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 <glib/glib-unix.h>
  35 #include "gioerror.h"
  36 #include "gsimpleasyncresult.h"
  37 #include "gunixinputstream.h"
  38 #include "gcancellable.h"
  39 #include "gasynchelper.h"
  40 #include "gfiledescriptorbased.h"
  41 #include "glibintl.h"
  42
  43
  44 /**
  45  * SECTION:gunixinputstream
  46  * @short_description: Streaming input operations for UNIX file descriptors
  47  * @include: gio/gunixinputstream.h
  48  * @see_also: #GInputStream
  49  *
  50  * #GUnixInputStream implements #GInputStream for reading from a UNIX
  51  * file descriptor, including asynchronous operations. (If the file
  52  * descriptor refers to a socket or pipe, this will use poll() to do
  53  * asynchronous I/O. If it refers to a regular file, it will fall back
  54  * to doing asynchronous I/O in another thread.)
  55  *
  56  * Note that <filename>&lt;gio/gunixinputstream.h&gt;</filename> belongs
  57  * to the UNIX-specific GIO interfaces, thus you have to use the
  58  * <filename>gio-unix-2.0.pc</filename> pkg-config file when using it.
  59  */
  60
  61 enum {
  62   PROP_0,
  63   PROP_FD,
  64   PROP_CLOSE_FD
  65 };
  66
  67 struct _GUnixInputStreamPrivate {
  68   int fd;
  69   guint close_fd : 1;
  70   guint is_pipe_or_socket : 1;
  71 };
  72
  73 static void g_unix_input_stream_pollable_iface_init (GPollableInputStreamInterface *iface);
  74 static void g_unix_input_stream_file_descriptor_based_iface_init (GFileDescriptorBasedIface *iface);
  75
  76 G_DEFINE_TYPE_WITH_CODE (GUnixInputStream, g_unix_input_stream, G_TYPE_INPUT_STREAM,
  77                          G_ADD_PRIVATE (GUnixInputStream)
  78                          G_IMPLEMENT_INTERFACE (G_TYPE_POLLABLE_INPUT_STREAM,
  79                                                 g_unix_input_stream_pollable_iface_init)
  80                          G_IMPLEMENT_INTERFACE (G_TYPE_FILE_DESCRIPTOR_BASED,
  81                                                 g_unix_input_stream_file_descriptor_based_iface_init)
  82                          )
  83
  84 static void     g_unix_input_stream_set_property (GObject              *object,
  85                                                   guint                 prop_id,
  86                                                   const GValue         *value,
  87                                                   GParamSpec           *pspec);
  88 static void     g_unix_input_stream_get_property (GObject              *object,
  89                                                   guint                 prop_id,
  90                                                   GValue               *value,
  91                                                   GParamSpec           *pspec);
  92 static gssize   g_unix_input_stream_read         (GInputStream         *stream,
  93                                                   void                 *buffer,
  94                                                   gsize                 count,
  95                                                   GCancellable         *cancellable,
  96                                                   GError              **error);
  97 static gboolean g_unix_input_stream_close        (GInputStream         *stream,
  98                                                   GCancellable         *cancellable,
  99                                                   GError              **error);
 100 static void     g_unix_input_stream_skip_async   (GInputStream         *stream,
 101                                                   gsize                 count,
 102                                                   int                   io_priority,
 103                                                   GCancellable         *cancellable,
 104                                                   GAsyncReadyCallback   callback,
 105                                                   gpointer              data);
 106 static gssize   g_unix_input_stream_skip_finish  (GInputStream         *stream,
 107                                                   GAsyncResult         *result,
 108                                                   GError              **error);
 109 static void     g_unix_input_stream_close_async  (GInputStream         *stream,
 110                                                   int                   io_priority,
 111                                                   GCancellable         *cancellable,
 112                                                   GAsyncReadyCallback   callback,
 113                                                   gpointer              data);
 114 static gboolean g_unix_input_stream_close_finish (GInputStream         *stream,
 115                                                   GAsyncResult         *result,
 116                                                   GError              **error);
 117
 118 static gboolean g_unix_input_stream_pollable_can_poll      (GPollableInputStream *stream);
 119 static gboolean g_unix_input_stream_pollable_is_readable   (GPollableInputStream *stream);
 120 static GSource *g_unix_input_stream_pollable_create_source (GPollableInputStream *stream,
 121                                                             GCancellable         *cancellable);
 122
 123 static void
 124 g_unix_input_stream_class_init (GUnixInputStreamClass *klass)
 125 {
 126   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 127   GInputStreamClass *stream_class = G_INPUT_STREAM_CLASS (klass);
 128
 129   gobject_class->get_property = g_unix_input_stream_get_property;
 130   gobject_class->set_property = g_unix_input_stream_set_property;
 131
 132   stream_class->read_fn = g_unix_input_stream_read;
 133   stream_class->close_fn = g_unix_input_stream_close;
 134   if (0)
 135     {
 136       /* TODO: Implement instead of using fallbacks */
 137       stream_class->skip_async = g_unix_input_stream_skip_async;
 138       stream_class->skip_finish = g_unix_input_stream_skip_finish;
 139     }
 140   stream_class->close_async = g_unix_input_stream_close_async;
 141   stream_class->close_finish = g_unix_input_stream_close_finish;
 142
 143   /**
 144    * GUnixInputStream:fd:
 145    *
 146    * The file descriptor that the stream reads from.
 147    *
 148    * Since: 2.20
 149    */
 150   g_object_class_install_property (gobject_class,
 151                                    PROP_FD,
 152                                    g_param_spec_int ("fd",
 153                                                      P_("File descriptor"),
 154                                                      P_("The file descriptor to read from"),
 155                                                      G_MININT, G_MAXINT, -1,
 156                                                      G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
 157
 158   /**
 159    * GUnixInputStream:close-fd:
 160    *
 161    * Whether to close the file descriptor when the stream is closed.
 162    *
 163    * Since: 2.20
 164    */
 165   g_object_class_install_property (gobject_class,
 166                                    PROP_CLOSE_FD,
 167                                    g_param_spec_boolean ("close-fd",
 168                                                          P_("Close file descriptor"),
 169                                                          P_("Whether to close the file descriptor when the stream is closed"),
 170                                                          TRUE,
 171                                                          G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
 172 }
 173
 174 static void
 175 g_unix_input_stream_pollable_iface_init (GPollableInputStreamInterface *iface)
 176 {
 177   iface->can_poll = g_unix_input_stream_pollable_can_poll;
 178   iface->is_readable = g_unix_input_stream_pollable_is_readable;
 179   iface->create_source = g_unix_input_stream_pollable_create_source;
 180 }
 181
 182 static void
 183 g_unix_input_stream_file_descriptor_based_iface_init (GFileDescriptorBasedIface *iface)
 184 {
 185   iface->get_fd = (int (*) (GFileDescriptorBased *))g_unix_input_stream_get_fd;
 186 }
 187
 188 static void
 189 g_unix_input_stream_set_property (GObject         *object,
 190                                   guint            prop_id,
 191                                   const GValue    *value,
 192                                   GParamSpec      *pspec)
 193 {
 194   GUnixInputStream *unix_stream;
 195
 196   unix_stream = G_UNIX_INPUT_STREAM (object);
 197
 198   switch (prop_id)
 199     {
 200     case PROP_FD:
 201       unix_stream->priv->fd = g_value_get_int (value);
 202       if (lseek (unix_stream->priv->fd, 0, SEEK_CUR) == -1 && errno == ESPIPE)
 203         unix_stream->priv->is_pipe_or_socket = TRUE;
 204       else
 205         unix_stream->priv->is_pipe_or_socket = FALSE;
 206       break;
 207     case PROP_CLOSE_FD:
 208       unix_stream->priv->close_fd = g_value_get_boolean (value);
 209       break;
 210     default:
 211       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 212       break;
 213     }
 214 }
 215
 216 static void
 217 g_unix_input_stream_get_property (GObject    *object,
 218                                   guint       prop_id,
 219                                   GValue     *value,
 220                                   GParamSpec *pspec)
 221 {
 222   GUnixInputStream *unix_stream;
 223
 224   unix_stream = G_UNIX_INPUT_STREAM (object);
 225
 226   switch (prop_id)
 227     {
 228     case PROP_FD:
 229       g_value_set_int (value, unix_stream->priv->fd);
 230       break;
 231     case PROP_CLOSE_FD:
 232       g_value_set_boolean (value, unix_stream->priv->close_fd);
 233       break;
 234     default:
 235       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 236     }
 237 }
 238
 239 static void
 240 g_unix_input_stream_init (GUnixInputStream *unix_stream)
 241 {
 242   unix_stream->priv = g_unix_input_stream_get_instance_private (unix_stream);
 243   unix_stream->priv->fd = -1;
 244   unix_stream->priv->close_fd = TRUE;
 245 }
 246
 247 /**
 248  * g_unix_input_stream_new:
 249  * @fd: a UNIX file descriptor
 250  * @close_fd: %TRUE to close the file descriptor when done
 251  *
 252  * Creates a new #GUnixInputStream for the given @fd.
 253  *
 254  * If @close_fd is %TRUE, the file descriptor will be closed
 255  * when the stream is closed.
 256  *
 257  * Returns: a new #GUnixInputStream
 258  **/
 259 GInputStream *
 260 g_unix_input_stream_new (gint     fd,
 261                          gboolean close_fd)
 262 {
 263   GUnixInputStream *stream;
 264
 265   g_return_val_if_fail (fd != -1, NULL);
 266
 267   stream = g_object_new (G_TYPE_UNIX_INPUT_STREAM,
 268                          "fd", fd,
 269                          "close-fd", close_fd,
 270                          NULL);
 271
 272   return G_INPUT_STREAM (stream);
 273 }
 274
 275 /**
 276  * g_unix_input_stream_set_close_fd:
 277  * @stream: a #GUnixInputStream
 278  * @close_fd: %TRUE to close the file descriptor when done
 279  *
 280  * Sets whether the file descriptor of @stream shall be closed
 281  * when the stream is closed.
 282  *
 283  * Since: 2.20
 284  */
 285 void
 286 g_unix_input_stream_set_close_fd (GUnixInputStream *stream,
 287                                   gboolean          close_fd)
 288 {
 289   g_return_if_fail (G_IS_UNIX_INPUT_STREAM (stream));
 290
 291   close_fd = close_fd != FALSE;
 292   if (stream->priv->close_fd != close_fd)
 293     {
 294       stream->priv->close_fd = close_fd;
 295       g_object_notify (G_OBJECT (stream), "close-fd");
 296     }
 297 }
 298
 299 /**
 300  * g_unix_input_stream_get_close_fd:
 301  * @stream: a #GUnixInputStream
 302  *
 303  * Returns whether the file descriptor of @stream will be
 304  * closed when the stream is closed.
 305  *
 306  * Return value: %TRUE if the file descriptor is closed when done
 307  *
 308  * Since: 2.20
 309  */
 310 gboolean
 311 g_unix_input_stream_get_close_fd (GUnixInputStream *stream)
 312 {
 313   g_return_val_if_fail (G_IS_UNIX_INPUT_STREAM (stream), FALSE);
 314
 315   return stream->priv->close_fd;
 316 }
 317
 318 /**
 319  * g_unix_input_stream_get_fd:
 320  * @stream: a #GUnixInputStream
 321  *
 322  * Return the UNIX file descriptor that the stream reads from.
 323  *
 324  * Return value: The file descriptor of @stream
 325  *
 326  * Since: 2.20
 327  */
 328 gint
 329 g_unix_input_stream_get_fd (GUnixInputStream *stream)
 330 {
 331   g_return_val_if_fail (G_IS_UNIX_INPUT_STREAM (stream), -1);
 332
 333   return stream->priv->fd;
 334 }
 335
 336 static gssize
 337 g_unix_input_stream_read (GInputStream  *stream,
 338                           void          *buffer,
 339                           gsize          count,
 340                           GCancellable  *cancellable,
 341                           GError       **error)
 342 {
 343   GUnixInputStream *unix_stream;
 344   gssize res = -1;
 345   GPollFD poll_fds[2];
 346   int nfds;
 347   int poll_ret;
 348
 349   unix_stream = G_UNIX_INPUT_STREAM (stream);
 350
 351   poll_fds[0].fd = unix_stream->priv->fd;
 352   poll_fds[0].events = G_IO_IN;
 353   if (unix_stream->priv->is_pipe_or_socket &&
 354       g_cancellable_make_pollfd (cancellable, &poll_fds[1]))
 355     nfds = 2;
 356   else
 357     nfds = 1;
 358
 359   while (1)
 360     {
 361       poll_fds[0].revents = poll_fds[1].revents = 0;
 362       do
 363         poll_ret = g_poll (poll_fds, nfds, -1);
 364       while (poll_ret == -1 && errno == EINTR);
 365
 366       if (poll_ret == -1)
 367         {
 368           int errsv = errno;
 369
 370           g_set_error (error, G_IO_ERROR,
 371                        g_io_error_from_errno (errsv),
 372                        _("Error reading from file descriptor: %s"),
 373                        g_strerror (errsv));
 374           break;
 375         }
 376
 377       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 378         break;
 379
 380       if (!poll_fds[0].revents)
 381         continue;
 382
 383       res = read (unix_stream->priv->fd, buffer, count);
 384       if (res == -1)
 385         {
 386           int errsv = errno;
 387
 388           if (errsv == EINTR || errsv == EAGAIN)
 389             continue;
 390
 391           g_set_error (error, G_IO_ERROR,
 392                        g_io_error_from_errno (errsv),
 393                        _("Error reading from file descriptor: %s"),
 394                        g_strerror (errsv));
 395         }
 396
 397       break;
 398     }
 399
 400   if (nfds == 2)
 401     g_cancellable_release_fd (cancellable);
 402   return res;
 403 }
 404
 405 static gboolean
 406 g_unix_input_stream_close (GInputStream  *stream,
 407                            GCancellable  *cancellable,
 408                            GError       **error)
 409 {
 410   GUnixInputStream *unix_stream;
 411   int res;
 412
 413   unix_stream = G_UNIX_INPUT_STREAM (stream);
 414
 415   if (!unix_stream->priv->close_fd)
 416     return TRUE;
 417
 418   /* This might block during the close. Doesn't seem to be a way to avoid it though. */
 419   res = close (unix_stream->priv->fd);
 420   if (res == -1)
 421     {
 422       int errsv = errno;
 423
 424       g_set_error (error, G_IO_ERROR,
 425                    g_io_error_from_errno (errsv),
 426                    _("Error closing file descriptor: %s"),
 427                    g_strerror (errsv));
 428     }
 429
 430   return res != -1;
 431 }
 432
 433 static void
 434 g_unix_input_stream_skip_async (GInputStream        *stream,
 435                                 gsize                count,
 436                                 int                  io_priority,
 437                                 GCancellable        *cancellable,
 438                                 GAsyncReadyCallback  callback,
 439                                 gpointer             data)
 440 {
 441   g_warn_if_reached ();
 442   /* TODO: Not implemented */
 443 }
 444
 445 static gssize
 446 g_unix_input_stream_skip_finish  (GInputStream  *stream,
 447                                   GAsyncResult  *result,
 448                                   GError       **error)
 449 {
 450   g_warn_if_reached ();
 451   return 0;
 452   /* TODO: Not implemented */
 453 }
 454
 455 static void
 456 g_unix_input_stream_close_async (GInputStream        *stream,
 457                                  int                  io_priority,
 458                                  GCancellable        *cancellable,
 459                                  GAsyncReadyCallback  callback,
 460                                  gpointer             user_data)
 461 {
 462   GTask *task;
 463   GError *error = NULL;
 464
 465   task = g_task_new (stream, cancellable, callback, user_data);
 466   g_task_set_priority (task, io_priority);
 467
 468   if (g_unix_input_stream_close (stream, cancellable, &error))
 469     g_task_return_boolean (task, TRUE);
 470   else
 471     g_task_return_error (task, error);
 472   g_object_unref (task);
 473 }
 474
 475 static gboolean
 476 g_unix_input_stream_close_finish (GInputStream  *stream,
 477                                   GAsyncResult  *result,
 478                                   GError       **error)
 479 {
 480   g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
 481
 482   return g_task_propagate_boolean (G_TASK (result), error);
 483 }
 484
 485 static gboolean
 486 g_unix_input_stream_pollable_can_poll (GPollableInputStream *stream)
 487 {
 488   return G_UNIX_INPUT_STREAM (stream)->priv->is_pipe_or_socket;
 489 }
 490
 491 static gboolean
 492 g_unix_input_stream_pollable_is_readable (GPollableInputStream *stream)
 493 {
 494   GUnixInputStream *unix_stream = G_UNIX_INPUT_STREAM (stream);
 495   GPollFD poll_fd;
 496   gint result;
 497
 498   poll_fd.fd = unix_stream->priv->fd;
 499   poll_fd.events = G_IO_IN;
 500   poll_fd.revents = 0;
 501
 502   do
 503     result = g_poll (&poll_fd, 1, 0);
 504   while (result == -1 && errno == EINTR);
 505
 506   return poll_fd.revents != 0;
 507 }
 508
 509 static GSource *
 510 g_unix_input_stream_pollable_create_source (GPollableInputStream *stream,
 511                                             GCancellable         *cancellable)
 512 {
 513   GUnixInputStream *unix_stream = G_UNIX_INPUT_STREAM (stream);
 514   GSource *inner_source, *cancellable_source, *pollable_source;
 515
 516   pollable_source = g_pollable_source_new (G_OBJECT (stream));
 517
 518   inner_source = g_unix_fd_source_new (unix_stream->priv->fd, G_IO_IN);
 519   g_source_set_dummy_callback (inner_source);
 520   g_source_add_child_source (pollable_source, inner_source);
 521   g_source_unref (inner_source);
 522
 523   if (cancellable)
 524     {
 525       cancellable_source = g_cancellable_source_new (cancellable);
 526       g_source_set_dummy_callback (cancellable_source);
 527       g_source_add_child_source (pollable_source, cancellable_source);
 528       g_source_unref (cancellable_source);
 529     }
 530
 531   return pollable_source;
 532 }