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
  54 G_DEFINE_TYPE (GUnixInputStream, g_unix_input_stream, G_TYPE_INPUT_STREAM);
  55
  56 struct _GUnixInputStreamPrivate {
  57   int fd;
  58   gboolean close_fd_at_close;
  59 };
  60
  61 static gssize   g_unix_input_stream_read         (GInputStream         *stream,
  62                                                   void                 *buffer,
  63                                                   gsize                 count,
  64                                                   GCancellable         *cancellable,
  65                                                   GError              **error);
  66 static gboolean g_unix_input_stream_close        (GInputStream         *stream,
  67                                                   GCancellable         *cancellable,
  68                                                   GError              **error);
  69 static void     g_unix_input_stream_read_async   (GInputStream         *stream,
  70                                                   void                 *buffer,
  71                                                   gsize                 count,
  72                                                   int                   io_priority,
  73                                                   GCancellable         *cancellable,
  74                                                   GAsyncReadyCallback   callback,
  75                                                   gpointer              data);
  76 static gssize   g_unix_input_stream_read_finish  (GInputStream         *stream,
  77                                                   GAsyncResult         *result,
  78                                                   GError              **error);
  79 static void     g_unix_input_stream_skip_async   (GInputStream         *stream,
  80                                                   gsize                 count,
  81                                                   int                   io_priority,
  82                                                   GCancellable         *cancellable,
  83                                                   GAsyncReadyCallback   callback,
  84                                                   gpointer              data);
  85 static gssize   g_unix_input_stream_skip_finish  (GInputStream         *stream,
  86                                                   GAsyncResult         *result,
  87                                                   GError              **error);
  88 static void     g_unix_input_stream_close_async  (GInputStream         *stream,
  89                                                   int                   io_priority,
  90                                                   GCancellable         *cancellable,
  91                                                   GAsyncReadyCallback   callback,
  92                                                   gpointer              data);
  93 static gboolean g_unix_input_stream_close_finish (GInputStream         *stream,
  94                                                   GAsyncResult         *result,
  95                                                   GError              **error);
  96
  97
  98 static void
  99 g_unix_input_stream_finalize (GObject *object)
 100 {
 101   GUnixInputStream *stream;
 102
 103   stream = G_UNIX_INPUT_STREAM (object);
 104
 105   G_OBJECT_CLASS (g_unix_input_stream_parent_class)->finalize (object);
 106 }
 107
 108 static void
 109 g_unix_input_stream_class_init (GUnixInputStreamClass *klass)
 110 {
 111   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 112   GInputStreamClass *stream_class = G_INPUT_STREAM_CLASS (klass);
 113
 114   g_type_class_add_private (klass, sizeof (GUnixInputStreamPrivate));
 115
 116   gobject_class->finalize = g_unix_input_stream_finalize;
 117
 118   stream_class->read_fn = g_unix_input_stream_read;
 119   stream_class->close_fn = g_unix_input_stream_close;
 120   stream_class->read_async = g_unix_input_stream_read_async;
 121   stream_class->read_finish = g_unix_input_stream_read_finish;
 122   if (0)
 123     {
 124       /* TODO: Implement instead of using fallbacks */
 125       stream_class->skip_async = g_unix_input_stream_skip_async;
 126       stream_class->skip_finish = g_unix_input_stream_skip_finish;
 127     }
 128   stream_class->close_async = g_unix_input_stream_close_async;
 129   stream_class->close_finish = g_unix_input_stream_close_finish;
 130 }
 131
 132 static void
 133 g_unix_input_stream_init (GUnixInputStream *unix_stream)
 134 {
 135   unix_stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (unix_stream,
 136                                                    G_TYPE_UNIX_INPUT_STREAM,
 137                                                    GUnixInputStreamPrivate);
 138 }
 139
 140 /**
 141  * g_unix_input_stream_new:
 142  * @fd: unix file descriptor.
 143  * @close_fd_at_close: a #gboolean.
 144  *
 145  * Creates a new #GUnixInputStream for the given @fd. If @close_fd_at_close
 146  * is %TRUE, the file descriptor will be closed when the stream is closed.
 147  *
 148  * Returns: a #GUnixInputStream.
 149  **/
 150 GInputStream *
 151 g_unix_input_stream_new (int      fd,
 152                          gboolean close_fd_at_close)
 153 {
 154   GUnixInputStream *stream;
 155
 156   g_return_val_if_fail (fd != -1, NULL);
 157
 158   stream = g_object_new (G_TYPE_UNIX_INPUT_STREAM, NULL);
 159
 160   stream->priv->fd = fd;
 161   stream->priv->close_fd_at_close = close_fd_at_close;
 162
 163   return G_INPUT_STREAM (stream);
 164 }
 165
 166 static gssize
 167 g_unix_input_stream_read (GInputStream  *stream,
 168                           void          *buffer,
 169                           gsize          count,
 170                           GCancellable  *cancellable,
 171                           GError       **error)
 172 {
 173   GUnixInputStream *unix_stream;
 174   gssize res;
 175   GPollFD poll_fds[2];
 176   int poll_ret;
 177
 178   unix_stream = G_UNIX_INPUT_STREAM (stream);
 179
 180   if (cancellable)
 181     {
 182       poll_fds[0].fd = unix_stream->priv->fd;
 183       poll_fds[0].events = G_IO_IN;
 184       g_cancellable_make_pollfd (cancellable, &poll_fds[1]);
 185       do
 186         poll_ret = g_poll (poll_fds, 2, -1);
 187       while (poll_ret == -1 && errno == EINTR);
 188
 189       if (poll_ret == -1)
 190         {
 191           int errsv = errno;
 192
 193           g_set_error (error, G_IO_ERROR,
 194                        g_io_error_from_errno (errsv),
 195                        _("Error reading from unix: %s"),
 196                        g_strerror (errsv));
 197           return -1;
 198         }
 199     }
 200
 201   while (1)
 202     {
 203       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 204         return -1;
 205       res = read (unix_stream->priv->fd, buffer, count);
 206       if (res == -1)
 207         {
 208           int errsv = errno;
 209
 210           if (errsv == EINTR)
 211             continue;
 212
 213           g_set_error (error, G_IO_ERROR,
 214                        g_io_error_from_errno (errsv),
 215                        _("Error reading from unix: %s"),
 216                        g_strerror (errsv));
 217         }
 218
 219       break;
 220     }
 221
 222   return res;
 223 }
 224
 225 static gboolean
 226 g_unix_input_stream_close (GInputStream  *stream,
 227                            GCancellable  *cancellable,
 228                            GError       **error)
 229 {
 230   GUnixInputStream *unix_stream;
 231   int res;
 232
 233   unix_stream = G_UNIX_INPUT_STREAM (stream);
 234
 235   if (!unix_stream->priv->close_fd_at_close)
 236     return TRUE;
 237
 238   while (1)
 239     {
 240       /* This might block during the close. Doesn't seem to be a way to avoid it though. */
 241       res = close (unix_stream->priv->fd);
 242       if (res == -1)
 243         {
 244           int errsv = errno;
 245
 246           g_set_error (error, G_IO_ERROR,
 247                        g_io_error_from_errno (errsv),
 248                        _("Error closing unix: %s"),
 249                        g_strerror (errsv));
 250         }
 251       break;
 252     }
 253
 254   return res != -1;
 255 }
 256
 257 typedef struct {
 258   gsize count;
 259   void *buffer;
 260   GAsyncReadyCallback callback;
 261   gpointer user_data;
 262   GCancellable *cancellable;
 263   GUnixInputStream *stream;
 264 } ReadAsyncData;
 265
 266 static gboolean
 267 read_async_cb (ReadAsyncData *data,
 268                GIOCondition   condition,
 269                int            fd)
 270 {
 271   GSimpleAsyncResult *simple;
 272   GError *error = NULL;
 273   gssize count_read;
 274
 275   /* We know that we can read from fd once without blocking */
 276   while (1)
 277     {
 278       if (g_cancellable_set_error_if_cancelled (data->cancellable, &error))
 279         {
 280           count_read = -1;
 281           break;
 282         }
 283       count_read = read (data->stream->priv->fd, data->buffer, data->count);
 284       if (count_read == -1)
 285         {
 286           int errsv = errno;
 287
 288           if (errsv == EINTR)
 289             continue;
 290
 291           g_set_error (&error, G_IO_ERROR,
 292                        g_io_error_from_errno (errsv),
 293                        _("Error reading from unix: %s"),
 294                        g_strerror (errsv));
 295         }
 296       break;
 297     }
 298
 299   simple = g_simple_async_result_new (G_OBJECT (data->stream),
 300                                       data->callback,
 301                                       data->user_data,
 302                                       g_unix_input_stream_read_async);
 303
 304   g_simple_async_result_set_op_res_gssize (simple, count_read);
 305
 306   if (count_read == -1)
 307     {
 308       g_simple_async_result_set_from_error (simple, error);
 309       g_error_free (error);
 310     }
 311
 312   /* Complete immediately, not in idle, since we're already in a mainloop callout */
 313   g_simple_async_result_complete (simple);
 314   g_object_unref (simple);
 315
 316   return FALSE;
 317 }
 318
 319 static void
 320 g_unix_input_stream_read_async (GInputStream        *stream,
 321                                 void                *buffer,
 322                                 gsize                count,
 323                                 int                  io_priority,
 324                                 GCancellable        *cancellable,
 325                                 GAsyncReadyCallback  callback,
 326                                 gpointer             user_data)
 327 {
 328   GSource *source;
 329   GUnixInputStream *unix_stream;
 330   ReadAsyncData *data;
 331
 332   unix_stream = G_UNIX_INPUT_STREAM (stream);
 333
 334   data = g_new0 (ReadAsyncData, 1);
 335   data->count = count;
 336   data->buffer = buffer;
 337   data->callback = callback;
 338   data->user_data = user_data;
 339   data->cancellable = cancellable;
 340   data->stream = unix_stream;
 341
 342   source = _g_fd_source_new (unix_stream->priv->fd,
 343                              G_IO_IN,
 344                              cancellable);
 345
 346   g_source_set_callback (source, (GSourceFunc)read_async_cb, data, g_free);
 347   g_source_attach (source, NULL);
 348
 349   g_source_unref (source);
 350 }
 351
 352 static gssize
 353 g_unix_input_stream_read_finish (GInputStream  *stream,
 354                                  GAsyncResult  *result,
 355                                  GError       **error)
 356 {
 357   GSimpleAsyncResult *simple;
 358   gssize nread;
 359
 360   simple = G_SIMPLE_ASYNC_RESULT (result);
 361   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_unix_input_stream_read_async);
 362
 363   nread = g_simple_async_result_get_op_res_gssize (simple);
 364   return nread;
 365 }
 366
 367 static void
 368 g_unix_input_stream_skip_async (GInputStream        *stream,
 369                                 gsize                count,
 370                                 int                  io_priority,
 371                                 GCancellable        *cancellable,
 372                                 GAsyncReadyCallback  callback,
 373                                 gpointer             data)
 374 {
 375   g_warn_if_reached ();
 376   /* TODO: Not implemented */
 377 }
 378
 379 static gssize
 380 g_unix_input_stream_skip_finish  (GInputStream  *stream,
 381                                   GAsyncResult  *result,
 382                                   GError       **error)
 383 {
 384   g_warn_if_reached ();
 385   return 0;
 386   /* TODO: Not implemented */
 387 }
 388
 389
 390 typedef struct {
 391   GInputStream *stream;
 392   GAsyncReadyCallback callback;
 393   gpointer user_data;
 394 } CloseAsyncData;
 395
 396 static void
 397 close_async_data_free (gpointer _data)
 398 {
 399   CloseAsyncData *data = _data;
 400
 401   g_free (data);
 402 }
 403
 404 static gboolean
 405 close_async_cb (CloseAsyncData *data)
 406 {
 407   GUnixInputStream *unix_stream;
 408   GSimpleAsyncResult *simple;
 409   GError *error = NULL;
 410   gboolean result;
 411   int res;
 412
 413   unix_stream = G_UNIX_INPUT_STREAM (data->stream);
 414
 415   if (!unix_stream->priv->close_fd_at_close)
 416     {
 417       result = TRUE;
 418       goto out;
 419     }
 420
 421   while (1)
 422     {
 423       res = close (unix_stream->priv->fd);
 424       if (res == -1)
 425         {
 426           int errsv = errno;
 427
 428           g_set_error (&error, G_IO_ERROR,
 429                        g_io_error_from_errno (errsv),
 430                        _("Error closing unix: %s"),
 431                        g_strerror (errsv));
 432         }
 433       break;
 434     }
 435
 436   result = res != -1;
 437
 438  out:
 439   simple = g_simple_async_result_new (G_OBJECT (data->stream),
 440                                       data->callback,
 441                                       data->user_data,
 442                                       g_unix_input_stream_close_async);
 443
 444   if (!result)
 445     {
 446       g_simple_async_result_set_from_error (simple, error);
 447       g_error_free (error);
 448     }
 449
 450   /* Complete immediately, not in idle, since we're already in a mainloop callout */
 451   g_simple_async_result_complete (simple);
 452   g_object_unref (simple);
 453
 454   return FALSE;
 455 }
 456
 457 static void
 458 g_unix_input_stream_close_async (GInputStream        *stream,
 459                                  int                  io_priority,
 460                                  GCancellable        *cancellable,
 461                                  GAsyncReadyCallback  callback,
 462                                  gpointer             user_data)
 463 {
 464   GSource *idle;
 465   CloseAsyncData *data;
 466
 467   data = g_new0 (CloseAsyncData, 1);
 468
 469   data->stream = stream;
 470   data->callback = callback;
 471   data->user_data = user_data;
 472
 473   idle = g_idle_source_new ();
 474   g_source_set_callback (idle, (GSourceFunc)close_async_cb, data, close_async_data_free);
 475   g_source_attach (idle, NULL);
 476   g_source_unref (idle);
 477 }
 478
 479 static gboolean
 480 g_unix_input_stream_close_finish (GInputStream  *stream,
 481                                   GAsyncResult  *result,
 482                                   GError       **error)
 483 {
 484   /* Failures handled in generic close_finish code */
 485   return TRUE;
 486 }
 487
 488 #define __G_UNIX_INPUT_STREAM_C__
 489 #include "gioaliasdef.c"