_readable   (GPollableInputStream *stream);
 119 static GSource *g_unix_input_stream_pollable_create_source (GPollableInputStream *stream,
 120                                                             GCancellable         *cancellable);
 121
 122 static void
 123 g_unix_input_stream_class_init (GUnixInputStreamClass *klass)
 124 {
 125   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 126   GInputStreamClass *stream_class = G_INPUT_STREAM_CLASS (klass);
 127
 128   gobject_class->get_property = g_unix_input_stream_get_property;
 129   gobject_class->set_property = g_unix_input_stream_set_property;
 130
 131   stream_class->read_fn = g_unix_input_stream_read;
 132   stream_class->close_fn = g_unix_input_stream_close;
 133   if (0)
 134     {
 135       /* TODO: Implement instead of using fallbacks */
 136       stream_class->skip_async = g_unix_input_stream_skip_async;
 137       stream_class->skip_finish = g_unix_input_stream_skip_finish;
 138     }
 139   stream_class->close_async = g_unix_input_stream_close_async;
 140   stream_class->close_finish = g_unix_input_stream_close_finish;
 141
 142   /**
 143    * GUnixInputStream:fd:
 144    *
 145    * The file descriptor that the stream reads from.
 146    *
 147    * Since: 2.20
 148    */
 149   g_object_class_install_property (gobject_class,
 150                                    PROP_FD,
 151                                    g_param_spec_int ("fd",
 152                                                      P_("File descriptor"),
 153                                                      P_("The file descriptor to read from"),
 154                                                      G_MININT, G_MAXINT, -1,
 155                                                      G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
 156
 157   /**
 158    * GUnixInputStream:close-fd:
 159    *
 160    * Whether to close the file descriptor when the stream is closed.
 161    *
 162    * Since: 2.20
 163    */
 164   g_object_class_install_property (gobject_class,
 165                                    PROP_CLOSE_FD,
 166                                    g_param_spec_boolean ("close-fd",
 167                                                          P_("Close file descriptor"),
 168                                                          P_("Whether to close the file descriptor when the stream is closed"),
 169                                                          TRUE,
 170                                                          G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
 171 }
 172
 173 static void
 174 g_unix_input_stream_pollable_iface_init (GPollableInputStreamInterface *iface)
 175 {
 176   iface->can_poll = g_unix_input_stream_pollable_can_poll;
 177   iface->is_readable = g_unix_input_stream_pollable_is_readable;
 178   iface->create_source = g_unix_input_stream_pollable_create_source;
 179 }
 180
 181 static void
 182 g_unix_input_stream_file_descriptor_based_iface_init (GFileDescriptorBasedIface *iface)
 183 {
 184   iface->get_fd = (int (*) (GFileDescriptorBased *))g_unix_input_stream_get_fd;
 185 }
 186
 187 static void
 188 g_unix_input_stream_set_property (GObject         *object,
 189                                   guint            prop_id,
 190                                   const GValue    *value,
 191                                   GParamSpec      *pspec)
 192 {
 193   GUnixInputStream *unix_stream;
 194
 195   unix_stream = G_UNIX_INPUT_STREAM (object);
 196
 197   switch (prop_id)
 198     {
 199     case PROP_FD:
 200       unix_stream->priv->fd = g_value_get_int (value);
 201       if (lseek (unix_stream->priv->fd, 0, SEEK_CUR) == -1 && errno == ESPIPE)
 202         unix_stream->priv->is_pipe_or_socket = TRUE;
 203       else
 204         unix_stream->priv->is_pipe_or_socket = FALSE;
 205       break;
 206     case PROP_CLOSE_FD:
 207       unix_stream->priv->close_fd = g_value_get_boolean (value);
 208       break;
 209     default:
 210       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 211       break;
 212     }
 213 }
 214
 215 static void
 216 g_unix_input_stream_get_property (GObject    *object,
 217                                   guint       prop_id,
 218                                   GValue     *value,
 219                                   GParamSpec *pspec)
 220 {
 221   GUnixInputStream *unix_stream;
 222
 223   unix_stream = G_UNIX_INPUT_STREAM (object);
 224
 225   switch (prop_id)
 226     {
 227     case PROP_FD:
 228       g_value_set_int (value, unix_stream->priv->fd);
 229       break;
 230     case PROP_CLOSE_FD:
 231       g_value_set_boolean (value, unix_stream->priv->close_fd);
 232       break;
 233     default:
 234       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 235     }
 236 }
 237
 238 static void
 239 g_unix_input_stream_init (GUnixInputStream *unix_stream)
 240 {
 241   unix_stream->priv = g_unix_input_stream_get_instance_private (unix_stream);
 242   unix_stream->priv->fd = -1;
 243   unix_stream->priv->close_fd = TRUE;
 244 }
 245
 246 /**
 247  * g_unix_input_stream_new:
 248  * @fd: a UNIX file descriptor
 249  * @close_fd: %TRUE to close the file descriptor when done
 250  *
 251  * Creates a new #GUnixInputStream for the given @fd.
 252  *
 253  * If @close_fd is %TRUE, the file descriptor will be closed
 254  * when the stream is closed.
 255  *
 256  * Returns: a new #GUnixInputStream
 257  **/
 258 GInputStream *
 259 g_unix_input_stream_new (gint     fd,
 260                          gboolean close_fd)
 261 {
 262   GUnixInputStream *stream;
 263
 264   g_return_val_if_fail (fd != -1, NULL);
 265
 266   stream = g_object_new (G_TYPE_UNIX_INPUT_STREAM,
 267                          "fd", fd,
 268                          "close-fd", close_fd,
 269                          NULL);
 270
 271   return G_INPUT_STREAM (stream);
 272 }
 273
 274 /**
 275  * g_unix_input_stream_set_close_fd:
 276  * @stream: a #GUnixInputStream
 277  * @close_fd: %TRUE to close the file descriptor when done
 278  *
 279  * Sets whether the file descriptor of @stream shall be closed
 280  * when the stream is closed.
 281  *
 282  * Since: 2.20
 283  */
 284 void
 285 g_unix_input_stream_set_close_fd (GUnixInputStream *stream,
 286                                   gboolean          close_fd)
 287 {
 288   g_return_if_fail (G_IS_UNIX_INPUT_STREAM (stream));
 289
 290   close_fd = close_fd != FALSE;
 291   if (stream->priv->close_fd != close_fd)
 292     {
 293       stream->priv->close_fd = close_fd;
 294       g_object_notify (G_OBJECT (stream), "close-fd");
 295     }
 296 }
 297
 298 /**
 299  * g_unix_input_stream_get_close_fd:
 300  * @stream: a #GUnixInputStream
 301  *
 302  * Returns whether the file descriptor of @stream will be
 303  * closed when the stream is closed.
 304  *
 305  * Return value: %TRUE if the file descriptor is closed when done
 306  *
 307  * Since: 2.20
 308  */
 309 gboolean
 310 g_unix_input_stream_get_close_fd (GUnixInputStream *stream)
 311 {
 312   g_return_val_if_fail (G_IS_UNIX_INPUT_STREAM (stream), FALSE);
 313
 314   return stream->priv->close_fd;
 315 }
 316
 317 /**
 318  * g_unix_input_stream_get_fd:
 319  * @stream: a #GUnixInputStream
 320  *
 321  * Return the UNIX file descriptor that the stream reads from.
 322  *
 323  * Return value: The file descriptor of @stream
 324  *
 325  * Since: 2.20
 326  */
 327 gint
 328 g_unix_input_stream_get_fd (GUnixInputStream *stream)
 329 {
 330   g_return_val_if_fail (G_IS_UNIX_INPUT_STREAM (stream), -1);
 331
 332   return stream->priv->fd;
 333 }
 334
 335 static gssize
 336 g_unix_input_stream_read (GInputStream  *stream,
 337                           void          *buffer,
 338                           gsize          count,
 339                           GCancellable  *cancellable,
 340                           GError       **error)
 341 {
 342   GUnixInputStream *unix_stream;
 343   gssize res = -1;
 344   GPollFD poll_fds[2];
 345   int nfds;
 346   int poll_ret;
 347
 348   unix_stream = G_UNIX_INPUT_STREAM (stream);
 349
 350   poll_fds[0].fd = unix_stream->priv->fd;
 351   poll_fds[0].events = G_IO_IN;
 352   if (unix_stream->priv->is_pipe_or_socket &&
 353       g_cancellable_make_pollfd (cancellable, &poll_fds[1]))
 354     nfds = 2;
 355   else
 356     nfds = 1;
 357
 358   while (1)
 359     {
 360       poll_fds[0].revents = poll_fds[1].revents = 0;
 361       do
 362         poll_ret = g_poll (poll_fds, nfds, -1);
 363       while (poll_ret == -1 && errno == EINTR);
 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 reading from file descriptor: %s"),
 372                        g_strerror (errsv));
 373           break;
 374         }
 375
 376       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 377         break;
 378
 379       if (!poll_fds[0].revents)
 380         continue;
 381
 382       res = read (unix_stream->priv->fd, buffer, count);
 383       if (res == -1)
 384         {
 385           int errsv = errno;
 386
 387           if (errsv == EINTR || errsv == EAGAIN)
 388             continue;
 389
 390           g_set_error (error, G_IO_ERROR,
 391                        g_io_error_from_errno (errsv),
 392                        _("Error reading from file descriptor: %s"),
 393                        g_strerror (errsv));
 394         }
 395
 396       break;
 397     }
 398
 399   if (nfds == 2)
 400     g_cancellable_release_fd (cancellable);
 401   return res;
 402 }
 403
 404 static gboolean
 405 g_unix_input_stream_close (GInputStream  *stream,
 406                            GCancellable  *cancellable,
 407                            GError       **error)
 408 {
 409   GUnixInputStream *unix_stream;
 410   int res;
 411
 412   unix_stream = G_UNIX_INPUT_STREAM (stream);
 413
 414   if (!unix_stream->priv->close_fd)
 415     return TRUE;
 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 file descriptor: %s"),
 426                    g_strerror (errsv));
 427     }
 428
 429   return res != -1;
 430 }
 431
 432 static void
 433 g_unix_input_stream_skip_async (GInputStream        *stream,
 434                                 gsize                count,
 435                                 int                  io_priority,
 436                                 GCancellable        *cancellable,
 437                                 GAsyncReadyCallback  callback,
 438                                 gpointer             data)
 439 {
 440   g_warn_if_reached ();
 441   /* TODO: Not implemented */
 442 }
 443
 444 static gssize
 445 g_unix_input_stream_skip_finish  (GInputStream  *stream,
 446                                   GAsyncResult  *result,
 447                                   GError       **error)
 448 {
 449   g_warn_if_reached ();
 450   return 0;
 451   /* TODO: Not implemented */
 452 }
 453
 454 static void
 455 g_unix_input_stream_close_async (GInputStream        *stream,
 456                                  int                  io_priority,
 457                                  GCancellable        *cancellable,
 458                                  GAsyncReadyCallback  callback,
 459                                  gpointer             user_data)
 460 {
 461   GTask *task;
 462   GError *error = NULL;
 463
 464   task = g_task_new (stream, cancellable, callback, user_data);
 465   g_task_set_priority (task, io_priority);
 466
 467   if (g_unix_input_stream_close (stream, cancellable, &error))
 468     g_task_return_boolean (task, TRUE);
 469   else
 470     g_task_return_error (task, error);
 471   g_object_unref (task);
 472 }
 473
 474 static gboolean
 475 g_unix_input_stream_close_finish (GInputStream  *stream,
 476                                   GAsyncResult  *result,
 477                                   GError       **error)
 478 {
 479   g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
 480
 481   return g_task_propagate_boolean (G_TASK (result), error);
 482 }
 483
 484 static gboolean
 485 g_unix_input_stream_pollable_can_poll (GPollableInputStream *stream)
 486 {
 487   return G_UNIX_INPUT_STREAM (stream)->priv->is_pipe_or_socket;
 488 }
 489
 490 static gboolean
 491 g_unix_input_stream_pollable_is_readable (GPollableInputStream *stream)
 492 {
 493   GUnixInputStream *unix_stream = G_UNIX_INPUT_STREAM (stream);
 494   GPollFD poll_fd;
 495   gint result;
 496
 497   poll_fd.fd = unix_stream->priv->fd;
 498   poll_fd.events = G_IO_IN;
 499   poll_fd.revents = 0;
 500
 501   do
 502     result = g_poll (&poll_fd, 1, 0);
 503   while (result == -1 && errno == EINTR);
 504
 505   return poll_fd.revents != 0;
 506 }
 507
 508 static GSource *
 509 g_unix_input_stream_pollable_create_source (GPollableInputStream *stream,
 510                                             GCancellable         *cancellable)
 511 {
 512   GUnixInputStream *unix_stream = G_UNIX_INPUT_STREAM (stream);
 513   GSource *inner_source, *pollable_source;
 514
 515   pollable_source = g_pollable_source_new (G_OBJECT (stream));
 516
 517   inner_source = _g_fd_source_new (unix_stream->priv->fd, G_IO_IN, cancellable);
 518   g_source_set_dummy_callback (inner_source);
 519   g_source_add_child_source (pollable_source, inner_source);
 520   g_source_unref (inner_source);
 521
 522   return pollable_source;
 523 }