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   GUnixInputStream *stream;
 120
 121   stream = G_UNIX_INPUT_STREAM (object);
 122
 123   G_OBJECT_CLASS (g_unix_input_stream_parent_class)->finalize (object);
 124 }
 125
 126 static void
 127 g_unix_input_stream_class_init (GUnixInputStreamClass *klass)
 128 {
 129   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 130   GInputStreamClass *stream_class = G_INPUT_STREAM_CLASS (klass);
 131
 132   g_type_class_add_private (klass, sizeof (GUnixInputStreamPrivate));
 133
 134   gobject_class->get_property = g_unix_input_stream_get_property;
 135   gobject_class->set_property = g_unix_input_stream_set_property;
 136   gobject_class->finalize = g_unix_input_stream_finalize;
 137
 138   stream_class->read_fn = g_unix_input_stream_read;
 139   stream_class->close_fn = g_unix_input_stream_close;
 140   stream_class->read_async = g_unix_input_stream_read_async;
 141   stream_class->read_finish = g_unix_input_stream_read_finish;
 142   if (0)
 143     {
 144       /* TODO: Implement instead of using fallbacks */
 145       stream_class->skip_async = g_unix_input_stream_skip_async;
 146       stream_class->skip_finish = g_unix_input_stream_skip_finish;
 147     }
 148   stream_class->close_async = g_unix_input_stream_close_async;
 149   stream_class->close_finish = g_unix_input_stream_close_finish;
 150
 151   /**
 152    * GUnixInputStream:fd:
 153    *
 154    * The file descriptor that the stream reads from.
 155    *
 156    * Since: 2.20
 157    */
 158   g_object_class_install_property (gobject_class,
 159                                    PROP_FD,
 160                                    g_param_spec_int ("fd",
 161                                                      P_("File descriptor"),
 162                                                      P_("The file descriptor to read from"),
 163                                                      G_MININT, G_MAXINT, -1,
 164                                                      G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
 165
 166   /**
 167    * GUnixInputStream:close-fd:
 168    *
 169    * Whether to close the file descriptor when the stream is closed.
 170    *
 171    * Since: 2.20
 172    */
 173   g_object_class_install_property (gobject_class,
 174                                    PROP_CLOSE_FD,
 175                                    g_param_spec_boolean ("close-fd",
 176                                                          P_("Close file descriptor"),
 177                                                          P_("Whether to close the file descriptor when the stream is closed"),
 178                                                          TRUE,
 179                                                          G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
 180 }
 181
 182 static void
 183 g_unix_input_stream_set_property (GObject         *object,
 184                                   guint            prop_id,
 185                                   const GValue    *value,
 186                                   GParamSpec      *pspec)
 187 {
 188   GUnixInputStream *unix_stream;
 189
 190   unix_stream = G_UNIX_INPUT_STREAM (object);
 191
 192   switch (prop_id)
 193     {
 194     case PROP_FD:
 195       unix_stream->priv->fd = g_value_get_int (value);
 196       break;
 197     case PROP_CLOSE_FD:
 198       unix_stream->priv->close_fd = g_value_get_boolean (value);
 199       break;
 200     default:
 201       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 202       break;
 203     }
 204 }
 205
 206 static void
 207 g_unix_input_stream_get_property (GObject    *object,
 208                                   guint       prop_id,
 209                                   GValue     *value,
 210                                   GParamSpec *pspec)
 211 {
 212   GUnixInputStream *unix_stream;
 213
 214   unix_stream = G_UNIX_INPUT_STREAM (object);
 215
 216   switch (prop_id)
 217     {
 218     case PROP_FD:
 219       g_value_set_int (value, unix_stream->priv->fd);
 220       break;
 221     case PROP_CLOSE_FD:
 222       g_value_set_boolean (value, unix_stream->priv->close_fd);
 223       break;
 224     default:
 225       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 226     }
 227 }
 228
 229 static void
 230 g_unix_input_stream_init (GUnixInputStream *unix_stream)
 231 {
 232   unix_stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (unix_stream,
 233                                                    G_TYPE_UNIX_INPUT_STREAM,
 234                                                    GUnixInputStreamPrivate);
 235
 236   unix_stream->priv->fd = -1;
 237   unix_stream->priv->close_fd = TRUE;
 238 }
 239
 240 /**
 241  * g_unix_input_stream_new:
 242  * @fd: a UNIX file descriptor
 243  * @close_fd: %TRUE to close the file descriptor when done
 244  *
 245  * Creates a new #GUnixInputStream for the given @fd.
 246  *
 247  * If @close_fd is %TRUE, the file descriptor will be closed
 248  * when the stream is closed.
 249  *
 250  * Returns: a new #GUnixInputStream
 251  **/
 252 GInputStream *
 253 g_unix_input_stream_new (gint     fd,
 254                          gboolean close_fd)
 255 {
 256   GUnixInputStream *stream;
 257
 258   g_return_val_if_fail (fd != -1, NULL);
 259
 260   stream = g_object_new (G_TYPE_UNIX_INPUT_STREAM,
 261                          "fd", fd,
 262                          "close-fd", close_fd,
 263                          NULL);
 264
 265   return G_INPUT_STREAM (stream);
 266 }
 267
 268 /**
 269  * g_unix_input_stream_set_close_fd:
 270  * @stream: a #GUnixInputStream
 271  * @close_fd: %TRUE to close the file descriptor when done
 272  *
 273  * Sets whether the file descriptor of @stream shall be closed
 274  * when the stream is closed.
 275  *
 276  * Since: 2.20
 277  */
 278 void
 279 g_unix_input_stream_set_close_fd (GUnixInputStream *stream,
 280                                   gboolean          close_fd)
 281 {
 282   g_return_if_fail (G_IS_UNIX_INPUT_STREAM (stream));
 283
 284   close_fd = close_fd != FALSE;
 285   if (stream->priv->close_fd != close_fd)
 286     {
 287       stream->priv->close_fd = close_fd;
 288       g_object_notify (G_OBJECT (stream), "close-fd");
 289     }
 290 }
 291
 292 /**
 293  * g_unix_input_stream_get_close_fd:
 294  * @stream: a #GUnixInputStream
 295  *
 296  * Returns whether the file descriptor of @stream will be
 297  * closed when the stream is closed.
 298  *
 299  * Return value: %TRUE if the file descriptor is closed when done
 300  *
 301  * Since: 2.20
 302  */
 303 gboolean
 304 g_unix_input_stream_get_close_fd (GUnixInputStream *stream)
 305 {
 306   g_return_val_if_fail (G_IS_UNIX_INPUT_STREAM (stream), FALSE);
 307
 308   return stream->priv->close_fd;
 309 }
 310
 311 /**
 312  * g_unix_input_stream_get_fd:
 313  * @stream: a #GUnixInputStream
 314  *
 315  * Return the UNIX file descriptor that the stream reads from.
 316  *
 317  * Return value: The file descriptor of @stream
 318  *
 319  * Since: 2.20
 320  */
 321 gint
 322 g_unix_input_stream_get_fd (GUnixInputStream *stream)
 323 {
 324   g_return_val_if_fail (G_IS_UNIX_INPUT_STREAM (stream), -1);
 325
 326   return stream->priv->fd;
 327 }
 328
 329 static gssize
 330 g_unix_input_stream_read (GInputStream  *stream,
 331                           void          *buffer,
 332                           gsize          count,
 333                           GCancellable  *cancellable,
 334                           GError       **error)
 335 {
 336   GUnixInputStream *unix_stream;
 337   gssize res;
 338   GPollFD poll_fds[2];
 339   int poll_ret;
 340
 341   unix_stream = G_UNIX_INPUT_STREAM (stream);
 342
 343   if (cancellable)
 344     {
 345       poll_fds[0].fd = unix_stream->priv->fd;
 346       poll_fds[0].events = G_IO_IN;
 347       g_cancellable_make_pollfd (cancellable, &poll_fds[1]);
 348       do
 349         poll_ret = g_poll (poll_fds, 2, -1);
 350       while (poll_ret == -1 && errno == EINTR);
 351
 352       if (poll_ret == -1)
 353         {
 354           int errsv = errno;
 355
 356           g_set_error (error, G_IO_ERROR,
 357                        g_io_error_from_errno (errsv),
 358                        _("Error reading from unix: %s"),
 359                        g_strerror (errsv));
 360           return -1;
 361         }
 362     }
 363
 364   while (1)
 365     {
 366       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 367         return -1;
 368       res = read (unix_stream->priv->fd, buffer, count);
 369       if (res == -1)
 370         {
 371           int errsv = errno;
 372
 373           if (errsv == EINTR)
 374             continue;
 375
 376           g_set_error (error, G_IO_ERROR,
 377                        g_io_error_from_errno (errsv),
 378                        _("Error reading from unix: %s"),
 379                        g_strerror (errsv));
 380         }
 381
 382       break;
 383     }
 384
 385   return res;
 386 }
 387
 388 static gboolean
 389 g_unix_input_stream_close (GInputStream  *stream,
 390                            GCancellable  *cancellable,
 391                            GError       **error)
 392 {
 393   GUnixInputStream *unix_stream;
 394   int res;
 395
 396   unix_stream = G_UNIX_INPUT_STREAM (stream);
 397
 398   if (!unix_stream->priv->close_fd)
 399     return TRUE;
 400
 401   while (1)
 402     {
 403       /* This might block during the close. Doesn't seem to be a way to avoid it though. */
 404       res = close (unix_stream->priv->fd);
 405       if (res == -1)
 406         {
 407           int errsv = errno;
 408
 409           g_set_error (error, G_IO_ERROR,
 410                        g_io_error_from_errno (errsv),
 411                        _("Error closing unix: %s"),
 412                        g_strerror (errsv));
 413         }
 414       break;
 415     }
 416
 417   return res != -1;
 418 }
 419
 420 typedef struct {
 421   gsize count;
 422   void *buffer;
 423   GAsyncReadyCallback callback;
 424   gpointer user_data;
 425   GCancellable *cancellable;
 426   GUnixInputStream *stream;
 427 } ReadAsyncData;
 428
 429 static gboolean
 430 read_async_cb (ReadAsyncData *data,
 431                GIOCondition   condition,
 432                int            fd)
 433 {
 434   GSimpleAsyncResult *simple;
 435   GError *error = NULL;
 436   gssize count_read;
 437
 438   /* We know that we can read from fd once without blocking */
 439   while (1)
 440     {
 441       if (g_cancellable_set_error_if_cancelled (data->cancellable, &error))
 442         {
 443           count_read = -1;
 444           break;
 445         }
 446       count_read = read (data->stream->priv->fd, data->buffer, data->count);
 447       if (count_read == -1)
 448         {
 449           int errsv = errno;
 450
 451           if (errsv == EINTR)
 452             continue;
 453
 454           g_set_error (&error, G_IO_ERROR,
 455                        g_io_error_from_errno (errsv),
 456                        _("Error reading from unix: %s"),
 457                        g_strerror (errsv));
 458         }
 459       break;
 460     }
 461
 462   simple = g_simple_async_result_new (G_OBJECT (data->stream),
 463                                       data->callback,
 464                                       data->user_data,
 465                                       g_unix_input_stream_read_async);
 466
 467   g_simple_async_result_set_op_res_gssize (simple, count_read);
 468
 469   if (count_read == -1)
 470     {
 471       g_simple_async_result_set_from_error (simple, error);
 472       g_error_free (error);
 473     }
 474
 475   /* Complete immediately, not in idle, since we're already in a mainloop callout */
 476   g_simple_async_result_complete (simple);
 477   g_object_unref (simple);
 478
 479   return FALSE;
 480 }
 481
 482 static void
 483 g_unix_input_stream_read_async (GInputStream        *stream,
 484                                 void                *buffer,
 485                                 gsize                count,
 486                                 int                  io_priority,
 487                                 GCancellable        *cancellable,
 488                                 GAsyncReadyCallback  callback,
 489                                 gpointer             user_data)
 490 {
 491   GSource *source;
 492   GUnixInputStream *unix_stream;
 493   ReadAsyncData *data;
 494
 495   unix_stream = G_UNIX_INPUT_STREAM (stream);
 496
 497   data = g_new0 (ReadAsyncData, 1);
 498   data->count = count;
 499   data->buffer = buffer;
 500   data->callback = callback;
 501   data->user_data = user_data;
 502   data->cancellable = cancellable;
 503   data->stream = unix_stream;
 504
 505   source = _g_fd_source_new (unix_stream->priv->fd,
 506                              G_IO_IN,
 507                              cancellable);
 508
 509   g_source_set_callback (source, (GSourceFunc)read_async_cb, data, g_free);
 510   g_source_attach (source, g_main_context_get_thread_default ());
 511
 512   g_source_unref (source);
 513 }
 514
 515 static gssize
 516 g_unix_input_stream_read_finish (GInputStream  *stream,
 517                                  GAsyncResult  *result,
 518                                  GError       **error)
 519 {
 520   GSimpleAsyncResult *simple;
 521   gssize nread;
 522
 523   simple = G_SIMPLE_ASYNC_RESULT (result);
 524   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_unix_input_stream_read_async);
 525
 526   nread = g_simple_async_result_get_op_res_gssize (simple);
 527   return nread;
 528 }
 529
 530 static void
 531 g_unix_input_stream_skip_async (GInputStream        *stream,
 532                                 gsize                count,
 533                                 int                  io_priority,
 534                                 GCancellable        *cancellable,
 535                                 GAsyncReadyCallback  callback,
 536                                 gpointer             data)
 537 {
 538   g_warn_if_reached ();
 539   /* TODO: Not implemented */
 540 }
 541
 542 static gssize
 543 g_unix_input_stream_skip_finish  (GInputStream  *stream,
 544                                   GAsyncResult  *result,
 545                                   GError       **error)
 546 {
 547   g_warn_if_reached ();
 548   return 0;
 549   /* TODO: Not implemented */
 550 }
 551
 552
 553 typedef struct {
 554   GInputStream *stream;
 555   GAsyncReadyCallback callback;
 556   gpointer user_data;
 557 } CloseAsyncData;
 558
 559 static void
 560 close_async_data_free (gpointer _data)
 561 {
 562   CloseAsyncData *data = _data;
 563
 564   g_free (data);
 565 }
 566
 567 static gboolean
 568 close_async_cb (CloseAsyncData *data)
 569 {
 570   GUnixInputStream *unix_stream;
 571   GSimpleAsyncResult *simple;
 572   GError *error = NULL;
 573   gboolean result;
 574   int res;
 575
 576   unix_stream = G_UNIX_INPUT_STREAM (data->stream);
 577
 578   if (!unix_stream->priv->close_fd)
 579     {
 580       result = TRUE;
 581       goto out;
 582     }
 583
 584   while (1)
 585     {
 586       res = close (unix_stream->priv->fd);
 587       if (res == -1)
 588         {
 589           int errsv = errno;
 590
 591           g_set_error (&error, G_IO_ERROR,
 592                        g_io_error_from_errno (errsv),
 593                        _("Error closing unix: %s"),
 594                        g_strerror (errsv));
 595         }
 596       break;
 597     }
 598
 599   result = res != -1;
 600
 601  out:
 602   simple = g_simple_async_result_new (G_OBJECT (data->stream),
 603                                       data->callback,
 604                                       data->user_data,
 605                                       g_unix_input_stream_close_async);
 606
 607   if (!result)
 608     {
 609       g_simple_async_result_set_from_error (simple, error);
 610       g_error_free (error);
 611     }
 612
 613   /* Complete immediately, not in idle, since we're already in a mainloop callout */
 614   g_simple_async_result_complete (simple);
 615   g_object_unref (simple);
 616
 617   return FALSE;
 618 }
 619
 620 static void
 621 g_unix_input_stream_close_async (GInputStream        *stream,
 622                                  int                  io_priority,
 623                                  GCancellable        *cancellable,
 624                                  GAsyncReadyCallback  callback,
 625                                  gpointer             user_data)
 626 {
 627   GSource *idle;
 628   CloseAsyncData *data;
 629
 630   data = g_new0 (CloseAsyncData, 1);
 631
 632   data->stream = stream;
 633   data->callback = callback;
 634   data->user_data = user_data;
 635
 636   idle = g_idle_source_new ();
 637   g_source_set_callback (idle, (GSourceFunc)close_async_cb, data, close_async_data_free);
 638   g_source_attach (idle, g_main_context_get_thread_default ());
 639   g_source_unref (idle);
 640 }
 641
 642 static gboolean
 643 g_unix_input_stream_close_finish (GInputStream  *stream,
 644                                   GAsyncResult  *result,
 645                                   GError       **error)
 646 {
 647   /* Failures handled in generic close_finish code */
 648   return TRUE;
 649 }
 650
 651 #define __G_UNIX_INPUT_STREAM_C__
 652 #include "gioaliasdef.c"