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 "gtask.h"
  28 #include "ginputstream.h"
  29 #include "gioerror.h"
  30 #include "glibintl.h"
  31 #include "gpollableoutputstream.h"
  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 struct _GOutputStreamPrivate {
  49   guint closed : 1;
  50   guint pending : 1;
  51   guint closing : 1;
  52   GAsyncReadyCallback outstanding_callback;
  53 };
  54
  55 G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (GOutputStream, g_output_stream, G_TYPE_OBJECT)
  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 static gboolean _g_output_stream_close_internal    (GOutputStream             *stream,
  99                                                     GCancellable              *cancellable,
 100                                                     GError                   **error);
 101
 102 static void
 103 g_output_stream_dispose (GObject *object)
 104 {
 105   GOutputStream *stream;
 106
 107   stream = G_OUTPUT_STREAM (object);
 108
 109   if (!stream->priv->closed)
 110     g_output_stream_close (stream, NULL, NULL);
 111
 112   G_OBJECT_CLASS (g_output_stream_parent_class)->dispose (object);
 113 }
 114
 115 static void
 116 g_output_stream_class_init (GOutputStreamClass *klass)
 117 {
 118   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 119
 120   gobject_class->dispose = g_output_stream_dispose;
 121
 122   klass->splice = g_output_stream_real_splice;
 123
 124   klass->write_async = g_output_stream_real_write_async;
 125   klass->write_finish = g_output_stream_real_write_finish;
 126   klass->splice_async = g_output_stream_real_splice_async;
 127   klass->splice_finish = g_output_stream_real_splice_finish;
 128   klass->flush_async = g_output_stream_real_flush_async;
 129   klass->flush_finish = g_output_stream_real_flush_finish;
 130   klass->close_async = g_output_stream_real_close_async;
 131   klass->close_finish = g_output_stream_real_close_finish;
 132 }
 133
 134 static void
 135 g_output_stream_init (GOutputStream *stream)
 136 {
 137   stream->priv = g_output_stream_get_private (stream);
 138 }
 139
 140 /**
 141  * g_output_stream_write:
 142  * @stream: a #GOutputStream.
 143  * @buffer: (array length=count) (element-type guint8): the buffer containing the data to write.
 144  * @count: the number of bytes to write
 145  * @cancellable: (allow-none): optional cancellable object
 146  * @error: location to store the error occurring, or %NULL to ignore
 147  *
 148  * Tries to write @count bytes from @buffer into the stream. Will block
 149  * during the operation.
 150  *
 151  * If count is 0, returns 0 and does nothing. A value of @count
 152  * larger than %G_MAXSSIZE will cause a %G_IO_ERROR_INVALID_ARGUMENT error.
 153  *
 154  * On success, the number of bytes written to the stream is returned.
 155  * It is not an error if this is not the same as the requested size, as it
 156  * can happen e.g. on a partial I/O error, or if there is not enough
 157  * storage in the stream. All writes block until at least one byte
 158  * is written or an error occurs; 0 is never returned (unless
 159  * @count is 0).
 160  *
 161  * If @cancellable is not %NULL, then the operation can be cancelled by
 162  * triggering the cancellable object from another thread. If the operation
 163  * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned. If an
 164  * operation was partially finished when the operation was cancelled the
 165  * partial result will be returned, without an error.
 166  *
 167  * On error -1 is returned and @error is set accordingly.
 168  *
 169  * Virtual: write_fn
 170  *
 171  * Return value: Number of bytes written, or -1 on error
 172  **/
 173 gssize
 174 g_output_stream_write (GOutputStream  *stream,
 175                        const void     *buffer,
 176                        gsize           count,
 177                        GCancellable   *cancellable,
 178                        GError        **error)
 179 {
 180   GOutputStreamClass *class;
 181   gssize res;
 182
 183   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
 184   g_return_val_if_fail (buffer != NULL, 0);
 185
 186   if (count == 0)
 187     return 0;
 188
 189   if (((gssize) count) < 0)
 190     {
 191       g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
 192                    _("Too large count value passed to %s"), G_STRFUNC);
 193       return -1;
 194     }
 195
 196   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 197
 198   if (class->write_fn == NULL)
 199     {
 200       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
 201                            _("Output stream doesn't implement write"));
 202       return -1;
 203     }
 204
 205   if (!g_output_stream_set_pending (stream, error))
 206     return -1;
 207
 208   if (cancellable)
 209     g_cancellable_push_current (cancellable);
 210
 211   res = class->write_fn (stream, buffer, count, cancellable, error);
 212
 213   if (cancellable)
 214     g_cancellable_pop_current (cancellable);
 215
 216   g_output_stream_clear_pending (stream);
 217
 218   return res;
 219 }
 220
 221 /**
 222  * g_output_stream_write_all:
 223  * @stream: a #GOutputStream.
 224  * @buffer: (array length=count) (element-type guint8): the buffer containing the data to write.
 225  * @count: the number of bytes to write
 226  * @bytes_written: (out): location to store the number of bytes that was
 227  *     written to the stream
 228  * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
 229  * @error: location to store the error occurring, or %NULL to ignore
 230  *
 231  * Tries to write @count bytes from @buffer into the stream. Will block
 232  * during the operation.
 233  *
 234  * This function is similar to g_output_stream_write(), except it tries to
 235  * write as many bytes as requested, only stopping on an error.
 236  *
 237  * On a successful write of @count bytes, %TRUE is returned, and @bytes_written
 238  * is set to @count.
 239  *
 240  * If there is an error during the operation %FALSE is returned and @error
 241  * is set to indicate the error status, @bytes_written is updated to contain
 242  * the number of bytes written into the stream before the error occurred.
 243  *
 244  * Return value: %TRUE on success, %FALSE if there was an error
 245  **/
 246 gboolean
 247 g_output_stream_write_all (GOutputStream  *stream,
 248                            const void     *buffer,
 249                            gsize           count,
 250                            gsize          *bytes_written,
 251                            GCancellable   *cancellable,
 252                            GError        **error)
 253 {
 254   gsize _bytes_written;
 255   gssize res;
 256
 257   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 258   g_return_val_if_fail (buffer != NULL, FALSE);
 259
 260   _bytes_written = 0;
 261   while (_bytes_written < count)
 262     {
 263       res = g_output_stream_write (stream, (char *)buffer + _bytes_written, count - _bytes_written,
 264                                    cancellable, error);
 265       if (res == -1)
 266         {
 267           if (bytes_written)
 268             *bytes_written = _bytes_written;
 269           return FALSE;
 270         }
 271
 272       if (res == 0)
 273         g_warning ("Write returned zero without error");
 274
 275       _bytes_written += res;
 276     }
 277
 278   if (bytes_written)
 279     *bytes_written = _bytes_written;
 280
 281   return TRUE;
 282 }
 283
 284 /**
 285  * g_output_stream_write_bytes:
 286  * @stream: a #GOutputStream.
 287  * @bytes: the #GBytes to write
 288  * @cancellable: (allow-none): optional cancellable object
 289  * @error: location to store the error occurring, or %NULL to ignore
 290  *
 291  * Tries to write the data from @bytes into the stream. Will block
 292  * during the operation.
 293  *
 294  * If @bytes is 0-length, returns 0 and does nothing. A #GBytes larger
 295  * than %G_MAXSSIZE will cause a %G_IO_ERROR_INVALID_ARGUMENT error.
 296  *
 297  * On success, the number of bytes written to the stream is returned.
 298  * It is not an error if this is not the same as the requested size, as it
 299  * can happen e.g. on a partial I/O error, or if there is not enough
 300  * storage in the stream. All writes block until at least one byte
 301  * is written or an error occurs; 0 is never returned (unless
 302  * the size of @bytes is 0).
 303  *
 304  * If @cancellable is not %NULL, then the operation can be cancelled by
 305  * triggering the cancellable object from another thread. If the operation
 306  * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned. If an
 307  * operation was partially finished when the operation was cancelled the
 308  * partial result will be returned, without an error.
 309  *
 310  * On error -1 is returned and @error is set accordingly.
 311  *
 312  * Return value: Number of bytes written, or -1 on error
 313  **/
 314 gssize
 315 g_output_stream_write_bytes (GOutputStream  *stream,
 316                              GBytes         *bytes,
 317                              GCancellable   *cancellable,
 318                              GError        **error)
 319 {
 320   gsize size;
 321   gconstpointer data;
 322
 323   data = g_bytes_get_data (bytes, &size);
 324
 325   return g_output_stream_write (stream,
 326                                 data, size,
 327                                 cancellable,
 328                                 error);
 329 }
 330
 331 /**
 332  * g_output_stream_flush:
 333  * @stream: a #GOutputStream.
 334  * @cancellable: (allow-none): optional cancellable object
 335  * @error: location to store the error occurring, or %NULL to ignore
 336  *
 337  * Forces a write of all user-space buffered data for the given
 338  * @stream. Will block during the operation. Closing the stream will
 339  * implicitly cause a flush.
 340  *
 341  * This function is optional for inherited classes.
 342  *
 343  * If @cancellable is not %NULL, then the operation can be cancelled by
 344  * triggering the cancellable object from another thread. If the operation
 345  * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned.
 346  *
 347  * Return value: %TRUE on success, %FALSE on error
 348  **/
 349 gboolean
 350 g_output_stream_flush (GOutputStream  *stream,
 351                        GCancellable   *cancellable,
 352                        GError        **error)
 353 {
 354   GOutputStreamClass *class;
 355   gboolean res;
 356
 357   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 358
 359   if (!g_output_stream_set_pending (stream, error))
 360     return FALSE;
 361
 362   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 363
 364   res = TRUE;
 365   if (class->flush)
 366     {
 367       if (cancellable)
 368         g_cancellable_push_current (cancellable);
 369
 370       res = class->flush (stream, cancellable, error);
 371
 372       if (cancellable)
 373         g_cancellable_pop_current (cancellable);
 374     }
 375
 376   g_output_stream_clear_pending (stream);
 377
 378   return res;
 379 }
 380
 381 /**
 382  * g_output_stream_splice:
 383  * @stream: a #GOutputStream.
 384  * @source: a #GInputStream.
 385  * @flags: a set of #GOutputStreamSpliceFlags.
 386  * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
 387  * @error: a #GError location to store the error occurring, or %NULL to
 388  * ignore.
 389  *
 390  * Splices an input stream into an output stream.
 391  *
 392  * Returns: a #gssize containing the size of the data spliced, or
 393  *     -1 if an error occurred. Note that if the number of bytes
 394  *     spliced is greater than %G_MAXSSIZE, then that will be
 395  *     returned, and there is no way to determine the actual number
 396  *     of bytes spliced.
 397  **/
 398 gssize
 399 g_output_stream_splice (GOutputStream             *stream,
 400                         GInputStream              *source,
 401                         GOutputStreamSpliceFlags   flags,
 402                         GCancellable              *cancellable,
 403                         GError                   **error)
 404 {
 405   GOutputStreamClass *class;
 406   gssize bytes_copied;
 407
 408   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
 409   g_return_val_if_fail (G_IS_INPUT_STREAM (source), -1);
 410
 411   if (g_input_stream_is_closed (source))
 412     {
 413       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
 414                            _("Source stream is already closed"));
 415       return -1;
 416     }
 417
 418   if (!g_output_stream_set_pending (stream, error))
 419     return -1;
 420
 421   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 422
 423   if (cancellable)
 424     g_cancellable_push_current (cancellable);
 425
 426   bytes_copied = class->splice (stream, source, flags, cancellable, error);
 427
 428   if (cancellable)
 429     g_cancellable_pop_current (cancellable);
 430
 431   g_output_stream_clear_pending (stream);
 432
 433   return bytes_copied;
 434 }
 435
 436 static gssize
 437 g_output_stream_real_splice (GOutputStream             *stream,
 438                              GInputStream              *source,
 439                              GOutputStreamSpliceFlags   flags,
 440                              GCancellable              *cancellable,
 441                              GError                   **error)
 442 {
 443   GOutputStreamClass *class = G_OUTPUT_STREAM_GET_CLASS (stream);
 444   gssize n_read, n_written;
 445   gsize bytes_copied;
 446   char buffer[8192], *p;
 447   gboolean res;
 448
 449   bytes_copied = 0;
 450   if (class->write_fn == NULL)
 451     {
 452       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
 453                            _("Output stream doesn't implement write"));
 454       res = FALSE;
 455       goto notsupported;
 456     }
 457
 458   res = TRUE;
 459   do
 460     {
 461       n_read = g_input_stream_read (source, buffer, sizeof (buffer), cancellable, error);
 462       if (n_read == -1)
 463         {
 464           res = FALSE;
 465           break;
 466         }
 467
 468       if (n_read == 0)
 469         break;
 470
 471       p = buffer;
 472       while (n_read > 0)
 473         {
 474           n_written = class->write_fn (stream, p, n_read, cancellable, error);
 475           if (n_written == -1)
 476             {
 477               res = FALSE;
 478               break;
 479             }
 480
 481           p += n_written;
 482           n_read -= n_written;
 483           bytes_copied += n_written;
 484         }
 485
 486       if (bytes_copied > G_MAXSSIZE)
 487         bytes_copied = G_MAXSSIZE;
 488     }
 489   while (res);
 490
 491  notsupported:
 492   if (!res)
 493     error = NULL; /* Ignore further errors */
 494
 495   if (flags & G_OUTPUT_STREAM_SPLICE_CLOSE_SOURCE)
 496     {
 497       /* Don't care about errors in source here */
 498       g_input_stream_close (source, cancellable, NULL);
 499     }
 500
 501   if (flags & G_OUTPUT_STREAM_SPLICE_CLOSE_TARGET)
 502     {
 503       /* But write errors on close are bad! */
 504       res = _g_output_stream_close_internal (stream, cancellable, error);
 505     }
 506
 507   if (res)
 508     return bytes_copied;
 509
 510   return -1;
 511 }
 512
 513 /* Must always be called inside
 514  * g_output_stream_set_pending()/g_output_stream_clear_pending(). */
 515 static gboolean
 516 _g_output_stream_close_internal (GOutputStream  *stream,
 517                                  GCancellable   *cancellable,
 518                                  GError        **error)
 519 {
 520   GOutputStreamClass *class;
 521   gboolean res;
 522
 523   if (stream->priv->closed)
 524     return TRUE;
 525
 526   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 527
 528   stream->priv->closing = TRUE;
 529
 530   if (cancellable)
 531     g_cancellable_push_current (cancellable);
 532
 533   if (class->flush)
 534     res = class->flush (stream, cancellable, error);
 535   else
 536     res = TRUE;
 537
 538   if (!res)
 539     {
 540       /* flushing caused the error that we want to return,
 541        * but we still want to close the underlying stream if possible
 542        */
 543       if (class->close_fn)
 544         class->close_fn (stream, cancellable, NULL);
 545     }
 546   else
 547     {
 548       res = TRUE;
 549       if (class->close_fn)
 550         res = class->close_fn (stream, cancellable, error);
 551     }
 552
 553   if (cancellable)
 554     g_cancellable_pop_current (cancellable);
 555
 556   stream->priv->closing = FALSE;
 557   stream->priv->closed = TRUE;
 558
 559   return res;
 560 }
 561
 562 /**
 563  * g_output_stream_close:
 564  * @stream: A #GOutputStream.
 565  * @cancellable: (allow-none): optional cancellable object
 566  * @error: location to store the error occurring, or %NULL to ignore
 567  *
 568  * Closes the stream, releasing resources related to it.
 569  *
 570  * Once the stream is closed, all other operations will return %G_IO_ERROR_CLOSED.
 571  * Closing a stream multiple times will not return an error.
 572  *
 573  * Closing a stream will automatically flush any outstanding buffers in the
 574  * stream.
 575  *
 576  * Streams will be automatically closed when the last reference
 577  * is dropped, but you might want to call this function to make sure
 578  * resources are released as early as possible.
 579  *
 580  * Some streams might keep the backing store of the stream (e.g. a file descriptor)
 581  * open after the stream is closed. See the documentation for the individual
 582  * stream for details.
 583  *
 584  * On failure the first error that happened will be reported, but the close
 585  * operation will finish as much as possible. A stream that failed to
 586  * close will still return %G_IO_ERROR_CLOSED for all operations. Still, it
 587  * is important to check and report the error to the user, otherwise
 588  * there might be a loss of data as all data might not be written.
 589  *
 590  * If @cancellable is not %NULL, then the operation can be cancelled by
 591  * triggering the cancellable object from another thread. If the operation
 592  * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned.
 593  * Cancelling a close will still leave the stream closed, but there some streams
 594  * can use a faster close that doesn't block to e.g. check errors. On
 595  * cancellation (as with any error) there is no guarantee that all written
 596  * data will reach the target.
 597  *
 598  * Return value: %TRUE on success, %FALSE on failure
 599  **/
 600 gboolean
 601 g_output_stream_close (GOutputStream  *stream,
 602                        GCancellable   *cancellable,
 603                        GError        **error)
 604 {
 605   gboolean res;
 606
 607   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 608
 609   if (stream->priv->closed)
 610     return TRUE;
 611
 612   if (!g_output_stream_set_pending (stream, error))
 613     return FALSE;
 614
 615   res = _g_output_stream_close_internal (stream, cancellable, error);
 616
 617   g_output_stream_clear_pending (stream);
 618
 619   return res;
 620 }
 621
 622 static void
 623 async_ready_write_callback_wrapper (GObject      *source_object,
 624                                     GAsyncResult *res,
 625                                     gpointer      user_data)
 626 {
 627   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 628   GOutputStreamClass *class;
 629   GTask *task = user_data;
 630   gssize nwrote;
 631   GError *error = NULL;
 632
 633   g_output_stream_clear_pending (stream);
 634
 635   if (g_async_result_legacy_propagate_error (res, &error))
 636     nwrote = -1;
 637   else
 638     {
 639       class = G_OUTPUT_STREAM_GET_CLASS (stream);
 640       nwrote = class->write_finish (stream, res, &error);
 641     }
 642
 643   if (nwrote >= 0)
 644     g_task_return_int (task, nwrote);
 645   else
 646     g_task_return_error (task, error);
 647   g_object_unref (task);
 648 }
 649
 650 /**
 651  * g_output_stream_write_async:
 652  * @stream: A #GOutputStream.
 653  * @buffer: (array length=count) (element-type guint8): the buffer containing the data to write.
 654  * @count: the number of bytes to write
 655  * @io_priority: the io priority of the request.
 656  * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
 657  * @callback: (scope async): callback to call when the request is satisfied
 658  * @user_data: (closure): the data to pass to callback function
 659  *
 660  * Request an asynchronous write of @count bytes from @buffer into
 661  * the stream. When the operation is finished @callback will be called.
 662  * You can then call g_output_stream_write_finish() to get the result of the
 663  * operation.
 664  *
 665  * During an async request no other sync and async calls are allowed,
 666  * and will result in %G_IO_ERROR_PENDING errors.
 667  *
 668  * A value of @count larger than %G_MAXSSIZE will cause a
 669  * %G_IO_ERROR_INVALID_ARGUMENT error.
 670  *
 671  * On success, the number of bytes written will be passed to the
 672  * @callback. It is not an error if this is not the same as the
 673  * requested size, as it can happen e.g. on a partial I/O error,
 674  * but generally we try to write as many bytes as requested.
 675  *
 676  * You are guaranteed that this method will never fail with
 677  * %G_IO_ERROR_WOULD_BLOCK - if @stream can't accept more data, the
 678  * method will just wait until this changes.
 679  *
 680  * Any outstanding I/O request with higher priority (lower numerical
 681  * value) will be executed before an outstanding request with lower
 682  * priority. Default priority is %G_PRIORITY_DEFAULT.
 683  *
 684  * The asyncronous methods have a default fallback that uses threads
 685  * to implement asynchronicity, so they are optional for inheriting
 686  * classes. However, if you override one you must override all.
 687  *
 688  * For the synchronous, blocking version of this function, see
 689  * g_output_stream_write().
 690  **/
 691 void
 692 g_output_stream_write_async (GOutputStream       *stream,
 693                              const void          *buffer,
 694                              gsize                count,
 695                              int                  io_priority,
 696                              GCancellable        *cancellable,
 697                              GAsyncReadyCallback  callback,
 698                              gpointer             user_data)
 699 {
 700   GOutputStreamClass *class;
 701   GError *error = NULL;
 702   GTask *task;
 703
 704   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 705   g_return_if_fail (buffer != NULL);
 706
 707   task = g_task_new (stream, cancellable, callback, user_data);
 708   g_task_set_source_tag (task, g_output_stream_write_async);
 709   g_task_set_priority (task, io_priority);
 710
 711   if (count == 0)
 712     {
 713       g_task_return_int (task, 0);
 714       g_object_unref (task);
 715       return;
 716     }
 717
 718   if (((gssize) count) < 0)
 719     {
 720       g_task_return_new_error (task, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
 721                                _("Too large count value passed to %s"),
 722                                G_STRFUNC);
 723       g_object_unref (task);
 724       return;
 725     }
 726
 727   if (!g_output_stream_set_pending (stream, &error))
 728     {
 729       g_task_return_error (task, error);
 730       g_object_unref (task);
 731       return;
 732     }
 733
 734   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 735
 736   class->write_async (stream, buffer, count, io_priority, cancellable,
 737                       async_ready_write_callback_wrapper, task);
 738 }
 739
 740 /**
 741  * g_output_stream_write_finish:
 742  * @stream: a #GOutputStream.
 743  * @result: a #GAsyncResult.
 744  * @error: a #GError location to store the error occurring, or %NULL to
 745  * ignore.
 746  *
 747  * Finishes a stream write operation.
 748  *
 749  * Returns: a #gssize containing the number of bytes written to the stream.
 750  **/
 751 gssize
 752 g_output_stream_write_finish (GOutputStream  *stream,
 753                               GAsyncResult   *result,
 754                               GError        **error)
 755 {
 756   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 757   g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
 758   g_return_val_if_fail (g_async_result_is_tagged (result, g_output_stream_write_async), FALSE);
 759
 760   /* @result is always the GTask created by g_output_stream_write_async();
 761    * we called class->write_finish() from async_ready_write_callback_wrapper.
 762    */
 763   return g_task_propagate_int (G_TASK (result), error);
 764 }
 765
 766 static void
 767 write_bytes_callback (GObject      *stream,
 768                       GAsyncResult *result,
 769                       gpointer      user_data)
 770 {
 771   GTask *task = user_data;
 772   GError *error = NULL;
 773   gssize nwrote;
 774
 775   nwrote = g_output_stream_write_finish (G_OUTPUT_STREAM (stream),
 776                                          result, &error);
 777   if (nwrote == -1)
 778     g_task_return_error (task, error);
 779   else
 780     g_task_return_int (task, nwrote);
 781   g_object_unref (task);
 782 }
 783
 784 /**
 785  * g_output_stream_write_bytes_async:
 786  * @stream: A #GOutputStream.
 787  * @bytes: The bytes to write
 788  * @io_priority: the io priority of the request.
 789  * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
 790  * @callback: (scope async): callback to call when the request is satisfied
 791  * @user_data: (closure): the data to pass to callback function
 792  *
 793  * Request an asynchronous write of the data in @bytes to the stream.
 794  * When the operation is finished @callback will be called. You can
 795  * then call g_output_stream_write_bytes_finish() to get the result of
 796  * the operation.
 797  *
 798  * During an async request no other sync and async calls are allowed,
 799  * and will result in %G_IO_ERROR_PENDING errors.
 800  *
 801  * A #GBytes larger than %G_MAXSSIZE will cause a
 802  * %G_IO_ERROR_INVALID_ARGUMENT error.
 803  *
 804  * On success, the number of bytes written will be passed to the
 805  * @callback. It is not an error if this is not the same as the
 806  * requested size, as it can happen e.g. on a partial I/O error,
 807  * but generally we try to write as many bytes as requested.
 808  *
 809  * You are guaranteed that this method will never fail with
 810  * %G_IO_ERROR_WOULD_BLOCK - if @stream can't accept more data, the
 811  * method will just wait until this changes.
 812  *
 813  * Any outstanding I/O request with higher priority (lower numerical
 814  * value) will be executed before an outstanding request with lower
 815  * priority. Default priority is %G_PRIORITY_DEFAULT.
 816  *
 817  * For the synchronous, blocking version of this function, see
 818  * g_output_stream_write_bytes().
 819  **/
 820 void
 821 g_output_stream_write_bytes_async (GOutputStream       *stream,
 822                                    GBytes              *bytes,
 823                                    int                  io_priority,
 824                                    GCancellable        *cancellable,
 825                                    GAsyncReadyCallback  callback,
 826                                    gpointer             user_data)
 827 {
 828   GTask *task;
 829   gsize size;
 830   gconstpointer data;
 831
 832   data = g_bytes_get_data (bytes, &size);
 833
 834   task = g_task_new (stream, cancellable, callback, user_data);
 835   g_task_set_task_data (task, g_bytes_ref (bytes),
 836                         (GDestroyNotify) g_bytes_unref);
 837
 838   g_output_stream_write_async (stream,
 839                                data, size,
 840                                io_priority,
 841                                cancellable,
 842                                write_bytes_callback,
 843                                task);
 844 }
 845
 846 /**
 847  * g_output_stream_write_bytes_finish:
 848  * @stream: a #GOutputStream.
 849  * @result: a #GAsyncResult.
 850  * @error: a #GError location to store the error occurring, or %NULL to
 851  * ignore.
 852  *
 853  * Finishes a stream write-from-#GBytes operation.
 854  *
 855  * Returns: a #gssize containing the number of bytes written to the stream.
 856  **/
 857 gssize
 858 g_output_stream_write_bytes_finish (GOutputStream  *stream,
 859                                     GAsyncResult   *result,
 860                                     GError        **error)
 861 {
 862   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
 863   g_return_val_if_fail (g_task_is_valid (result, stream), -1);
 864
 865   return g_task_propagate_int (G_TASK (result), error);
 866 }
 867
 868 static void
 869 async_ready_splice_callback_wrapper (GObject      *source_object,
 870                                      GAsyncResult *res,
 871                                      gpointer     _data)
 872 {
 873   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 874   GOutputStreamClass *class;
 875   GTask *task = _data;
 876   gssize nspliced;
 877   GError *error = NULL;
 878
 879   g_output_stream_clear_pending (stream);
 880
 881   if (g_async_result_legacy_propagate_error (res, &error))
 882     nspliced = -1;
 883   else
 884     {
 885       class = G_OUTPUT_STREAM_GET_CLASS (stream);
 886       nspliced = class->splice_finish (stream, res, &error);
 887     }
 888
 889   if (nspliced >= 0)
 890     g_task_return_int (task, nspliced);
 891   else
 892     g_task_return_error (task, error);
 893   g_object_unref (task);
 894 }
 895
 896 /**
 897  * g_output_stream_splice_async:
 898  * @stream: a #GOutputStream.
 899  * @source: a #GInputStream.
 900  * @flags: a set of #GOutputStreamSpliceFlags.
 901  * @io_priority: the io priority of the request.
 902  * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
 903  * @callback: (scope async): a #GAsyncReadyCallback.
 904  * @user_data: (closure): user data passed to @callback.
 905  *
 906  * Splices a stream asynchronously.
 907  * When the operation is finished @callback will be called.
 908  * You can then call g_output_stream_splice_finish() to get the
 909  * result of the operation.
 910  *
 911  * For the synchronous, blocking version of this function, see
 912  * g_output_stream_splice().
 913  **/
 914 void
 915 g_output_stream_splice_async (GOutputStream            *stream,
 916                               GInputStream             *source,
 917                               GOutputStreamSpliceFlags  flags,
 918                               int                       io_priority,
 919                               GCancellable             *cancellable,
 920                               GAsyncReadyCallback       callback,
 921                               gpointer                  user_data)
 922 {
 923   GOutputStreamClass *class;
 924   GTask *task;
 925   GError *error = NULL;
 926
 927   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 928   g_return_if_fail (G_IS_INPUT_STREAM (source));
 929
 930   task = g_task_new (stream, cancellable, callback, user_data);
 931   g_task_set_source_tag (task, g_output_stream_splice_async);
 932   g_task_set_priority (task, io_priority);
 933   g_task_set_task_data (task, g_object_ref (source), g_object_unref);
 934
 935   if (g_input_stream_is_closed (source))
 936     {
 937       g_task_return_new_error (task,
 938                                G_IO_ERROR, G_IO_ERROR_CLOSED,
 939                                _("Source stream is already closed"));
 940       g_object_unref (task);
 941       return;
 942     }
 943
 944   if (!g_output_stream_set_pending (stream, &error))
 945     {
 946       g_task_return_error (task, error);
 947       g_object_unref (task);
 948       return;
 949     }
 950
 951   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 952
 953   class->splice_async (stream, source, flags, io_priority, cancellable,
 954                        async_ready_splice_callback_wrapper, task);
 955 }
 956
 957 /**
 958  * g_output_stream_splice_finish:
 959  * @stream: a #GOutputStream.
 960  * @result: a #GAsyncResult.
 961  * @error: a #GError location to store the error occurring, or %NULL to
 962  * ignore.
 963  *
 964  * Finishes an asynchronous stream splice operation.
 965  *
 966  * Returns: a #gssize of the number of bytes spliced. Note that if the
 967  *     number of bytes spliced is greater than %G_MAXSSIZE, then that
 968  *     will be returned, and there is no way to determine the actual
 969  *     number of bytes spliced.
 970  **/
 971 gssize
 972 g_output_stream_splice_finish (GOutputStream  *stream,
 973                                GAsyncResult   *result,
 974                                GError        **error)
 975 {
 976   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 977   g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
 978   g_return_val_if_fail (g_async_result_is_tagged (result, g_output_stream_splice_async), FALSE);
 979
 980   /* @result is always the GTask created by g_output_stream_splice_async();
 981    * we called class->splice_finish() from async_ready_splice_callback_wrapper.
 982    */
 983   return g_task_propagate_int (G_TASK (result), error);
 984 }
 985
 986 static void
 987 async_ready_flush_callback_wrapper (GObject      *source_object,
 988                                     GAsyncResult *res,
 989                                     gpointer      user_data)
 990 {
 991   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 992   GOutputStreamClass *class;
 993   GTask *task = user_data;
 994   gboolean flushed;
 995   GError *error = NULL;
 996
 997   g_output_stream_clear_pending (stream);
 998
 999   if (g_async_result_legacy_propagate_error (res, &error))
1000     flushed = FALSE;
1001   else
1002     {
1003       class = G_OUTPUT_STREAM_GET_CLASS (stream);
1004       flushed = class->flush_finish (stream, res, &error);
1005     }
1006
1007   if (flushed)
1008     g_task_return_boolean (task, TRUE);
1009   else
1010     g_task_return_error (task, error);
1011   g_object_unref (task);
1012 }
1013
1014 /**
1015  * g_output_stream_flush_async:
1016  * @stream: a #GOutputStream.
1017  * @io_priority: the io priority of the request.
1018  * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
1019  * @callback: (scope async): a #GAsyncReadyCallback to call when the request is satisfied
1020  * @user_data: (closure): the data to pass to callback function
1021  *
1022  * Forces an asynchronous write of all user-space buffered data for
1023  * the given @stream.
1024  * For behaviour details see g_output_stream_flush().
1025  *
1026  * When the operation is finished @callback will be
1027  * called. You can then call g_output_stream_flush_finish() to get the
1028  * result of the operation.
1029  **/
1030 void
1031 g_output_stream_flush_async (GOutputStream       *stream,
1032                              int                  io_priority,
1033                              GCancellable        *cancellable,
1034                              GAsyncReadyCallback  callback,
1035                              gpointer             user_data)
1036 {
1037   GOutputStreamClass *class;
1038   GTask *task;
1039   GError *error = NULL;
1040
1041   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
1042
1043   task = g_task_new (stream, cancellable, callback, user_data);
1044   g_task_set_source_tag (task, g_output_stream_flush_async);
1045   g_task_set_priority (task, io_priority);
1046
1047   if (!g_output_stream_set_pending (stream, &error))
1048     {
1049       g_task_return_error (task, error);
1050       g_object_unref (task);
1051       return;
1052     }
1053
1054   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1055
1056   if (class->flush_async == NULL)
1057     {
1058       g_task_return_boolean (task, TRUE);
1059       g_object_unref (task);
1060       return;
1061     }
1062
1063   class->flush_async (stream, io_priority, cancellable,
1064                       async_ready_flush_callback_wrapper, task);
1065 }
1066
1067 /**
1068  * g_output_stream_flush_finish:
1069  * @stream: a #GOutputStream.
1070  * @result: a GAsyncResult.
1071  * @error: a #GError location to store the error occurring, or %NULL to
1072  * ignore.
1073  *
1074  * Finishes flushing an output stream.
1075  *
1076  * Returns: %TRUE if flush operation succeeded, %FALSE otherwise.
1077  **/
1078 gboolean
1079 g_output_stream_flush_finish (GOutputStream  *stream,
1080                               GAsyncResult   *result,
1081                               GError        **error)
1082 {
1083   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1084   g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
1085   g_return_val_if_fail (g_async_result_is_tagged (result, g_output_stream_flush_async), FALSE);
1086
1087   /* @result is always the GTask created by g_output_stream_flush_async();
1088    * we called class->flush_finish() from async_ready_flush_callback_wrapper.
1089    */
1090   return g_task_propagate_boolean (G_TASK (result), error);
1091 }
1092
1093
1094 static void
1095 async_ready_close_callback_wrapper (GObject      *source_object,
1096                                     GAsyncResult *res,
1097                                     gpointer      user_data)
1098 {
1099   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
1100   GOutputStreamClass *class;
1101   GTask *task = user_data;
1102   GError *error = g_task_get_task_data (task);
1103
1104   stream->priv->closing = FALSE;
1105   stream->priv->closed = TRUE;
1106
1107   if (!error && !g_async_result_legacy_propagate_error (res, &error))
1108     {
1109       class = G_OUTPUT_STREAM_GET_CLASS (stream);
1110
1111       class->close_finish (stream, res,
1112                            error ? NULL : &error);
1113     }
1114
1115   g_output_stream_clear_pending (stream);
1116
1117   if (error != NULL)
1118     g_task_return_error (task, error);
1119   else
1120     g_task_return_boolean (task, TRUE);
1121   g_object_unref (task);
1122 }
1123
1124 static void
1125 async_ready_close_flushed_callback_wrapper (GObject      *source_object,
1126                                             GAsyncResult *res,
1127                                             gpointer      user_data)
1128 {
1129   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
1130   GOutputStreamClass *class;
1131   GTask *task = user_data;
1132   GError *error = NULL;
1133
1134   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1135
1136   if (!g_async_result_legacy_propagate_error (res, &error))
1137     {
1138       class->flush_finish (stream, res, &error);
1139     }
1140
1141   /* propagate the possible error */
1142   if (error)
1143     g_task_set_task_data (task, error, NULL);
1144
1145   /* we still close, even if there was a flush error */
1146   class->close_async (stream,
1147                       g_task_get_priority (task),
1148                       g_task_get_cancellable (task),
1149                       async_ready_close_callback_wrapper, task);
1150 }
1151
1152 /**
1153  * g_output_stream_close_async:
1154  * @stream: A #GOutputStream.
1155  * @io_priority: the io priority of the request.
1156  * @cancellable: (allow-none): optional cancellable object
1157  * @callback: (scope async): callback to call when the request is satisfied
1158  * @user_data: (closure): the data to pass to callback function
1159  *
1160  * Requests an asynchronous close of the stream, releasing resources
1161  * related to it. When the operation is finished @callback will be
1162  * called. You can then call g_output_stream_close_finish() to get
1163  * the result of the operation.
1164  *
1165  * For behaviour details see g_output_stream_close().
1166  *
1167  * The asyncronous methods have a default fallback that uses threads
1168  * to implement asynchronicity, so they are optional for inheriting
1169  * classes. However, if you override one you must override all.
1170  **/
1171 void
1172 g_output_stream_close_async (GOutputStream       *stream,
1173                              int                  io_priority,
1174                              GCancellable        *cancellable,
1175                              GAsyncReadyCallback  callback,
1176                              gpointer             user_data)
1177 {
1178   GOutputStreamClass *class;
1179   GTask *task;
1180   GError *error = NULL;
1181
1182   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
1183
1184   task = g_task_new (stream, cancellable, callback, user_data);
1185   g_task_set_source_tag (task, g_output_stream_close_async);
1186   g_task_set_priority (task, io_priority);
1187
1188   if (stream->priv->closed)
1189     {
1190       g_task_return_boolean (task, TRUE);
1191       g_object_unref (task);
1192       return;
1193     }
1194
1195   if (!g_output_stream_set_pending (stream, &error))
1196     {
1197       g_task_return_error (task, error);
1198       g_object_unref (task);
1199       return;
1200     }
1201
1202   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1203   stream->priv->closing = TRUE;
1204
1205   /* Call close_async directly if there is no need to flush, or if the flush
1206      can be done sync (in the output stream async close thread) */
1207   if (class->flush_async == NULL ||
1208       (class->flush_async == g_output_stream_real_flush_async &&
1209        (class->flush == NULL || class->close_async == g_output_stream_real_close_async)))
1210     {
1211       class->close_async (stream, io_priority, cancellable,
1212                           async_ready_close_callback_wrapper, task);
1213     }
1214   else
1215     {
1216       /* First do an async flush, then do the async close in the callback
1217          wrapper (see async_ready_close_flushed_callback_wrapper) */
1218       class->flush_async (stream, io_priority, cancellable,
1219                           async_ready_close_flushed_callback_wrapper, task);
1220     }
1221 }
1222
1223 /**
1224  * g_output_stream_close_finish:
1225  * @stream: a #GOutputStream.
1226  * @result: a #GAsyncResult.
1227  * @error: a #GError location to store the error occurring, or %NULL to
1228  * ignore.
1229  *
1230  * Closes an output stream.
1231  *
1232  * Returns: %TRUE if stream was successfully closed, %FALSE otherwise.
1233  **/
1234 gboolean
1235 g_output_stream_close_finish (GOutputStream  *stream,
1236                               GAsyncResult   *result,
1237                               GError        **error)
1238 {
1239   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1240   g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
1241   g_return_val_if_fail (g_async_result_is_tagged (result, g_output_stream_close_async), FALSE);
1242
1243   /* @result is always the GTask created by g_output_stream_close_async();
1244    * we called class->close_finish() from async_ready_close_callback_wrapper.
1245    */
1246   return g_task_propagate_boolean (G_TASK (result), error);
1247 }
1248
1249 /**
1250  * g_output_stream_is_closed:
1251  * @stream: a #GOutputStream.
1252  *
1253  * Checks if an output stream has already been closed.
1254  *
1255  * Returns: %TRUE if @stream is closed. %FALSE otherwise.
1256  **/
1257 gboolean
1258 g_output_stream_is_closed (GOutputStream *stream)
1259 {
1260   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), TRUE);
1261
1262   return stream->priv->closed;
1263 }
1264
1265 /**
1266  * g_output_stream_is_closing:
1267  * @stream: a #GOutputStream.
1268  *
1269  * Checks if an output stream is being closed. This can be
1270  * used inside e.g. a flush implementation to see if the
1271  * flush (or other i/o operation) is called from within
1272  * the closing operation.
1273  *
1274  * Returns: %TRUE if @stream is being closed. %FALSE otherwise.
1275  *
1276  * Since: 2.24
1277  **/
1278 gboolean
1279 g_output_stream_is_closing (GOutputStream *stream)
1280 {
1281   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), TRUE);
1282
1283   return stream->priv->closing;
1284 }
1285
1286 /**
1287  * g_output_stream_has_pending:
1288  * @stream: a #GOutputStream.
1289  *
1290  * Checks if an ouput stream has pending actions.
1291  *
1292  * Returns: %TRUE if @stream has pending actions.
1293  **/
1294 gboolean
1295 g_output_stream_has_pending (GOutputStream *stream)
1296 {
1297   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1298
1299   return stream->priv->pending;
1300 }
1301
1302 /**
1303  * g_output_stream_set_pending:
1304  * @stream: a #GOutputStream.
1305  * @error: a #GError location to store the error occurring, or %NULL to
1306  * ignore.
1307  *
1308  * Sets @stream to have actions pending. If the pending flag is
1309  * already set or @stream is closed, it will return %FALSE and set
1310  * @error.
1311  *
1312  * Return value: %TRUE if pending was previously unset and is now set.
1313  **/
1314 gboolean
1315 g_output_stream_set_pending (GOutputStream *stream,
1316                              GError **error)
1317 {
1318   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1319
1320   if (stream->priv->closed)
1321     {
1322       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
1323                            _("Stream is already closed"));
1324       return FALSE;
1325     }
1326
1327   if (stream->priv->pending)
1328     {
1329       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PENDING,
1330                            /* Translators: This is an error you get if there is
1331                             * already an operation running against this stream when
1332                             * you try to start one */
1333                            _("Stream has outstanding operation"));
1334       return FALSE;
1335     }
1336
1337   stream->priv->pending = TRUE;
1338   return TRUE;
1339 }
1340
1341 /**
1342  * g_output_stream_clear_pending:
1343  * @stream: output stream
1344  *
1345  * Clears the pending flag on @stream.
1346  **/
1347 void
1348 g_output_stream_clear_pending (GOutputStream *stream)
1349 {
1350   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
1351
1352   stream->priv->pending = FALSE;
1353 }
1354
1355
1356 /********************************************
1357  *   Default implementation of async ops    *
1358  ********************************************/
1359
1360 typedef struct {
1361   const void         *buffer;
1362   gsize               count_requested;
1363   gssize              count_written;
1364 } WriteData;
1365
1366 static void
1367 free_write_data (WriteData *op)
1368 {
1369   g_slice_free (WriteData, op);
1370 }
1371
1372 static void
1373 write_async_thread (GTask        *task,
1374                     gpointer      source_object,
1375                     gpointer      task_data,
1376                     GCancellable *cancellable)
1377 {
1378   GOutputStream *stream = source_object;
1379   WriteData *op = task_data;
1380   GOutputStreamClass *class;
1381   GError *error = NULL;
1382   gssize count_written;
1383
1384   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1385   count_written = class->write_fn (stream, op->buffer, op->count_requested,
1386                                    cancellable, &error);
1387   if (count_written == -1)
1388     g_task_return_error (task, error);
1389   else
1390     g_task_return_int (task, count_written);
1391 }
1392
1393 static void write_async_pollable (GPollableOutputStream *stream,
1394                                   GTask                 *task);
1395
1396 static gboolean
1397 write_async_pollable_ready (GPollableOutputStream *stream,
1398                             gpointer               user_data)
1399 {
1400   GTask *task = user_data;
1401
1402   write_async_pollable (stream, task);
1403   return FALSE;
1404 }
1405
1406 static void
1407 write_async_pollable (GPollableOutputStream *stream,
1408                       GTask                 *task)
1409 {
1410   GError *error = NULL;
1411   WriteData *op = g_task_get_task_data (task);
1412   gssize count_written;
1413
1414   if (g_task_return_error_if_cancelled (task))
1415     return;
1416
1417   count_written = G_POLLABLE_OUTPUT_STREAM_GET_INTERFACE (stream)->
1418     write_nonblocking (stream, op->buffer, op->count_requested, &error);
1419
1420   if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_WOULD_BLOCK))
1421     {
1422       GSource *source;
1423
1424       g_error_free (error);
1425
1426       source = g_pollable_output_stream_create_source (stream,
1427                                                        g_task_get_cancellable (task));
1428       g_task_attach_source (task, source,
1429                             (GSourceFunc) write_async_pollable_ready);
1430       g_source_unref (source);
1431       return;
1432     }
1433
1434   if (count_written == -1)
1435     g_task_return_error (task, error);
1436   else
1437     g_task_return_int (task, count_written);
1438 }
1439
1440 static void
1441 g_output_stream_real_write_async (GOutputStream       *stream,
1442                                   const void          *buffer,
1443                                   gsize                count,
1444                                   int                  io_priority,
1445                                   GCancellable        *cancellable,
1446                                   GAsyncReadyCallback  callback,
1447                                   gpointer             user_data)
1448 {
1449   GTask *task;
1450   WriteData *op;
1451
1452   op = g_slice_new0 (WriteData);
1453   task = g_task_new (stream, cancellable, callback, user_data);
1454   g_task_set_check_cancellable (task, FALSE);
1455   g_task_set_task_data (task, op, (GDestroyNotify) free_write_data);
1456   op->buffer = buffer;
1457   op->count_requested = count;
1458
1459   if (G_IS_POLLABLE_OUTPUT_STREAM (stream) &&
1460       g_pollable_output_stream_can_poll (G_POLLABLE_OUTPUT_STREAM (stream)))
1461     write_async_pollable (G_POLLABLE_OUTPUT_STREAM (stream), task);
1462   else
1463     g_task_run_in_thread (task, write_async_thread);
1464   g_object_unref (task);
1465 }
1466
1467 static gssize
1468 g_output_stream_real_write_finish (GOutputStream  *stream,
1469                                    GAsyncResult   *result,
1470                                    GError        **error)
1471 {
1472   g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
1473
1474   return g_task_propagate_int (G_TASK (result), error);
1475 }
1476
1477 typedef struct {
1478   GInputStream *source;
1479   GOutputStreamSpliceFlags flags;
1480 } SpliceData;
1481
1482 static void
1483 free_splice_data (SpliceData *op)
1484 {
1485   g_object_unref (op->source);
1486   g_free (op);
1487 }
1488
1489 static void
1490 splice_async_thread (GTask        *task,
1491                      gpointer      source_object,
1492                      gpointer      task_data,
1493                      GCancellable *cancellable)
1494 {
1495   GOutputStream *stream = source_object;
1496   SpliceData *op = task_data;
1497   GOutputStreamClass *class;
1498   GError *error = NULL;
1499   gssize bytes_copied;
1500
1501   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1502
1503   bytes_copied = class->splice (stream,
1504                                 op->source,
1505                                 op->flags,
1506                                 cancellable,
1507                                 &error);
1508   if (bytes_copied == -1)
1509     g_task_return_error (task, error);
1510   else
1511     g_task_return_int (task, bytes_copied);
1512 }
1513
1514 static void
1515 g_output_stream_real_splice_async (GOutputStream             *stream,
1516                                    GInputStream              *source,
1517                                    GOutputStreamSpliceFlags   flags,
1518                                    int                        io_priority,
1519                                    GCancellable              *cancellable,
1520                                    GAsyncReadyCallback        callback,
1521                                    gpointer                   user_data)
1522 {
1523   GTask *task;
1524   SpliceData *op;
1525
1526   op = g_new0 (SpliceData, 1);
1527   task = g_task_new (stream, cancellable, callback, user_data);
1528   g_task_set_task_data (task, op, (GDestroyNotify)free_splice_data);
1529   op->flags = flags;
1530   op->source = g_object_ref (source);
1531
1532   /* TODO: In the case where both source and destintion have
1533      non-threadbased async calls we can use a true async copy here */
1534
1535   g_task_run_in_thread (task, splice_async_thread);
1536   g_object_unref (task);
1537 }
1538
1539 static gssize
1540 g_output_stream_real_splice_finish (GOutputStream  *stream,
1541                                     GAsyncResult   *result,
1542                                     GError        **error)
1543 {
1544   g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
1545
1546   return g_task_propagate_int (G_TASK (result), error);
1547 }
1548
1549
1550 static void
1551 flush_async_thread (GTask        *task,
1552                     gpointer      source_object,
1553                     gpointer      task_data,
1554                     GCancellable *cancellable)
1555 {
1556   GOutputStream *stream = source_object;
1557   GOutputStreamClass *class;
1558   gboolean result;
1559   GError *error = NULL;
1560
1561   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1562   result = TRUE;
1563   if (class->flush)
1564     result = class->flush (stream, cancellable, &error);
1565
1566   if (result)
1567     g_task_return_boolean (task, TRUE);
1568   else
1569     g_task_return_error (task, error);
1570 }
1571
1572 static void
1573 g_output_stream_real_flush_async (GOutputStream       *stream,
1574                                   int                  io_priority,
1575                                   GCancellable        *cancellable,
1576                                   GAsyncReadyCallback  callback,
1577                                   gpointer             user_data)
1578 {
1579   GTask *task;
1580
1581   task = g_task_new (stream, cancellable, callback, user_data);
1582   g_task_set_priority (task, io_priority);
1583   g_task_run_in_thread (task, flush_async_thread);
1584   g_object_unref (task);
1585 }
1586
1587 static gboolean
1588 g_output_stream_real_flush_finish (GOutputStream  *stream,
1589                                    GAsyncResult   *result,
1590                                    GError        **error)
1591 {
1592   g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
1593
1594   return g_task_propagate_boolean (G_TASK (result), error);
1595 }
1596
1597 static void
1598 close_async_thread (GTask        *task,
1599                     gpointer      source_object,
1600                     gpointer      task_data,
1601                     GCancellable *cancellable)
1602 {
1603   GOutputStream *stream = source_object;
1604   GOutputStreamClass *class;
1605   GError *error = NULL;
1606   gboolean result = TRUE;
1607
1608   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1609
1610   /* Do a flush here if there is a flush function, and we did not have to do
1611    * an async flush before (see g_output_stream_close_async)
1612    */
1613   if (class->flush != NULL &&
1614       (class->flush_async == NULL ||
1615        class->flush_async == g_output_stream_real_flush_async))
1616     {
1617       result = class->flush (stream, cancellable, &error);
1618     }
1619
1620   /* Auto handling of cancelation disabled, and ignore
1621      cancellation, since we want to close things anyway, although
1622      possibly in a quick-n-dirty way. At least we never want to leak
1623      open handles */
1624
1625   if (class->close_fn)
1626     {
1627       /* Make sure to close, even if the flush failed (see sync close) */
1628       if (!result)
1629         class->close_fn (stream, cancellable, NULL);
1630       else
1631         result = class->close_fn (stream, cancellable, &error);
1632     }
1633
1634   if (result)
1635     g_task_return_boolean (task, TRUE);
1636   else
1637     g_task_return_error (task, error);
1638 }
1639
1640 static void
1641 g_output_stream_real_close_async (GOutputStream       *stream,
1642                                   int                  io_priority,
1643                                   GCancellable        *cancellable,
1644                                   GAsyncReadyCallback  callback,
1645                                   gpointer             user_data)
1646 {
1647   GTask *task;
1648
1649   task = g_task_new (stream, cancellable, callback, user_data);
1650   g_task_set_priority (task, io_priority);
1651   g_task_run_in_thread (task, close_async_thread);
1652   g_object_unref (task);
1653 }
1654
1655 static gboolean
1656 g_output_stream_real_close_finish (GOutputStream  *stream,
1657                                    GAsyncResult   *result,
1658                                    GError        **error)
1659 {
1660   g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
1661
1662   return g_task_propagate_boolean (G_TASK (result), error);
1663 }