gio/goutputstream.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 #include "goutputstream.h"
  25 #include "gcancellable.h"
  26 #include "gasyncresult.h"
  27 #include "gsimpleasyncresult.h"
  28 #include "ginputstream.h"
  29 #include "gioerror.h"
  30 #include "glibintl.h"
  31
  32
  33 /**
  34  * SECTION:goutputstream
  35  * @short_description: Base class for implementing streaming output
  36  * @include: gio/gio.h
  37  *
  38  * GOutputStream has functions to write to a stream (g_output_stream_write()),
  39  * to close a stream (g_output_stream_close()) and to flush pending writes
  40  * (g_output_stream_flush()).
  41  *
  42  * To copy the content of an input stream to an output stream without
  43  * manually handling the reads and writes, use g_output_stream_splice().
  44  *
  45  * All of these functions have async variants too.
  46  **/
  47
  48 G_DEFINE_ABSTRACT_TYPE (GOutputStream, g_output_stream, G_TYPE_OBJECT);
  49
  50 struct _GOutputStreamPrivate {
  51   guint closed : 1;
  52   guint pending : 1;
  53   guint closing : 1;
  54   GAsyncReadyCallback outstanding_callback;
  55 };
  56
  57 static gssize   g_output_stream_real_splice        (GOutputStream             *stream,
  58                                                     GInputStream              *source,
  59                                                     GOutputStreamSpliceFlags   flags,
  60                                                     GCancellable              *cancellable,
  61                                                     GError                   **error);
  62 static void     g_output_stream_real_write_async   (GOutputStream             *stream,
  63                                                     const void                *buffer,
  64                                                     gsize                      count,
  65                                                     int                        io_priority,
  66                                                     GCancellable              *cancellable,
  67                                                     GAsyncReadyCallback        callback,
  68                                                     gpointer                   data);
  69 static gssize   g_output_stream_real_write_finish  (GOutputStream             *stream,
  70                                                     GAsyncResult              *result,
  71                                                     GError                   **error);
  72 static void     g_output_stream_real_splice_async  (GOutputStream             *stream,
  73                                                     GInputStream              *source,
  74                                                     GOutputStreamSpliceFlags   flags,
  75                                                     int                        io_priority,
  76                                                     GCancellable              *cancellable,
  77                                                     GAsyncReadyCallback        callback,
  78                                                     gpointer                   data);
  79 static gssize   g_output_stream_real_splice_finish (GOutputStream             *stream,
  80                                                     GAsyncResult              *result,
  81                                                     GError                   **error);
  82 static void     g_output_stream_real_flush_async   (GOutputStream             *stream,
  83                                                     int                        io_priority,
  84                                                     GCancellable              *cancellable,
  85                                                     GAsyncReadyCallback        callback,
  86                                                     gpointer                   data);
  87 static gboolean g_output_stream_real_flush_finish  (GOutputStream             *stream,
  88                                                     GAsyncResult              *result,
  89                                                     GError                   **error);
  90 static void     g_output_stream_real_close_async   (GOutputStream             *stream,
  91                                                     int                        io_priority,
  92                                                     GCancellable              *cancellable,
  93                                                     GAsyncReadyCallback        callback,
  94                                                     gpointer                   data);
  95 static gboolean g_output_stream_real_close_finish  (GOutputStream             *stream,
  96                                                     GAsyncResult              *result,
  97                                                     GError                   **error);
  98
  99 static void
 100 g_output_stream_finalize (GObject *object)
 101 {
 102   G_OBJECT_CLASS (g_output_stream_parent_class)->finalize (object);
 103 }
 104
 105 static void
 106 g_output_stream_dispose (GObject *object)
 107 {
 108   GOutputStream *stream;
 109
 110   stream = G_OUTPUT_STREAM (object);
 111
 112   if (!stream->priv->closed)
 113     g_output_stream_close (stream, NULL, NULL);
 114
 115   G_OBJECT_CLASS (g_output_stream_parent_class)->dispose (object);
 116 }
 117
 118 static void
 119 g_output_stream_class_init (GOutputStreamClass *klass)
 120 {
 121   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 122
 123   g_type_class_add_private (klass, sizeof (GOutputStreamPrivate));
 124
 125   gobject_class->finalize = g_output_stream_finalize;
 126   gobject_class->dispose = g_output_stream_dispose;
 127
 128   klass->splice = g_output_stream_real_splice;
 129
 130   klass->write_async = g_output_stream_real_write_async;
 131   klass->write_finish = g_output_stream_real_write_finish;
 132   klass->splice_async = g_output_stream_real_splice_async;
 133   klass->splice_finish = g_output_stream_real_splice_finish;
 134   klass->flush_async = g_output_stream_real_flush_async;
 135   klass->flush_finish = g_output_stream_real_flush_finish;
 136   klass->close_async = g_output_stream_real_close_async;
 137   klass->close_finish = g_output_stream_real_close_finish;
 138 }
 139
 140 static void
 141 g_output_stream_init (GOutputStream *stream)
 142 {
 143   stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (stream,
 144                                               G_TYPE_OUTPUT_STREAM,
 145                                               GOutputStreamPrivate);
 146 }
 147
 148 /**
 149  * g_output_stream_write:
 150  * @stream: a #GOutputStream.
 151  * @buffer: (array length=count) (element-type guint8): the buffer containing the data to write.
 152  * @count: the number of bytes to write
 153  * @cancellable: optional cancellable object
 154  * @error: location to store the error occuring, or %NULL to ignore
 155  *
 156  * Tries to write @count bytes from @buffer into the stream. Will block
 157  * during the operation.
 158  *
 159  * If count is 0, returns 0 and does nothing. A value of @count
 160  * larger than %G_MAXSSIZE will cause a %G_IO_ERROR_INVALID_ARGUMENT error.
 161  *
 162  * On success, the number of bytes written to the stream is returned.
 163  * It is not an error if this is not the same as the requested size, as it
 164  * can happen e.g. on a partial I/O error, or if there is not enough
 165  * storage in the stream. All writes block until at least one byte
 166  * is written or an error occurs; 0 is never returned (unless
 167  * @count is 0).
 168  *
 169  * If @cancellable is not NULL, then the operation can be cancelled by
 170  * triggering the cancellable object from another thread. If the operation
 171  * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned. If an
 172  * operation was partially finished when the operation was cancelled the
 173  * partial result will be returned, without an error.
 174  *
 175  * On error -1 is returned and @error is set accordingly.
 176  *
 177  * Return value: Number of bytes written, or -1 on error
 178  **/
 179 gssize
 180 g_output_stream_write (GOutputStream  *stream,
 181                        const void     *buffer,
 182                        gsize           count,
 183                        GCancellable   *cancellable,
 184                        GError        **error)
 185 {
 186   GOutputStreamClass *class;
 187   gssize res;
 188
 189   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
 190   g_return_val_if_fail (buffer != NULL, 0);
 191
 192   if (count == 0)
 193     return 0;
 194
 195   if (((gssize) count) < 0)
 196     {
 197       g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
 198                    _("Too large count value passed to %s"), G_STRFUNC);
 199       return -1;
 200     }
 201
 202   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 203
 204   if (class->write_fn == NULL)
 205     {
 206       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
 207                            _("Output stream doesn't implement write"));
 208       return -1;
 209     }
 210
 211   if (!g_output_stream_set_pending (stream, error))
 212     return -1;
 213
 214   if (cancellable)
 215     g_cancellable_push_current (cancellable);
 216
 217   res = class->write_fn (stream, buffer, count, cancellable, error);
 218
 219   if (cancellable)
 220     g_cancellable_pop_current (cancellable);
 221
 222   g_output_stream_clear_pending (stream);
 223
 224   return res;
 225 }
 226
 227 /**
 228  * g_output_stream_write_all:
 229  * @stream: a #GOutputStream.
 230  * @buffer: (array length=count) (element-type guint8): the buffer containing the data to write.
 231  * @count: the number of bytes to write
 232  * @bytes_written: location to store the number of bytes that was
 233  *     written to the stream
 234  * @cancellable: optional #GCancellable object, %NULL to ignore.
 235  * @error: location to store the error occuring, or %NULL to ignore
 236  *
 237  * Tries to write @count bytes from @buffer into the stream. Will block
 238  * during the operation.
 239  *
 240  * This function is similar to g_output_stream_write(), except it tries to
 241  * write as many bytes as requested, only stopping on an error.
 242  *
 243  * On a successful write of @count bytes, %TRUE is returned, and @bytes_written
 244  * is set to @count.
 245  *
 246  * If there is an error during the operation FALSE is returned and @error
 247  * is set to indicate the error status, @bytes_written is updated to contain
 248  * the number of bytes written into the stream before the error occurred.
 249  *
 250  * Return value: %TRUE on success, %FALSE if there was an error
 251  **/
 252 gboolean
 253 g_output_stream_write_all (GOutputStream  *stream,
 254                            const void     *buffer,
 255                            gsize           count,
 256                            gsize          *bytes_written,
 257                            GCancellable   *cancellable,
 258                            GError        **error)
 259 {
 260   gsize _bytes_written;
 261   gssize res;
 262
 263   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 264   g_return_val_if_fail (buffer != NULL, FALSE);
 265
 266   _bytes_written = 0;
 267   while (_bytes_written < count)
 268     {
 269       res = g_output_stream_write (stream, (char *)buffer + _bytes_written, count - _bytes_written,
 270                                    cancellable, error);
 271       if (res == -1)
 272         {
 273           if (bytes_written)
 274             *bytes_written = _bytes_written;
 275           return FALSE;
 276         }
 277
 278       if (res == 0)
 279         g_warning ("Write returned zero without error");
 280
 281       _bytes_written += res;
 282     }
 283
 284   if (bytes_written)
 285     *bytes_written = _bytes_written;
 286
 287   return TRUE;
 288 }
 289
 290 /**
 291  * g_output_stream_flush:
 292  * @stream: a #GOutputStream.
 293  * @cancellable: optional cancellable object
 294  * @error: location to store the error occuring, or %NULL to ignore
 295  *
 296  * Flushed any outstanding buffers in the stream. Will block during
 297  * the operation. Closing the stream will implicitly cause a flush.
 298  *
 299  * This function is optional for inherited classes.
 300  *
 301  * If @cancellable is not %NULL, then the operation can be cancelled by
 302  * triggering the cancellable object from another thread. If the operation
 303  * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned.
 304  *
 305  * Return value: %TRUE on success, %FALSE on error
 306  **/
 307 gboolean
 308 g_output_stream_flush (GOutputStream  *stream,
 309                        GCancellable   *cancellable,
 310                        GError        **error)
 311 {
 312   GOutputStreamClass *class;
 313   gboolean res;
 314
 315   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 316
 317   if (!g_output_stream_set_pending (stream, error))
 318     return FALSE;
 319
 320   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 321
 322   res = TRUE;
 323   if (class->flush)
 324     {
 325       if (cancellable)
 326         g_cancellable_push_current (cancellable);
 327
 328       res = class->flush (stream, cancellable, error);
 329
 330       if (cancellable)
 331         g_cancellable_pop_current (cancellable);
 332     }
 333
 334   g_output_stream_clear_pending (stream);
 335
 336   return res;
 337 }
 338
 339 /**
 340  * g_output_stream_splice:
 341  * @stream: a #GOutputStream.
 342  * @source: a #GInputStream.
 343  * @flags: a set of #GOutputStreamSpliceFlags.
 344  * @cancellable: optional #GCancellable object, %NULL to ignore.
 345  * @error: a #GError location to store the error occuring, or %NULL to
 346  * ignore.
 347  *
 348  * Splices an input stream into an output stream.
 349  *
 350  * Returns: a #gssize containing the size of the data spliced, or
 351  *     -1 if an error occurred.
 352  **/
 353 gssize
 354 g_output_stream_splice (GOutputStream             *stream,
 355                         GInputStream              *source,
 356                         GOutputStreamSpliceFlags   flags,
 357                         GCancellable              *cancellable,
 358                         GError                   **error)
 359 {
 360   GOutputStreamClass *class;
 361   gssize bytes_copied;
 362
 363   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
 364   g_return_val_if_fail (G_IS_INPUT_STREAM (source), -1);
 365
 366   if (g_input_stream_is_closed (source))
 367     {
 368       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
 369                            _("Source stream is already closed"));
 370       return -1;
 371     }
 372
 373   if (!g_output_stream_set_pending (stream, error))
 374     return -1;
 375
 376   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 377
 378   if (cancellable)
 379     g_cancellable_push_current (cancellable);
 380
 381   bytes_copied = class->splice (stream, source, flags, cancellable, error);
 382
 383   if (cancellable)
 384     g_cancellable_pop_current (cancellable);
 385
 386   g_output_stream_clear_pending (stream);
 387
 388   return bytes_copied;
 389 }
 390
 391 static gssize
 392 g_output_stream_real_splice (GOutputStream             *stream,
 393                              GInputStream              *source,
 394                              GOutputStreamSpliceFlags   flags,
 395                              GCancellable              *cancellable,
 396                              GError                   **error)
 397 {
 398   GOutputStreamClass *class = G_OUTPUT_STREAM_GET_CLASS (stream);
 399   gssize n_read, n_written;
 400   gssize bytes_copied;
 401   char buffer[8192], *p;
 402   gboolean res;
 403
 404   bytes_copied = 0;
 405   if (class->write_fn == NULL)
 406     {
 407       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
 408                            _("Output stream doesn't implement write"));
 409       res = FALSE;
 410       goto notsupported;
 411     }
 412
 413   res = TRUE;
 414   do
 415     {
 416       n_read = g_input_stream_read (source, buffer, sizeof (buffer), cancellable, error);
 417       if (n_read == -1)
 418         {
 419           res = FALSE;
 420           break;
 421         }
 422
 423       if (n_read == 0)
 424         break;
 425
 426       p = buffer;
 427       while (n_read > 0)
 428         {
 429           n_written = class->write_fn (stream, p, n_read, cancellable, error);
 430           if (n_written == -1)
 431             {
 432               res = FALSE;
 433               break;
 434             }
 435
 436           p += n_written;
 437           n_read -= n_written;
 438           bytes_copied += n_written;
 439         }
 440     }
 441   while (res);
 442
 443  notsupported:
 444   if (!res)
 445     error = NULL; /* Ignore further errors */
 446
 447   if (flags & G_OUTPUT_STREAM_SPLICE_CLOSE_SOURCE)
 448     {
 449       /* Don't care about errors in source here */
 450       g_input_stream_close (source, cancellable, NULL);
 451     }
 452
 453   if (flags & G_OUTPUT_STREAM_SPLICE_CLOSE_TARGET)
 454     {
 455       /* But write errors on close are bad! */
 456       if (class->close_fn &&
 457           !class->close_fn (stream, cancellable, error))
 458         res = FALSE;
 459     }
 460
 461   if (res)
 462     return bytes_copied;
 463
 464   return -1;
 465 }
 466
 467
 468 /**
 469  * g_output_stream_close:
 470  * @stream: A #GOutputStream.
 471  * @cancellable: optional cancellable object
 472  * @error: location to store the error occuring, or %NULL to ignore
 473  *
 474  * Closes the stream, releasing resources related to it.
 475  *
 476  * Once the stream is closed, all other operations will return %G_IO_ERROR_CLOSED.
 477  * Closing a stream multiple times will not return an error.
 478  *
 479  * Closing a stream will automatically flush any outstanding buffers in the
 480  * stream.
 481  *
 482  * Streams will be automatically closed when the last reference
 483  * is dropped, but you might want to call this function to make sure
 484  * resources are released as early as possible.
 485  *
 486  * Some streams might keep the backing store of the stream (e.g. a file descriptor)
 487  * open after the stream is closed. See the documentation for the individual
 488  * stream for details.
 489  *
 490  * On failure the first error that happened will be reported, but the close
 491  * operation will finish as much as possible. A stream that failed to
 492  * close will still return %G_IO_ERROR_CLOSED for all operations. Still, it
 493  * is important to check and report the error to the user, otherwise
 494  * there might be a loss of data as all data might not be written.
 495  *
 496  * If @cancellable is not NULL, then the operation can be cancelled by
 497  * triggering the cancellable object from another thread. If the operation
 498  * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned.
 499  * Cancelling a close will still leave the stream closed, but there some streams
 500  * can use a faster close that doesn't block to e.g. check errors. On
 501  * cancellation (as with any error) there is no guarantee that all written
 502  * data will reach the target.
 503  *
 504  * Return value: %TRUE on success, %FALSE on failure
 505  **/
 506 gboolean
 507 g_output_stream_close (GOutputStream  *stream,
 508                        GCancellable   *cancellable,
 509                        GError        **error)
 510 {
 511   GOutputStreamClass *class;
 512   gboolean res;
 513
 514   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 515
 516   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 517
 518   if (stream->priv->closed)
 519     return TRUE;
 520
 521   if (!g_output_stream_set_pending (stream, error))
 522     return FALSE;
 523
 524   stream->priv->closing = TRUE;
 525
 526   if (cancellable)
 527     g_cancellable_push_current (cancellable);
 528
 529   if (class->flush)
 530     res = class->flush (stream, cancellable, error);
 531   else
 532     res = TRUE;
 533
 534   if (!res)
 535     {
 536       /* flushing caused the error that we want to return,
 537        * but we still want to close the underlying stream if possible
 538        */
 539       if (class->close_fn)
 540         class->close_fn (stream, cancellable, NULL);
 541     }
 542   else
 543     {
 544       res = TRUE;
 545       if (class->close_fn)
 546         res = class->close_fn (stream, cancellable, error);
 547     }
 548
 549   if (cancellable)
 550     g_cancellable_pop_current (cancellable);
 551
 552   stream->priv->closing = FALSE;
 553   stream->priv->closed = TRUE;
 554   g_output_stream_clear_pending (stream);
 555
 556   return res;
 557 }
 558
 559 static void
 560 async_ready_callback_wrapper (GObject      *source_object,
 561                               GAsyncResult *res,
 562                               gpointer      user_data)
 563 {
 564   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 565
 566   g_output_stream_clear_pending (stream);
 567   if (stream->priv->outstanding_callback)
 568     (*stream->priv->outstanding_callback) (source_object, res, user_data);
 569   g_object_unref (stream);
 570 }
 571
 572 typedef struct {
 573   gint io_priority;
 574   GCancellable *cancellable;
 575   GError *flush_error;
 576   gpointer user_data;
 577 } CloseUserData;
 578
 579 static void
 580 async_ready_close_callback_wrapper (GObject      *source_object,
 581                                     GAsyncResult *res,
 582                                     gpointer      user_data)
 583 {
 584   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 585   CloseUserData *data = user_data;
 586
 587   stream->priv->closing = FALSE;
 588   stream->priv->closed = TRUE;
 589
 590   g_output_stream_clear_pending (stream);
 591
 592   if (stream->priv->outstanding_callback)
 593     {
 594       if (data->flush_error != NULL)
 595         {
 596           GSimpleAsyncResult *err;
 597
 598           err = g_simple_async_result_new_take_error (source_object,
 599                                                       stream->priv->outstanding_callback,
 600                                                       data->user_data,
 601                                                       data->flush_error);
 602           data->flush_error = NULL;
 603
 604           (*stream->priv->outstanding_callback) (source_object,
 605                                                  G_ASYNC_RESULT (err),
 606                                                  data->user_data);
 607           g_object_unref (err);
 608         }
 609       else
 610         {
 611           (*stream->priv->outstanding_callback) (source_object,
 612                                                  res,
 613                                                  data->user_data);
 614         }
 615     }
 616
 617   g_object_unref (stream);
 618
 619   if (data->cancellable)
 620     g_object_unref (data->cancellable);
 621
 622   if (data->flush_error)
 623     g_error_free (data->flush_error);
 624
 625   g_slice_free (CloseUserData, data);
 626 }
 627
 628 static void
 629 async_ready_close_flushed_callback_wrapper (GObject      *source_object,
 630                                             GAsyncResult *res,
 631                                             gpointer      user_data)
 632 {
 633   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 634   GOutputStreamClass *class;
 635   CloseUserData *data = user_data;
 636   GSimpleAsyncResult *simple;
 637
 638   /* propagate the possible error */
 639   if (G_IS_SIMPLE_ASYNC_RESULT (res))
 640     {
 641       simple = G_SIMPLE_ASYNC_RESULT (res);
 642       g_simple_async_result_propagate_error (simple, &data->flush_error);
 643     }
 644
 645   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 646
 647   /* we still close, even if there was a flush error */
 648   class->close_async (stream, data->io_priority, data->cancellable,
 649                       async_ready_close_callback_wrapper, user_data);
 650 }
 651
 652 /**
 653  * g_output_stream_write_async:
 654  * @stream: A #GOutputStream.
 655  * @buffer: (array length=count) (element-type guint8): the buffer containing the data to write.
 656  * @count: the number of bytes to write
 657  * @io_priority: the io priority of the request.
 658  * @cancellable: optional #GCancellable object, %NULL to ignore.
 659  * @callback: callback to call when the request is satisfied
 660  * @user_data: the data to pass to callback function
 661  *
 662  * Request an asynchronous write of @count bytes from @buffer into
 663  * the stream. When the operation is finished @callback will be called.
 664  * You can then call g_output_stream_write_finish() to get the result of the
 665  * operation.
 666  *
 667  * During an async request no other sync and async calls are allowed,
 668  * and will result in %G_IO_ERROR_PENDING errors.
 669  *
 670  * A value of @count larger than %G_MAXSSIZE will cause a
 671  * %G_IO_ERROR_INVALID_ARGUMENT error.
 672  *
 673  * On success, the number of bytes written will be passed to the
 674  * @callback. It is not an error if this is not the same as the
 675  * requested size, as it can happen e.g. on a partial I/O error,
 676  * but generally we try to write as many bytes as requested.
 677  *
 678  * You are guaranteed that this method will never fail with
 679  * %G_IO_ERROR_WOULD_BLOCK - if @stream can't accept more data, the
 680  * method will just wait until this changes.
 681  *
 682  * Any outstanding I/O request with higher priority (lower numerical
 683  * value) will be executed before an outstanding request with lower
 684  * priority. Default priority is %G_PRIORITY_DEFAULT.
 685  *
 686  * The asyncronous methods have a default fallback that uses threads
 687  * to implement asynchronicity, so they are optional for inheriting
 688  * classes. However, if you override one you must override all.
 689  *
 690  * For the synchronous, blocking version of this function, see
 691  * g_output_stream_write().
 692  **/
 693 void
 694 g_output_stream_write_async (GOutputStream       *stream,
 695                              const void          *buffer,
 696                              gsize                count,
 697                              int                  io_priority,
 698                              GCancellable        *cancellable,
 699                              GAsyncReadyCallback  callback,
 700                              gpointer             user_data)
 701 {
 702   GOutputStreamClass *class;
 703   GSimpleAsyncResult *simple;
 704   GError *error = NULL;
 705
 706   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 707   g_return_if_fail (buffer != NULL);
 708
 709   if (count == 0)
 710     {
 711       simple = g_simple_async_result_new (G_OBJECT (stream),
 712                                           callback,
 713                                           user_data,
 714                                           g_output_stream_write_async);
 715       g_simple_async_result_complete_in_idle (simple);
 716       g_object_unref (simple);
 717       return;
 718     }
 719
 720   if (((gssize) count) < 0)
 721     {
 722       g_simple_async_report_error_in_idle (G_OBJECT (stream),
 723                                            callback,
 724                                            user_data,
 725                                            G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
 726                                            _("Too large count value passed to %s"),
 727                                            G_STRFUNC);
 728       return;
 729     }
 730
 731   if (!g_output_stream_set_pending (stream, &error))
 732     {
 733       g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
 734                                             callback,
 735                                             user_data,
 736                                             error);
 737       g_error_free (error);
 738       return;
 739     }
 740
 741   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 742
 743   stream->priv->outstanding_callback = callback;
 744   g_object_ref (stream);
 745   class->write_async (stream, buffer, count, io_priority, cancellable,
 746                       async_ready_callback_wrapper, user_data);
 747 }
 748
 749 /**
 750  * g_output_stream_write_finish:
 751  * @stream: a #GOutputStream.
 752  * @result: a #GAsyncResult.
 753  * @error: a #GError location to store the error occuring, or %NULL to
 754  * ignore.
 755  *
 756  * Finishes a stream write operation.
 757  *
 758  * Returns: a #gssize containing the number of bytes written to the stream.
 759  **/
 760 gssize
 761 g_output_stream_write_finish (GOutputStream  *stream,
 762                               GAsyncResult   *result,
 763                               GError        **error)
 764 {
 765   GSimpleAsyncResult *simple;
 766   GOutputStreamClass *class;
 767
 768   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
 769   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), -1);
 770
 771   if (G_IS_SIMPLE_ASYNC_RESULT (result))
 772     {
 773       simple = G_SIMPLE_ASYNC_RESULT (result);
 774       if (g_simple_async_result_propagate_error (simple, error))
 775         return -1;
 776
 777       /* Special case writes of 0 bytes */
 778       if (g_simple_async_result_get_source_tag (simple) == g_output_stream_write_async)
 779         return 0;
 780     }
 781
 782   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 783   return class->write_finish (stream, result, error);
 784 }
 785
 786 typedef struct {
 787   GInputStream *source;
 788   gpointer user_data;
 789   GAsyncReadyCallback callback;
 790 } SpliceUserData;
 791
 792 static void
 793 async_ready_splice_callback_wrapper (GObject      *source_object,
 794                                      GAsyncResult *res,
 795                                      gpointer     _data)
 796 {
 797   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 798   SpliceUserData *data = _data;
 799
 800   g_output_stream_clear_pending (stream);
 801
 802   if (data->callback)
 803     (*data->callback) (source_object, res, data->user_data);
 804
 805   g_object_unref (stream);
 806   g_object_unref (data->source);
 807   g_free (data);
 808 }
 809
 810 /**
 811  * g_output_stream_splice_async:
 812  * @stream: a #GOutputStream.
 813  * @source: a #GInputStream.
 814  * @flags: a set of #GOutputStreamSpliceFlags.
 815  * @io_priority: the io priority of the request.
 816  * @cancellable: optional #GCancellable object, %NULL to ignore.
 817  * @callback: a #GAsyncReadyCallback.
 818  * @user_data: user data passed to @callback.
 819  *
 820  * Splices a stream asynchronously.
 821  * When the operation is finished @callback will be called.
 822  * You can then call g_output_stream_splice_finish() to get the
 823  * result of the operation.
 824  *
 825  * For the synchronous, blocking version of this function, see
 826  * g_output_stream_splice().
 827  **/
 828 void
 829 g_output_stream_splice_async (GOutputStream            *stream,
 830                               GInputStream             *source,
 831                               GOutputStreamSpliceFlags  flags,
 832                               int                       io_priority,
 833                               GCancellable             *cancellable,
 834                               GAsyncReadyCallback       callback,
 835                               gpointer                  user_data)
 836 {
 837   GOutputStreamClass *class;
 838   SpliceUserData *data;
 839   GError *error = NULL;
 840
 841   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 842   g_return_if_fail (G_IS_INPUT_STREAM (source));
 843
 844   if (g_input_stream_is_closed (source))
 845     {
 846       g_simple_async_report_error_in_idle (G_OBJECT (stream),
 847                                            callback,
 848                                            user_data,
 849                                            G_IO_ERROR, G_IO_ERROR_CLOSED,
 850                                            _("Source stream is already closed"));
 851       return;
 852     }
 853
 854   if (!g_output_stream_set_pending (stream, &error))
 855     {
 856       g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
 857                                             callback,
 858                                             user_data,
 859                                             error);
 860       g_error_free (error);
 861       return;
 862     }
 863
 864   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 865
 866   data = g_new0 (SpliceUserData, 1);
 867   data->callback = callback;
 868   data->user_data = user_data;
 869   data->source = g_object_ref (source);
 870
 871   g_object_ref (stream);
 872   class->splice_async (stream, source, flags, io_priority, cancellable,
 873                       async_ready_splice_callback_wrapper, data);
 874 }
 875
 876 /**
 877  * g_output_stream_splice_finish:
 878  * @stream: a #GOutputStream.
 879  * @result: a #GAsyncResult.
 880  * @error: a #GError location to store the error occuring, or %NULL to
 881  * ignore.
 882  *
 883  * Finishes an asynchronous stream splice operation.
 884  *
 885  * Returns: a #gssize of the number of bytes spliced.
 886  **/
 887 gssize
 888 g_output_stream_splice_finish (GOutputStream  *stream,
 889                                GAsyncResult   *result,
 890                                GError        **error)
 891 {
 892   GSimpleAsyncResult *simple;
 893   GOutputStreamClass *class;
 894
 895   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
 896   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), -1);
 897
 898   if (G_IS_SIMPLE_ASYNC_RESULT (result))
 899     {
 900       simple = G_SIMPLE_ASYNC_RESULT (result);
 901       if (g_simple_async_result_propagate_error (simple, error))
 902         return -1;
 903     }
 904
 905   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 906   return class->splice_finish (stream, result, error);
 907 }
 908
 909 /**
 910  * g_output_stream_flush_async:
 911  * @stream: a #GOutputStream.
 912  * @io_priority: the io priority of the request.
 913  * @cancellable: optional #GCancellable object, %NULL to ignore.
 914  * @callback: a #GAsyncReadyCallback to call when the request is satisfied
 915  * @user_data: the data to pass to callback function
 916  *
 917  * Flushes a stream asynchronously.
 918  * For behaviour details see g_output_stream_flush().
 919  *
 920  * When the operation is finished @callback will be
 921  * called. You can then call g_output_stream_flush_finish() to get the
 922  * result of the operation.
 923  **/
 924 void
 925 g_output_stream_flush_async (GOutputStream       *stream,
 926                              int                  io_priority,
 927                              GCancellable        *cancellable,
 928                              GAsyncReadyCallback  callback,
 929                              gpointer             user_data)
 930 {
 931   GOutputStreamClass *class;
 932   GSimpleAsyncResult *simple;
 933   GError *error = NULL;
 934
 935   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 936
 937   if (!g_output_stream_set_pending (stream, &error))
 938     {
 939       g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
 940                                             callback,
 941                                             user_data,
 942                                             error);
 943       g_error_free (error);
 944       return;
 945     }
 946
 947   stream->priv->outstanding_callback = callback;
 948   g_object_ref (stream);
 949
 950   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 951
 952   if (class->flush_async == NULL)
 953     {
 954       simple = g_simple_async_result_new (G_OBJECT (stream),
 955                                           async_ready_callback_wrapper,
 956                                           user_data,
 957                                           g_output_stream_flush_async);
 958       g_simple_async_result_complete_in_idle (simple);
 959       g_object_unref (simple);
 960       return;
 961     }
 962
 963   class->flush_async (stream, io_priority, cancellable,
 964                       async_ready_callback_wrapper, user_data);
 965 }
 966
 967 /**
 968  * g_output_stream_flush_finish:
 969  * @stream: a #GOutputStream.
 970  * @result: a GAsyncResult.
 971  * @error: a #GError location to store the error occuring, or %NULL to
 972  * ignore.
 973  *
 974  * Finishes flushing an output stream.
 975  *
 976  * Returns: %TRUE if flush operation suceeded, %FALSE otherwise.
 977  **/
 978 gboolean
 979 g_output_stream_flush_finish (GOutputStream  *stream,
 980                               GAsyncResult   *result,
 981                               GError        **error)
 982 {
 983   GSimpleAsyncResult *simple;
 984   GOutputStreamClass *klass;
 985
 986   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 987   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), FALSE);
 988
 989   if (G_IS_SIMPLE_ASYNC_RESULT (result))
 990     {
 991       simple = G_SIMPLE_ASYNC_RESULT (result);
 992       if (g_simple_async_result_propagate_error (simple, error))
 993         return FALSE;
 994
 995       /* Special case default implementation */
 996       if (g_simple_async_result_get_source_tag (simple) == g_output_stream_flush_async)
 997         return TRUE;
 998     }
 999
1000   klass = G_OUTPUT_STREAM_GET_CLASS (stream);
1001   return klass->flush_finish (stream, result, error);
1002 }
1003
1004
1005 /**
1006  * g_output_stream_close_async:
1007  * @stream: A #GOutputStream.
1008  * @io_priority: the io priority of the request.
1009  * @callback: callback to call when the request is satisfied
1010  * @user_data: the data to pass to callback function
1011  * @cancellable: optional cancellable object
1012  *
1013  * Requests an asynchronous close of the stream, releasing resources
1014  * related to it. When the operation is finished @callback will be
1015  * called. You can then call g_output_stream_close_finish() to get
1016  * the result of the operation.
1017  *
1018  * For behaviour details see g_output_stream_close().
1019  *
1020  * The asyncronous methods have a default fallback that uses threads
1021  * to implement asynchronicity, so they are optional for inheriting
1022  * classes. However, if you override one you must override all.
1023  **/
1024 void
1025 g_output_stream_close_async (GOutputStream       *stream,
1026                              int                  io_priority,
1027                              GCancellable        *cancellable,
1028                              GAsyncReadyCallback  callback,
1029                              gpointer             user_data)
1030 {
1031   GOutputStreamClass *class;
1032   GSimpleAsyncResult *simple;
1033   GError *error = NULL;
1034   CloseUserData *data;
1035
1036   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
1037
1038   if (stream->priv->closed)
1039     {
1040       simple = g_simple_async_result_new (G_OBJECT (stream),
1041                                           callback,
1042                                           user_data,
1043                                           g_output_stream_close_async);
1044       g_simple_async_result_complete_in_idle (simple);
1045       g_object_unref (simple);
1046       return;
1047     }
1048
1049   if (!g_output_stream_set_pending (stream, &error))
1050     {
1051       g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
1052                                             callback,
1053                                             user_data,
1054                                             error);
1055       g_error_free (error);
1056       return;
1057     }
1058
1059   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1060   stream->priv->closing = TRUE;
1061   stream->priv->outstanding_callback = callback;
1062   g_object_ref (stream);
1063
1064   data = g_slice_new0 (CloseUserData);
1065
1066   if (cancellable != NULL)
1067     data->cancellable = g_object_ref (cancellable);
1068
1069   data->io_priority = io_priority;
1070   data->user_data = user_data;
1071
1072   /* Call close_async directly if there is no need to flush, or if the flush
1073      can be done sync (in the output stream async close thread) */
1074   if (class->flush_async == NULL ||
1075       (class->flush_async == g_output_stream_real_flush_async &&
1076        (class->flush == NULL || class->close_async == g_output_stream_real_close_async)))
1077     {
1078       class->close_async (stream, io_priority, cancellable,
1079                           async_ready_close_callback_wrapper, data);
1080     }
1081   else
1082     {
1083       /* First do an async flush, then do the async close in the callback
1084          wrapper (see async_ready_close_flushed_callback_wrapper) */
1085       class->flush_async (stream, io_priority, cancellable,
1086                           async_ready_close_flushed_callback_wrapper, data);
1087     }
1088 }
1089
1090 /**
1091  * g_output_stream_close_finish:
1092  * @stream: a #GOutputStream.
1093  * @result: a #GAsyncResult.
1094  * @error: a #GError location to store the error occuring, or %NULL to
1095  * ignore.
1096  *
1097  * Closes an output stream.
1098  *
1099  * Returns: %TRUE if stream was successfully closed, %FALSE otherwise.
1100  **/
1101 gboolean
1102 g_output_stream_close_finish (GOutputStream  *stream,
1103                               GAsyncResult   *result,
1104                               GError        **error)
1105 {
1106   GSimpleAsyncResult *simple;
1107   GOutputStreamClass *class;
1108
1109   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1110   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), FALSE);
1111
1112   if (G_IS_SIMPLE_ASYNC_RESULT (result))
1113     {
1114       simple = G_SIMPLE_ASYNC_RESULT (result);
1115       if (g_simple_async_result_propagate_error (simple, error))
1116         return FALSE;
1117
1118       /* Special case already closed */
1119       if (g_simple_async_result_get_source_tag (simple) == g_output_stream_close_async)
1120         return TRUE;
1121     }
1122
1123   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1124   return class->close_finish (stream, result, error);
1125 }
1126
1127 /**
1128  * g_output_stream_is_closed:
1129  * @stream: a #GOutputStream.
1130  *
1131  * Checks if an output stream has already been closed.
1132  *
1133  * Returns: %TRUE if @stream is closed. %FALSE otherwise.
1134  **/
1135 gboolean
1136 g_output_stream_is_closed (GOutputStream *stream)
1137 {
1138   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), TRUE);
1139
1140   return stream->priv->closed;
1141 }
1142
1143 /**
1144  * g_output_stream_is_closing:
1145  * @stream: a #GOutputStream.
1146  *
1147  * Checks if an output stream is being closed. This can be
1148  * used inside e.g. a flush implementation to see if the
1149  * flush (or other i/o operation) is called from within
1150  * the closing operation.
1151  *
1152  * Returns: %TRUE if @stream is being closed. %FALSE otherwise.
1153  *
1154  * Since: 2.24
1155  **/
1156 gboolean
1157 g_output_stream_is_closing (GOutputStream *stream)
1158 {
1159   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), TRUE);
1160
1161   return stream->priv->closing;
1162 }
1163
1164 /**
1165  * g_output_stream_has_pending:
1166  * @stream: a #GOutputStream.
1167  *
1168  * Checks if an ouput stream has pending actions.
1169  *
1170  * Returns: %TRUE if @stream has pending actions.
1171  **/
1172 gboolean
1173 g_output_stream_has_pending (GOutputStream *stream)
1174 {
1175   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1176
1177   return stream->priv->pending;
1178 }
1179
1180 /**
1181  * g_output_stream_set_pending:
1182  * @stream: a #GOutputStream.
1183  * @error: a #GError location to store the error occuring, or %NULL to
1184  * ignore.
1185  *
1186  * Sets @stream to have actions pending. If the pending flag is
1187  * already set or @stream is closed, it will return %FALSE and set
1188  * @error.
1189  *
1190  * Return value: %TRUE if pending was previously unset and is now set.
1191  **/
1192 gboolean
1193 g_output_stream_set_pending (GOutputStream *stream,
1194                              GError **error)
1195 {
1196   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1197
1198   if (stream->priv->closed)
1199     {
1200       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
1201                            _("Stream is already closed"));
1202       return FALSE;
1203     }
1204
1205   if (stream->priv->pending)
1206     {
1207       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PENDING,
1208                            /* Translators: This is an error you get if there is
1209                             * already an operation running against this stream when
1210                             * you try to start one */
1211                            _("Stream has outstanding operation"));
1212       return FALSE;
1213     }
1214
1215   stream->priv->pending = TRUE;
1216   return TRUE;
1217 }
1218
1219 /**
1220  * g_output_stream_clear_pending:
1221  * @stream: output stream
1222  *
1223  * Clears the pending flag on @stream.
1224  **/
1225 void
1226 g_output_stream_clear_pending (GOutputStream *stream)
1227 {
1228   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
1229
1230   stream->priv->pending = FALSE;
1231 }
1232
1233
1234 /********************************************
1235  *   Default implementation of async ops    *
1236  ********************************************/
1237
1238 typedef struct {
1239   const void         *buffer;
1240   gsize               count_requested;
1241   gssize              count_written;
1242 } WriteData;
1243
1244 static void
1245 write_async_thread (GSimpleAsyncResult *res,
1246                     GObject            *object,
1247                     GCancellable       *cancellable)
1248 {
1249   WriteData *op;
1250   GOutputStreamClass *class;
1251   GError *error = NULL;
1252
1253   class = G_OUTPUT_STREAM_GET_CLASS (object);
1254   op = g_simple_async_result_get_op_res_gpointer (res);
1255   op->count_written = class->write_fn (G_OUTPUT_STREAM (object), op->buffer, op->count_requested,
1256                                        cancellable, &error);
1257   if (op->count_written == -1)
1258     g_simple_async_result_take_error (res, error);
1259 }
1260
1261 static void
1262 g_output_stream_real_write_async (GOutputStream       *stream,
1263                                   const void          *buffer,
1264                                   gsize                count,
1265                                   int                  io_priority,
1266                                   GCancellable        *cancellable,
1267                                   GAsyncReadyCallback  callback,
1268                                   gpointer             user_data)
1269 {
1270   GSimpleAsyncResult *res;
1271   WriteData *op;
1272
1273   op = g_new0 (WriteData, 1);
1274   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_write_async);
1275   g_simple_async_result_set_op_res_gpointer (res, op, g_free);
1276   op->buffer = buffer;
1277   op->count_requested = count;
1278
1279   g_simple_async_result_run_in_thread (res, write_async_thread, io_priority, cancellable);
1280   g_object_unref (res);
1281 }
1282
1283 static gssize
1284 g_output_stream_real_write_finish (GOutputStream  *stream,
1285                                    GAsyncResult   *result,
1286                                    GError        **error)
1287 {
1288   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
1289   WriteData *op;
1290
1291   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_output_stream_real_write_async);
1292   op = g_simple_async_result_get_op_res_gpointer (simple);
1293   return op->count_written;
1294 }
1295
1296 typedef struct {
1297   GInputStream *source;
1298   GOutputStreamSpliceFlags flags;
1299   gssize bytes_copied;
1300 } SpliceData;
1301
1302 static void
1303 splice_async_thread (GSimpleAsyncResult *result,
1304                      GObject            *object,
1305                      GCancellable       *cancellable)
1306 {
1307   SpliceData *op;
1308   GOutputStreamClass *class;
1309   GError *error = NULL;
1310   GOutputStream *stream;
1311
1312   stream = G_OUTPUT_STREAM (object);
1313   class = G_OUTPUT_STREAM_GET_CLASS (object);
1314   op = g_simple_async_result_get_op_res_gpointer (result);
1315
1316   op->bytes_copied = class->splice (stream,
1317                                     op->source,
1318                                     op->flags,
1319                                     cancellable,
1320                                     &error);
1321   if (op->bytes_copied == -1)
1322     g_simple_async_result_take_error (result, error);
1323 }
1324
1325 static void
1326 g_output_stream_real_splice_async (GOutputStream             *stream,
1327                                    GInputStream              *source,
1328                                    GOutputStreamSpliceFlags   flags,
1329                                    int                        io_priority,
1330                                    GCancellable              *cancellable,
1331                                    GAsyncReadyCallback        callback,
1332                                    gpointer                   user_data)
1333 {
1334   GSimpleAsyncResult *res;
1335   SpliceData *op;
1336
1337   op = g_new0 (SpliceData, 1);
1338   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_splice_async);
1339   g_simple_async_result_set_op_res_gpointer (res, op, g_free);
1340   op->flags = flags;
1341   op->source = source;
1342
1343   /* TODO: In the case where both source and destintion have
1344      non-threadbased async calls we can use a true async copy here */
1345
1346   g_simple_async_result_run_in_thread (res, splice_async_thread, io_priority, cancellable);
1347   g_object_unref (res);
1348 }
1349
1350 static gssize
1351 g_output_stream_real_splice_finish (GOutputStream  *stream,
1352                                     GAsyncResult   *result,
1353                                     GError        **error)
1354 {
1355   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
1356   SpliceData *op;
1357
1358   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_output_stream_real_splice_async);
1359   op = g_simple_async_result_get_op_res_gpointer (simple);
1360   return op->bytes_copied;
1361 }
1362
1363
1364 static void
1365 flush_async_thread (GSimpleAsyncResult *res,
1366                     GObject            *object,
1367                     GCancellable       *cancellable)
1368 {
1369   GOutputStreamClass *class;
1370   gboolean result;
1371   GError *error = NULL;
1372
1373   class = G_OUTPUT_STREAM_GET_CLASS (object);
1374   result = TRUE;
1375   if (class->flush)
1376     result = class->flush (G_OUTPUT_STREAM (object), cancellable, &error);
1377
1378   if (!result)
1379     g_simple_async_result_take_error (res, error);
1380 }
1381
1382 static void
1383 g_output_stream_real_flush_async (GOutputStream       *stream,
1384                                   int                  io_priority,
1385                                   GCancellable        *cancellable,
1386                                   GAsyncReadyCallback  callback,
1387                                   gpointer             user_data)
1388 {
1389   GSimpleAsyncResult *res;
1390
1391   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_write_async);
1392
1393   g_simple_async_result_run_in_thread (res, flush_async_thread, io_priority, cancellable);
1394   g_object_unref (res);
1395 }
1396
1397 static gboolean
1398 g_output_stream_real_flush_finish (GOutputStream  *stream,
1399                                    GAsyncResult   *result,
1400                                    GError        **error)
1401 {
1402   return TRUE;
1403 }
1404
1405 static void
1406 close_async_thread (GSimpleAsyncResult *res,
1407                     GObject            *object,
1408                     GCancellable       *cancellable)
1409 {
1410   GOutputStreamClass *class;
1411   GError *error = NULL;
1412   gboolean result = TRUE;
1413
1414   class = G_OUTPUT_STREAM_GET_CLASS (object);
1415
1416   /* Do a flush here if there is a flush function, and we did not have to do
1417      an async flush before (see g_output_stream_close_async) */
1418   if (class->flush != NULL &&
1419       (class->flush_async == NULL ||
1420        class->flush_async == g_output_stream_real_flush_async))
1421     {
1422       result = class->flush (G_OUTPUT_STREAM (object), cancellable, &error);
1423     }
1424
1425   /* Auto handling of cancelation disabled, and ignore
1426      cancellation, since we want to close things anyway, although
1427      possibly in a quick-n-dirty way. At least we never want to leak
1428      open handles */
1429
1430   if (class->close_fn)
1431     {
1432       /* Make sure to close, even if the flush failed (see sync close) */
1433       if (!result)
1434         class->close_fn (G_OUTPUT_STREAM (object), cancellable, NULL);
1435       else
1436         result = class->close_fn (G_OUTPUT_STREAM (object), cancellable, &error);
1437
1438       if (!result)
1439         g_simple_async_result_take_error (res, error);
1440     }
1441 }
1442
1443 static void
1444 g_output_stream_real_close_async (GOutputStream       *stream,
1445                                   int                  io_priority,
1446                                   GCancellable        *cancellable,
1447                                   GAsyncReadyCallback  callback,
1448                                   gpointer             user_data)
1449 {
1450   GSimpleAsyncResult *res;
1451
1452   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_close_async);
1453
1454   g_simple_async_result_set_handle_cancellation (res, FALSE);
1455
1456   g_simple_async_result_run_in_thread (res, close_async_thread, io_priority, cancellable);
1457   g_object_unref (res);
1458 }
1459
1460 static gboolean
1461 g_output_stream_real_close_finish (GOutputStream  *stream,
1462                                    GAsyncResult   *result,
1463                                    GError        **error)
1464 {
1465   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
1466   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_output_stream_real_close_async);
1467   return TRUE;
1468 }