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: (allow-none): optional cancellable object
 154  * @error: location to store the error occurring, 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: (out): location to store the number of bytes that was
 233  *     written to the stream
 234  * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
 235  * @error: location to store the error occurring, 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: (allow-none): optional cancellable object
 294  * @error: location to store the error occurring, 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: (allow-none): optional #GCancellable object, %NULL to ignore.
 345  * @error: a #GError location to store the error occurring, 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. Note that if the number of bytes
 352  *     spliced is greater than %G_MAXSSIZE, then that will be
 353  *     returned, and there is no way to determine the actual number
 354  *     of bytes spliced.
 355  **/
 356 gssize
 357 g_output_stream_splice (GOutputStream             *stream,
 358                         GInputStream              *source,
 359                         GOutputStreamSpliceFlags   flags,
 360                         GCancellable              *cancellable,
 361                         GError                   **error)
 362 {
 363   GOutputStreamClass *class;
 364   gssize bytes_copied;
 365
 366   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
 367   g_return_val_if_fail (G_IS_INPUT_STREAM (source), -1);
 368
 369   if (g_input_stream_is_closed (source))
 370     {
 371       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
 372                            _("Source stream is already closed"));
 373       return -1;
 374     }
 375
 376   if (!g_output_stream_set_pending (stream, error))
 377     return -1;
 378
 379   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 380
 381   if (cancellable)
 382     g_cancellable_push_current (cancellable);
 383
 384   bytes_copied = class->splice (stream, source, flags, cancellable, error);
 385
 386   if (cancellable)
 387     g_cancellable_pop_current (cancellable);
 388
 389   g_output_stream_clear_pending (stream);
 390
 391   return bytes_copied;
 392 }
 393
 394 static gssize
 395 g_output_stream_real_splice (GOutputStream             *stream,
 396                              GInputStream              *source,
 397                              GOutputStreamSpliceFlags   flags,
 398                              GCancellable              *cancellable,
 399                              GError                   **error)
 400 {
 401   GOutputStreamClass *class = G_OUTPUT_STREAM_GET_CLASS (stream);
 402   gssize n_read, n_written;
 403   gsize bytes_copied;
 404   char buffer[8192], *p;
 405   gboolean res;
 406
 407   bytes_copied = 0;
 408   if (class->write_fn == NULL)
 409     {
 410       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
 411                            _("Output stream doesn't implement write"));
 412       res = FALSE;
 413       goto notsupported;
 414     }
 415
 416   res = TRUE;
 417   do
 418     {
 419       n_read = g_input_stream_read (source, buffer, sizeof (buffer), cancellable, error);
 420       if (n_read == -1)
 421         {
 422           res = FALSE;
 423           break;
 424         }
 425
 426       if (n_read == 0)
 427         break;
 428
 429       p = buffer;
 430       while (n_read > 0)
 431         {
 432           n_written = class->write_fn (stream, p, n_read, cancellable, error);
 433           if (n_written == -1)
 434             {
 435               res = FALSE;
 436               break;
 437             }
 438
 439           p += n_written;
 440           n_read -= n_written;
 441           bytes_copied += n_written;
 442         }
 443
 444       if (bytes_copied > G_MAXSSIZE)
 445         bytes_copied = G_MAXSSIZE;
 446     }
 447   while (res);
 448
 449  notsupported:
 450   if (!res)
 451     error = NULL; /* Ignore further errors */
 452
 453   if (flags & G_OUTPUT_STREAM_SPLICE_CLOSE_SOURCE)
 454     {
 455       /* Don't care about errors in source here */
 456       g_input_stream_close (source, cancellable, NULL);
 457     }
 458
 459   if (flags & G_OUTPUT_STREAM_SPLICE_CLOSE_TARGET)
 460     {
 461       /* But write errors on close are bad! */
 462       if (class->close_fn &&
 463           !class->close_fn (stream, cancellable, error))
 464         res = FALSE;
 465     }
 466
 467   if (res)
 468     return bytes_copied;
 469
 470   return -1;
 471 }
 472
 473
 474 /**
 475  * g_output_stream_close:
 476  * @stream: A #GOutputStream.
 477  * @cancellable: (allow-none): optional cancellable object
 478  * @error: location to store the error occurring, or %NULL to ignore
 479  *
 480  * Closes the stream, releasing resources related to it.
 481  *
 482  * Once the stream is closed, all other operations will return %G_IO_ERROR_CLOSED.
 483  * Closing a stream multiple times will not return an error.
 484  *
 485  * Closing a stream will automatically flush any outstanding buffers in the
 486  * stream.
 487  *
 488  * Streams will be automatically closed when the last reference
 489  * is dropped, but you might want to call this function to make sure
 490  * resources are released as early as possible.
 491  *
 492  * Some streams might keep the backing store of the stream (e.g. a file descriptor)
 493  * open after the stream is closed. See the documentation for the individual
 494  * stream for details.
 495  *
 496  * On failure the first error that happened will be reported, but the close
 497  * operation will finish as much as possible. A stream that failed to
 498  * close will still return %G_IO_ERROR_CLOSED for all operations. Still, it
 499  * is important to check and report the error to the user, otherwise
 500  * there might be a loss of data as all data might not be written.
 501  *
 502  * If @cancellable is not NULL, then the operation can be cancelled by
 503  * triggering the cancellable object from another thread. If the operation
 504  * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned.
 505  * Cancelling a close will still leave the stream closed, but there some streams
 506  * can use a faster close that doesn't block to e.g. check errors. On
 507  * cancellation (as with any error) there is no guarantee that all written
 508  * data will reach the target.
 509  *
 510  * Return value: %TRUE on success, %FALSE on failure
 511  **/
 512 gboolean
 513 g_output_stream_close (GOutputStream  *stream,
 514                        GCancellable   *cancellable,
 515                        GError        **error)
 516 {
 517   GOutputStreamClass *class;
 518   gboolean res;
 519
 520   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 521
 522   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 523
 524   if (stream->priv->closed)
 525     return TRUE;
 526
 527   if (!g_output_stream_set_pending (stream, error))
 528     return FALSE;
 529
 530   stream->priv->closing = TRUE;
 531
 532   if (cancellable)
 533     g_cancellable_push_current (cancellable);
 534
 535   if (class->flush)
 536     res = class->flush (stream, cancellable, error);
 537   else
 538     res = TRUE;
 539
 540   if (!res)
 541     {
 542       /* flushing caused the error that we want to return,
 543        * but we still want to close the underlying stream if possible
 544        */
 545       if (class->close_fn)
 546         class->close_fn (stream, cancellable, NULL);
 547     }
 548   else
 549     {
 550       res = TRUE;
 551       if (class->close_fn)
 552         res = class->close_fn (stream, cancellable, error);
 553     }
 554
 555   if (cancellable)
 556     g_cancellable_pop_current (cancellable);
 557
 558   stream->priv->closing = FALSE;
 559   stream->priv->closed = TRUE;
 560   g_output_stream_clear_pending (stream);
 561
 562   return res;
 563 }
 564
 565 static void
 566 async_ready_callback_wrapper (GObject      *source_object,
 567                               GAsyncResult *res,
 568                               gpointer      user_data)
 569 {
 570   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 571
 572   g_output_stream_clear_pending (stream);
 573   if (stream->priv->outstanding_callback)
 574     (*stream->priv->outstanding_callback) (source_object, res, user_data);
 575   g_object_unref (stream);
 576 }
 577
 578 typedef struct {
 579   gint io_priority;
 580   GCancellable *cancellable;
 581   GError *flush_error;
 582   gpointer user_data;
 583 } CloseUserData;
 584
 585 static void
 586 async_ready_close_callback_wrapper (GObject      *source_object,
 587                                     GAsyncResult *res,
 588                                     gpointer      user_data)
 589 {
 590   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 591   CloseUserData *data = user_data;
 592
 593   stream->priv->closing = FALSE;
 594   stream->priv->closed = TRUE;
 595
 596   g_output_stream_clear_pending (stream);
 597
 598   if (stream->priv->outstanding_callback)
 599     {
 600       if (data->flush_error != NULL)
 601         {
 602           GSimpleAsyncResult *err;
 603
 604           err = g_simple_async_result_new_take_error (source_object,
 605                                                       stream->priv->outstanding_callback,
 606                                                       data->user_data,
 607                                                       data->flush_error);
 608           data->flush_error = NULL;
 609
 610           (*stream->priv->outstanding_callback) (source_object,
 611                                                  G_ASYNC_RESULT (err),
 612                                                  data->user_data);
 613           g_object_unref (err);
 614         }
 615       else
 616         {
 617           (*stream->priv->outstanding_callback) (source_object,
 618                                                  res,
 619                                                  data->user_data);
 620         }
 621     }
 622
 623   g_object_unref (stream);
 624
 625   if (data->cancellable)
 626     g_object_unref (data->cancellable);
 627
 628   if (data->flush_error)
 629     g_error_free (data->flush_error);
 630
 631   g_slice_free (CloseUserData, data);
 632 }
 633
 634 static void
 635 async_ready_close_flushed_callback_wrapper (GObject      *source_object,
 636                                             GAsyncResult *res,
 637                                             gpointer      user_data)
 638 {
 639   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 640   GOutputStreamClass *class;
 641   CloseUserData *data = user_data;
 642   GSimpleAsyncResult *simple;
 643
 644   /* propagate the possible error */
 645   if (G_IS_SIMPLE_ASYNC_RESULT (res))
 646     {
 647       simple = G_SIMPLE_ASYNC_RESULT (res);
 648       g_simple_async_result_propagate_error (simple, &data->flush_error);
 649     }
 650
 651   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 652
 653   /* we still close, even if there was a flush error */
 654   class->close_async (stream, data->io_priority, data->cancellable,
 655                       async_ready_close_callback_wrapper, user_data);
 656 }
 657
 658 /**
 659  * g_output_stream_write_async:
 660  * @stream: A #GOutputStream.
 661  * @buffer: (array length=count) (element-type guint8): the buffer containing the data to write.
 662  * @count: the number of bytes to write
 663  * @io_priority: the io priority of the request.
 664  * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
 665  * @callback: (scope async): callback to call when the request is satisfied
 666  * @user_data: (closure): the data to pass to callback function
 667  *
 668  * Request an asynchronous write of @count bytes from @buffer into
 669  * the stream. When the operation is finished @callback will be called.
 670  * You can then call g_output_stream_write_finish() to get the result of the
 671  * operation.
 672  *
 673  * During an async request no other sync and async calls are allowed,
 674  * and will result in %G_IO_ERROR_PENDING errors.
 675  *
 676  * A value of @count larger than %G_MAXSSIZE will cause a
 677  * %G_IO_ERROR_INVALID_ARGUMENT error.
 678  *
 679  * On success, the number of bytes written will be passed to the
 680  * @callback. It is not an error if this is not the same as the
 681  * requested size, as it can happen e.g. on a partial I/O error,
 682  * but generally we try to write as many bytes as requested.
 683  *
 684  * You are guaranteed that this method will never fail with
 685  * %G_IO_ERROR_WOULD_BLOCK - if @stream can't accept more data, the
 686  * method will just wait until this changes.
 687  *
 688  * Any outstanding I/O request with higher priority (lower numerical
 689  * value) will be executed before an outstanding request with lower
 690  * priority. Default priority is %G_PRIORITY_DEFAULT.
 691  *
 692  * The asyncronous methods have a default fallback that uses threads
 693  * to implement asynchronicity, so they are optional for inheriting
 694  * classes. However, if you override one you must override all.
 695  *
 696  * For the synchronous, blocking version of this function, see
 697  * g_output_stream_write().
 698  **/
 699 void
 700 g_output_stream_write_async (GOutputStream       *stream,
 701                              const void          *buffer,
 702                              gsize                count,
 703                              int                  io_priority,
 704                              GCancellable        *cancellable,
 705                              GAsyncReadyCallback  callback,
 706                              gpointer             user_data)
 707 {
 708   GOutputStreamClass *class;
 709   GSimpleAsyncResult *simple;
 710   GError *error = NULL;
 711
 712   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 713   g_return_if_fail (buffer != NULL);
 714
 715   if (count == 0)
 716     {
 717       simple = g_simple_async_result_new (G_OBJECT (stream),
 718                                           callback,
 719                                           user_data,
 720                                           g_output_stream_write_async);
 721       g_simple_async_result_complete_in_idle (simple);
 722       g_object_unref (simple);
 723       return;
 724     }
 725
 726   if (((gssize) count) < 0)
 727     {
 728       g_simple_async_report_error_in_idle (G_OBJECT (stream),
 729                                            callback,
 730                                            user_data,
 731                                            G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
 732                                            _("Too large count value passed to %s"),
 733                                            G_STRFUNC);
 734       return;
 735     }
 736
 737   if (!g_output_stream_set_pending (stream, &error))
 738     {
 739       g_simple_async_report_take_gerror_in_idle (G_OBJECT (stream),
 740                                             callback,
 741                                             user_data,
 742                                             error);
 743       return;
 744     }
 745
 746   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 747
 748   stream->priv->outstanding_callback = callback;
 749   g_object_ref (stream);
 750   class->write_async (stream, buffer, count, io_priority, cancellable,
 751                       async_ready_callback_wrapper, user_data);
 752 }
 753
 754 /**
 755  * g_output_stream_write_finish:
 756  * @stream: a #GOutputStream.
 757  * @result: a #GAsyncResult.
 758  * @error: a #GError location to store the error occurring, or %NULL to
 759  * ignore.
 760  *
 761  * Finishes a stream write operation.
 762  *
 763  * Returns: a #gssize containing the number of bytes written to the stream.
 764  **/
 765 gssize
 766 g_output_stream_write_finish (GOutputStream  *stream,
 767                               GAsyncResult   *result,
 768                               GError        **error)
 769 {
 770   GSimpleAsyncResult *simple;
 771   GOutputStreamClass *class;
 772
 773   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
 774   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), -1);
 775
 776   if (G_IS_SIMPLE_ASYNC_RESULT (result))
 777     {
 778       simple = G_SIMPLE_ASYNC_RESULT (result);
 779       if (g_simple_async_result_propagate_error (simple, error))
 780         return -1;
 781
 782       /* Special case writes of 0 bytes */
 783       if (g_simple_async_result_get_source_tag (simple) == g_output_stream_write_async)
 784         return 0;
 785     }
 786
 787   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 788   return class->write_finish (stream, result, error);
 789 }
 790
 791 typedef struct {
 792   GInputStream *source;
 793   gpointer user_data;
 794   GAsyncReadyCallback callback;
 795 } SpliceUserData;
 796
 797 static void
 798 async_ready_splice_callback_wrapper (GObject      *source_object,
 799                                      GAsyncResult *res,
 800                                      gpointer     _data)
 801 {
 802   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 803   SpliceUserData *data = _data;
 804
 805   g_output_stream_clear_pending (stream);
 806
 807   if (data->callback)
 808     (*data->callback) (source_object, res, data->user_data);
 809
 810   g_object_unref (stream);
 811   g_object_unref (data->source);
 812   g_free (data);
 813 }
 814
 815 /**
 816  * g_output_stream_splice_async:
 817  * @stream: a #GOutputStream.
 818  * @source: a #GInputStream.
 819  * @flags: a set of #GOutputStreamSpliceFlags.
 820  * @io_priority: the io priority of the request.
 821  * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
 822  * @callback: (scope async): a #GAsyncReadyCallback.
 823  * @user_data: (closure): user data passed to @callback.
 824  *
 825  * Splices a stream asynchronously.
 826  * When the operation is finished @callback will be called.
 827  * You can then call g_output_stream_splice_finish() to get the
 828  * result of the operation.
 829  *
 830  * For the synchronous, blocking version of this function, see
 831  * g_output_stream_splice().
 832  **/
 833 void
 834 g_output_stream_splice_async (GOutputStream            *stream,
 835                               GInputStream             *source,
 836                               GOutputStreamSpliceFlags  flags,
 837                               int                       io_priority,
 838                               GCancellable             *cancellable,
 839                               GAsyncReadyCallback       callback,
 840                               gpointer                  user_data)
 841 {
 842   GOutputStreamClass *class;
 843   SpliceUserData *data;
 844   GError *error = NULL;
 845
 846   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 847   g_return_if_fail (G_IS_INPUT_STREAM (source));
 848
 849   if (g_input_stream_is_closed (source))
 850     {
 851       g_simple_async_report_error_in_idle (G_OBJECT (stream),
 852                                            callback,
 853                                            user_data,
 854                                            G_IO_ERROR, G_IO_ERROR_CLOSED,
 855                                            _("Source stream is already closed"));
 856       return;
 857     }
 858
 859   if (!g_output_stream_set_pending (stream, &error))
 860     {
 861       g_simple_async_report_take_gerror_in_idle (G_OBJECT (stream),
 862                                             callback,
 863                                             user_data,
 864                                             error);
 865       return;
 866     }
 867
 868   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 869
 870   data = g_new0 (SpliceUserData, 1);
 871   data->callback = callback;
 872   data->user_data = user_data;
 873   data->source = g_object_ref (source);
 874
 875   g_object_ref (stream);
 876   class->splice_async (stream, source, flags, io_priority, cancellable,
 877                       async_ready_splice_callback_wrapper, data);
 878 }
 879
 880 /**
 881  * g_output_stream_splice_finish:
 882  * @stream: a #GOutputStream.
 883  * @result: a #GAsyncResult.
 884  * @error: a #GError location to store the error occurring, or %NULL to
 885  * ignore.
 886  *
 887  * Finishes an asynchronous stream splice operation.
 888  *
 889  * Returns: a #gssize of the number of bytes spliced. Note that if the
 890  *     number of bytes spliced is greater than %G_MAXSSIZE, then that
 891  *     will be returned, and there is no way to determine the actual
 892  *     number of bytes spliced.
 893  **/
 894 gssize
 895 g_output_stream_splice_finish (GOutputStream  *stream,
 896                                GAsyncResult   *result,
 897                                GError        **error)
 898 {
 899   GSimpleAsyncResult *simple;
 900   GOutputStreamClass *class;
 901
 902   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
 903   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), -1);
 904
 905   if (G_IS_SIMPLE_ASYNC_RESULT (result))
 906     {
 907       simple = G_SIMPLE_ASYNC_RESULT (result);
 908       if (g_simple_async_result_propagate_error (simple, error))
 909         return -1;
 910     }
 911
 912   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 913   return class->splice_finish (stream, result, error);
 914 }
 915
 916 /**
 917  * g_output_stream_flush_async:
 918  * @stream: a #GOutputStream.
 919  * @io_priority: the io priority of the request.
 920  * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
 921  * @callback: (scope async): a #GAsyncReadyCallback to call when the request is satisfied
 922  * @user_data: (closure): the data to pass to callback function
 923  *
 924  * Flushes a stream asynchronously.
 925  * For behaviour details see g_output_stream_flush().
 926  *
 927  * When the operation is finished @callback will be
 928  * called. You can then call g_output_stream_flush_finish() to get the
 929  * result of the operation.
 930  **/
 931 void
 932 g_output_stream_flush_async (GOutputStream       *stream,
 933                              int                  io_priority,
 934                              GCancellable        *cancellable,
 935                              GAsyncReadyCallback  callback,
 936                              gpointer             user_data)
 937 {
 938   GOutputStreamClass *class;
 939   GSimpleAsyncResult *simple;
 940   GError *error = NULL;
 941
 942   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 943
 944   if (!g_output_stream_set_pending (stream, &error))
 945     {
 946       g_simple_async_report_take_gerror_in_idle (G_OBJECT (stream),
 947                                             callback,
 948                                             user_data,
 949                                             error);
 950       return;
 951     }
 952
 953   stream->priv->outstanding_callback = callback;
 954   g_object_ref (stream);
 955
 956   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 957
 958   if (class->flush_async == NULL)
 959     {
 960       simple = g_simple_async_result_new (G_OBJECT (stream),
 961                                           async_ready_callback_wrapper,
 962                                           user_data,
 963                                           g_output_stream_flush_async);
 964       g_simple_async_result_complete_in_idle (simple);
 965       g_object_unref (simple);
 966       return;
 967     }
 968
 969   class->flush_async (stream, io_priority, cancellable,
 970                       async_ready_callback_wrapper, user_data);
 971 }
 972
 973 /**
 974  * g_output_stream_flush_finish:
 975  * @stream: a #GOutputStream.
 976  * @result: a GAsyncResult.
 977  * @error: a #GError location to store the error occurring, or %NULL to
 978  * ignore.
 979  *
 980  * Finishes flushing an output stream.
 981  *
 982  * Returns: %TRUE if flush operation succeeded, %FALSE otherwise.
 983  **/
 984 gboolean
 985 g_output_stream_flush_finish (GOutputStream  *stream,
 986                               GAsyncResult   *result,
 987                               GError        **error)
 988 {
 989   GSimpleAsyncResult *simple;
 990   GOutputStreamClass *klass;
 991
 992   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 993   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), FALSE);
 994
 995   if (G_IS_SIMPLE_ASYNC_RESULT (result))
 996     {
 997       simple = G_SIMPLE_ASYNC_RESULT (result);
 998       if (g_simple_async_result_propagate_error (simple, error))
 999         return FALSE;
1000
1001       /* Special case default implementation */
1002       if (g_simple_async_result_get_source_tag (simple) == g_output_stream_flush_async)
1003         return TRUE;
1004     }
1005
1006   klass = G_OUTPUT_STREAM_GET_CLASS (stream);
1007   return klass->flush_finish (stream, result, error);
1008 }
1009
1010
1011 /**
1012  * g_output_stream_close_async:
1013  * @stream: A #GOutputStream.
1014  * @io_priority: the io priority of the request.
1015  * @cancellable: (allow-none): optional cancellable object
1016  * @callback: (scope async): callback to call when the request is satisfied
1017  * @user_data: (closure): the data to pass to callback function
1018  *
1019  * Requests an asynchronous close of the stream, releasing resources
1020  * related to it. When the operation is finished @callback will be
1021  * called. You can then call g_output_stream_close_finish() to get
1022  * the result of the operation.
1023  *
1024  * For behaviour details see g_output_stream_close().
1025  *
1026  * The asyncronous methods have a default fallback that uses threads
1027  * to implement asynchronicity, so they are optional for inheriting
1028  * classes. However, if you override one you must override all.
1029  **/
1030 void
1031 g_output_stream_close_async (GOutputStream       *stream,
1032                              int                  io_priority,
1033                              GCancellable        *cancellable,
1034                              GAsyncReadyCallback  callback,
1035                              gpointer             user_data)
1036 {
1037   GOutputStreamClass *class;
1038   GSimpleAsyncResult *simple;
1039   GError *error = NULL;
1040   CloseUserData *data;
1041
1042   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
1043
1044   if (stream->priv->closed)
1045     {
1046       simple = g_simple_async_result_new (G_OBJECT (stream),
1047                                           callback,
1048                                           user_data,
1049                                           g_output_stream_close_async);
1050       g_simple_async_result_complete_in_idle (simple);
1051       g_object_unref (simple);
1052       return;
1053     }
1054
1055   if (!g_output_stream_set_pending (stream, &error))
1056     {
1057       g_simple_async_report_take_gerror_in_idle (G_OBJECT (stream),
1058                                             callback,
1059                                             user_data,
1060                                             error);
1061       return;
1062     }
1063
1064   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1065   stream->priv->closing = TRUE;
1066   stream->priv->outstanding_callback = callback;
1067   g_object_ref (stream);
1068
1069   data = g_slice_new0 (CloseUserData);
1070
1071   if (cancellable != NULL)
1072     data->cancellable = g_object_ref (cancellable);
1073
1074   data->io_priority = io_priority;
1075   data->user_data = user_data;
1076
1077   /* Call close_async directly if there is no need to flush, or if the flush
1078      can be done sync (in the output stream async close thread) */
1079   if (class->flush_async == NULL ||
1080       (class->flush_async == g_output_stream_real_flush_async &&
1081        (class->flush == NULL || class->close_async == g_output_stream_real_close_async)))
1082     {
1083       class->close_async (stream, io_priority, cancellable,
1084                           async_ready_close_callback_wrapper, data);
1085     }
1086   else
1087     {
1088       /* First do an async flush, then do the async close in the callback
1089          wrapper (see async_ready_close_flushed_callback_wrapper) */
1090       class->flush_async (stream, io_priority, cancellable,
1091                           async_ready_close_flushed_callback_wrapper, data);
1092     }
1093 }
1094
1095 /**
1096  * g_output_stream_close_finish:
1097  * @stream: a #GOutputStream.
1098  * @result: a #GAsyncResult.
1099  * @error: a #GError location to store the error occurring, or %NULL to
1100  * ignore.
1101  *
1102  * Closes an output stream.
1103  *
1104  * Returns: %TRUE if stream was successfully closed, %FALSE otherwise.
1105  **/
1106 gboolean
1107 g_output_stream_close_finish (GOutputStream  *stream,
1108                               GAsyncResult   *result,
1109                               GError        **error)
1110 {
1111   GSimpleAsyncResult *simple;
1112   GOutputStreamClass *class;
1113
1114   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1115   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), FALSE);
1116
1117   if (G_IS_SIMPLE_ASYNC_RESULT (result))
1118     {
1119       simple = G_SIMPLE_ASYNC_RESULT (result);
1120       if (g_simple_async_result_propagate_error (simple, error))
1121         return FALSE;
1122
1123       /* Special case already closed */
1124       if (g_simple_async_result_get_source_tag (simple) == g_output_stream_close_async)
1125         return TRUE;
1126     }
1127
1128   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1129   return class->close_finish (stream, result, error);
1130 }
1131
1132 /**
1133  * g_output_stream_is_closed:
1134  * @stream: a #GOutputStream.
1135  *
1136  * Checks if an output stream has already been closed.
1137  *
1138  * Returns: %TRUE if @stream is closed. %FALSE otherwise.
1139  **/
1140 gboolean
1141 g_output_stream_is_closed (GOutputStream *stream)
1142 {
1143   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), TRUE);
1144
1145   return stream->priv->closed;
1146 }
1147
1148 /**
1149  * g_output_stream_is_closing:
1150  * @stream: a #GOutputStream.
1151  *
1152  * Checks if an output stream is being closed. This can be
1153  * used inside e.g. a flush implementation to see if the
1154  * flush (or other i/o operation) is called from within
1155  * the closing operation.
1156  *
1157  * Returns: %TRUE if @stream is being closed. %FALSE otherwise.
1158  *
1159  * Since: 2.24
1160  **/
1161 gboolean
1162 g_output_stream_is_closing (GOutputStream *stream)
1163 {
1164   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), TRUE);
1165
1166   return stream->priv->closing;
1167 }
1168
1169 /**
1170  * g_output_stream_has_pending:
1171  * @stream: a #GOutputStream.
1172  *
1173  * Checks if an ouput stream has pending actions.
1174  *
1175  * Returns: %TRUE if @stream has pending actions.
1176  **/
1177 gboolean
1178 g_output_stream_has_pending (GOutputStream *stream)
1179 {
1180   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1181
1182   return stream->priv->pending;
1183 }
1184
1185 /**
1186  * g_output_stream_set_pending:
1187  * @stream: a #GOutputStream.
1188  * @error: a #GError location to store the error occurring, or %NULL to
1189  * ignore.
1190  *
1191  * Sets @stream to have actions pending. If the pending flag is
1192  * already set or @stream is closed, it will return %FALSE and set
1193  * @error.
1194  *
1195  * Return value: %TRUE if pending was previously unset and is now set.
1196  **/
1197 gboolean
1198 g_output_stream_set_pending (GOutputStream *stream,
1199                              GError **error)
1200 {
1201   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1202
1203   if (stream->priv->closed)
1204     {
1205       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
1206                            _("Stream is already closed"));
1207       return FALSE;
1208     }
1209
1210   if (stream->priv->pending)
1211     {
1212       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PENDING,
1213                            /* Translators: This is an error you get if there is
1214                             * already an operation running against this stream when
1215                             * you try to start one */
1216                            _("Stream has outstanding operation"));
1217       return FALSE;
1218     }
1219
1220   stream->priv->pending = TRUE;
1221   return TRUE;
1222 }
1223
1224 /**
1225  * g_output_stream_clear_pending:
1226  * @stream: output stream
1227  *
1228  * Clears the pending flag on @stream.
1229  **/
1230 void
1231 g_output_stream_clear_pending (GOutputStream *stream)
1232 {
1233   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
1234
1235   stream->priv->pending = FALSE;
1236 }
1237
1238
1239 /********************************************
1240  *   Default implementation of async ops    *
1241  ********************************************/
1242
1243 typedef struct {
1244   const void         *buffer;
1245   gsize               count_requested;
1246   gssize              count_written;
1247 } WriteData;
1248
1249 static void
1250 write_async_thread (GSimpleAsyncResult *res,
1251                     GObject            *object,
1252                     GCancellable       *cancellable)
1253 {
1254   WriteData *op;
1255   GOutputStreamClass *class;
1256   GError *error = NULL;
1257
1258   class = G_OUTPUT_STREAM_GET_CLASS (object);
1259   op = g_simple_async_result_get_op_res_gpointer (res);
1260   op->count_written = class->write_fn (G_OUTPUT_STREAM (object), op->buffer, op->count_requested,
1261                                        cancellable, &error);
1262   if (op->count_written == -1)
1263     g_simple_async_result_take_error (res, error);
1264 }
1265
1266 static void
1267 g_output_stream_real_write_async (GOutputStream       *stream,
1268                                   const void          *buffer,
1269                                   gsize                count,
1270                                   int                  io_priority,
1271                                   GCancellable        *cancellable,
1272                                   GAsyncReadyCallback  callback,
1273                                   gpointer             user_data)
1274 {
1275   GSimpleAsyncResult *res;
1276   WriteData *op;
1277
1278   op = g_new0 (WriteData, 1);
1279   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_write_async);
1280   g_simple_async_result_set_op_res_gpointer (res, op, g_free);
1281   op->buffer = buffer;
1282   op->count_requested = count;
1283
1284   g_simple_async_result_run_in_thread (res, write_async_thread, io_priority, cancellable);
1285   g_object_unref (res);
1286 }
1287
1288 static gssize
1289 g_output_stream_real_write_finish (GOutputStream  *stream,
1290                                    GAsyncResult   *result,
1291                                    GError        **error)
1292 {
1293   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
1294   WriteData *op;
1295
1296   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_output_stream_real_write_async);
1297   op = g_simple_async_result_get_op_res_gpointer (simple);
1298   return op->count_written;
1299 }
1300
1301 typedef struct {
1302   GInputStream *source;
1303   GOutputStreamSpliceFlags flags;
1304   gssize bytes_copied;
1305 } SpliceData;
1306
1307 static void
1308 splice_async_thread (GSimpleAsyncResult *result,
1309                      GObject            *object,
1310                      GCancellable       *cancellable)
1311 {
1312   SpliceData *op;
1313   GOutputStreamClass *class;
1314   GError *error = NULL;
1315   GOutputStream *stream;
1316
1317   stream = G_OUTPUT_STREAM (object);
1318   class = G_OUTPUT_STREAM_GET_CLASS (object);
1319   op = g_simple_async_result_get_op_res_gpointer (result);
1320
1321   op->bytes_copied = class->splice (stream,
1322                                     op->source,
1323                                     op->flags,
1324                                     cancellable,
1325                                     &error);
1326   if (op->bytes_copied == -1)
1327     g_simple_async_result_take_error (result, error);
1328 }
1329
1330 static void
1331 g_output_stream_real_splice_async (GOutputStream             *stream,
1332                                    GInputStream              *source,
1333                                    GOutputStreamSpliceFlags   flags,
1334                                    int                        io_priority,
1335                                    GCancellable              *cancellable,
1336                                    GAsyncReadyCallback        callback,
1337                                    gpointer                   user_data)
1338 {
1339   GSimpleAsyncResult *res;
1340   SpliceData *op;
1341
1342   op = g_new0 (SpliceData, 1);
1343   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_splice_async);
1344   g_simple_async_result_set_op_res_gpointer (res, op, g_free);
1345   op->flags = flags;
1346   op->source = source;
1347
1348   /* TODO: In the case where both source and destintion have
1349      non-threadbased async calls we can use a true async copy here */
1350
1351   g_simple_async_result_run_in_thread (res, splice_async_thread, io_priority, cancellable);
1352   g_object_unref (res);
1353 }
1354
1355 static gssize
1356 g_output_stream_real_splice_finish (GOutputStream  *stream,
1357                                     GAsyncResult   *result,
1358                                     GError        **error)
1359 {
1360   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
1361   SpliceData *op;
1362
1363   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_output_stream_real_splice_async);
1364   op = g_simple_async_result_get_op_res_gpointer (simple);
1365   return op->bytes_copied;
1366 }
1367
1368
1369 static void
1370 flush_async_thread (GSimpleAsyncResult *res,
1371                     GObject            *object,
1372                     GCancellable       *cancellable)
1373 {
1374   GOutputStreamClass *class;
1375   gboolean result;
1376   GError *error = NULL;
1377
1378   class = G_OUTPUT_STREAM_GET_CLASS (object);
1379   result = TRUE;
1380   if (class->flush)
1381     result = class->flush (G_OUTPUT_STREAM (object), cancellable, &error);
1382
1383   if (!result)
1384     g_simple_async_result_take_error (res, error);
1385 }
1386
1387 static void
1388 g_output_stream_real_flush_async (GOutputStream       *stream,
1389                                   int                  io_priority,
1390                                   GCancellable        *cancellable,
1391                                   GAsyncReadyCallback  callback,
1392                                   gpointer             user_data)
1393 {
1394   GSimpleAsyncResult *res;
1395
1396   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_write_async);
1397
1398   g_simple_async_result_run_in_thread (res, flush_async_thread, io_priority, cancellable);
1399   g_object_unref (res);
1400 }
1401
1402 static gboolean
1403 g_output_stream_real_flush_finish (GOutputStream  *stream,
1404                                    GAsyncResult   *result,
1405                                    GError        **error)
1406 {
1407   return TRUE;
1408 }
1409
1410 static void
1411 close_async_thread (GSimpleAsyncResult *res,
1412                     GObject            *object,
1413                     GCancellable       *cancellable)
1414 {
1415   GOutputStreamClass *class;
1416   GError *error = NULL;
1417   gboolean result = TRUE;
1418
1419   class = G_OUTPUT_STREAM_GET_CLASS (object);
1420
1421   /* Do a flush here if there is a flush function, and we did not have to do
1422      an async flush before (see g_output_stream_close_async) */
1423   if (class->flush != NULL &&
1424       (class->flush_async == NULL ||
1425        class->flush_async == g_output_stream_real_flush_async))
1426     {
1427       result = class->flush (G_OUTPUT_STREAM (object), cancellable, &error);
1428     }
1429
1430   /* Auto handling of cancelation disabled, and ignore
1431      cancellation, since we want to close things anyway, although
1432      possibly in a quick-n-dirty way. At least we never want to leak
1433      open handles */
1434
1435   if (class->close_fn)
1436     {
1437       /* Make sure to close, even if the flush failed (see sync close) */
1438       if (!result)
1439         class->close_fn (G_OUTPUT_STREAM (object), cancellable, NULL);
1440       else
1441         result = class->close_fn (G_OUTPUT_STREAM (object), cancellable, &error);
1442
1443       if (!result)
1444         g_simple_async_result_take_error (res, error);
1445     }
1446 }
1447
1448 static void
1449 g_output_stream_real_close_async (GOutputStream       *stream,
1450                                   int                  io_priority,
1451                                   GCancellable        *cancellable,
1452                                   GAsyncReadyCallback  callback,
1453                                   gpointer             user_data)
1454 {
1455   GSimpleAsyncResult *res;
1456
1457   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_close_async);
1458
1459   g_simple_async_result_set_handle_cancellation (res, FALSE);
1460
1461   g_simple_async_result_run_in_thread (res, close_async_thread, io_priority, cancellable);
1462   g_object_unref (res);
1463 }
1464
1465 static gboolean
1466 g_output_stream_real_close_finish (GOutputStream  *stream,
1467                                    GAsyncResult   *result,
1468                                    GError        **error)
1469 {
1470   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
1471   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_output_stream_real_close_async);
1472   return TRUE;
1473 }