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