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           g_set_error (error, G_IO_ERROR,
 199                        g_io_error_from_errno (errno),
 200                        _("Error reading from unix: %s"),
 201                        g_strerror (errno));
 202           return -1;
 203         }
 204     }
 205
 206   while (1)
 207     {
 208       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 209         break;
 210       res = read (unix_stream->priv->fd, buffer, count);
 211       if (res == -1)
 212         {
 213           if (errno == EINTR)
 214             continue;
 215
 216           g_set_error (error, G_IO_ERROR,
 217                        g_io_error_from_errno (errno),
 218                        _("Error reading from unix: %s"),
 219                        g_strerror (errno));
 220         }
 221
 222       break;
 223     }
 224
 225   return res;
 226 }
 227
 228 static gboolean
 229 g_unix_input_stream_close (GInputStream  *stream,
 230                            GCancellable  *cancellable,
 231                            GError       **error)
 232 {
 233   GUnixInputStream *unix_stream;
 234   int res;
 235
 236   unix_stream = G_UNIX_INPUT_STREAM (stream);
 237
 238   if (!unix_stream->priv->close_fd_at_close)
 239     return TRUE;
 240
 241   while (1)
 242     {
 243       /* This might block during the close. Doesn't seem to be a way to avoid it though. */
 244       res = close (unix_stream->priv->fd);
 245       if (res == -1)
 246         g_set_error (error, G_IO_ERROR,
 247                      g_io_error_from_errno (errno),
 248                      _("Error closing unix: %s"),
 249                      g_strerror (errno));
 250       break;
 251     }
 252
 253   return res != -1;
 254 }
 255
 256 typedef struct {
 257   gsize count;
 258   void *buffer;
 259   GAsyncReadyCallback callback;
 260   gpointer user_data;
 261   GCancellable *cancellable;
 262   GUnixInputStream *stream;
 263 } ReadAsyncData;
 264
 265 static gboolean
 266 read_async_cb (ReadAsyncData *data,
 267                GIOCondition   condition,
 268                int            fd)
 269 {
 270   GSimpleAsyncResult *simple;
 271   GError *error = NULL;
 272   gssize count_read;
 273
 274   /* We know that we can read from fd once without blocking */
 275   while (1)
 276     {
 277       if (g_cancellable_set_error_if_cancelled (data->cancellable, &error))
 278         {
 279           count_read = -1;
 280           break;
 281         }
 282       count_read = read (data->stream->priv->fd, data->buffer, data->count);
 283       if (count_read == -1)
 284         {
 285           if (errno == EINTR)
 286             continue;
 287
 288           g_set_error (&error, G_IO_ERROR,
 289                        g_io_error_from_errno (errno),
 290                        _("Error reading from unix: %s"),
 291                        g_strerror (errno));
 292         }
 293       break;
 294     }
 295
 296   simple = g_simple_async_result_new (G_OBJECT (data->stream),
 297                                       data->callback,
 298                                       data->user_data,
 299                                       g_unix_input_stream_read_async);
 300
 301   g_simple_async_result_set_op_res_gssize (simple, count_read);
 302
 303   if (count_read == -1)
 304     {
 305       g_simple_async_result_set_from_error (simple, error);
 306       g_error_free (error);
 307     }
 308
 309   /* Complete immediately, not in idle, since we're already in a mainloop callout */
 310   g_simple_async_result_complete (simple);
 311   g_object_unref (simple);
 312
 313   return FALSE;
 314 }
 315
 316 static void
 317 g_unix_input_stream_read_async (GInputStream        *stream,
 318                                 void                *buffer,
 319                                 gsize                count,
 320                                 int                  io_priority,
 321                                 GCancellable        *cancellable,
 322                                 GAsyncReadyCallback  callback,
 323                                 gpointer             user_data)
 324 {
 325   GSource *source;
 326   GUnixInputStream *unix_stream;
 327   ReadAsyncData *data;
 328
 329   unix_stream = G_UNIX_INPUT_STREAM (stream);
 330
 331   data = g_new0 (ReadAsyncData, 1);
 332   data->count = count;
 333   data->buffer = buffer;
 334   data->callback = callback;
 335   data->user_data = user_data;
 336   data->cancellable = cancellable;
 337   data->stream = unix_stream;
 338
 339   source = _g_fd_source_new (unix_stream->priv->fd,
 340                              POLLIN,
 341                              cancellable);
 342
 343   g_source_set_callback (source, (GSourceFunc)read_async_cb, data, g_free);
 344   g_source_attach (source, NULL);
 345
 346   g_source_unref (source);
 347 }
 348
 349 static gssize
 350 g_unix_input_stream_read_finish (GInputStream  *stream,
 351                                  GAsyncResult  *result,
 352                                  GError       **error)
 353 {
 354   GSimpleAsyncResult *simple;
 355   gssize nread;
 356
 357   simple = G_SIMPLE_ASYNC_RESULT (result);
 358   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_unix_input_stream_read_async);
 359
 360   nread = g_simple_async_result_get_op_res_gssize (simple);
 361   return nread;
 362 }
 363
 364 static void
 365 g_unix_input_stream_skip_async (GInputStream        *stream,
 366                                 gsize                count,
 367                                 int                  io_priority,
 368                                 GCancellable        *cancellable,
 369                                 GAsyncReadyCallback  callback,
 370                                 gpointer             data)
 371 {
 372   g_warn_if_reached ();
 373   /* TODO: Not implemented */
 374 }
 375
 376 static gssize
 377 g_unix_input_stream_skip_finish  (GInputStream  *stream,
 378                                   GAsyncResult  *result,
 379                                   GError       **error)
 380 {
 381   g_warn_if_reached ();
 382   /* TODO: Not implemented */
 383 }
 384
 385
 386 typedef struct {
 387   GInputStream *stream;
 388   GAsyncReadyCallback callback;
 389   gpointer user_data;
 390 } CloseAsyncData;
 391
 392 static void
 393 close_async_data_free (gpointer _data)
 394 {
 395   CloseAsyncData *data = _data;
 396
 397   g_free (data);
 398 }
 399
 400 static gboolean
 401 close_async_cb (CloseAsyncData *data)
 402 {
 403   GUnixInputStream *unix_stream;
 404   GSimpleAsyncResult *simple;
 405   GError *error = NULL;
 406   gboolean result;
 407   int res;
 408
 409   unix_stream = G_UNIX_INPUT_STREAM (data->stream);
 410
 411   if (!unix_stream->priv->close_fd_at_close)
 412     {
 413       result = TRUE;
 414       goto out;
 415     }
 416
 417   while (1)
 418     {
 419       res = close (unix_stream->priv->fd);
 420       if (res == -1)
 421         g_set_error (&error, G_IO_ERROR,
 422                      g_io_error_from_errno (errno),
 423                      _("Error closing unix: %s"),
 424                      g_strerror (errno));
 425       break;
 426     }
 427
 428   result = res != -1;
 429
 430  out:
 431   simple = g_simple_async_result_new (G_OBJECT (data->stream),
 432                                       data->callback,
 433                                       data->user_data,
 434                                       g_unix_input_stream_close_async);
 435
 436   if (!result)
 437     {
 438       g_simple_async_result_set_from_error (simple, error);
 439       g_error_free (error);
 440     }
 441
 442   /* Complete immediately, not in idle, since we're already in a mainloop callout */
 443   g_simple_async_result_complete (simple);
 444   g_object_unref (simple);
 445
 446   return FALSE;
 447 }
 448
 449 static void
 450 g_unix_input_stream_close_async (GInputStream        *stream,
 451                                  int                  io_priority,
 452                                  GCancellable        *cancellable,
 453                                  GAsyncReadyCallback  callback,
 454                                  gpointer             user_data)
 455 {
 456   GSource *idle;
 457   CloseAsyncData *data;
 458
 459   data = g_new0 (CloseAsyncData, 1);
 460
 461   data->stream = stream;
 462   data->callback = callback;
 463   data->user_data = user_data;
 464
 465   idle = g_idle_source_new ();
 466   g_source_set_callback (idle, (GSourceFunc)close_async_cb, data, close_async_data_free);
 467   g_source_attach (idle, NULL);
 468   g_source_unref (idle);
 469 }
 470
 471 static gboolean
 472 g_unix_input_stream_close_finish (GInputStream  *stream,
 473                                   GAsyncResult  *result,
 474                                   GError       **error)
 475 {
 476   /* Failures handled in generic close_finish code */
 477   return TRUE;
 478 }
 479
 480 #define __G_UNIX_INPUT_STREAM_C__
 481 #include "gioaliasdef.c"