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  * @see_also: #GOutputStream
  48  *
  49  * #GUnixOutputStream implements #GOutputStream for writing to a a
  50  * unix file descriptor, including asynchronous operations. The file
  51  * descriptor much be selectable, so it doesn't work with opened files.
  52  **/
  53
  54 G_DEFINE_TYPE (GUnixOutputStream, g_unix_output_stream, G_TYPE_OUTPUT_STREAM);
  55
  56
  57 struct _GUnixOutputStreamPrivate {
  58   int fd;
  59   gboolean close_fd_at_close;
  60 };
  61
  62 static gssize   g_unix_output_stream_write        (GOutputStream        *stream,
  63                                                    const void           *buffer,
  64                                                    gsize                 count,
  65                                                    GCancellable         *cancellable,
  66                                                    GError              **error);
  67 static gboolean g_unix_output_stream_close        (GOutputStream        *stream,
  68                                                    GCancellable         *cancellable,
  69                                                    GError              **error);
  70 static void     g_unix_output_stream_write_async  (GOutputStream        *stream,
  71                                                    const void           *buffer,
  72                                                    gsize                 count,
  73                                                    int                   io_priority,
  74                                                    GCancellable         *cancellable,
  75                                                    GAsyncReadyCallback   callback,
  76                                                    gpointer              data);
  77 static gssize   g_unix_output_stream_write_finish (GOutputStream        *stream,
  78                                                    GAsyncResult         *result,
  79                                                    GError              **error);
  80 static void     g_unix_output_stream_close_async  (GOutputStream        *stream,
  81                                                    int                   io_priority,
  82                                                    GCancellable         *cancellable,
  83                                                    GAsyncReadyCallback   callback,
  84                                                    gpointer              data);
  85 static gboolean g_unix_output_stream_close_finish (GOutputStream        *stream,
  86                                                    GAsyncResult         *result,
  87                                                    GError              **error);
  88
  89
  90 static void
  91 g_unix_output_stream_finalize (GObject *object)
  92 {
  93   GUnixOutputStream *stream;
  94
  95   stream = G_UNIX_OUTPUT_STREAM (object);
  96
  97   if (G_OBJECT_CLASS (g_unix_output_stream_parent_class)->finalize)
  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           g_set_error (error, G_IO_ERROR,
 186                        g_io_error_from_errno (errno),
 187                        _("Error writing to unix: %s"),
 188                        g_strerror (errno));
 189           return -1;
 190         }
 191     }
 192
 193   while (1)
 194     {
 195       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 196         return -1;
 197
 198       res = write (unix_stream->priv->fd, buffer, count);
 199       if (res == -1)
 200         {
 201           if (errno == EINTR)
 202             continue;
 203
 204           g_set_error (error, G_IO_ERROR,
 205                        g_io_error_from_errno (errno),
 206                        _("Error writing to unix: %s"),
 207                        g_strerror (errno));
 208         }
 209
 210       break;
 211     }
 212
 213   return res;
 214 }
 215
 216 static gboolean
 217 g_unix_output_stream_close (GOutputStream  *stream,
 218                             GCancellable   *cancellable,
 219                             GError        **error)
 220 {
 221   GUnixOutputStream *unix_stream;
 222   int res;
 223
 224   unix_stream = G_UNIX_OUTPUT_STREAM (stream);
 225
 226   if (!unix_stream->priv->close_fd_at_close)
 227     return TRUE;
 228
 229   while (1)
 230     {
 231       /* This might block during the close. Doesn't seem to be a way to avoid it though. */
 232       res = close (unix_stream->priv->fd);
 233       if (res == -1)
 234         {
 235           g_set_error (error, G_IO_ERROR,
 236                        g_io_error_from_errno (errno),
 237                        _("Error closing unix: %s"),
 238                        g_strerror (errno));
 239         }
 240       break;
 241     }
 242
 243   return res != -1;
 244 }
 245
 246 typedef struct {
 247   gsize count;
 248   const void *buffer;
 249   GAsyncReadyCallback callback;
 250   gpointer user_data;
 251   GCancellable *cancellable;
 252   GUnixOutputStream *stream;
 253 } WriteAsyncData;
 254
 255 static gboolean
 256 write_async_cb (WriteAsyncData *data,
 257                 GIOCondition    condition,
 258                 int             fd)
 259 {
 260   GSimpleAsyncResult *simple;
 261   GError *error = NULL;
 262   gssize count_written;
 263
 264   while (1)
 265     {
 266       if (g_cancellable_set_error_if_cancelled (data->cancellable, &error))
 267         {
 268           count_written = -1;
 269           break;
 270         }
 271
 272       count_written = write (data->stream->priv->fd, data->buffer, data->count);
 273       if (count_written == -1)
 274         {
 275           if (errno == EINTR)
 276             continue;
 277
 278           g_set_error (&error, G_IO_ERROR,
 279                        g_io_error_from_errno (errno),
 280                        _("Error reading from unix: %s"),
 281                        g_strerror (errno));
 282         }
 283       break;
 284     }
 285
 286   simple = g_simple_async_result_new (G_OBJECT (data->stream),
 287                                       data->callback,
 288                                       data->user_data,
 289                                       g_unix_output_stream_write_async);
 290
 291   g_simple_async_result_set_op_res_gssize (simple, count_written);
 292
 293   if (count_written == -1)
 294     {
 295       g_simple_async_result_set_from_error (simple, error);
 296       g_error_free (error);
 297     }
 298
 299   /* Complete immediately, not in idle, since we're already in a mainloop callout */
 300   g_simple_async_result_complete (simple);
 301   g_object_unref (simple);
 302
 303   return FALSE;
 304 }
 305
 306 static void
 307 g_unix_output_stream_write_async (GOutputStream       *stream,
 308                                   const void          *buffer,
 309                                   gsize                count,
 310                                   int                  io_priority,
 311                                   GCancellable        *cancellable,
 312                                   GAsyncReadyCallback  callback,
 313                                   gpointer             user_data)
 314 {
 315   GSource *source;
 316   GUnixOutputStream *unix_stream;
 317   WriteAsyncData *data;
 318
 319   unix_stream = G_UNIX_OUTPUT_STREAM (stream);
 320
 321   data = g_new0 (WriteAsyncData, 1);
 322   data->count = count;
 323   data->buffer = buffer;
 324   data->callback = callback;
 325   data->user_data = user_data;
 326   data->cancellable = cancellable;
 327   data->stream = unix_stream;
 328
 329   source = _g_fd_source_new (unix_stream->priv->fd,
 330                              POLLOUT,
 331                              cancellable);
 332
 333   g_source_set_callback (source, (GSourceFunc)write_async_cb, data, g_free);
 334   g_source_attach (source, NULL);
 335
 336   g_source_unref (source);
 337 }
 338
 339 static gssize
 340 g_unix_output_stream_write_finish (GOutputStream  *stream,
 341                                    GAsyncResult   *result,
 342                                    GError        **error)
 343 {
 344   GSimpleAsyncResult *simple;
 345   gssize nwritten;
 346
 347   simple = G_SIMPLE_ASYNC_RESULT (result);
 348   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_unix_output_stream_write_async);
 349
 350   nwritten = g_simple_async_result_get_op_res_gssize (simple);
 351   return nwritten;
 352 }
 353
 354 typedef struct {
 355   GOutputStream *stream;
 356   GAsyncReadyCallback callback;
 357   gpointer user_data;
 358 } CloseAsyncData;
 359
 360 static gboolean
 361 close_async_cb (CloseAsyncData *data)
 362 {
 363   GUnixOutputStream *unix_stream;
 364   GSimpleAsyncResult *simple;
 365   GError *error = NULL;
 366   gboolean result;
 367   int res;
 368
 369   unix_stream = G_UNIX_OUTPUT_STREAM (data->stream);
 370
 371   if (!unix_stream->priv->close_fd_at_close)
 372     {
 373       result = TRUE;
 374       goto out;
 375     }
 376
 377   while (1)
 378     {
 379       res = close (unix_stream->priv->fd);
 380       if (res == -1)
 381         {
 382           g_set_error (&error, G_IO_ERROR,
 383                        g_io_error_from_errno (errno),
 384                        _("Error closing unix: %s"),
 385                        g_strerror (errno));
 386         }
 387       break;
 388     }
 389
 390   result = res != -1;
 391
 392  out:
 393   simple = g_simple_async_result_new (G_OBJECT (data->stream),
 394                                       data->callback,
 395                                       data->user_data,
 396                                       g_unix_output_stream_close_async);
 397
 398   if (!result)
 399     {
 400       g_simple_async_result_set_from_error (simple, error);
 401       g_error_free (error);
 402     }
 403
 404   /* Complete immediately, not in idle, since we're already in a mainloop callout */
 405   g_simple_async_result_complete (simple);
 406   g_object_unref (simple);
 407
 408   return FALSE;
 409 }
 410
 411 static void
 412 g_unix_output_stream_close_async (GOutputStream        *stream,
 413                                   int                  io_priority,
 414                                   GCancellable        *cancellable,
 415                                   GAsyncReadyCallback  callback,
 416                                   gpointer             user_data)
 417 {
 418   GSource *idle;
 419   CloseAsyncData *data;
 420
 421   data = g_new0 (CloseAsyncData, 1);
 422
 423   data->stream = stream;
 424   data->callback = callback;
 425   data->user_data = user_data;
 426
 427   idle = g_idle_source_new ();
 428   g_source_set_callback (idle, (GSourceFunc)close_async_cb, data, g_free);
 429   g_source_attach (idle, NULL);
 430   g_source_unref (idle);
 431 }
 432
 433 static gboolean
 434 g_unix_output_stream_close_finish (GOutputStream  *stream,
 435                                    GAsyncResult   *result,
 436                                    GError        **error)
 437 {
 438   /* Failures handled in generic close_finish code */
 439   return TRUE;
 440 }
 441
 442 #define __G_UNIX_OUTPUT_STREAM_C__
 443 #include "gioaliasdef.c"