gio/gunixoutputstream.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 "gunixoutputstream.h"
  37 #include "gcancellable.h"
  38 #include "gsimpleasyncresult.h"
  39 #include "gasynchelper.h"
  40 #include "glibintl.h"
  41
  42 #include "gioalias.h"
  43
  44 /**
  45  * SECTION:gunixoutputstream
  46  * @short_description: Streaming output operations for Unix file descriptors
  47  * @include: gio/gunixoutputstream.h
  48  * @see_also: #GOutputStream
  49  *
  50  * #GUnixOutputStream implements #GOutputStream for writing to 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 (GUnixOutputStream, g_unix_output_stream, G_TYPE_OUTPUT_STREAM);
  56
  57
  58 struct _GUnixOutputStreamPrivate {
  59   int fd;
  60   gboolean close_fd_at_close;
  61 };
  62
  63 static gssize   g_unix_output_stream_write        (GOutputStream        *stream,
  64                                                    const void           *buffer,
  65                                                    gsize                 count,
  66                                                    GCancellable         *cancellable,
  67                                                    GError              **error);
  68 static gboolean g_unix_output_stream_close        (GOutputStream        *stream,
  69                                                    GCancellable         *cancellable,
  70                                                    GError              **error);
  71 static void     g_unix_output_stream_write_async  (GOutputStream        *stream,
  72                                                    const void           *buffer,
  73                                                    gsize                 count,
  74                                                    int                   io_priority,
  75                                                    GCancellable         *cancellable,
  76                                                    GAsyncReadyCallback   callback,
  77                                                    gpointer              data);
  78 static gssize   g_unix_output_stream_write_finish (GOutputStream        *stream,
  79                                                    GAsyncResult         *result,
  80                                                    GError              **error);
  81 static void     g_unix_output_stream_close_async  (GOutputStream        *stream,
  82                                                    int                   io_priority,
  83                                                    GCancellable         *cancellable,
  84                                                    GAsyncReadyCallback   callback,
  85                                                    gpointer              data);
  86 static gboolean g_unix_output_stream_close_finish (GOutputStream        *stream,
  87                                                    GAsyncResult         *result,
  88                                                    GError              **error);
  89
  90
  91 static void
  92 g_unix_output_stream_finalize (GObject *object)
  93 {
  94   GUnixOutputStream *stream;
  95
  96   stream = G_UNIX_OUTPUT_STREAM (object);
  97
  98   G_OBJECT_CLASS (g_unix_output_stream_parent_class)->finalize (object);
  99 }
 100
 101 static void
 102 g_unix_output_stream_class_init (GUnixOutputStreamClass *klass)
 103 {
 104   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 105   GOutputStreamClass *stream_class = G_OUTPUT_STREAM_CLASS (klass);
 106
 107   g_type_class_add_private (klass, sizeof (GUnixOutputStreamPrivate));
 108
 109   gobject_class->finalize = g_unix_output_stream_finalize;
 110
 111   stream_class->write_fn = g_unix_output_stream_write;
 112   stream_class->close_fn = g_unix_output_stream_close;
 113   stream_class->write_async = g_unix_output_stream_write_async;
 114   stream_class->write_finish = g_unix_output_stream_write_finish;
 115   stream_class->close_async = g_unix_output_stream_close_async;
 116   stream_class->close_finish = g_unix_output_stream_close_finish;
 117 }
 118
 119 static void
 120 g_unix_output_stream_init (GUnixOutputStream *unix_stream)
 121 {
 122   unix_stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (unix_stream,
 123                                                    G_TYPE_UNIX_OUTPUT_STREAM,
 124                                                    GUnixOutputStreamPrivate);
 125 }
 126
 127
 128 /**
 129  * g_unix_output_stream_new:
 130  * @fd: unix's file descriptor.
 131  * @close_fd_at_close: a #gboolean.
 132  *
 133  * Creates a new unix output stream for @fd. If @close_fd_at_close
 134  * is %TRUE, the fd will be closed when the output stream is destroyed.
 135  *
 136  * Returns: #GOutputStream. If @close_fd_at_close is %TRUE, then
 137  * @fd will be closed when the #GOutputStream is closed.
 138  **/
 139 GOutputStream *
 140 g_unix_output_stream_new (int      fd,
 141                           gboolean close_fd_at_close)
 142 {
 143   GUnixOutputStream *stream;
 144
 145   g_return_val_if_fail (fd != -1, NULL);
 146
 147   stream = g_object_new (G_TYPE_UNIX_OUTPUT_STREAM, NULL);
 148
 149   stream->priv->fd = fd;
 150   stream->priv->close_fd_at_close = close_fd_at_close;
 151
 152   return G_OUTPUT_STREAM (stream);
 153 }
 154
 155 static gssize
 156 g_unix_output_stream_write (GOutputStream  *stream,
 157                             const void     *buffer,
 158                             gsize           count,
 159                             GCancellable   *cancellable,
 160                             GError        **error)
 161 {
 162   GUnixOutputStream *unix_stream;
 163   gssize res;
 164   struct pollfd poll_fds[2];
 165   int poll_ret;
 166   int cancel_fd;
 167
 168   unix_stream = G_UNIX_OUTPUT_STREAM (stream);
 169
 170   cancel_fd = g_cancellable_get_fd (cancellable);
 171   if (cancel_fd != -1)
 172     {
 173       do
 174         {
 175           poll_fds[0].events = POLLOUT;
 176           poll_fds[0].fd = unix_stream->priv->fd;
 177           poll_fds[1].events = POLLIN;
 178           poll_fds[1].fd = cancel_fd;
 179           poll_ret = poll (poll_fds, 2, -1);
 180         }
 181       while (poll_ret == -1 && errno == EINTR);
 182
 183       if (poll_ret == -1)
 184         {
 185           int errsv = errno;
 186
 187           g_set_error (error, G_IO_ERROR,
 188                        g_io_error_from_errno (errsv),
 189                        _("Error writing to unix: %s"),
 190                        g_strerror (errsv));
 191           return -1;
 192         }
 193     }
 194
 195   while (1)
 196     {
 197       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 198         return -1;
 199
 200       res = write (unix_stream->priv->fd, buffer, count);
 201       if (res == -1)
 202         {
 203           int errsv = errno;
 204
 205           if (errsv == EINTR)
 206             continue;
 207
 208           g_set_error (error, G_IO_ERROR,
 209                        g_io_error_from_errno (errsv),
 210                        _("Error writing to unix: %s"),
 211                        g_strerror (errsv));
 212         }
 213
 214       break;
 215     }
 216
 217   return res;
 218 }
 219
 220 static gboolean
 221 g_unix_output_stream_close (GOutputStream  *stream,
 222                             GCancellable   *cancellable,
 223                             GError        **error)
 224 {
 225   GUnixOutputStream *unix_stream;
 226   int res;
 227
 228   unix_stream = G_UNIX_OUTPUT_STREAM (stream);
 229
 230   if (!unix_stream->priv->close_fd_at_close)
 231     return TRUE;
 232
 233   while (1)
 234     {
 235       /* This might block during the close. Doesn't seem to be a way to avoid it though. */
 236       res = close (unix_stream->priv->fd);
 237       if (res == -1)
 238         {
 239           int errsv = errno;
 240
 241           g_set_error (error, G_IO_ERROR,
 242                        g_io_error_from_errno (errsv),
 243                        _("Error closing unix: %s"),
 244                        g_strerror (errsv));
 245         }
 246       break;
 247     }
 248
 249   return res != -1;
 250 }
 251
 252 typedef struct {
 253   gsize count;
 254   const void *buffer;
 255   GAsyncReadyCallback callback;
 256   gpointer user_data;
 257   GCancellable *cancellable;
 258   GUnixOutputStream *stream;
 259 } WriteAsyncData;
 260
 261 static gboolean
 262 write_async_cb (WriteAsyncData *data,
 263                 GIOCondition    condition,
 264                 int             fd)
 265 {
 266   GSimpleAsyncResult *simple;
 267   GError *error = NULL;
 268   gssize count_written;
 269
 270   while (1)
 271     {
 272       if (g_cancellable_set_error_if_cancelled (data->cancellable, &error))
 273         {
 274           count_written = -1;
 275           break;
 276         }
 277
 278       count_written = write (data->stream->priv->fd, data->buffer, data->count);
 279       if (count_written == -1)
 280         {
 281           int errsv = errno;
 282
 283           if (errsv == EINTR)
 284             continue;
 285
 286           g_set_error (&error, G_IO_ERROR,
 287                        g_io_error_from_errno (errsv),
 288                        _("Error reading from unix: %s"),
 289                        g_strerror (errsv));
 290         }
 291       break;
 292     }
 293
 294   simple = g_simple_async_result_new (G_OBJECT (data->stream),
 295                                       data->callback,
 296                                       data->user_data,
 297                                       g_unix_output_stream_write_async);
 298
 299   g_simple_async_result_set_op_res_gssize (simple, count_written);
 300
 301   if (count_written == -1)
 302     {
 303       g_simple_async_result_set_from_error (simple, error);
 304       g_error_free (error);
 305     }
 306
 307   /* Complete immediately, not in idle, since we're already in a mainloop callout */
 308   g_simple_async_result_complete (simple);
 309   g_object_unref (simple);
 310
 311   return FALSE;
 312 }
 313
 314 static void
 315 g_unix_output_stream_write_async (GOutputStream       *stream,
 316                                   const void          *buffer,
 317                                   gsize                count,
 318                                   int                  io_priority,
 319                                   GCancellable        *cancellable,
 320                                   GAsyncReadyCallback  callback,
 321                                   gpointer             user_data)
 322 {
 323   GSource *source;
 324   GUnixOutputStream *unix_stream;
 325   WriteAsyncData *data;
 326
 327   unix_stream = G_UNIX_OUTPUT_STREAM (stream);
 328
 329   data = g_new0 (WriteAsyncData, 1);
 330   data->count = count;
 331   data->buffer = buffer;
 332   data->callback = callback;
 333   data->user_data = user_data;
 334   data->cancellable = cancellable;
 335   data->stream = unix_stream;
 336
 337   source = _g_fd_source_new (unix_stream->priv->fd,
 338                              POLLOUT,
 339                              cancellable);
 340
 341   g_source_set_callback (source, (GSourceFunc)write_async_cb, data, g_free);
 342   g_source_attach (source, NULL);
 343
 344   g_source_unref (source);
 345 }
 346
 347 static gssize
 348 g_unix_output_stream_write_finish (GOutputStream  *stream,
 349                                    GAsyncResult   *result,
 350                                    GError        **error)
 351 {
 352   GSimpleAsyncResult *simple;
 353   gssize nwritten;
 354
 355   simple = G_SIMPLE_ASYNC_RESULT (result);
 356   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_unix_output_stream_write_async);
 357
 358   nwritten = g_simple_async_result_get_op_res_gssize (simple);
 359   return nwritten;
 360 }
 361
 362 typedef struct {
 363   GOutputStream *stream;
 364   GAsyncReadyCallback callback;
 365   gpointer user_data;
 366 } CloseAsyncData;
 367
 368 static gboolean
 369 close_async_cb (CloseAsyncData *data)
 370 {
 371   GUnixOutputStream *unix_stream;
 372   GSimpleAsyncResult *simple;
 373   GError *error = NULL;
 374   gboolean result;
 375   int res;
 376
 377   unix_stream = G_UNIX_OUTPUT_STREAM (data->stream);
 378
 379   if (!unix_stream->priv->close_fd_at_close)
 380     {
 381       result = TRUE;
 382       goto out;
 383     }
 384
 385   while (1)
 386     {
 387       res = close (unix_stream->priv->fd);
 388       if (res == -1)
 389         {
 390           int errsv = errno;
 391
 392           g_set_error (&error, G_IO_ERROR,
 393                        g_io_error_from_errno (errsv),
 394                        _("Error closing unix: %s"),
 395                        g_strerror (errsv));
 396         }
 397       break;
 398     }
 399
 400   result = res != -1;
 401
 402  out:
 403   simple = g_simple_async_result_new (G_OBJECT (data->stream),
 404                                       data->callback,
 405                                       data->user_data,
 406                                       g_unix_output_stream_close_async);
 407
 408   if (!result)
 409     {
 410       g_simple_async_result_set_from_error (simple, error);
 411       g_error_free (error);
 412     }
 413
 414   /* Complete immediately, not in idle, since we're already in a mainloop callout */
 415   g_simple_async_result_complete (simple);
 416   g_object_unref (simple);
 417
 418   return FALSE;
 419 }
 420
 421 static void
 422 g_unix_output_stream_close_async (GOutputStream        *stream,
 423                                   int                  io_priority,
 424                                   GCancellable        *cancellable,
 425                                   GAsyncReadyCallback  callback,
 426                                   gpointer             user_data)
 427 {
 428   GSource *idle;
 429   CloseAsyncData *data;
 430
 431   data = g_new0 (CloseAsyncData, 1);
 432
 433   data->stream = stream;
 434   data->callback = callback;
 435   data->user_data = user_data;
 436
 437   idle = g_idle_source_new ();
 438   g_source_set_callback (idle, (GSourceFunc)close_async_cb, data, g_free);
 439   g_source_attach (idle, NULL);
 440   g_source_unref (idle);
 441 }
 442
 443 static gboolean
 444 g_unix_output_stream_close_finish (GOutputStream  *stream,
 445                                    GAsyncResult   *result,
 446                                    GError        **error)
 447 {
 448   /* Failures handled in generic close_finish code */
 449   return TRUE;
 450 }
 451
 452 #define __G_UNIX_OUTPUT_STREAM_C__
 453 #include "gioaliasdef.c"