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 #include <poll.h>
  32
  33 #include <glib.h>
  34 #include <glib/gstdio.h>
  35 #include "gioerror.h"
  36 #include "gsimpleasyncresult.h"
  37 #include "gunixinputstream.h"
  38 #include "gcancellable.h"
  39 #include "gasynchelper.h"
  40 #include "glibintl.h"
  41
  42 #include "gioalias.h"
  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
  51  * unix file descriptor, including asynchronous operations. The file
  52  * descriptor must be selectable, so it doesn't work with opened files.
  53  **/
  54
  55 G_DEFINE_TYPE (GUnixInputStream, g_unix_input_stream, G_TYPE_INPUT_STREAM);
  56
  57 struct _GUnixInputStreamPrivate {
  58   int fd;
  59   gboolean close_fd_at_close;
  60 };
  61
  62 static gssize   g_unix_input_stream_read         (GInputStream         *stream,
  63                                                   void                 *buffer,
  64                                                   gsize                 count,
  65                                                   GCancellable         *cancellable,
  66                                                   GError              **error);
  67 static gboolean g_unix_input_stream_close        (GInputStream         *stream,
  68                                                   GCancellable         *cancellable,
  69                                                   GError              **error);
  70 static void     g_unix_input_stream_read_async   (GInputStream         *stream,
  71                                                   void                 *buffer,
  72                                                   gsize                 count,
  73                                                   int                   io_priority,
  74                                                   GCancellable         *cancellable,
  75                                                   GAsyncReadyCallback   callback,
  76                                                   gpointer              data);
  77 static gssize   g_unix_input_stream_read_finish  (GInputStream         *stream,
  78                                                   GAsyncResult         *result,
  79                                                   GError              **error);
  80 static void     g_unix_input_stream_skip_async   (GInputStream         *stream,
  81                                                   gsize                 count,
  82                                                   int                   io_priority,
  83                                                   GCancellable         *cancellable,
  84                                                   GAsyncReadyCallback   callback,
  85                                                   gpointer              data);
  86 static gssize   g_unix_input_stream_skip_finish  (GInputStream         *stream,
  87                                                   GAsyncResult         *result,
  88                                                   GError              **error);
  89 static void     g_unix_input_stream_close_async  (GInputStream         *stream,
  90                                                   int                   io_priority,
  91                                                   GCancellable         *cancellable,
  92                                                   GAsyncReadyCallback   callback,
  93                                                   gpointer              data);
  94 static gboolean g_unix_input_stream_close_finish (GInputStream         *stream,
  95                                                   GAsyncResult         *result,
  96                                                   GError              **error);
  97
  98
  99 static void
 100 g_unix_input_stream_finalize (GObject *object)
 101 {
 102   GUnixInputStream *stream;
 103
 104   stream = G_UNIX_INPUT_STREAM (object);
 105
 106   G_OBJECT_CLASS (g_unix_input_stream_parent_class)->finalize (object);
 107 }
 108
 109 static void
 110 g_unix_input_stream_class_init (GUnixInputStreamClass *klass)
 111 {
 112   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 113   GInputStreamClass *stream_class = G_INPUT_STREAM_CLASS (klass);
 114
 115   g_type_class_add_private (klass, sizeof (GUnixInputStreamPrivate));
 116
 117   gobject_class->finalize = g_unix_input_stream_finalize;
 118
 119   stream_class->read_fn = g_unix_input_stream_read;
 120   stream_class->close_fn = g_unix_input_stream_close;
 121   stream_class->read_async = g_unix_input_stream_read_async;
 122   stream_class->read_finish = g_unix_input_stream_read_finish;
 123   if (0)
 124     {
 125       /* TODO: Implement instead of using fallbacks */
 126       stream_class->skip_async = g_unix_input_stream_skip_async;
 127       stream_class->skip_finish = g_unix_input_stream_skip_finish;
 128     }
 129   stream_class->close_async = g_unix_input_stream_close_async;
 130   stream_class->close_finish = g_unix_input_stream_close_finish;
 131 }
 132
 133 static void
 134 g_unix_input_stream_init (GUnixInputStream *unix_stream)
 135 {
 136   unix_stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (unix_stream,
 137                                                    G_TYPE_UNIX_INPUT_STREAM,
 138                                                    GUnixInputStreamPrivate);
 139 }
 140
 141 /**
 142  * g_unix_input_stream_new:
 143  * @fd: unix file descriptor.
 144  * @close_fd_at_close: a #gboolean.
 145  *
 146  * Creates a new #GUnixInputStream for the given @fd. If @close_fd_at_close
 147  * is %TRUE, the file descriptor will be closed when the stream is closed.
 148  *
 149  * Returns: a #GUnixInputStream.
 150  **/
 151 GInputStream *
 152 g_unix_input_stream_new (int      fd,
 153                          gboolean close_fd_at_close)
 154 {
 155   GUnixInputStream *stream;
 156
 157   g_return_val_if_fail (fd != -1, NULL);
 158
 159   stream = g_object_new (G_TYPE_UNIX_INPUT_STREAM, NULL);
 160
 161   stream->priv->fd = fd;
 162   stream->priv->close_fd_at_close = close_fd_at_close;
 163
 164   return G_INPUT_STREAM (stream);
 165 }
 166
 167 static gssize
 168 g_unix_input_stream_read (GInputStream  *stream,
 169                           void          *buffer,
 170                           gsize          count,
 171                           GCancellable  *cancellable,
 172                           GError       **error)
 173 {
 174   GUnixInputStream *unix_stream;
 175   gssize res;
 176   struct pollfd poll_fds[2];
 177   int poll_ret;
 178   int cancel_fd;
 179
 180   unix_stream = G_UNIX_INPUT_STREAM (stream);
 181
 182   cancel_fd = g_cancellable_get_fd (cancellable);
 183   if (cancel_fd != -1)
 184     {
 185       do
 186         {
 187           poll_fds[0].events = POLLIN;
 188           poll_fds[0].fd = unix_stream->priv->fd;
 189           poll_fds[1].events = POLLIN;
 190           poll_fds[1].fd = cancel_fd;
 191           poll_ret = poll (poll_fds, 2, -1);
 192         }
 193       while (poll_ret == -1 && errno == EINTR);
 194
 195       if (poll_ret == -1)
 196         {
 197           int errsv = errno;
 198
 199           g_set_error (error, G_IO_ERROR,
 200                        g_io_error_from_errno (errsv),
 201                        _("Error reading from unix: %s"),
 202                        g_strerror (errsv));
 203           return -1;
 204         }
 205     }
 206
 207   while (1)
 208     {
 209       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 210         break;
 211       res = read (unix_stream->priv->fd, buffer, count);
 212       if (res == -1)
 213         {
 214           int errsv = errno;
 215
 216           if (errsv == EINTR)
 217             continue;
 218
 219           g_set_error (error, G_IO_ERROR,
 220                        g_io_error_from_errno (errsv),
 221                        _("Error reading from unix: %s"),
 222                        g_strerror (errsv));
 223         }
 224
 225       break;
 226     }
 227
 228   return res;
 229 }
 230
 231 static gboolean
 232 g_unix_input_stream_close (GInputStream  *stream,
 233                            GCancellable  *cancellable,
 234                            GError       **error)
 235 {
 236   GUnixInputStream *unix_stream;
 237   int res;
 238
 239   unix_stream = G_UNIX_INPUT_STREAM (stream);
 240
 241   if (!unix_stream->priv->close_fd_at_close)
 242     return TRUE;
 243
 244   while (1)
 245     {
 246       /* This might block during the close. Doesn't seem to be a way to avoid it though. */
 247       res = close (unix_stream->priv->fd);
 248       if (res == -1)
 249         {
 250           int errsv = errno;
 251
 252           g_set_error (error, G_IO_ERROR,
 253                        g_io_error_from_errno (errsv),
 254                        _("Error closing unix: %s"),
 255                        g_strerror (errsv));
 256         }
 257       break;
 258     }
 259
 260   return res != -1;
 261 }
 262
 263 typedef struct {
 264   gsize count;
 265   void *buffer;
 266   GAsyncReadyCallback callback;
 267   gpointer user_data;
 268   GCancellable *cancellable;
 269   GUnixInputStream *stream;
 270 } ReadAsyncData;
 271
 272 static gboolean
 273 read_async_cb (ReadAsyncData *data,
 274                GIOCondition   condition,
 275                int            fd)
 276 {
 277   GSimpleAsyncResult *simple;
 278   GError *error = NULL;
 279   gssize count_read;
 280
 281   /* We know that we can read from fd once without blocking */
 282   while (1)
 283     {
 284       if (g_cancellable_set_error_if_cancelled (data->cancellable, &error))
 285         {
 286           count_read = -1;
 287           break;
 288         }
 289       count_read = read (data->stream->priv->fd, data->buffer, data->count);
 290       if (count_read == -1)
 291         {
 292           int errsv = errno;
 293
 294           if (errsv == EINTR)
 295             continue;
 296
 297           g_set_error (&error, G_IO_ERROR,
 298                        g_io_error_from_errno (errsv),
 299                        _("Error reading from unix: %s"),
 300                        g_strerror (errsv));
 301         }
 302       break;
 303     }
 304
 305   simple = g_simple_async_result_new (G_OBJECT (data->stream),
 306                                       data->callback,
 307                                       data->user_data,
 308                                       g_unix_input_stream_read_async);
 309
 310   g_simple_async_result_set_op_res_gssize (simple, count_read);
 311
 312   if (count_read == -1)
 313     {
 314       g_simple_async_result_set_from_error (simple, error);
 315       g_error_free (error);
 316     }
 317
 318   /* Complete immediately, not in idle, since we're already in a mainloop callout */
 319   g_simple_async_result_complete (simple);
 320   g_object_unref (simple);
 321
 322   return FALSE;
 323 }
 324
 325 static void
 326 g_unix_input_stream_read_async (GInputStream        *stream,
 327                                 void                *buffer,
 328                                 gsize                count,
 329                                 int                  io_priority,
 330                                 GCancellable        *cancellable,
 331                                 GAsyncReadyCallback  callback,
 332                                 gpointer             user_data)
 333 {
 334   GSource *source;
 335   GUnixInputStream *unix_stream;
 336   ReadAsyncData *data;
 337
 338   unix_stream = G_UNIX_INPUT_STREAM (stream);
 339
 340   data = g_new0 (ReadAsyncData, 1);
 341   data->count = count;
 342   data->buffer = buffer;
 343   data->callback = callback;
 344   data->user_data = user_data;
 345   data->cancellable = cancellable;
 346   data->stream = unix_stream;
 347
 348   source = _g_fd_source_new (unix_stream->priv->fd,
 349                              POLLIN,
 350                              cancellable);
 351
 352   g_source_set_callback (source, (GSourceFunc)read_async_cb, data, g_free);
 353   g_source_attach (source, NULL);
 354
 355   g_source_unref (source);
 356 }
 357
 358 static gssize
 359 g_unix_input_stream_read_finish (GInputStream  *stream,
 360                                  GAsyncResult  *result,
 361                                  GError       **error)
 362 {
 363   GSimpleAsyncResult *simple;
 364   gssize nread;
 365
 366   simple = G_SIMPLE_ASYNC_RESULT (result);
 367   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_unix_input_stream_read_async);
 368
 369   nread = g_simple_async_result_get_op_res_gssize (simple);
 370   return nread;
 371 }
 372
 373 static void
 374 g_unix_input_stream_skip_async (GInputStream        *stream,
 375                                 gsize                count,
 376                                 int                  io_priority,
 377                                 GCancellable        *cancellable,
 378                                 GAsyncReadyCallback  callback,
 379                                 gpointer             data)
 380 {
 381   g_warn_if_reached ();
 382   /* TODO: Not implemented */
 383 }
 384
 385 static gssize
 386 g_unix_input_stream_skip_finish  (GInputStream  *stream,
 387                                   GAsyncResult  *result,
 388                                   GError       **error)
 389 {
 390   g_warn_if_reached ();
 391   return 0;
 392   /* TODO: Not implemented */
 393 }
 394
 395
 396 typedef struct {
 397   GInputStream *stream;
 398   GAsyncReadyCallback callback;
 399   gpointer user_data;
 400 } CloseAsyncData;
 401
 402 static void
 403 close_async_data_free (gpointer _data)
 404 {
 405   CloseAsyncData *data = _data;
 406
 407   g_free (data);
 408 }
 409
 410 static gboolean
 411 close_async_cb (CloseAsyncData *data)
 412 {
 413   GUnixInputStream *unix_stream;
 414   GSimpleAsyncResult *simple;
 415   GError *error = NULL;
 416   gboolean result;
 417   int res;
 418
 419   unix_stream = G_UNIX_INPUT_STREAM (data->stream);
 420
 421   if (!unix_stream->priv->close_fd_at_close)
 422     {
 423       result = TRUE;
 424       goto out;
 425     }
 426
 427   while (1)
 428     {
 429       res = close (unix_stream->priv->fd);
 430       if (res == -1)
 431         {
 432           int errsv = errno;
 433
 434           g_set_error (&error, G_IO_ERROR,
 435                        g_io_error_from_errno (errsv),
 436                        _("Error closing unix: %s"),
 437                        g_strerror (errsv));
 438         }
 439       break;
 440     }
 441
 442   result = res != -1;
 443
 444  out:
 445   simple = g_simple_async_result_new (G_OBJECT (data->stream),
 446                                       data->callback,
 447                                       data->user_data,
 448                                       g_unix_input_stream_close_async);
 449
 450   if (!result)
 451     {
 452       g_simple_async_result_set_from_error (simple, error);
 453       g_error_free (error);
 454     }
 455
 456   /* Complete immediately, not in idle, since we're already in a mainloop callout */
 457   g_simple_async_result_complete (simple);
 458   g_object_unref (simple);
 459
 460   return FALSE;
 461 }
 462
 463 static void
 464 g_unix_input_stream_close_async (GInputStream        *stream,
 465                                  int                  io_priority,
 466                                  GCancellable        *cancellable,
 467                                  GAsyncReadyCallback  callback,
 468                                  gpointer             user_data)
 469 {
 470   GSource *idle;
 471   CloseAsyncData *data;
 472
 473   data = g_new0 (CloseAsyncData, 1);
 474
 475   data->stream = stream;
 476   data->callback = callback;
 477   data->user_data = user_data;
 478
 479   idle = g_idle_source_new ();
 480   g_source_set_callback (idle, (GSourceFunc)close_async_cb, data, close_async_data_free);
 481   g_source_attach (idle, NULL);
 482   g_source_unref (idle);
 483 }
 484
 485 static gboolean
 486 g_unix_input_stream_close_finish (GInputStream  *stream,
 487                                   GAsyncResult  *result,
 488                                   GError       **error)
 489 {
 490   /* Failures handled in generic close_finish code */
 491   return TRUE;
 492 }
 493
 494 #define __G_UNIX_INPUT_STREAM_C__
 495 #include "gioaliasdef.c"