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, see <http://www.gnu.org/licenses/>.
  17  *
  18  * Author: Alexander Larsson <alexl@redhat.com>
  19  */
  20
  21 #include "config.h"
  22 #include <string.h>
  23 #include "goutputstream.h"
  24 #include "gcancellable.h"
  25 #include "gasyncresult.h"
  26 #include "gtask.h"
  27 #include "ginputstream.h"
  28 #include "gioerror.h"
  29 #include "gioprivate.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  * See the documentation for #GIOStream for details of thread safety of
  46  * streaming APIs.
  47  *
  48  * All of these functions have async variants too.
  49  **/
  50
  51 struct _GOutputStreamPrivate {
  52   guint closed : 1;
  53   guint pending : 1;
  54   guint closing : 1;
  55   GAsyncReadyCallback outstanding_callback;
  56 };
  57
  58 G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (GOutputStream, g_output_stream, G_TYPE_OBJECT)
  59
  60 static gssize   g_output_stream_real_splice        (GOutputStream             *stream,
  61                                                     GInputStream              *source,
  62                                                     GOutputStreamSpliceFlags   flags,
  63                                                     GCancellable              *cancellable,
  64                                                     GError                   **error);
  65 static void     g_output_stream_real_write_async   (GOutputStream             *stream,
  66                                                     const void                *buffer,
  67                                                     gsize                      count,
  68                                                     int                        io_priority,
  69                                                     GCancellable              *cancellable,
  70                                                     GAsyncReadyCallback        callback,
  71                                                     gpointer                   data);
  72 static gssize   g_output_stream_real_write_finish  (GOutputStream             *stream,
  73                                                     GAsyncResult              *result,
  74                                                     GError                   **error);
  75 static void     g_output_stream_real_splice_async  (GOutputStream             *stream,
  76                                                     GInputStream              *source,
  77                                                     GOutputStreamSpliceFlags   flags,
  78                                                     int                        io_priority,
  79                                                     GCancellable              *cancellable,
  80                                                     GAsyncReadyCallback        callback,
  81                                                     gpointer                   data);
  82 static gssize   g_output_stream_real_splice_finish (GOutputStream             *stream,
  83                                                     GAsyncResult              *result,
  84                                                     GError                   **error);
  85 static void     g_output_stream_real_flush_async   (GOutputStream             *stream,
  86                                                     int                        io_priority,
  87                                                     GCancellable              *cancellable,
  88                                                     GAsyncReadyCallback        callback,
  89                                                     gpointer                   data);
  90 static gboolean g_output_stream_real_flush_finish  (GOutputStream             *stream,
  91                                                     GAsyncResult              *result,
  92                                                     GError                   **error);
  93 static void     g_output_stream_real_close_async   (GOutputStream             *stream,
  94                                                     int                        io_priority,
  95                                                     GCancellable              *cancellable,
  96                                                     GAsyncReadyCallback        callback,
  97                                                     gpointer                   data);
  98 static gboolean g_output_stream_real_close_finish  (GOutputStream             *stream,
  99                                                     GAsyncResult              *result,
 100                                                     GError                   **error);
 101 static gboolean g_output_stream_internal_close     (GOutputStream             *stream,
 102                                                     GCancellable              *cancellable,
 103                                                     GError                   **error);
 104 static void     g_output_stream_internal_close_async (GOutputStream           *stream,
 105                                                       int                      io_priority,
 106                                                       GCancellable            *cancellable,
 107                                                       GAsyncReadyCallback      callback,
 108                                                       gpointer                 data);
 109 static gboolean g_output_stream_internal_close_finish (GOutputStream          *stream,
 110                                                        GAsyncResult           *result,
 111                                                        GError                **error);
 112
 113 static void
 114 g_output_stream_dispose (GObject *object)
 115 {
 116   GOutputStream *stream;
 117
 118   stream = G_OUTPUT_STREAM (object);
 119
 120   if (!stream->priv->closed)
 121     g_output_stream_close (stream, NULL, NULL);
 122
 123   G_OBJECT_CLASS (g_output_stream_parent_class)->dispose (object);
 124 }
 125
 126 static void
 127 g_output_stream_class_init (GOutputStreamClass *klass)
 128 {
 129   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 130
 131   gobject_class->dispose = g_output_stream_dispose;
 132
 133   klass->splice = g_output_stream_real_splice;
 134
 135   klass->write_async = g_output_stream_real_write_async;
 136   klass->write_finish = g_output_stream_real_write_finish;
 137   klass->splice_async = g_output_stream_real_splice_async;
 138   klass->splice_finish = g_output_stream_real_splice_finish;
 139   klass->flush_async = g_output_stream_real_flush_async;
 140   klass->flush_finish = g_output_stream_real_flush_finish;
 141   klass->close_async = g_output_stream_real_close_async;
 142   klass->close_finish = g_output_stream_real_close_finish;
 143 }
 144
 145 static void
 146 g_output_stream_init (GOutputStream *stream)
 147 {
 148   stream->priv = g_output_stream_get_instance_private (stream);
 149 }
 150
 151 /**
 152  * g_output_stream_write:
 153  * @stream: a #GOutputStream.
 154  * @buffer: (array length=count) (element-type guint8): the buffer containing the data to write.
 155  * @count: the number of bytes to write
 156  * @cancellable: (nullable): optional cancellable object
 157  * @error: location to store the error occurring, or %NULL to ignore
 158  *
 159  * Tries to write @count bytes from @buffer into the stream. Will block
 160  * during the operation.
 161  *
 162  * If count is 0, returns 0 and does nothing. A value of @count
 163  * larger than %G_MAXSSIZE will cause a %G_IO_ERROR_INVALID_ARGUMENT error.
 164  *
 165  * On success, the number of bytes written to the stream is returned.
 166  * It is not an error if this is not the same as the requested size, as it
 167  * can happen e.g. on a partial I/O error, or if there is not enough
 168  * storage in the stream. All writes block until at least one byte
 169  * is written or an error occurs; 0 is never returned (unless
 170  * @count is 0).
 171  *
 172  * If @cancellable is not %NULL, then the operation can be cancelled by
 173  * triggering the cancellable object from another thread. If the operation
 174  * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned. If an
 175  * operation was partially finished when the operation was cancelled the
 176  * partial result will be returned, without an error.
 177  *
 178  * On error -1 is returned and @error is set accordingly.
 179  *
 180  * Virtual: write_fn
 181  *
 182  * Returns: Number of bytes written, or -1 on error
 183  **/
 184 gssize
 185 g_output_stream_write (GOutputStream  *stream,
 186                        const void     *buffer,
 187                        gsize           count,
 188                        GCancellable   *cancellable,
 189                        GError        **error)
 190 {
 191   GOutputStreamClass *class;
 192   gssize res;
 193
 194   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
 195   g_return_val_if_fail (buffer != NULL, 0);
 196
 197   if (count == 0)
 198     return 0;
 199
 200   if (((gssize) count) < 0)
 201     {
 202       g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
 203                    _("Too large count value passed to %s"), G_STRFUNC);
 204       return -1;
 205     }
 206
 207   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 208
 209   if (class->write_fn == NULL)
 210     {
 211       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
 212                            _("Output stream doesn’t implement write"));
 213       return -1;
 214     }
 215
 216   if (!g_output_stream_set_pending (stream, error))
 217     return -1;
 218
 219   if (cancellable)
 220     g_cancellable_push_current (cancellable);
 221
 222   res = class->write_fn (stream, buffer, count, cancellable, error);
 223
 224   if (cancellable)
 225     g_cancellable_pop_current (cancellable);
 226
 227   g_output_stream_clear_pending (stream);
 228
 229   return res;
 230 }
 231
 232 /**
 233  * g_output_stream_write_all:
 234  * @stream: a #GOutputStream.
 235  * @buffer: (array length=count) (element-type guint8): the buffer containing the data to write.
 236  * @count: the number of bytes to write
 237  * @bytes_written: (out): location to store the number of bytes that was
 238  *     written to the stream
 239  * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
 240  * @error: location to store the error occurring, or %NULL to ignore
 241  *
 242  * Tries to write @count bytes from @buffer into the stream. Will block
 243  * during the operation.
 244  *
 245  * This function is similar to g_output_stream_write(), except it tries to
 246  * write as many bytes as requested, only stopping on an error.
 247  *
 248  * On a successful write of @count bytes, %TRUE is returned, and @bytes_written
 249  * is set to @count.
 250  *
 251  * If there is an error during the operation %FALSE is returned and @error
 252  * is set to indicate the error status.
 253  *
 254  * As a special exception to the normal conventions for functions that
 255  * use #GError, if this function returns %FALSE (and sets @error) then
 256  * @bytes_written will be set to the number of bytes that were
 257  * successfully written before the error was encountered.  This
 258  * functionality is only available from C.  If you need it from another
 259  * language then you must write your own loop around
 260  * g_output_stream_write().
 261  *
 262  * Returns: %TRUE on success, %FALSE if there was an error
 263  **/
 264 gboolean
 265 g_output_stream_write_all (GOutputStream  *stream,
 266                            const void     *buffer,
 267                            gsize           count,
 268                            gsize          *bytes_written,
 269                            GCancellable   *cancellable,
 270                            GError        **error)
 271 {
 272   gsize _bytes_written;
 273   gssize res;
 274
 275   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 276   g_return_val_if_fail (buffer != NULL, FALSE);
 277
 278   _bytes_written = 0;
 279   while (_bytes_written < count)
 280     {
 281       res = g_output_stream_write (stream, (char *)buffer + _bytes_written, count - _bytes_written,
 282                                    cancellable, error);
 283       if (res == -1)
 284         {
 285           if (bytes_written)
 286             *bytes_written = _bytes_written;
 287           return FALSE;
 288         }
 289
 290       if (res == 0)
 291         g_warning ("Write returned zero without error");
 292
 293       _bytes_written += res;
 294     }
 295
 296   if (bytes_written)
 297     *bytes_written = _bytes_written;
 298
 299   return TRUE;
 300 }
 301
 302 /**
 303  * g_output_stream_printf:
 304  * @stream: a #GOutputStream.
 305  * @bytes_written: (out): location to store the number of bytes that was
 306  *     written to the stream
 307  * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
 308  * @error: location to store the error occurring, or %NULL to ignore
 309  * @format: the format string. See the printf() documentation
 310  * @...: the parameters to insert into the format string
 311  *
 312  * This is a utility function around g_output_stream_write_all(). It
 313  * uses g_strdup_vprintf() to turn @format and @... into a string that
 314  * is then written to @stream.
 315  *
 316  * See the documentation of g_output_stream_write_all() about the
 317  * behavior of the actual write operation.
 318  *
 319  * Note that partial writes cannot be properly checked with this
 320  * function due to the variable length of the written string, if you
 321  * need precise control over partial write failures, you need to
 322  * create you own printf()-like wrapper around g_output_stream_write()
 323  * or g_output_stream_write_all().
 324  *
 325  * Since: 2.40
 326  *
 327  * Returns: %TRUE on success, %FALSE if there was an error
 328  **/
 329 gboolean
 330 g_output_stream_printf (GOutputStream  *stream,
 331                         gsize          *bytes_written,
 332                         GCancellable   *cancellable,
 333                         GError        **error,
 334                         const gchar    *format,
 335                         ...)
 336 {
 337   va_list  args;
 338   gboolean success;
 339
 340   va_start (args, format);
 341   success = g_output_stream_vprintf (stream, bytes_written, cancellable,
 342                                      error, format, args);
 343   va_end (args);
 344
 345   return success;
 346 }
 347
 348 /**
 349  * g_output_stream_vprintf:
 350  * @stream: a #GOutputStream.
 351  * @bytes_written: (out): location to store the number of bytes that was
 352  *     written to the stream
 353  * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
 354  * @error: location to store the error occurring, or %NULL to ignore
 355  * @format: the format string. See the printf() documentation
 356  * @args: the parameters to insert into the format string
 357  *
 358  * This is a utility function around g_output_stream_write_all(). It
 359  * uses g_strdup_vprintf() to turn @format and @args into a string that
 360  * is then written to @stream.
 361  *
 362  * See the documentation of g_output_stream_write_all() about the
 363  * behavior of the actual write operation.
 364  *
 365  * Note that partial writes cannot be properly checked with this
 366  * function due to the variable length of the written string, if you
 367  * need precise control over partial write failures, you need to
 368  * create you own printf()-like wrapper around g_output_stream_write()
 369  * or g_output_stream_write_all().
 370  *
 371  * Since: 2.40
 372  *
 373  * Returns: %TRUE on success, %FALSE if there was an error
 374  **/
 375 gboolean
 376 g_output_stream_vprintf (GOutputStream  *stream,
 377                          gsize          *bytes_written,
 378                          GCancellable   *cancellable,
 379                          GError        **error,
 380                          const gchar    *format,
 381                          va_list         args)
 382 {
 383   gchar    *text;
 384   gboolean  success;
 385
 386   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 387   g_return_val_if_fail (cancellable == NULL || G_IS_CANCELLABLE (stream), FALSE);
 388   g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
 389   g_return_val_if_fail (format != NULL, FALSE);
 390
 391   text = g_strdup_vprintf (format, args);
 392   success = g_output_stream_write_all (stream,
 393                                        text, strlen (text),
 394                                        bytes_written, cancellable, error);
 395   g_free (text);
 396
 397   return success;
 398 }
 399
 400 /**
 401  * g_output_stream_write_bytes:
 402  * @stream: a #GOutputStream.
 403  * @bytes: the #GBytes to write
 404  * @cancellable: (nullable): optional cancellable object
 405  * @error: location to store the error occurring, or %NULL to ignore
 406  *
 407  * A wrapper function for g_output_stream_write() which takes a
 408  * #GBytes as input.  This can be more convenient for use by language
 409  * bindings or in other cases where the refcounted nature of #GBytes
 410  * is helpful over a bare pointer interface.
 411  *
 412  * However, note that this function may still perform partial writes,
 413  * just like g_output_stream_write().  If that occurs, to continue
 414  * writing, you will need to create a new #GBytes containing just the
 415  * remaining bytes, using g_bytes_new_from_bytes(). Passing the same
 416  * #GBytes instance multiple times potentially can result in duplicated
 417  * data in the output stream.
 418  *
 419  * Returns: Number of bytes written, or -1 on error
 420  **/
 421 gssize
 422 g_output_stream_write_bytes (GOutputStream  *stream,
 423                              GBytes         *bytes,
 424                              GCancellable   *cancellable,
 425                              GError        **error)
 426 {
 427   gsize size;
 428   gconstpointer data;
 429
 430   data = g_bytes_get_data (bytes, &size);
 431
 432   return g_output_stream_write (stream,
 433                                 data, size,
 434                                 cancellable,
 435                                 error);
 436 }
 437
 438 /**
 439  * g_output_stream_flush:
 440  * @stream: a #GOutputStream.
 441  * @cancellable: (nullable): optional cancellable object
 442  * @error: location to store the error occurring, or %NULL to ignore
 443  *
 444  * Forces a write of all user-space buffered data for the given
 445  * @stream. Will block during the operation. Closing the stream will
 446  * implicitly cause a flush.
 447  *
 448  * This function is optional for inherited classes.
 449  *
 450  * If @cancellable is not %NULL, then the operation can be cancelled by
 451  * triggering the cancellable object from another thread. If the operation
 452  * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned.
 453  *
 454  * Returns: %TRUE on success, %FALSE on error
 455  **/
 456 gboolean
 457 g_output_stream_flush (GOutputStream  *stream,
 458                        GCancellable   *cancellable,
 459                        GError        **error)
 460 {
 461   GOutputStreamClass *class;
 462   gboolean res;
 463
 464   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 465
 466   if (!g_output_stream_set_pending (stream, error))
 467     return FALSE;
 468
 469   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 470
 471   res = TRUE;
 472   if (class->flush)
 473     {
 474       if (cancellable)
 475         g_cancellable_push_current (cancellable);
 476
 477       res = class->flush (stream, cancellable, error);
 478
 479       if (cancellable)
 480         g_cancellable_pop_current (cancellable);
 481     }
 482
 483   g_output_stream_clear_pending (stream);
 484
 485   return res;
 486 }
 487
 488 /**
 489  * g_output_stream_splice:
 490  * @stream: a #GOutputStream.
 491  * @source: a #GInputStream.
 492  * @flags: a set of #GOutputStreamSpliceFlags.
 493  * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
 494  * @error: a #GError location to store the error occurring, or %NULL to
 495  * ignore.
 496  *
 497  * Splices an input stream into an output stream.
 498  *
 499  * Returns: a #gssize containing the size of the data spliced, or
 500  *     -1 if an error occurred. Note that if the number of bytes
 501  *     spliced is greater than %G_MAXSSIZE, then that will be
 502  *     returned, and there is no way to determine the actual number
 503  *     of bytes spliced.
 504  **/
 505 gssize
 506 g_output_stream_splice (GOutputStream             *stream,
 507                         GInputStream              *source,
 508                         GOutputStreamSpliceFlags   flags,
 509                         GCancellable              *cancellable,
 510                         GError                   **error)
 511 {
 512   GOutputStreamClass *class;
 513   gssize bytes_copied;
 514
 515   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
 516   g_return_val_if_fail (G_IS_INPUT_STREAM (source), -1);
 517
 518   if (g_input_stream_is_closed (source))
 519     {
 520       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
 521                            _("Source stream is already closed"));
 522       return -1;
 523     }
 524
 525   if (!g_output_stream_set_pending (stream, error))
 526     return -1;
 527
 528   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 529
 530   if (cancellable)
 531     g_cancellable_push_current (cancellable);
 532
 533   bytes_copied = class->splice (stream, source, flags, cancellable, error);
 534
 535   if (cancellable)
 536     g_cancellable_pop_current (cancellable);
 537
 538   g_output_stream_clear_pending (stream);
 539
 540   return bytes_copied;
 541 }
 542
 543 static gssize
 544 g_output_stream_real_splice (GOutputStream             *stream,
 545                              GInputStream              *source,
 546                              GOutputStreamSpliceFlags   flags,
 547                              GCancellable              *cancellable,
 548                              GError                   **error)
 549 {
 550   GOutputStreamClass *class = G_OUTPUT_STREAM_GET_CLASS (stream);
 551   gssize n_read, n_written;
 552   gsize bytes_copied;
 553   char buffer[8192], *p;
 554   gboolean res;
 555
 556   bytes_copied = 0;
 557   if (class->write_fn == NULL)
 558     {
 559       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
 560                            _("Output stream doesn’t implement write"));
 561       res = FALSE;
 562       goto notsupported;
 563     }
 564
 565   res = TRUE;
 566   do
 567     {
 568       n_read = g_input_stream_read (source, buffer, sizeof (buffer), cancellable, error);
 569       if (n_read == -1)
 570         {
 571           res = FALSE;
 572           break;
 573         }
 574
 575       if (n_read == 0)
 576         break;
 577
 578       p = buffer;
 579       while (n_read > 0)
 580         {
 581           n_written = class->write_fn (stream, p, n_read, cancellable, error);
 582           if (n_written == -1)
 583             {
 584               res = FALSE;
 585               break;
 586             }
 587
 588           p += n_written;
 589           n_read -= n_written;
 590           bytes_copied += n_written;
 591         }
 592
 593       if (bytes_copied > G_MAXSSIZE)
 594         bytes_copied = G_MAXSSIZE;
 595     }
 596   while (res);
 597
 598  notsupported:
 599   if (!res)
 600     error = NULL; /* Ignore further errors */
 601
 602   if (flags & G_OUTPUT_STREAM_SPLICE_CLOSE_SOURCE)
 603     {
 604       /* Don't care about errors in source here */
 605       g_input_stream_close (source, cancellable, NULL);
 606     }
 607
 608   if (flags & G_OUTPUT_STREAM_SPLICE_CLOSE_TARGET)
 609     {
 610       /* But write errors on close are bad! */
 611       if (!g_output_stream_internal_close (stream, cancellable, error))
 612         res = FALSE;
 613     }
 614
 615   if (res)
 616     return bytes_copied;
 617
 618   return -1;
 619 }
 620
 621 /* Must always be called inside
 622  * g_output_stream_set_pending()/g_output_stream_clear_pending(). */
 623 static gboolean
 624 g_output_stream_internal_close (GOutputStream  *stream,
 625                                 GCancellable   *cancellable,
 626                                 GError        **error)
 627 {
 628   GOutputStreamClass *class;
 629   gboolean res;
 630
 631   if (stream->priv->closed)
 632     return TRUE;
 633
 634   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 635
 636   stream->priv->closing = TRUE;
 637
 638   if (cancellable)
 639     g_cancellable_push_current (cancellable);
 640
 641   if (class->flush)
 642     res = class->flush (stream, cancellable, error);
 643   else
 644     res = TRUE;
 645
 646   if (!res)
 647     {
 648       /* flushing caused the error that we want to return,
 649        * but we still want to close the underlying stream if possible
 650        */
 651       if (class->close_fn)
 652         class->close_fn (stream, cancellable, NULL);
 653     }
 654   else
 655     {
 656       res = TRUE;
 657       if (class->close_fn)
 658         res = class->close_fn (stream, cancellable, error);
 659     }
 660
 661   if (cancellable)
 662     g_cancellable_pop_current (cancellable);
 663
 664   stream->priv->closing = FALSE;
 665   stream->priv->closed = TRUE;
 666
 667   return res;
 668 }
 669
 670 /**
 671  * g_output_stream_close:
 672  * @stream: A #GOutputStream.
 673  * @cancellable: (nullable): optional cancellable object
 674  * @error: location to store the error occurring, or %NULL to ignore
 675  *
 676  * Closes the stream, releasing resources related to it.
 677  *
 678  * Once the stream is closed, all other operations will return %G_IO_ERROR_CLOSED.
 679  * Closing a stream multiple times will not return an error.
 680  *
 681  * Closing a stream will automatically flush any outstanding buffers in the
 682  * stream.
 683  *
 684  * Streams will be automatically closed when the last reference
 685  * is dropped, but you might want to call this function to make sure
 686  * resources are released as early as possible.
 687  *
 688  * Some streams might keep the backing store of the stream (e.g. a file descriptor)
 689  * open after the stream is closed. See the documentation for the individual
 690  * stream for details.
 691  *
 692  * On failure the first error that happened will be reported, but the close
 693  * operation will finish as much as possible. A stream that failed to
 694  * close will still return %G_IO_ERROR_CLOSED for all operations. Still, it
 695  * is important to check and report the error to the user, otherwise
 696  * there might be a loss of data as all data might not be written.
 697  *
 698  * If @cancellable is not %NULL, then the operation can be cancelled by
 699  * triggering the cancellable object from another thread. If the operation
 700  * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned.
 701  * Cancelling a close will still leave the stream closed, but there some streams
 702  * can use a faster close that doesn't block to e.g. check errors. On
 703  * cancellation (as with any error) there is no guarantee that all written
 704  * data will reach the target.
 705  *
 706  * Returns: %TRUE on success, %FALSE on failure
 707  **/
 708 gboolean
 709 g_output_stream_close (GOutputStream  *stream,
 710                        GCancellable   *cancellable,
 711                        GError        **error)
 712 {
 713   gboolean res;
 714
 715   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 716
 717   if (stream->priv->closed)
 718     return TRUE;
 719
 720   if (!g_output_stream_set_pending (stream, error))
 721     return FALSE;
 722
 723   res = g_output_stream_internal_close (stream, cancellable, error);
 724
 725   g_output_stream_clear_pending (stream);
 726
 727   return res;
 728 }
 729
 730 static void
 731 async_ready_write_callback_wrapper (GObject      *source_object,
 732                                     GAsyncResult *res,
 733                                     gpointer      user_data)
 734 {
 735   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 736   GOutputStreamClass *class;
 737   GTask *task = user_data;
 738   gssize nwrote;
 739   GError *error = NULL;
 740
 741   g_output_stream_clear_pending (stream);
 742
 743   if (g_async_result_legacy_propagate_error (res, &error))
 744     nwrote = -1;
 745   else
 746     {
 747       class = G_OUTPUT_STREAM_GET_CLASS (stream);
 748       nwrote = class->write_finish (stream, res, &error);
 749     }
 750
 751   if (nwrote >= 0)
 752     g_task_return_int (task, nwrote);
 753   else
 754     g_task_return_error (task, error);
 755   g_object_unref (task);
 756 }
 757
 758 /**
 759  * g_output_stream_write_async:
 760  * @stream: A #GOutputStream.
 761  * @buffer: (array length=count) (element-type guint8): the buffer containing the data to write.
 762  * @count: the number of bytes to write
 763  * @io_priority: the io priority of the request.
 764  * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
 765  * @callback: (scope async): callback to call when the request is satisfied
 766  * @user_data: (closure): the data to pass to callback function
 767  *
 768  * Request an asynchronous write of @count bytes from @buffer into
 769  * the stream. When the operation is finished @callback will be called.
 770  * You can then call g_output_stream_write_finish() to get the result of the
 771  * operation.
 772  *
 773  * During an async request no other sync and async calls are allowed,
 774  * and will result in %G_IO_ERROR_PENDING errors.
 775  *
 776  * A value of @count larger than %G_MAXSSIZE will cause a
 777  * %G_IO_ERROR_INVALID_ARGUMENT error.
 778  *
 779  * On success, the number of bytes written will be passed to the
 780  * @callback. It is not an error if this is not the same as the
 781  * requested size, as it can happen e.g. on a partial I/O error,
 782  * but generally we try to write as many bytes as requested.
 783  *
 784  * You are guaranteed that this method will never fail with
 785  * %G_IO_ERROR_WOULD_BLOCK - if @stream can't accept more data, the
 786  * method will just wait until this changes.
 787  *
 788  * Any outstanding I/O request with higher priority (lower numerical
 789  * value) will be executed before an outstanding request with lower
 790  * priority. Default priority is %G_PRIORITY_DEFAULT.
 791  *
 792  * The asynchronous methods have a default fallback that uses threads
 793  * to implement asynchronicity, so they are optional for inheriting
 794  * classes. However, if you override one you must override all.
 795  *
 796  * For the synchronous, blocking version of this function, see
 797  * g_output_stream_write().
 798  *
 799  * Note that no copy of @buffer will be made, so it must stay valid
 800  * until @callback is called. See g_output_stream_write_bytes_async()
 801  * for a #GBytes version that will automatically hold a reference to
 802  * the contents (without copying) for the duration of the call.
 803  */
 804 void
 805 g_output_stream_write_async (GOutputStream       *stream,
 806                              const void          *buffer,
 807                              gsize                count,
 808                              int                  io_priority,
 809                              GCancellable        *cancellable,
 810                              GAsyncReadyCallback  callback,
 811                              gpointer             user_data)
 812 {
 813   GOutputStreamClass *class;
 814   GError *error = NULL;
 815   GTask *task;
 816
 817   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 818   g_return_if_fail (buffer != NULL);
 819
 820   task = g_task_new (stream, cancellable, callback, user_data);
 821   g_task_set_source_tag (task, g_output_stream_write_async);
 822   g_task_set_priority (task, io_priority);
 823
 824   if (count == 0)
 825     {
 826       g_task_return_int (task, 0);
 827       g_object_unref (task);
 828       return;
 829     }
 830
 831   if (((gssize) count) < 0)
 832     {
 833       g_task_return_new_error (task, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
 834                                _("Too large count value passed to %s"),
 835                                G_STRFUNC);
 836       g_object_unref (task);
 837       return;
 838     }
 839
 840   if (!g_output_stream_set_pending (stream, &error))
 841     {
 842       g_task_return_error (task, error);
 843       g_object_unref (task);
 844       return;
 845     }
 846
 847   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 848
 849   class->write_async (stream, buffer, count, io_priority, cancellable,
 850                       async_ready_write_callback_wrapper, task);
 851 }
 852
 853 /**
 854  * g_output_stream_write_finish:
 855  * @stream: a #GOutputStream.
 856  * @result: a #GAsyncResult.
 857  * @error: a #GError location to store the error occurring, or %NULL to
 858  * ignore.
 859  *
 860  * Finishes a stream write operation.
 861  *
 862  * Returns: a #gssize containing the number of bytes written to the stream.
 863  **/
 864 gssize
 865 g_output_stream_write_finish (GOutputStream  *stream,
 866                               GAsyncResult   *result,
 867                               GError        **error)
 868 {
 869   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 870   g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
 871   g_return_val_if_fail (g_async_result_is_tagged (result, g_output_stream_write_async), FALSE);
 872
 873   /* @result is always the GTask created by g_output_stream_write_async();
 874    * we called class->write_finish() from async_ready_write_callback_wrapper.
 875    */
 876   return g_task_propagate_int (G_TASK (result), error);
 877 }
 878
 879 typedef struct
 880 {
 881   const guint8 *buffer;
 882   gsize to_write;
 883   gsize bytes_written;
 884 } AsyncWriteAll;
 885
 886 static void
 887 free_async_write_all (gpointer data)
 888 {
 889   g_slice_free (AsyncWriteAll, data);
 890 }
 891
 892 static void
 893 write_all_callback (GObject      *stream,
 894                     GAsyncResult *result,
 895                     gpointer      user_data)
 896 {
 897   GTask *task = user_data;
 898   AsyncWriteAll *data = g_task_get_task_data (task);
 899
 900   if (result)
 901     {
 902       GError *error = NULL;
 903       gssize nwritten;
 904
 905       nwritten = g_output_stream_write_finish (G_OUTPUT_STREAM (stream), result, &error);
 906
 907       if (nwritten == -1)
 908         {
 909           g_task_return_error (task, error);
 910           g_object_unref (task);
 911           return;
 912         }
 913
 914       g_assert_cmpint (nwritten, <=, data->to_write);
 915       g_warn_if_fail (nwritten > 0);
 916
 917       data->to_write -= nwritten;
 918       data->bytes_written += nwritten;
 919     }
 920
 921   if (data->to_write == 0)
 922     {
 923       g_task_return_boolean (task, TRUE);
 924       g_object_unref (task);
 925     }
 926
 927   else
 928     g_output_stream_write_async (G_OUTPUT_STREAM (stream),
 929                                  data->buffer + data->bytes_written,
 930                                  data->to_write,
 931                                  g_task_get_priority (task),
 932                                  g_task_get_cancellable (task),
 933                                  write_all_callback, task);
 934 }
 935
 936 static void
 937 write_all_async_thread (GTask        *task,
 938                         gpointer      source_object,
 939                         gpointer      task_data,
 940                         GCancellable *cancellable)
 941 {
 942   GOutputStream *stream = source_object;
 943   AsyncWriteAll *data = task_data;
 944   GError *error = NULL;
 945
 946   if (g_output_stream_write_all (stream, data->buffer, data->to_write, &data->bytes_written,
 947                                  g_task_get_cancellable (task), &error))
 948     g_task_return_boolean (task, TRUE);
 949   else
 950     g_task_return_error (task, error);
 951 }
 952
 953 /**
 954  * g_output_stream_write_all_async:
 955  * @stream: A #GOutputStream
 956  * @buffer: (array length=count) (element-type guint8): the buffer containing the data to write
 957  * @count: the number of bytes to write
 958  * @io_priority: the io priority of the request
 959  * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore
 960  * @callback: (scope async): callback to call when the request is satisfied
 961  * @user_data: (closure): the data to pass to callback function
 962  *
 963  * Request an asynchronous write of @count bytes from @buffer into
 964  * the stream. When the operation is finished @callback will be called.
 965  * You can then call g_output_stream_write_all_finish() to get the result of the
 966  * operation.
 967  *
 968  * This is the asynchronous version of g_output_stream_write_all().
 969  *
 970  * Call g_output_stream_write_all_finish() to collect the result.
 971  *
 972  * Any outstanding I/O request with higher priority (lower numerical
 973  * value) will be executed before an outstanding request with lower
 974  * priority. Default priority is %G_PRIORITY_DEFAULT.
 975  *
 976  * Note that no copy of @buffer will be made, so it must stay valid
 977  * until @callback is called.
 978  *
 979  * Since: 2.44
 980  */
 981 void
 982 g_output_stream_write_all_async (GOutputStream       *stream,
 983                                  const void          *buffer,
 984                                  gsize                count,
 985                                  int                  io_priority,
 986                                  GCancellable        *cancellable,
 987                                  GAsyncReadyCallback  callback,
 988                                  gpointer             user_data)
 989 {
 990   AsyncWriteAll *data;
 991   GTask *task;
 992
 993   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 994   g_return_if_fail (buffer != NULL || count == 0);
 995
 996   task = g_task_new (stream, cancellable, callback, user_data);
 997   data = g_slice_new0 (AsyncWriteAll);
 998   data->buffer = buffer;
 999   data->to_write = count;
1000
1001   g_task_set_source_tag (task, g_output_stream_write_all_async);
1002   g_task_set_task_data (task, data, free_async_write_all);
1003   g_task_set_priority (task, io_priority);
1004
1005   /* If async writes are going to be handled via the threadpool anyway
1006    * then we may as well do it with a single dispatch instead of
1007    * bouncing in and out.
1008    */
1009   if (g_output_stream_async_write_is_via_threads (stream))
1010     {
1011       g_task_run_in_thread (task, write_all_async_thread);
1012       g_object_unref (task);
1013     }
1014   else
1015     write_all_callback (G_OBJECT (stream), NULL, task);
1016 }
1017
1018 /**
1019  * g_output_stream_write_all_finish:
1020  * @stream: a #GOutputStream
1021  * @result: a #GAsyncResult
1022  * @bytes_written: (out): location to store the number of bytes that was written to the stream
1023  * @error: a #GError location to store the error occurring, or %NULL to ignore.
1024  *
1025  * Finishes an asynchronous stream write operation started with
1026  * g_output_stream_write_all_async().
1027  *
1028  * As a special exception to the normal conventions for functions that
1029  * use #GError, if this function returns %FALSE (and sets @error) then
1030  * @bytes_written will be set to the number of bytes that were
1031  * successfully written before the error was encountered.  This
1032  * functionality is only available from C.  If you need it from another
1033  * language then you must write your own loop around
1034  * g_output_stream_write_async().
1035  *
1036  * Returns: %TRUE on success, %FALSE if there was an error
1037  *
1038  * Since: 2.44
1039  **/
1040 gboolean
1041 g_output_stream_write_all_finish (GOutputStream  *stream,
1042                                   GAsyncResult   *result,
1043                                   gsize          *bytes_written,
1044                                   GError        **error)
1045 {
1046   GTask *task;
1047
1048   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1049   g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
1050
1051   task = G_TASK (result);
1052
1053   if (bytes_written)
1054     {
1055       AsyncWriteAll *data = (AsyncWriteAll *)g_task_get_task_data (task);
1056
1057       *bytes_written = data->bytes_written;
1058     }
1059
1060   return g_task_propagate_boolean (task, error);
1061 }
1062
1063 static void
1064 write_bytes_callback (GObject      *stream,
1065                       GAsyncResult *result,
1066                       gpointer      user_data)
1067 {
1068   GTask *task = user_data;
1069   GError *error = NULL;
1070   gssize nwrote;
1071
1072   nwrote = g_output_stream_write_finish (G_OUTPUT_STREAM (stream),
1073                                          result, &error);
1074   if (nwrote == -1)
1075     g_task_return_error (task, error);
1076   else
1077     g_task_return_int (task, nwrote);
1078   g_object_unref (task);
1079 }
1080
1081 /**
1082  * g_output_stream_write_bytes_async:
1083  * @stream: A #GOutputStream.
1084  * @bytes: The bytes to write
1085  * @io_priority: the io priority of the request.
1086  * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
1087  * @callback: (scope async): callback to call when the request is satisfied
1088  * @user_data: (closure): the data to pass to callback function
1089  *
1090  * This function is similar to g_output_stream_write_async(), but
1091  * takes a #GBytes as input.  Due to the refcounted nature of #GBytes,
1092  * this allows the stream to avoid taking a copy of the data.
1093  *
1094  * However, note that this function may still perform partial writes,
1095  * just like g_output_stream_write_async(). If that occurs, to continue
1096  * writing, you will need to create a new #GBytes containing just the
1097  * remaining bytes, using g_bytes_new_from_bytes(). Passing the same
1098  * #GBytes instance multiple times potentially can result in duplicated
1099  * data in the output stream.
1100  *
1101  * For the synchronous, blocking version of this function, see
1102  * g_output_stream_write_bytes().
1103  **/
1104 void
1105 g_output_stream_write_bytes_async (GOutputStream       *stream,
1106                                    GBytes              *bytes,
1107                                    int                  io_priority,
1108                                    GCancellable        *cancellable,
1109                                    GAsyncReadyCallback  callback,
1110                                    gpointer             user_data)
1111 {
1112   GTask *task;
1113   gsize size;
1114   gconstpointer data;
1115
1116   data = g_bytes_get_data (bytes, &size);
1117
1118   task = g_task_new (stream, cancellable, callback, user_data);
1119   g_task_set_source_tag (task, g_output_stream_write_bytes_async);
1120   g_task_set_task_data (task, g_bytes_ref (bytes),
1121                         (GDestroyNotify) g_bytes_unref);
1122
1123   g_output_stream_write_async (stream,
1124                                data, size,
1125                                io_priority,
1126                                cancellable,
1127                                write_bytes_callback,
1128                                task);
1129 }
1130
1131 /**
1132  * g_output_stream_write_bytes_finish:
1133  * @stream: a #GOutputStream.
1134  * @result: a #GAsyncResult.
1135  * @error: a #GError location to store the error occurring, or %NULL to
1136  * ignore.
1137  *
1138  * Finishes a stream write-from-#GBytes operation.
1139  *
1140  * Returns: a #gssize containing the number of bytes written to the stream.
1141  **/
1142 gssize
1143 g_output_stream_write_bytes_finish (GOutputStream  *stream,
1144                                     GAsyncResult   *result,
1145                                     GError        **error)
1146 {
1147   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
1148   g_return_val_if_fail (g_task_is_valid (result, stream), -1);
1149
1150   return g_task_propagate_int (G_TASK (result), error);
1151 }
1152
1153 static void
1154 async_ready_splice_callback_wrapper (GObject      *source_object,
1155                                      GAsyncResult *res,
1156                                      gpointer     _data)
1157 {
1158   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
1159   GOutputStreamClass *class;
1160   GTask *task = _data;
1161   gssize nspliced;
1162   GError *error = NULL;
1163
1164   g_output_stream_clear_pending (stream);
1165
1166   if (g_async_result_legacy_propagate_error (res, &error))
1167     nspliced = -1;
1168   else
1169     {
1170       class = G_OUTPUT_STREAM_GET_CLASS (stream);
1171       nspliced = class->splice_finish (stream, res, &error);
1172     }
1173
1174   if (nspliced >= 0)
1175     g_task_return_int (task, nspliced);
1176   else
1177     g_task_return_error (task, error);
1178   g_object_unref (task);
1179 }
1180
1181 /**
1182  * g_output_stream_splice_async:
1183  * @stream: a #GOutputStream.
1184  * @source: a #GInputStream.
1185  * @flags: a set of #GOutputStreamSpliceFlags.
1186  * @io_priority: the io priority of the request.
1187  * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
1188  * @callback: (scope async): a #GAsyncReadyCallback.
1189  * @user_data: (closure): user data passed to @callback.
1190  *
1191  * Splices a stream asynchronously.
1192  * When the operation is finished @callback will be called.
1193  * You can then call g_output_stream_splice_finish() to get the
1194  * result of the operation.
1195  *
1196  * For the synchronous, blocking version of this function, see
1197  * g_output_stream_splice().
1198  **/
1199 void
1200 g_output_stream_splice_async (GOutputStream            *stream,
1201                               GInputStream             *source,
1202                               GOutputStreamSpliceFlags  flags,
1203                               int                       io_priority,
1204                               GCancellable             *cancellable,
1205                               GAsyncReadyCallback       callback,
1206                               gpointer                  user_data)
1207 {
1208   GOutputStreamClass *class;
1209   GTask *task;
1210   GError *error = NULL;
1211
1212   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
1213   g_return_if_fail (G_IS_INPUT_STREAM (source));
1214
1215   task = g_task_new (stream, cancellable, callback, user_data);
1216   g_task_set_source_tag (task, g_output_stream_splice_async);
1217   g_task_set_priority (task, io_priority);
1218   g_task_set_task_data (task, g_object_ref (source), g_object_unref);
1219
1220   if (g_input_stream_is_closed (source))
1221     {
1222       g_task_return_new_error (task,
1223                                G_IO_ERROR, G_IO_ERROR_CLOSED,
1224                                _("Source stream is already closed"));
1225       g_object_unref (task);
1226       return;
1227     }
1228
1229   if (!g_output_stream_set_pending (stream, &error))
1230     {
1231       g_task_return_error (task, error);
1232       g_object_unref (task);
1233       return;
1234     }
1235
1236   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1237
1238   class->splice_async (stream, source, flags, io_priority, cancellable,
1239                        async_ready_splice_callback_wrapper, task);
1240 }
1241
1242 /**
1243  * g_output_stream_splice_finish:
1244  * @stream: a #GOutputStream.
1245  * @result: a #GAsyncResult.
1246  * @error: a #GError location to store the error occurring, or %NULL to
1247  * ignore.
1248  *
1249  * Finishes an asynchronous stream splice operation.
1250  *
1251  * Returns: a #gssize of the number of bytes spliced. Note that if the
1252  *     number of bytes spliced is greater than %G_MAXSSIZE, then that
1253  *     will be returned, and there is no way to determine the actual
1254  *     number of bytes spliced.
1255  **/
1256 gssize
1257 g_output_stream_splice_finish (GOutputStream  *stream,
1258                                GAsyncResult   *result,
1259                                GError        **error)
1260 {
1261   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1262   g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
1263   g_return_val_if_fail (g_async_result_is_tagged (result, g_output_stream_splice_async), FALSE);
1264
1265   /* @result is always the GTask created by g_output_stream_splice_async();
1266    * we called class->splice_finish() from async_ready_splice_callback_wrapper.
1267    */
1268   return g_task_propagate_int (G_TASK (result), error);
1269 }
1270
1271 static void
1272 async_ready_flush_callback_wrapper (GObject      *source_object,
1273                                     GAsyncResult *res,
1274                                     gpointer      user_data)
1275 {
1276   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
1277   GOutputStreamClass *class;
1278   GTask *task = user_data;
1279   gboolean flushed;
1280   GError *error = NULL;
1281
1282   g_output_stream_clear_pending (stream);
1283
1284   if (g_async_result_legacy_propagate_error (res, &error))
1285     flushed = FALSE;
1286   else
1287     {
1288       class = G_OUTPUT_STREAM_GET_CLASS (stream);
1289       flushed = class->flush_finish (stream, res, &error);
1290     }
1291
1292   if (flushed)
1293     g_task_return_boolean (task, TRUE);
1294   else
1295     g_task_return_error (task, error);
1296   g_object_unref (task);
1297 }
1298
1299 /**
1300  * g_output_stream_flush_async:
1301  * @stream: a #GOutputStream.
1302  * @io_priority: the io priority of the request.
1303  * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
1304  * @callback: (scope async): a #GAsyncReadyCallback to call when the request is satisfied
1305  * @user_data: (closure): the data to pass to callback function
1306  *
1307  * Forces an asynchronous write of all user-space buffered data for
1308  * the given @stream.
1309  * For behaviour details see g_output_stream_flush().
1310  *
1311  * When the operation is finished @callback will be
1312  * called. You can then call g_output_stream_flush_finish() to get the
1313  * result of the operation.
1314  **/
1315 void
1316 g_output_stream_flush_async (GOutputStream       *stream,
1317                              int                  io_priority,
1318                              GCancellable        *cancellable,
1319                              GAsyncReadyCallback  callback,
1320                              gpointer             user_data)
1321 {
1322   GOutputStreamClass *class;
1323   GTask *task;
1324   GError *error = NULL;
1325
1326   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
1327
1328   task = g_task_new (stream, cancellable, callback, user_data);
1329   g_task_set_source_tag (task, g_output_stream_flush_async);
1330   g_task_set_priority (task, io_priority);
1331
1332   if (!g_output_stream_set_pending (stream, &error))
1333     {
1334       g_task_return_error (task, error);
1335       g_object_unref (task);
1336       return;
1337     }
1338
1339   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1340
1341   if (class->flush_async == NULL)
1342     {
1343       g_task_return_boolean (task, TRUE);
1344       g_object_unref (task);
1345       return;
1346     }
1347
1348   class->flush_async (stream, io_priority, cancellable,
1349                       async_ready_flush_callback_wrapper, task);
1350 }
1351
1352 /**
1353  * g_output_stream_flush_finish:
1354  * @stream: a #GOutputStream.
1355  * @result: a GAsyncResult.
1356  * @error: a #GError location to store the error occurring, or %NULL to
1357  * ignore.
1358  *
1359  * Finishes flushing an output stream.
1360  *
1361  * Returns: %TRUE if flush operation succeeded, %FALSE otherwise.
1362  **/
1363 gboolean
1364 g_output_stream_flush_finish (GOutputStream  *stream,
1365                               GAsyncResult   *result,
1366                               GError        **error)
1367 {
1368   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1369   g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
1370   g_return_val_if_fail (g_async_result_is_tagged (result, g_output_stream_flush_async), FALSE);
1371
1372   /* @result is always the GTask created by g_output_stream_flush_async();
1373    * we called class->flush_finish() from async_ready_flush_callback_wrapper.
1374    */
1375   return g_task_propagate_boolean (G_TASK (result), error);
1376 }
1377
1378
1379 static void
1380 async_ready_close_callback_wrapper (GObject      *source_object,
1381                                     GAsyncResult *res,
1382                                     gpointer      user_data)
1383 {
1384   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
1385   GOutputStreamClass *class;
1386   GTask *task = user_data;
1387   GError *error = g_task_get_task_data (task);
1388
1389   stream->priv->closing = FALSE;
1390   stream->priv->closed = TRUE;
1391
1392   if (!error && !g_async_result_legacy_propagate_error (res, &error))
1393     {
1394       class = G_OUTPUT_STREAM_GET_CLASS (stream);
1395
1396       class->close_finish (stream, res,
1397                            error ? NULL : &error);
1398     }
1399
1400   if (error != NULL)
1401     g_task_return_error (task, error);
1402   else
1403     g_task_return_boolean (task, TRUE);
1404   g_object_unref (task);
1405 }
1406
1407 static void
1408 async_ready_close_flushed_callback_wrapper (GObject      *source_object,
1409                                             GAsyncResult *res,
1410                                             gpointer      user_data)
1411 {
1412   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
1413   GOutputStreamClass *class;
1414   GTask *task = user_data;
1415   GError *error = NULL;
1416
1417   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1418
1419   if (!g_async_result_legacy_propagate_error (res, &error))
1420     {
1421       class->flush_finish (stream, res, &error);
1422     }
1423
1424   /* propagate the possible error */
1425   if (error)
1426     g_task_set_task_data (task, error, NULL);
1427
1428   /* we still close, even if there was a flush error */
1429   class->close_async (stream,
1430                       g_task_get_priority (task),
1431                       g_task_get_cancellable (task),
1432                       async_ready_close_callback_wrapper, task);
1433 }
1434
1435 static void
1436 real_close_async_cb (GObject      *source_object,
1437                      GAsyncResult *res,
1438                      gpointer      user_data)
1439 {
1440   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
1441   GTask *task = user_data;
1442   GError *error = NULL;
1443   gboolean ret;
1444
1445   g_output_stream_clear_pending (stream);
1446
1447   ret = g_output_stream_internal_close_finish (stream, res, &error);
1448
1449   if (error != NULL)
1450     g_task_return_error (task, error);
1451   else
1452     g_task_return_boolean (task, ret);
1453
1454   g_object_unref (task);
1455 }
1456
1457 /**
1458  * g_output_stream_close_async:
1459  * @stream: A #GOutputStream.
1460  * @io_priority: the io priority of the request.
1461  * @cancellable: (nullable): optional cancellable object
1462  * @callback: (scope async): callback to call when the request is satisfied
1463  * @user_data: (closure): the data to pass to callback function
1464  *
1465  * Requests an asynchronous close of the stream, releasing resources
1466  * related to it. When the operation is finished @callback will be
1467  * called. You can then call g_output_stream_close_finish() to get
1468  * the result of the operation.
1469  *
1470  * For behaviour details see g_output_stream_close().
1471  *
1472  * The asynchronous methods have a default fallback that uses threads
1473  * to implement asynchronicity, so they are optional for inheriting
1474  * classes. However, if you override one you must override all.
1475  **/
1476 void
1477 g_output_stream_close_async (GOutputStream       *stream,
1478                              int                  io_priority,
1479                              GCancellable        *cancellable,
1480                              GAsyncReadyCallback  callback,
1481                              gpointer             user_data)
1482 {
1483   GTask *task;
1484   GError *error = NULL;
1485
1486   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
1487
1488   task = g_task_new (stream, cancellable, callback, user_data);
1489   g_task_set_source_tag (task, g_output_stream_close_async);
1490   g_task_set_priority (task, io_priority);
1491
1492   if (!g_output_stream_set_pending (stream, &error))
1493     {
1494       g_task_return_error (task, error);
1495       g_object_unref (task);
1496       return;
1497     }
1498
1499   g_output_stream_internal_close_async (stream, io_priority, cancellable,
1500                                         real_close_async_cb, task);
1501 }
1502
1503 /* Must always be called inside
1504  * g_output_stream_set_pending()/g_output_stream_clear_pending().
1505  */
1506 void
1507 g_output_stream_internal_close_async (GOutputStream       *stream,
1508                                       int                  io_priority,
1509                                       GCancellable        *cancellable,
1510                                       GAsyncReadyCallback  callback,
1511                                       gpointer             user_data)
1512 {
1513   GOutputStreamClass *class;
1514   GTask *task;
1515
1516   task = g_task_new (stream, cancellable, callback, user_data);
1517   g_task_set_source_tag (task, g_output_stream_internal_close_async);
1518   g_task_set_priority (task, io_priority);
1519
1520   if (stream->priv->closed)
1521     {
1522       g_task_return_boolean (task, TRUE);
1523       g_object_unref (task);
1524       return;
1525     }
1526
1527   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1528   stream->priv->closing = TRUE;
1529
1530   /* Call close_async directly if there is no need to flush, or if the flush
1531      can be done sync (in the output stream async close thread) */
1532   if (class->flush_async == NULL ||
1533       (class->flush_async == g_output_stream_real_flush_async &&
1534        (class->flush == NULL || class->close_async == g_output_stream_real_close_async)))
1535     {
1536       class->close_async (stream, io_priority, cancellable,
1537                           async_ready_close_callback_wrapper, task);
1538     }
1539   else
1540     {
1541       /* First do an async flush, then do the async close in the callback
1542          wrapper (see async_ready_close_flushed_callback_wrapper) */
1543       class->flush_async (stream, io_priority, cancellable,
1544                           async_ready_close_flushed_callback_wrapper, task);
1545     }
1546 }
1547
1548 static gboolean
1549 g_output_stream_internal_close_finish (GOutputStream  *stream,
1550                                        GAsyncResult   *result,
1551                                        GError        **error)
1552 {
1553   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1554   g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
1555   g_return_val_if_fail (g_async_result_is_tagged (result, g_output_stream_internal_close_async), FALSE);
1556
1557   return g_task_propagate_boolean (G_TASK (result), error);
1558 }
1559
1560 /**
1561  * g_output_stream_close_finish:
1562  * @stream: a #GOutputStream.
1563  * @result: a #GAsyncResult.
1564  * @error: a #GError location to store the error occurring, or %NULL to
1565  * ignore.
1566  *
1567  * Closes an output stream.
1568  *
1569  * Returns: %TRUE if stream was successfully closed, %FALSE otherwise.
1570  **/
1571 gboolean
1572 g_output_stream_close_finish (GOutputStream  *stream,
1573                               GAsyncResult   *result,
1574                               GError        **error)
1575 {
1576   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1577   g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
1578   g_return_val_if_fail (g_async_result_is_tagged (result, g_output_stream_close_async), FALSE);
1579
1580   /* @result is always the GTask created by g_output_stream_close_async();
1581    * we called class->close_finish() from async_ready_close_callback_wrapper.
1582    */
1583   return g_task_propagate_boolean (G_TASK (result), error);
1584 }
1585
1586 /**
1587  * g_output_stream_is_closed:
1588  * @stream: a #GOutputStream.
1589  *
1590  * Checks if an output stream has already been closed.
1591  *
1592  * Returns: %TRUE if @stream is closed. %FALSE otherwise.
1593  **/
1594 gboolean
1595 g_output_stream_is_closed (GOutputStream *stream)
1596 {
1597   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), TRUE);
1598
1599   return stream->priv->closed;
1600 }
1601
1602 /**
1603  * g_output_stream_is_closing:
1604  * @stream: a #GOutputStream.
1605  *
1606  * Checks if an output stream is being closed. This can be
1607  * used inside e.g. a flush implementation to see if the
1608  * flush (or other i/o operation) is called from within
1609  * the closing operation.
1610  *
1611  * Returns: %TRUE if @stream is being closed. %FALSE otherwise.
1612  *
1613  * Since: 2.24
1614  **/
1615 gboolean
1616 g_output_stream_is_closing (GOutputStream *stream)
1617 {
1618   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), TRUE);
1619
1620   return stream->priv->closing;
1621 }
1622
1623 /**
1624  * g_output_stream_has_pending:
1625  * @stream: a #GOutputStream.
1626  *
1627  * Checks if an output stream has pending actions.
1628  *
1629  * Returns: %TRUE if @stream has pending actions.
1630  **/
1631 gboolean
1632 g_output_stream_has_pending (GOutputStream *stream)
1633 {
1634   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1635
1636   return stream->priv->pending;
1637 }
1638
1639 /**
1640  * g_output_stream_set_pending:
1641  * @stream: a #GOutputStream.
1642  * @error: a #GError location to store the error occurring, or %NULL to
1643  * ignore.
1644  *
1645  * Sets @stream to have actions pending. If the pending flag is
1646  * already set or @stream is closed, it will return %FALSE and set
1647  * @error.
1648  *
1649  * Returns: %TRUE if pending was previously unset and is now set.
1650  **/
1651 gboolean
1652 g_output_stream_set_pending (GOutputStream *stream,
1653                              GError **error)
1654 {
1655   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1656
1657   if (stream->priv->closed)
1658     {
1659       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
1660                            _("Stream is already closed"));
1661       return FALSE;
1662     }
1663
1664   if (stream->priv->pending)
1665     {
1666       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PENDING,
1667                            /* Translators: This is an error you get if there is
1668                             * already an operation running against this stream when
1669                             * you try to start one */
1670                            _("Stream has outstanding operation"));
1671       return FALSE;
1672     }
1673
1674   stream->priv->pending = TRUE;
1675   return TRUE;
1676 }
1677
1678 /**
1679  * g_output_stream_clear_pending:
1680  * @stream: output stream
1681  *
1682  * Clears the pending flag on @stream.
1683  **/
1684 void
1685 g_output_stream_clear_pending (GOutputStream *stream)
1686 {
1687   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
1688
1689   stream->priv->pending = FALSE;
1690 }
1691
1692 /*< internal >
1693  * g_output_stream_async_write_is_via_threads:
1694  * @stream: a #GOutputStream.
1695  *
1696  * Checks if an output stream's write_async function uses threads.
1697  *
1698  * Returns: %TRUE if @stream's write_async function uses threads.
1699  **/
1700 gboolean
1701 g_output_stream_async_write_is_via_threads (GOutputStream *stream)
1702 {
1703   GOutputStreamClass *class;
1704
1705   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1706
1707   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1708
1709   return (class->write_async == g_output_stream_real_write_async &&
1710       !(G_IS_POLLABLE_OUTPUT_STREAM (stream) &&
1711         g_pollable_output_stream_can_poll (G_POLLABLE_OUTPUT_STREAM (stream))));
1712 }
1713
1714 /*< internal >
1715  * g_output_stream_async_close_is_via_threads:
1716  * @stream: output stream
1717  *
1718  * Checks if an output stream's close_async function uses threads.
1719  *
1720  * Returns: %TRUE if @stream's close_async function uses threads.
1721  **/
1722 gboolean
1723 g_output_stream_async_close_is_via_threads (GOutputStream *stream)
1724 {
1725   GOutputStreamClass *class;
1726
1727   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1728
1729   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1730
1731   return class->close_async == g_output_stream_real_close_async;
1732 }
1733
1734 /********************************************
1735  *   Default implementation of async ops    *
1736  ********************************************/
1737
1738 typedef struct {
1739   const void         *buffer;
1740   gsize               count_requested;
1741   gssize              count_written;
1742 } WriteData;
1743
1744 static void
1745 free_write_data (WriteData *op)
1746 {
1747   g_slice_free (WriteData, op);
1748 }
1749
1750 static void
1751 write_async_thread (GTask        *task,
1752                     gpointer      source_object,
1753                     gpointer      task_data,
1754                     GCancellable *cancellable)
1755 {
1756   GOutputStream *stream = source_object;
1757   WriteData *op = task_data;
1758   GOutputStreamClass *class;
1759   GError *error = NULL;
1760   gssize count_written;
1761
1762   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1763   count_written = class->write_fn (stream, op->buffer, op->count_requested,
1764                                    cancellable, &error);
1765   if (count_written == -1)
1766     g_task_return_error (task, error);
1767   else
1768     g_task_return_int (task, count_written);
1769 }
1770
1771 static void write_async_pollable (GPollableOutputStream *stream,
1772                                   GTask                 *task);
1773
1774 static gboolean
1775 write_async_pollable_ready (GPollableOutputStream *stream,
1776                             gpointer               user_data)
1777 {
1778   GTask *task = user_data;
1779
1780   write_async_pollable (stream, task);
1781   return FALSE;
1782 }
1783
1784 static void
1785 write_async_pollable (GPollableOutputStream *stream,
1786                       GTask                 *task)
1787 {
1788   GError *error = NULL;
1789   WriteData *op = g_task_get_task_data (task);
1790   gssize count_written;
1791
1792   if (g_task_return_error_if_cancelled (task))
1793     return;
1794
1795   count_written = G_POLLABLE_OUTPUT_STREAM_GET_INTERFACE (stream)->
1796     write_nonblocking (stream, op->buffer, op->count_requested, &error);
1797
1798   if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_WOULD_BLOCK))
1799     {
1800       GSource *source;
1801
1802       g_error_free (error);
1803
1804       source = g_pollable_output_stream_create_source (stream,
1805                                                        g_task_get_cancellable (task));
1806       g_task_attach_source (task, source,
1807                             (GSourceFunc) write_async_pollable_ready);
1808       g_source_unref (source);
1809       return;
1810     }
1811
1812   if (count_written == -1)
1813     g_task_return_error (task, error);
1814   else
1815     g_task_return_int (task, count_written);
1816 }
1817
1818 static void
1819 g_output_stream_real_write_async (GOutputStream       *stream,
1820                                   const void          *buffer,
1821                                   gsize                count,
1822                                   int                  io_priority,
1823                                   GCancellable        *cancellable,
1824                                   GAsyncReadyCallback  callback,
1825                                   gpointer             user_data)
1826 {
1827   GTask *task;
1828   WriteData *op;
1829
1830   op = g_slice_new0 (WriteData);
1831   task = g_task_new (stream, cancellable, callback, user_data);
1832   g_task_set_check_cancellable (task, FALSE);
1833   g_task_set_task_data (task, op, (GDestroyNotify) free_write_data);
1834   op->buffer = buffer;
1835   op->count_requested = count;
1836
1837   if (!g_output_stream_async_write_is_via_threads (stream))
1838     write_async_pollable (G_POLLABLE_OUTPUT_STREAM (stream), task);
1839   else
1840     g_task_run_in_thread (task, write_async_thread);
1841   g_object_unref (task);
1842 }
1843
1844 static gssize
1845 g_output_stream_real_write_finish (GOutputStream  *stream,
1846                                    GAsyncResult   *result,
1847                                    GError        **error)
1848 {
1849   g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
1850
1851   return g_task_propagate_int (G_TASK (result), error);
1852 }
1853
1854 typedef struct {
1855   GInputStream *source;
1856   GOutputStreamSpliceFlags flags;
1857   gssize n_read;
1858   gssize n_written;
1859   gsize bytes_copied;
1860   GError *error;
1861   guint8 *buffer;
1862 } SpliceData;
1863
1864 static void
1865 free_splice_data (SpliceData *op)
1866 {
1867   g_clear_pointer (&op->buffer, g_free);
1868   g_object_unref (op->source);
1869   g_clear_error (&op->error);
1870   g_free (op);
1871 }
1872
1873 static void
1874 real_splice_async_complete_cb (GTask *task)
1875 {
1876   SpliceData *op = g_task_get_task_data (task);
1877
1878   if (op->flags & G_OUTPUT_STREAM_SPLICE_CLOSE_SOURCE &&
1879       !g_input_stream_is_closed (op->source))
1880     return;
1881
1882   if (op->flags & G_OUTPUT_STREAM_SPLICE_CLOSE_TARGET &&
1883       !g_output_stream_is_closed (g_task_get_source_object (task)))
1884     return;
1885
1886   if (op->error != NULL)
1887     {
1888       g_task_return_error (task, op->error);
1889       op->error = NULL;
1890     }
1891   else
1892     {
1893       g_task_return_int (task, op->bytes_copied);
1894     }
1895
1896   g_object_unref (task);
1897 }
1898
1899 static void
1900 real_splice_async_close_input_cb (GObject      *source,
1901                                   GAsyncResult *res,
1902                                   gpointer      user_data)
1903 {
1904   GTask *task = user_data;
1905
1906   g_input_stream_close_finish (G_INPUT_STREAM (source), res, NULL);
1907
1908   real_splice_async_complete_cb (task);
1909 }
1910
1911 static void
1912 real_splice_async_close_output_cb (GObject      *source,
1913                                    GAsyncResult *res,
1914                                    gpointer      user_data)
1915 {
1916   GTask *task = G_TASK (user_data);
1917   SpliceData *op = g_task_get_task_data (task);
1918   GError **error = (op->error == NULL) ? &op->error : NULL;
1919
1920   g_output_stream_internal_close_finish (G_OUTPUT_STREAM (source), res, error);
1921
1922   real_splice_async_complete_cb (task);
1923 }
1924
1925 static void
1926 real_splice_async_complete (GTask *task)
1927 {
1928   SpliceData *op = g_task_get_task_data (task);
1929   gboolean done = TRUE;
1930
1931   if (op->flags & G_OUTPUT_STREAM_SPLICE_CLOSE_SOURCE)
1932     {
1933       done = FALSE;
1934       g_input_stream_close_async (op->source, g_task_get_priority (task),
1935                                   g_task_get_cancellable (task),
1936                                   real_splice_async_close_input_cb, task);
1937     }
1938
1939   if (op->flags & G_OUTPUT_STREAM_SPLICE_CLOSE_TARGET)
1940     {
1941       done = FALSE;
1942       g_output_stream_internal_close_async (g_task_get_source_object (task),
1943                                             g_task_get_priority (task),
1944                                             g_task_get_cancellable (task),
1945                                             real_splice_async_close_output_cb,
1946                                             task);
1947     }
1948
1949   if (done)
1950     real_splice_async_complete_cb (task);
1951 }
1952
1953 static void real_splice_async_read_cb (GObject      *source,
1954                                        GAsyncResult *res,
1955                                        gpointer      user_data);
1956
1957 static void
1958 real_splice_async_write_cb (GObject      *source,
1959                             GAsyncResult *res,
1960                             gpointer      user_data)
1961 {
1962   GOutputStreamClass *class;
1963   GTask *task = G_TASK (user_data);
1964   SpliceData *op = g_task_get_task_data (task);
1965   gssize ret;
1966
1967   class = G_OUTPUT_STREAM_GET_CLASS (g_task_get_source_object (task));
1968
1969   ret = class->write_finish (G_OUTPUT_STREAM (source), res, &op->error);
1970
1971   if (ret == -1)
1972     {
1973       real_splice_async_complete (task);
1974       return;
1975     }
1976
1977   op->n_written += ret;
1978   op->bytes_copied += ret;
1979   if (op->bytes_copied > G_MAXSSIZE)
1980     op->bytes_copied = G_MAXSSIZE;
1981
1982   if (op->n_written < op->n_read)
1983     {
1984       class->write_async (g_task_get_source_object (task),
1985                           op->buffer + op->n_written,
1986                           op->n_read - op->n_written,
1987                           g_task_get_priority (task),
1988                           g_task_get_cancellable (task),
1989                           real_splice_async_write_cb, task);
1990       return;
1991     }
1992
1993   g_input_stream_read_async (op->source, op->buffer, 8192,
1994                              g_task_get_priority (task),
1995                              g_task_get_cancellable (task),
1996                              real_splice_async_read_cb, task);
1997 }
1998
1999 static void
2000 real_splice_async_read_cb (GObject      *source,
2001                            GAsyncResult *res,
2002                            gpointer      user_data)
2003 {
2004   GOutputStreamClass *class;
2005   GTask *task = G_TASK (user_data);
2006   SpliceData *op = g_task_get_task_data (task);
2007   gssize ret;
2008
2009   class = G_OUTPUT_STREAM_GET_CLASS (g_task_get_source_object (task));
2010
2011   ret = g_input_stream_read_finish (op->source, res, &op->error);
2012   if (ret == -1 || ret == 0)
2013     {
2014       real_splice_async_complete (task);
2015       return;
2016     }
2017
2018   op->n_read = ret;
2019   op->n_written = 0;
2020
2021   class->write_async (g_task_get_source_object (task), op->buffer,
2022                       op->n_read, g_task_get_priority (task),
2023                       g_task_get_cancellable (task),
2024                       real_splice_async_write_cb, task);
2025 }
2026
2027 static void
2028 splice_async_thread (GTask        *task,
2029                      gpointer      source_object,
2030                      gpointer      task_data,
2031                      GCancellable *cancellable)
2032 {
2033   GOutputStream *stream = source_object;
2034   SpliceData *op = task_data;
2035   GOutputStreamClass *class;
2036   GError *error = NULL;
2037   gssize bytes_copied;
2038
2039   class = G_OUTPUT_STREAM_GET_CLASS (stream);
2040
2041   bytes_copied = class->splice (stream,
2042                                 op->source,
2043                                 op->flags,
2044                                 cancellable,
2045                                 &error);
2046   if (bytes_copied == -1)
2047     g_task_return_error (task, error);
2048   else
2049     g_task_return_int (task, bytes_copied);
2050 }
2051
2052 static void
2053 g_output_stream_real_splice_async (GOutputStream             *stream,
2054                                    GInputStream              *source,
2055                                    GOutputStreamSpliceFlags   flags,
2056                                    int                        io_priority,
2057                                    GCancellable              *cancellable,
2058                                    GAsyncReadyCallback        callback,
2059                                    gpointer                   user_data)
2060 {
2061   GTask *task;
2062   SpliceData *op;
2063
2064   op = g_new0 (SpliceData, 1);
2065   task = g_task_new (stream, cancellable, callback, user_data);
2066   g_task_set_task_data (task, op, (GDestroyNotify)free_splice_data);
2067   op->flags = flags;
2068   op->source = g_object_ref (source);
2069
2070   if (g_input_stream_async_read_is_via_threads (source) &&
2071       g_output_stream_async_write_is_via_threads (stream))
2072     {
2073       g_task_run_in_thread (task, splice_async_thread);
2074       g_object_unref (task);
2075     }
2076   else
2077     {
2078       op->buffer = g_malloc (8192);
2079       g_input_stream_read_async (op->source, op->buffer, 8192,
2080                                  g_task_get_priority (task),
2081                                  g_task_get_cancellable (task),
2082                                  real_splice_async_read_cb, task);
2083     }
2084 }
2085
2086 static gssize
2087 g_output_stream_real_splice_finish (GOutputStream  *stream,
2088                                     GAsyncResult   *result,
2089                                     GError        **error)
2090 {
2091   g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
2092
2093   return g_task_propagate_int (G_TASK (result), error);
2094 }
2095
2096
2097 static void
2098 flush_async_thread (GTask        *task,
2099                     gpointer      source_object,
2100                     gpointer      task_data,
2101                     GCancellable *cancellable)
2102 {
2103   GOutputStream *stream = source_object;
2104   GOutputStreamClass *class;
2105   gboolean result;
2106   GError *error = NULL;
2107
2108   class = G_OUTPUT_STREAM_GET_CLASS (stream);
2109   result = TRUE;
2110   if (class->flush)
2111     result = class->flush (stream, cancellable, &error);
2112
2113   if (result)
2114     g_task_return_boolean (task, TRUE);
2115   else
2116     g_task_return_error (task, error);
2117 }
2118
2119 static void
2120 g_output_stream_real_flush_async (GOutputStream       *stream,
2121                                   int                  io_priority,
2122                                   GCancellable        *cancellable,
2123                                   GAsyncReadyCallback  callback,
2124                                   gpointer             user_data)
2125 {
2126   GTask *task;
2127
2128   task = g_task_new (stream, cancellable, callback, user_data);
2129   g_task_set_priority (task, io_priority);
2130   g_task_run_in_thread (task, flush_async_thread);
2131   g_object_unref (task);
2132 }
2133
2134 static gboolean
2135 g_output_stream_real_flush_finish (GOutputStream  *stream,
2136                                    GAsyncResult   *result,
2137                                    GError        **error)
2138 {
2139   g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
2140
2141   return g_task_propagate_boolean (G_TASK (result), error);
2142 }
2143
2144 static void
2145 close_async_thread (GTask        *task,
2146                     gpointer      source_object,
2147                     gpointer      task_data,
2148                     GCancellable *cancellable)
2149 {
2150   GOutputStream *stream = source_object;
2151   GOutputStreamClass *class;
2152   GError *error = NULL;
2153   gboolean result = TRUE;
2154
2155   class = G_OUTPUT_STREAM_GET_CLASS (stream);
2156
2157   /* Do a flush here if there is a flush function, and we did not have to do
2158    * an async flush before (see g_output_stream_close_async)
2159    */
2160   if (class->flush != NULL &&
2161       (class->flush_async == NULL ||
2162        class->flush_async == g_output_stream_real_flush_async))
2163     {
2164       result = class->flush (stream, cancellable, &error);
2165     }
2166
2167   /* Auto handling of cancelation disabled, and ignore
2168      cancellation, since we want to close things anyway, although
2169      possibly in a quick-n-dirty way. At least we never want to leak
2170      open handles */
2171
2172   if (class->close_fn)
2173     {
2174       /* Make sure to close, even if the flush failed (see sync close) */
2175       if (!result)
2176         class->close_fn (stream, cancellable, NULL);
2177       else
2178         result = class->close_fn (stream, cancellable, &error);
2179     }
2180
2181   if (result)
2182     g_task_return_boolean (task, TRUE);
2183   else
2184     g_task_return_error (task, error);
2185 }
2186
2187 static void
2188 g_output_stream_real_close_async (GOutputStream       *stream,
2189                                   int                  io_priority,
2190                                   GCancellable        *cancellable,
2191                                   GAsyncReadyCallback  callback,
2192                                   gpointer             user_data)
2193 {
2194   GTask *task;
2195
2196   task = g_task_new (stream, cancellable, callback, user_data);
2197   g_task_set_priority (task, io_priority);
2198   g_task_run_in_thread (task, close_async_thread);
2199   g_object_unref (task);
2200 }
2201
2202 static gboolean
2203 g_output_stream_real_close_finish (GOutputStream  *stream,
2204                                    GAsyncResult   *result,
2205                                    GError        **error)
2206 {
2207   g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
2208
2209   return g_task_propagate_boolean (G_TASK (result), error);
2210 }