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 #include "gioalias.h"
  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
  50  * UNIX file descriptor, including asynchronous operations. The file
  51  * descriptor must be selectable, so it doesn't work with opened files.
  52  *
  53  * Note that <filename>&lt;gio/gunixinputstream.h&gt;</filename> belongs
  54  * to the UNIX-specific GIO interfaces, thus you have to use the
  55  * <filename>gio-unix-2.0.pc</filename> pkg-config file when using it.
  56  */
  57
  58 enum {
  59   PROP_0,
  60   PROP_FD,
  61   PROP_CLOSE_FD
  62 };
  63
  64 G_DEFINE_TYPE (GUnixInputStream, g_unix_input_stream, G_TYPE_INPUT_STREAM);
  65
  66 struct _GUnixInputStreamPrivate {
  67   int fd;
  68   gboolean close_fd;
  69 };
  70
  71 static void     g_unix_input_stream_set_property (GObject              *object,
  72                                                   guint                 prop_id,
  73                                                   const GValue         *value,
  74                                                   GParamSpec           *pspec);
  75 static void     g_unix_input_stream_get_property (GObject              *object,
  76                                                   guint                 prop_id,
  77                                                   GValue               *value,
  78                                                   GParamSpec           *pspec);
  79 static gssize   g_unix_input_stream_read         (GInputStream         *stream,
  80                                                   void                 *buffer,
  81                                                   gsize                 count,
  82                                                   GCancellable         *cancellable,
  83                                                   GError              **error);
  84 static gboolean g_unix_input_stream_close        (GInputStream         *stream,
  85                                                   GCancellable         *cancellable,
  86                                                   GError              **error);
  87 static void     g_unix_input_stream_read_async   (GInputStream         *stream,
  88                                                   void                 *buffer,
  89                                                   gsize                 count,
  90                                                   int                   io_priority,
  91                                                   GCancellable         *cancellable,
  92                                                   GAsyncReadyCallback   callback,
  93                                                   gpointer              data);
  94 static gssize   g_unix_input_stream_read_finish  (GInputStream         *stream,
  95                                                   GAsyncResult         *result,
  96                                                   GError              **error);
  97 static void     g_unix_input_stream_skip_async   (GInputStream         *stream,
  98                                                   gsize                 count,
  99                                                   int                   io_priority,
 100                                                   GCancellable         *cancellable,
 101                                                   GAsyncReadyCallback   callback,
 102                                                   gpointer              data);
 103 static gssize   g_unix_input_stream_skip_finish  (GInputStream         *stream,
 104                                                   GAsyncResult         *result,
 105                                                   GError              **error);
 106 static void     g_unix_input_stream_close_async  (GInputStream         *stream,
 107                                                   int                   io_priority,
 108                                                   GCancellable         *cancellable,
 109                                                   GAsyncReadyCallback   callback,
 110                                                   gpointer              data);
 111 static gboolean g_unix_input_stream_close_finish (GInputStream         *stream,
 112                                                   GAsyncResult         *result,
 113                                                   GError              **error);
 114
 115
 116 static void
 117 g_unix_input_stream_finalize (GObject *object)
 118 {
 119   G_OBJECT_CLASS (g_unix_input_stream_parent_class)->finalize (object);
 120 }
 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   g_type_class_add_private (klass, sizeof (GUnixInputStreamPrivate));
 129
 130   gobject_class->get_property = g_unix_input_stream_get_property;
 131   gobject_class->set_property = g_unix_input_stream_set_property;
 132   gobject_class->finalize = g_unix_input_stream_finalize;
 133
 134   stream_class->read_fn = g_unix_input_stream_read;
 135   stream_class->close_fn = g_unix_input_stream_close;
 136   stream_class->read_async = g_unix_input_stream_read_async;
 137   stream_class->read_finish = g_unix_input_stream_read_finish;
 138   if (0)
 139     {
 140       /* TODO: Implement instead of using fallbacks */
 141       stream_class->skip_async = g_unix_input_stream_skip_async;
 142       stream_class->skip_finish = g_unix_input_stream_skip_finish;
 143     }
 144   stream_class->close_async = g_unix_input_stream_close_async;
 145   stream_class->close_finish = g_unix_input_stream_close_finish;
 146
 147   /**
 148    * GUnixInputStream:fd:
 149    *
 150    * The file descriptor that the stream reads from.
 151    *
 152    * Since: 2.20
 153    */
 154   g_object_class_install_property (gobject_class,
 155                                    PROP_FD,
 156                                    g_param_spec_int ("fd",
 157                                                      P_("File descriptor"),
 158                                                      P_("The file descriptor to read from"),
 159                                                      G_MININT, G_MAXINT, -1,
 160                                                      G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
 161
 162   /**
 163    * GUnixInputStream:close-fd:
 164    *
 165    * Whether to close the file descriptor when the stream is closed.
 166    *
 167    * Since: 2.20
 168    */
 169   g_object_class_install_property (gobject_class,
 170                                    PROP_CLOSE_FD,
 171                                    g_param_spec_boolean ("close-fd",
 172                                                          P_("Close file descriptor"),
 173                                                          P_("Whether to close the file descriptor when the stream is closed"),
 174                                                          TRUE,
 175                                                          G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
 176 }
 177
 178 static void
 179 g_unix_input_stream_set_property (GObject         *object,
 180                                   guint            prop_id,
 181                                   const GValue    *value,
 182                                   GParamSpec      *pspec)
 183 {
 184   GUnixInputStream *unix_stream;
 185
 186   unix_stream = G_UNIX_INPUT_STREAM (object);
 187
 188   switch (prop_id)
 189     {
 190     case PROP_FD:
 191       unix_stream->priv->fd = g_value_get_int (value);
 192       break;
 193     case PROP_CLOSE_FD:
 194       unix_stream->priv->close_fd = g_value_get_boolean (value);
 195       break;
 196     default:
 197       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 198       break;
 199     }
 200 }
 201
 202 static void
 203 g_unix_input_stream_get_property (GObject    *object,
 204                                   guint       prop_id,
 205                                   GValue     *value,
 206                                   GParamSpec *pspec)
 207 {
 208   GUnixInputStream *unix_stream;
 209
 210   unix_stream = G_UNIX_INPUT_STREAM (object);
 211
 212   switch (prop_id)
 213     {
 214     case PROP_FD:
 215       g_value_set_int (value, unix_stream->priv->fd);
 216       break;
 217     case PROP_CLOSE_FD:
 218       g_value_set_boolean (value, unix_stream->priv->close_fd);
 219       break;
 220     default:
 221       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 222     }
 223 }
 224
 225 static void
 226 g_unix_input_stream_init (GUnixInputStream *unix_stream)
 227 {
 228   unix_stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (unix_stream,
 229                                                    G_TYPE_UNIX_INPUT_STREAM,
 230                                                    GUnixInputStreamPrivate);
 231
 232   unix_stream->priv->fd = -1;
 233   unix_stream->priv->close_fd = TRUE;
 234 }
 235
 236 /**
 237  * g_unix_input_stream_new:
 238  * @fd: a UNIX file descriptor
 239  * @close_fd: %TRUE to close the file descriptor when done
 240  *
 241  * Creates a new #GUnixInputStream for the given @fd.
 242  *
 243  * If @close_fd is %TRUE, the file descriptor will be closed
 244  * when the stream is closed.
 245  *
 246  * Returns: a new #GUnixInputStream
 247  **/
 248 GInputStream *
 249 g_unix_input_stream_new (gint     fd,
 250                          gboolean close_fd)
 251 {
 252   GUnixInputStream *stream;
 253
 254   g_return_val_if_fail (fd != -1, NULL);
 255
 256   stream = g_object_new (G_TYPE_UNIX_INPUT_STREAM,
 257                          "fd", fd,
 258                          "close-fd", close_fd,
 259                          NULL);
 260
 261   return G_INPUT_STREAM (stream);
 262 }
 263
 264 /**
 265  * g_unix_input_stream_set_close_fd:
 266  * @stream: a #GUnixInputStream
 267  * @close_fd: %TRUE to close the file descriptor when done
 268  *
 269  * Sets whether the file descriptor of @stream shall be closed
 270  * when the stream is closed.
 271  *
 272  * Since: 2.20
 273  */
 274 void
 275 g_unix_input_stream_set_close_fd (GUnixInputStream *stream,
 276                                   gboolean          close_fd)
 277 {
 278   g_return_if_fail (G_IS_UNIX_INPUT_STREAM (stream));
 279
 280   close_fd = close_fd != FALSE;
 281   if (stream->priv->close_fd != close_fd)
 282     {
 283       stream->priv->close_fd = close_fd;
 284       g_object_notify (G_OBJECT (stream), "close-fd");
 285     }
 286 }
 287
 288 /**
 289  * g_unix_input_stream_get_close_fd:
 290  * @stream: a #GUnixInputStream
 291  *
 292  * Returns whether the file descriptor of @stream will be
 293  * closed when the stream is closed.
 294  *
 295  * Return value: %TRUE if the file descriptor is closed when done
 296  *
 297  * Since: 2.20
 298  */
 299 gboolean
 300 g_unix_input_stream_get_close_fd (GUnixInputStream *stream)
 301 {
 302   g_return_val_if_fail (G_IS_UNIX_INPUT_STREAM (stream), FALSE);
 303
 304   return stream->priv->close_fd;
 305 }
 306
 307 /**
 308  * g_unix_input_stream_get_fd:
 309  * @stream: a #GUnixInputStream
 310  *
 311  * Return the UNIX file descriptor that the stream reads from.
 312  *
 313  * Return value: The file descriptor of @stream
 314  *
 315  * Since: 2.20
 316  */
 317 gint
 318 g_unix_input_stream_get_fd (GUnixInputStream *stream)
 319 {
 320   g_return_val_if_fail (G_IS_UNIX_INPUT_STREAM (stream), -1);
 321
 322   return stream->priv->fd;
 323 }
 324
 325 static gssize
 326 g_unix_input_stream_read (GInputStream  *stream,
 327                           void          *buffer,
 328                           gsize          count,
 329                           GCancellable  *cancellable,
 330                           GError       **error)
 331 {
 332   GUnixInputStream *unix_stream;
 333   gssize res;
 334   GPollFD poll_fds[2];
 335   int poll_ret;
 336
 337   unix_stream = G_UNIX_INPUT_STREAM (stream);
 338
 339   if (g_cancellable_make_pollfd (cancellable, &poll_fds[1]))
 340     {
 341       poll_fds[0].fd = unix_stream->priv->fd;
 342       poll_fds[0].events = G_IO_IN;
 343       do
 344         poll_ret = g_poll (poll_fds, 2, -1);
 345       while (poll_ret == -1 && errno == EINTR);
 346       g_cancellable_release_fd (cancellable);
 347
 348       if (poll_ret == -1)
 349         {
 350           int errsv = errno;
 351
 352           g_set_error (error, G_IO_ERROR,
 353                        g_io_error_from_errno (errsv),
 354                        _("Error reading from unix: %s"),
 355                        g_strerror (errsv));
 356           return -1;
 357         }
 358     }
 359
 360   while (1)
 361     {
 362       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 363         return -1;
 364       res = read (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 reading from unix: %s"),
 375                        g_strerror (errsv));
 376         }
 377
 378       break;
 379     }
 380
 381   return res;
 382 }
 383
 384 static gboolean
 385 g_unix_input_stream_close (GInputStream  *stream,
 386                            GCancellable  *cancellable,
 387                            GError       **error)
 388 {
 389   GUnixInputStream *unix_stream;
 390   int res;
 391
 392   unix_stream = G_UNIX_INPUT_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   void *buffer;
 419   GAsyncReadyCallback callback;
 420   gpointer user_data;
 421   GCancellable *cancellable;
 422   GUnixInputStream *stream;
 423 } ReadAsyncData;
 424
 425 static gboolean
 426 read_async_cb (ReadAsyncData *data,
 427                GIOCondition   condition,
 428                int            fd)
 429 {
 430   GSimpleAsyncResult *simple;
 431   GError *error = NULL;
 432   gssize count_read;
 433
 434   /* We know that we can read from fd once without blocking */
 435   while (1)
 436     {
 437       if (g_cancellable_set_error_if_cancelled (data->cancellable, &error))
 438         {
 439           count_read = -1;
 440           break;
 441         }
 442       count_read = read (data->stream->priv->fd, data->buffer, data->count);
 443       if (count_read == -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 reading from 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_input_stream_read_async);
 462
 463   g_simple_async_result_set_op_res_gssize (simple, count_read);
 464
 465   if (count_read == -1)
 466     {
 467       g_simple_async_result_set_from_error (simple, error);
 468       g_error_free (error);
 469     }
 470
 471   /* Complete immediately, not in idle, since we're already in a mainloop callout */
 472   g_simple_async_result_complete (simple);
 473   g_object_unref (simple);
 474
 475   return FALSE;
 476 }
 477
 478 static void
 479 g_unix_input_stream_read_async (GInputStream        *stream,
 480                                 void                *buffer,
 481                                 gsize                count,
 482                                 int                  io_priority,
 483                                 GCancellable        *cancellable,
 484                                 GAsyncReadyCallback  callback,
 485                                 gpointer             user_data)
 486 {
 487   GSource *source;
 488   GUnixInputStream *unix_stream;
 489   ReadAsyncData *data;
 490
 491   unix_stream = G_UNIX_INPUT_STREAM (stream);
 492
 493   data = g_new0 (ReadAsyncData, 1);
 494   data->count = count;
 495   data->buffer = buffer;
 496   data->callback = callback;
 497   data->user_data = user_data;
 498   data->cancellable = cancellable;
 499   data->stream = unix_stream;
 500
 501   source = _g_fd_source_new (unix_stream->priv->fd,
 502                              G_IO_IN,
 503                              cancellable);
 504
 505   g_source_set_callback (source, (GSourceFunc)read_async_cb, data, g_free);
 506   g_source_attach (source, g_main_context_get_thread_default ());
 507
 508   g_source_unref (source);
 509 }
 510
 511 static gssize
 512 g_unix_input_stream_read_finish (GInputStream  *stream,
 513                                  GAsyncResult  *result,
 514                                  GError       **error)
 515 {
 516   GSimpleAsyncResult *simple;
 517   gssize nread;
 518
 519   simple = G_SIMPLE_ASYNC_RESULT (result);
 520   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_unix_input_stream_read_async);
 521
 522   nread = g_simple_async_result_get_op_res_gssize (simple);
 523   return nread;
 524 }
 525
 526 static void
 527 g_unix_input_stream_skip_async (GInputStream        *stream,
 528                                 gsize                count,
 529                                 int                  io_priority,
 530                                 GCancellable        *cancellable,
 531                                 GAsyncReadyCallback  callback,
 532                                 gpointer             data)
 533 {
 534   g_warn_if_reached ();
 535   /* TODO: Not implemented */
 536 }
 537
 538 static gssize
 539 g_unix_input_stream_skip_finish  (GInputStream  *stream,
 540                                   GAsyncResult  *result,
 541                                   GError       **error)
 542 {
 543   g_warn_if_reached ();
 544   return 0;
 545   /* TODO: Not implemented */
 546 }
 547
 548
 549 typedef struct {
 550   GInputStream *stream;
 551   GAsyncReadyCallback callback;
 552   gpointer user_data;
 553 } CloseAsyncData;
 554
 555 static void
 556 close_async_data_free (gpointer _data)
 557 {
 558   CloseAsyncData *data = _data;
 559
 560   g_free (data);
 561 }
 562
 563 static gboolean
 564 close_async_cb (CloseAsyncData *data)
 565 {
 566   GUnixInputStream *unix_stream;
 567   GSimpleAsyncResult *simple;
 568   GError *error = NULL;
 569   gboolean result;
 570   int res;
 571
 572   unix_stream = G_UNIX_INPUT_STREAM (data->stream);
 573
 574   if (!unix_stream->priv->close_fd)
 575     {
 576       result = TRUE;
 577       goto out;
 578     }
 579
 580   while (1)
 581     {
 582       res = close (unix_stream->priv->fd);
 583       if (res == -1)
 584         {
 585           int errsv = errno;
 586
 587           g_set_error (&error, G_IO_ERROR,
 588                        g_io_error_from_errno (errsv),
 589                        _("Error closing unix: %s"),
 590                        g_strerror (errsv));
 591         }
 592       break;
 593     }
 594
 595   result = res != -1;
 596
 597  out:
 598   simple = g_simple_async_result_new (G_OBJECT (data->stream),
 599                                       data->callback,
 600                                       data->user_data,
 601                                       g_unix_input_stream_close_async);
 602
 603   if (!result)
 604     {
 605       g_simple_async_result_set_from_error (simple, error);
 606       g_error_free (error);
 607     }
 608
 609   /* Complete immediately, not in idle, since we're already in a mainloop callout */
 610   g_simple_async_result_complete (simple);
 611   g_object_unref (simple);
 612
 613   return FALSE;
 614 }
 615
 616 static void
 617 g_unix_input_stream_close_async (GInputStream        *stream,
 618                                  int                  io_priority,
 619                                  GCancellable        *cancellable,
 620                                  GAsyncReadyCallback  callback,
 621                                  gpointer             user_data)
 622 {
 623   GSource *idle;
 624   CloseAsyncData *data;
 625
 626   data = g_new0 (CloseAsyncData, 1);
 627
 628   data->stream = stream;
 629   data->callback = callback;
 630   data->user_data = user_data;
 631
 632   idle = g_idle_source_new ();
 633   g_source_set_callback (idle, (GSourceFunc)close_async_cb, data, close_async_data_free);
 634   g_source_attach (idle, g_main_context_get_thread_default ());
 635   g_source_unref (idle);
 636 }
 637
 638 static gboolean
 639 g_unix_input_stream_close_finish (GInputStream  *stream,
 640                                   GAsyncResult  *result,
 641                                   GError       **error)
 642 {
 643   /* Failures handled in generic close_finish code */
 644   return TRUE;
 645 }
 646
 647 #define __G_UNIX_INPUT_STREAM_C__
 648 #include "gioaliasdef.c"