gio/goutputstream.c

   1 /* GIO - GLib Input, Output and Streaming Library
   2  *
   3  * Copyright (C) 2006-2007 Red Hat, Inc.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General
  16  * Public License along with this library; if not, write to the
  17  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  18  * Boston, MA 02111-1307, USA.
  19  *
  20  * Author: Alexander Larsson <alexl@redhat.com>
  21  */
  22
  23 #include "config.h"
  24 #include "goutputstream.h"
  25 #include "gcancellable.h"
  26 #include "gasyncresult.h"
  27 #include "gsimpleasyncresult.h"
  28 #include "ginputstream.h"
  29 #include "gioerror.h"
  30 #include "glibintl.h"
  31 #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 G_DEFINE_ABSTRACT_TYPE (GOutputStream, g_output_stream, G_TYPE_OBJECT);
  49
  50 struct _GOutputStreamPrivate {
  51   guint closed : 1;
  52   guint pending : 1;
  53   guint closing : 1;
  54   GAsyncReadyCallback outstanding_callback;
  55 };
  56
  57 static gssize   g_output_stream_real_splice        (GOutputStream             *stream,
  58                                                     GInputStream              *source,
  59                                                     GOutputStreamSpliceFlags   flags,
  60                                                     GCancellable              *cancellable,
  61                                                     GError                   **error);
  62 static void     g_output_stream_real_write_async   (GOutputStream             *stream,
  63                                                     const void                *buffer,
  64                                                     gsize                      count,
  65                                                     int                        io_priority,
  66                                                     GCancellable              *cancellable,
  67                                                     GAsyncReadyCallback        callback,
  68                                                     gpointer                   data);
  69 static gssize   g_output_stream_real_write_finish  (GOutputStream             *stream,
  70                                                     GAsyncResult              *result,
  71                                                     GError                   **error);
  72 static void     g_output_stream_real_splice_async  (GOutputStream             *stream,
  73                                                     GInputStream              *source,
  74                                                     GOutputStreamSpliceFlags   flags,
  75                                                     int                        io_priority,
  76                                                     GCancellable              *cancellable,
  77                                                     GAsyncReadyCallback        callback,
  78                                                     gpointer                   data);
  79 static gssize   g_output_stream_real_splice_finish (GOutputStream             *stream,
  80                                                     GAsyncResult              *result,
  81                                                     GError                   **error);
  82 static void     g_output_stream_real_flush_async   (GOutputStream             *stream,
  83                                                     int                        io_priority,
  84                                                     GCancellable              *cancellable,
  85                                                     GAsyncReadyCallback        callback,
  86                                                     gpointer                   data);
  87 static gboolean g_output_stream_real_flush_finish  (GOutputStream             *stream,
  88                                                     GAsyncResult              *result,
  89                                                     GError                   **error);
  90 static void     g_output_stream_real_close_async   (GOutputStream             *stream,
  91                                                     int                        io_priority,
  92                                                     GCancellable              *cancellable,
  93                                                     GAsyncReadyCallback        callback,
  94                                                     gpointer                   data);
  95 static gboolean g_output_stream_real_close_finish  (GOutputStream             *stream,
  96                                                     GAsyncResult              *result,
  97                                                     GError                   **error);
  98 static gboolean _g_output_stream_close_internal    (GOutputStream             *stream,
  99                                                     GCancellable              *cancellable,
 100                                                     GError                   **error);
 101
 102 static void
 103 g_output_stream_finalize (GObject *object)
 104 {
 105   G_OBJECT_CLASS (g_output_stream_parent_class)->finalize (object);
 106 }
 107
 108 static void
 109 g_output_stream_dispose (GObject *object)
 110 {
 111   GOutputStream *stream;
 112
 113   stream = G_OUTPUT_STREAM (object);
 114
 115   if (!stream->priv->closed)
 116     g_output_stream_close (stream, NULL, NULL);
 117
 118   G_OBJECT_CLASS (g_output_stream_parent_class)->dispose (object);
 119 }
 120
 121 static void
 122 g_output_stream_class_init (GOutputStreamClass *klass)
 123 {
 124   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 125
 126   g_type_class_add_private (klass, sizeof (GOutputStreamPrivate));
 127
 128   gobject_class->finalize = g_output_stream_finalize;
 129   gobject_class->dispose = g_output_stream_dispose;
 130
 131   klass->splice = g_output_stream_real_splice;
 132
 133   klass->write_async = g_output_stream_real_write_async;
 134   klass->write_finish = g_output_stream_real_write_finish;
 135   klass->splice_async = g_output_stream_real_splice_async;
 136   klass->splice_finish = g_output_stream_real_splice_finish;
 137   klass->flush_async = g_output_stream_real_flush_async;
 138   klass->flush_finish = g_output_stream_real_flush_finish;
 139   klass->close_async = g_output_stream_real_close_async;
 140   klass->close_finish = g_output_stream_real_close_finish;
 141 }
 142
 143 static void
 144 g_output_stream_init (GOutputStream *stream)
 145 {
 146   stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (stream,
 147                                               G_TYPE_OUTPUT_STREAM,
 148                                               GOutputStreamPrivate);
 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: (allow-none): 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  * Return value: 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: (allow-none): 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, @bytes_written is updated to contain
 253  * the number of bytes written into the stream before the error occurred.
 254  *
 255  * Return value: %TRUE on success, %FALSE if there was an error
 256  **/
 257 gboolean
 258 g_output_stream_write_all (GOutputStream  *stream,
 259                            const void     *buffer,
 260                            gsize           count,
 261                            gsize          *bytes_written,
 262                            GCancellable   *cancellable,
 263                            GError        **error)
 264 {
 265   gsize _bytes_written;
 266   gssize res;
 267
 268   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 269   g_return_val_if_fail (buffer != NULL, FALSE);
 270
 271   _bytes_written = 0;
 272   while (_bytes_written < count)
 273     {
 274       res = g_output_stream_write (stream, (char *)buffer + _bytes_written, count - _bytes_written,
 275                                    cancellable, error);
 276       if (res == -1)
 277         {
 278           if (bytes_written)
 279             *bytes_written = _bytes_written;
 280           return FALSE;
 281         }
 282
 283       if (res == 0)
 284         g_warning ("Write returned zero without error");
 285
 286       _bytes_written += res;
 287     }
 288
 289   if (bytes_written)
 290     *bytes_written = _bytes_written;
 291
 292   return TRUE;
 293 }
 294
 295 /**
 296  * g_output_stream_write_bytes:
 297  * @stream: a #GOutputStream.
 298  * @bytes: the #GBytes to write
 299  * @cancellable: (allow-none): optional cancellable object
 300  * @error: location to store the error occurring, or %NULL to ignore
 301  *
 302  * Tries to write the data from @bytes into the stream. Will block
 303  * during the operation.
 304  *
 305  * If @bytes is 0-length, returns 0 and does nothing. A #GBytes larger
 306  * than %G_MAXSSIZE will cause a %G_IO_ERROR_INVALID_ARGUMENT error.
 307  *
 308  * On success, the number of bytes written to the stream is returned.
 309  * It is not an error if this is not the same as the requested size, as it
 310  * can happen e.g. on a partial I/O error, or if there is not enough
 311  * storage in the stream. All writes block until at least one byte
 312  * is written or an error occurs; 0 is never returned (unless
 313  * the size of @bytes is 0).
 314  *
 315  * If @cancellable is not %NULL, then the operation can be cancelled by
 316  * triggering the cancellable object from another thread. If the operation
 317  * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned. If an
 318  * operation was partially finished when the operation was cancelled the
 319  * partial result will be returned, without an error.
 320  *
 321  * On error -1 is returned and @error is set accordingly.
 322  *
 323  * Return value: Number of bytes written, or -1 on error
 324  **/
 325 gssize
 326 g_output_stream_write_bytes (GOutputStream  *stream,
 327                              GBytes         *bytes,
 328                              GCancellable   *cancellable,
 329                              GError        **error)
 330 {
 331   gsize size;
 332   gconstpointer data;
 333
 334   data = g_bytes_get_data (bytes, &size);
 335
 336   return g_output_stream_write (stream,
 337                                 data, size,
 338                                 cancellable,
 339                                 error);
 340 }
 341
 342 /**
 343  * g_output_stream_flush:
 344  * @stream: a #GOutputStream.
 345  * @cancellable: (allow-none): optional cancellable object
 346  * @error: location to store the error occurring, or %NULL to ignore
 347  *
 348  * Forces a write of all user-space buffered data for the given
 349  * @stream. Will block during the operation. Closing the stream will
 350  * implicitly cause a flush.
 351  *
 352  * This function is optional for inherited classes.
 353  *
 354  * If @cancellable is not %NULL, then the operation can be cancelled by
 355  * triggering the cancellable object from another thread. If the operation
 356  * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned.
 357  *
 358  * Return value: %TRUE on success, %FALSE on error
 359  **/
 360 gboolean
 361 g_output_stream_flush (GOutputStream  *stream,
 362                        GCancellable   *cancellable,
 363                        GError        **error)
 364 {
 365   GOutputStreamClass *class;
 366   gboolean res;
 367
 368   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 369
 370   if (!g_output_stream_set_pending (stream, error))
 371     return FALSE;
 372
 373   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 374
 375   res = TRUE;
 376   if (class->flush)
 377     {
 378       if (cancellable)
 379         g_cancellable_push_current (cancellable);
 380
 381       res = class->flush (stream, cancellable, error);
 382
 383       if (cancellable)
 384         g_cancellable_pop_current (cancellable);
 385     }
 386
 387   g_output_stream_clear_pending (stream);
 388
 389   return res;
 390 }
 391
 392 /**
 393  * g_output_stream_splice:
 394  * @stream: a #GOutputStream.
 395  * @source: a #GInputStream.
 396  * @flags: a set of #GOutputStreamSpliceFlags.
 397  * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
 398  * @error: a #GError location to store the error occurring, or %NULL to
 399  * ignore.
 400  *
 401  * Splices an input stream into an output stream.
 402  *
 403  * Returns: a #gssize containing the size of the data spliced, or
 404  *     -1 if an error occurred. Note that if the number of bytes
 405  *     spliced is greater than %G_MAXSSIZE, then that will be
 406  *     returned, and there is no way to determine the actual number
 407  *     of bytes spliced.
 408  **/
 409 gssize
 410 g_output_stream_splice (GOutputStream             *stream,
 411                         GInputStream              *source,
 412                         GOutputStreamSpliceFlags   flags,
 413                         GCancellable              *cancellable,
 414                         GError                   **error)
 415 {
 416   GOutputStreamClass *class;
 417   gssize bytes_copied;
 418
 419   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
 420   g_return_val_if_fail (G_IS_INPUT_STREAM (source), -1);
 421
 422   if (g_input_stream_is_closed (source))
 423     {
 424       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
 425                            _("Source stream is already closed"));
 426       return -1;
 427     }
 428
 429   if (!g_output_stream_set_pending (stream, error))
 430     return -1;
 431
 432   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 433
 434   if (cancellable)
 435     g_cancellable_push_current (cancellable);
 436
 437   bytes_copied = class->splice (stream, source, flags, cancellable, error);
 438
 439   if (cancellable)
 440     g_cancellable_pop_current (cancellable);
 441
 442   g_output_stream_clear_pending (stream);
 443
 444   return bytes_copied;
 445 }
 446
 447 static gssize
 448 g_output_stream_real_splice (GOutputStream             *stream,
 449                              GInputStream              *source,
 450                              GOutputStreamSpliceFlags   flags,
 451                              GCancellable              *cancellable,
 452                              GError                   **error)
 453 {
 454   GOutputStreamClass *class = G_OUTPUT_STREAM_GET_CLASS (stream);
 455   gssize n_read, n_written;
 456   gsize bytes_copied;
 457   char buffer[8192], *p;
 458   gboolean res;
 459
 460   bytes_copied = 0;
 461   if (class->write_fn == NULL)
 462     {
 463       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
 464                            _("Output stream doesn't implement write"));
 465       res = FALSE;
 466       goto notsupported;
 467     }
 468
 469   res = TRUE;
 470   do
 471     {
 472       n_read = g_input_stream_read (source, buffer, sizeof (buffer), cancellable, error);
 473       if (n_read == -1)
 474         {
 475           res = FALSE;
 476           break;
 477         }
 478
 479       if (n_read == 0)
 480         break;
 481
 482       p = buffer;
 483       while (n_read > 0)
 484         {
 485           n_written = class->write_fn (stream, p, n_read, cancellable, error);
 486           if (n_written == -1)
 487             {
 488               res = FALSE;
 489               break;
 490             }
 491
 492           p += n_written;
 493           n_read -= n_written;
 494           bytes_copied += n_written;
 495         }
 496
 497       if (bytes_copied > G_MAXSSIZE)
 498         bytes_copied = G_MAXSSIZE;
 499     }
 500   while (res);
 501
 502  notsupported:
 503   if (!res)
 504     error = NULL; /* Ignore further errors */
 505
 506   if (flags & G_OUTPUT_STREAM_SPLICE_CLOSE_SOURCE)
 507     {
 508       /* Don't care about errors in source here */
 509       g_input_stream_close (source, cancellable, NULL);
 510     }
 511
 512   if (flags & G_OUTPUT_STREAM_SPLICE_CLOSE_TARGET)
 513     {
 514       /* But write errors on close are bad! */
 515       res = _g_output_stream_close_internal (stream, cancellable, error);
 516     }
 517
 518   if (res)
 519     return bytes_copied;
 520
 521   return -1;
 522 }
 523
 524 /* Must always be called inside
 525  * g_output_stream_set_pending()/g_output_stream_clear_pending(). */
 526 static gboolean
 527 _g_output_stream_close_internal (GOutputStream  *stream,
 528                                  GCancellable   *cancellable,
 529                                  GError        **error)
 530 {
 531   GOutputStreamClass *class;
 532   gboolean res;
 533
 534   if (stream->priv->closed)
 535     return TRUE;
 536
 537   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 538
 539   stream->priv->closing = TRUE;
 540
 541   if (cancellable)
 542     g_cancellable_push_current (cancellable);
 543
 544   if (class->flush)
 545     res = class->flush (stream, cancellable, error);
 546   else
 547     res = TRUE;
 548
 549   if (!res)
 550     {
 551       /* flushing caused the error that we want to return,
 552        * but we still want to close the underlying stream if possible
 553        */
 554       if (class->close_fn)
 555         class->close_fn (stream, cancellable, NULL);
 556     }
 557   else
 558     {
 559       res = TRUE;
 560       if (class->close_fn)
 561         res = class->close_fn (stream, cancellable, error);
 562     }
 563
 564   if (cancellable)
 565     g_cancellable_pop_current (cancellable);
 566
 567   stream->priv->closing = FALSE;
 568   stream->priv->closed = TRUE;
 569
 570   return res;
 571 }
 572
 573 /**
 574  * g_output_stream_close:
 575  * @stream: A #GOutputStream.
 576  * @cancellable: (allow-none): optional cancellable object
 577  * @error: location to store the error occurring, or %NULL to ignore
 578  *
 579  * Closes the stream, releasing resources related to it.
 580  *
 581  * Once the stream is closed, all other operations will return %G_IO_ERROR_CLOSED.
 582  * Closing a stream multiple times will not return an error.
 583  *
 584  * Closing a stream will automatically flush any outstanding buffers in the
 585  * stream.
 586  *
 587  * Streams will be automatically closed when the last reference
 588  * is dropped, but you might want to call this function to make sure
 589  * resources are released as early as possible.
 590  *
 591  * Some streams might keep the backing store of the stream (e.g. a file descriptor)
 592  * open after the stream is closed. See the documentation for the individual
 593  * stream for details.
 594  *
 595  * On failure the first error that happened will be reported, but the close
 596  * operation will finish as much as possible. A stream that failed to
 597  * close will still return %G_IO_ERROR_CLOSED for all operations. Still, it
 598  * is important to check and report the error to the user, otherwise
 599  * there might be a loss of data as all data might not be written.
 600  *
 601  * If @cancellable is not %NULL, then the operation can be cancelled by
 602  * triggering the cancellable object from another thread. If the operation
 603  * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned.
 604  * Cancelling a close will still leave the stream closed, but there some streams
 605  * can use a faster close that doesn't block to e.g. check errors. On
 606  * cancellation (as with any error) there is no guarantee that all written
 607  * data will reach the target.
 608  *
 609  * Return value: %TRUE on success, %FALSE on failure
 610  **/
 611 gboolean
 612 g_output_stream_close (GOutputStream  *stream,
 613                        GCancellable   *cancellable,
 614                        GError        **error)
 615 {
 616   gboolean res;
 617
 618   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 619
 620   if (stream->priv->closed)
 621     return TRUE;
 622
 623   if (!g_output_stream_set_pending (stream, error))
 624     return FALSE;
 625
 626   res = _g_output_stream_close_internal (stream, cancellable, error);
 627
 628   g_output_stream_clear_pending (stream);
 629
 630   return res;
 631 }
 632
 633 static void
 634 async_ready_callback_wrapper (GObject      *source_object,
 635                               GAsyncResult *res,
 636                               gpointer      user_data)
 637 {
 638   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 639
 640   g_output_stream_clear_pending (stream);
 641   if (stream->priv->outstanding_callback)
 642     (*stream->priv->outstanding_callback) (source_object, res, user_data);
 643   g_object_unref (stream);
 644 }
 645
 646 typedef struct {
 647   gint io_priority;
 648   GCancellable *cancellable;
 649   GError *flush_error;
 650   gpointer user_data;
 651 } CloseUserData;
 652
 653 static void
 654 async_ready_close_callback_wrapper (GObject      *source_object,
 655                                     GAsyncResult *res,
 656                                     gpointer      user_data)
 657 {
 658   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 659   CloseUserData *data = user_data;
 660
 661   stream->priv->closing = FALSE;
 662   stream->priv->closed = TRUE;
 663
 664   g_output_stream_clear_pending (stream);
 665
 666   if (stream->priv->outstanding_callback)
 667     {
 668       if (data->flush_error != NULL)
 669         {
 670           GSimpleAsyncResult *err;
 671
 672           err = g_simple_async_result_new_take_error (source_object,
 673                                                       stream->priv->outstanding_callback,
 674                                                       data->user_data,
 675                                                       data->flush_error);
 676           data->flush_error = NULL;
 677
 678           (*stream->priv->outstanding_callback) (source_object,
 679                                                  G_ASYNC_RESULT (err),
 680                                                  data->user_data);
 681           g_object_unref (err);
 682         }
 683       else
 684         {
 685           (*stream->priv->outstanding_callback) (source_object,
 686                                                  res,
 687                                                  data->user_data);
 688         }
 689     }
 690
 691   g_object_unref (stream);
 692
 693   if (data->cancellable)
 694     g_object_unref (data->cancellable);
 695
 696   if (data->flush_error)
 697     g_error_free (data->flush_error);
 698
 699   g_slice_free (CloseUserData, data);
 700 }
 701
 702 static void
 703 async_ready_close_flushed_callback_wrapper (GObject      *source_object,
 704                                             GAsyncResult *res,
 705                                             gpointer      user_data)
 706 {
 707   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 708   GOutputStreamClass *class;
 709   CloseUserData *data = user_data;
 710   GSimpleAsyncResult *simple;
 711
 712   /* propagate the possible error */
 713   if (G_IS_SIMPLE_ASYNC_RESULT (res))
 714     {
 715       simple = G_SIMPLE_ASYNC_RESULT (res);
 716       g_simple_async_result_propagate_error (simple, &data->flush_error);
 717     }
 718
 719   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 720
 721   /* we still close, even if there was a flush error */
 722   class->close_async (stream, data->io_priority, data->cancellable,
 723                       async_ready_close_callback_wrapper, user_data);
 724 }
 725
 726 /**
 727  * g_output_stream_write_async:
 728  * @stream: A #GOutputStream.
 729  * @buffer: (array length=count) (element-type guint8): the buffer containing the data to write.
 730  * @count: the number of bytes to write
 731  * @io_priority: the io priority of the request.
 732  * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
 733  * @callback: (scope async): callback to call when the request is satisfied
 734  * @user_data: (closure): the data to pass to callback function
 735  *
 736  * Request an asynchronous write of @count bytes from @buffer into
 737  * the stream. When the operation is finished @callback will be called.
 738  * You can then call g_output_stream_write_finish() to get the result of the
 739  * operation.
 740  *
 741  * During an async request no other sync and async calls are allowed,
 742  * and will result in %G_IO_ERROR_PENDING errors.
 743  *
 744  * A value of @count larger than %G_MAXSSIZE will cause a
 745  * %G_IO_ERROR_INVALID_ARGUMENT error.
 746  *
 747  * On success, the number of bytes written will be passed to the
 748  * @callback. It is not an error if this is not the same as the
 749  * requested size, as it can happen e.g. on a partial I/O error,
 750  * but generally we try to write as many bytes as requested.
 751  *
 752  * You are guaranteed that this method will never fail with
 753  * %G_IO_ERROR_WOULD_BLOCK - if @stream can't accept more data, the
 754  * method will just wait until this changes.
 755  *
 756  * Any outstanding I/O request with higher priority (lower numerical
 757  * value) will be executed before an outstanding request with lower
 758  * priority. Default priority is %G_PRIORITY_DEFAULT.
 759  *
 760  * The asyncronous methods have a default fallback that uses threads
 761  * to implement asynchronicity, so they are optional for inheriting
 762  * classes. However, if you override one you must override all.
 763  *
 764  * For the synchronous, blocking version of this function, see
 765  * g_output_stream_write().
 766  **/
 767 void
 768 g_output_stream_write_async (GOutputStream       *stream,
 769                              const void          *buffer,
 770                              gsize                count,
 771                              int                  io_priority,
 772                              GCancellable        *cancellable,
 773                              GAsyncReadyCallback  callback,
 774                              gpointer             user_data)
 775 {
 776   GOutputStreamClass *class;
 777   GSimpleAsyncResult *simple;
 778   GError *error = NULL;
 779
 780   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 781   g_return_if_fail (buffer != NULL);
 782
 783   if (count == 0)
 784     {
 785       simple = g_simple_async_result_new (G_OBJECT (stream),
 786                                           callback,
 787                                           user_data,
 788                                           g_output_stream_write_async);
 789       g_simple_async_result_complete_in_idle (simple);
 790       g_object_unref (simple);
 791       return;
 792     }
 793
 794   if (((gssize) count) < 0)
 795     {
 796       g_simple_async_report_error_in_idle (G_OBJECT (stream),
 797                                            callback,
 798                                            user_data,
 799                                            G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
 800                                            _("Too large count value passed to %s"),
 801                                            G_STRFUNC);
 802       return;
 803     }
 804
 805   if (!g_output_stream_set_pending (stream, &error))
 806     {
 807       g_simple_async_report_take_gerror_in_idle (G_OBJECT (stream),
 808                                             callback,
 809                                             user_data,
 810                                             error);
 811       return;
 812     }
 813
 814   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 815
 816   stream->priv->outstanding_callback = callback;
 817   g_object_ref (stream);
 818   class->write_async (stream, buffer, count, io_priority, cancellable,
 819                       async_ready_callback_wrapper, user_data);
 820 }
 821
 822 /**
 823  * g_output_stream_write_finish:
 824  * @stream: a #GOutputStream.
 825  * @result: a #GAsyncResult.
 826  * @error: a #GError location to store the error occurring, or %NULL to
 827  * ignore.
 828  *
 829  * Finishes a stream write operation.
 830  *
 831  * Returns: a #gssize containing the number of bytes written to the stream.
 832  **/
 833 gssize
 834 g_output_stream_write_finish (GOutputStream  *stream,
 835                               GAsyncResult   *result,
 836                               GError        **error)
 837 {
 838   GSimpleAsyncResult *simple;
 839   GOutputStreamClass *class;
 840
 841   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
 842   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), -1);
 843
 844   if (g_async_result_legacy_propagate_error (result, error))
 845     return -1;
 846
 847   if (G_IS_SIMPLE_ASYNC_RESULT (result))
 848     {
 849       simple = G_SIMPLE_ASYNC_RESULT (result);
 850
 851       /* Special case writes of 0 bytes */
 852       if (g_simple_async_result_get_source_tag (simple) == g_output_stream_write_async)
 853         return 0;
 854     }
 855
 856   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 857   return class->write_finish (stream, result, error);
 858 }
 859
 860 static void
 861 write_bytes_callback (GObject      *stream,
 862                       GAsyncResult *result,
 863                       gpointer      user_data)
 864 {
 865   GSimpleAsyncResult *simple = user_data;
 866   GError *error = NULL;
 867   gssize nwrote;
 868
 869   nwrote = g_output_stream_write_finish (G_OUTPUT_STREAM (stream),
 870                                          result, &error);
 871   if (nwrote == -1)
 872     g_simple_async_result_take_error (simple, error);
 873   else
 874     g_simple_async_result_set_op_res_gssize (simple, nwrote);
 875   g_simple_async_result_complete (simple);
 876   g_object_unref (simple);
 877 }
 878
 879 /**
 880  * g_output_stream_write_bytes_async:
 881  * @stream: A #GOutputStream.
 882  * @bytes: The bytes to write
 883  * @io_priority: the io priority of the request.
 884  * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
 885  * @callback: (scope async): callback to call when the request is satisfied
 886  * @user_data: (closure): the data to pass to callback function
 887  *
 888  * Request an asynchronous write of the data in @bytes to the stream.
 889  * When the operation is finished @callback will be called. You can
 890  * then call g_output_stream_write_bytes_finish() to get the result of
 891  * the operation.
 892  *
 893  * During an async request no other sync and async calls are allowed,
 894  * and will result in %G_IO_ERROR_PENDING errors.
 895  *
 896  * A #GBytes larger than %G_MAXSSIZE will cause a
 897  * %G_IO_ERROR_INVALID_ARGUMENT error.
 898  *
 899  * On success, the number of bytes written will be passed to the
 900  * @callback. It is not an error if this is not the same as the
 901  * requested size, as it can happen e.g. on a partial I/O error,
 902  * but generally we try to write as many bytes as requested.
 903  *
 904  * You are guaranteed that this method will never fail with
 905  * %G_IO_ERROR_WOULD_BLOCK - if @stream can't accept more data, the
 906  * method will just wait until this changes.
 907  *
 908  * Any outstanding I/O request with higher priority (lower numerical
 909  * value) will be executed before an outstanding request with lower
 910  * priority. Default priority is %G_PRIORITY_DEFAULT.
 911  *
 912  * For the synchronous, blocking version of this function, see
 913  * g_output_stream_write_bytes().
 914  **/
 915 void
 916 g_output_stream_write_bytes_async (GOutputStream       *stream,
 917                                    GBytes              *bytes,
 918                                    int                  io_priority,
 919                                    GCancellable        *cancellable,
 920                                    GAsyncReadyCallback  callback,
 921                                    gpointer             user_data)
 922 {
 923   GSimpleAsyncResult *simple;
 924   gsize size;
 925   gconstpointer data;
 926
 927   data = g_bytes_get_data (bytes, &size);
 928
 929   simple = g_simple_async_result_new (G_OBJECT (stream),
 930                                       callback, user_data,
 931                                       g_output_stream_write_bytes_async);
 932   g_simple_async_result_set_op_res_gpointer (simple, g_bytes_ref (bytes),
 933                                              (GDestroyNotify) g_bytes_unref);
 934
 935   g_output_stream_write_async (stream,
 936                                data, size,
 937                                io_priority,
 938                                cancellable,
 939                                write_bytes_callback,
 940                                simple);
 941 }
 942
 943 /**
 944  * g_output_stream_write_bytes_finish:
 945  * @stream: a #GOutputStream.
 946  * @result: a #GAsyncResult.
 947  * @error: a #GError location to store the error occurring, or %NULL to
 948  * ignore.
 949  *
 950  * Finishes a stream write-from-#GBytes operation.
 951  *
 952  * Returns: a #gssize containing the number of bytes written to the stream.
 953  **/
 954 gssize
 955 g_output_stream_write_bytes_finish (GOutputStream  *stream,
 956                                     GAsyncResult   *result,
 957                                     GError        **error)
 958 {
 959   GSimpleAsyncResult *simple;
 960
 961   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
 962   g_return_val_if_fail (g_simple_async_result_is_valid (result, G_OBJECT (stream), g_output_stream_write_bytes_async), -1);
 963
 964   simple = G_SIMPLE_ASYNC_RESULT (result);
 965   if (g_simple_async_result_propagate_error (simple, error))
 966     return -1;
 967   return g_simple_async_result_get_op_res_gssize (simple);
 968 }
 969
 970 typedef struct {
 971   GInputStream *source;
 972   gpointer user_data;
 973   GAsyncReadyCallback callback;
 974 } SpliceUserData;
 975
 976 static void
 977 async_ready_splice_callback_wrapper (GObject      *source_object,
 978                                      GAsyncResult *res,
 979                                      gpointer     _data)
 980 {
 981   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 982   SpliceUserData *data = _data;
 983
 984   g_output_stream_clear_pending (stream);
 985
 986   if (data->callback)
 987     (*data->callback) (source_object, res, data->user_data);
 988
 989   g_object_unref (stream);
 990   g_object_unref (data->source);
 991   g_free (data);
 992 }
 993
 994 /**
 995  * g_output_stream_splice_async:
 996  * @stream: a #GOutputStream.
 997  * @source: a #GInputStream.
 998  * @flags: a set of #GOutputStreamSpliceFlags.
 999  * @io_priority: the io priority of the request.
1000  * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
1001  * @callback: (scope async): a #GAsyncReadyCallback.
1002  * @user_data: (closure): user data passed to @callback.
1003  *
1004  * Splices a stream asynchronously.
1005  * When the operation is finished @callback will be called.
1006  * You can then call g_output_stream_splice_finish() to get the
1007  * result of the operation.
1008  *
1009  * For the synchronous, blocking version of this function, see
1010  * g_output_stream_splice().
1011  **/
1012 void
1013 g_output_stream_splice_async (GOutputStream            *stream,
1014                               GInputStream             *source,
1015                               GOutputStreamSpliceFlags  flags,
1016                               int                       io_priority,
1017                               GCancellable             *cancellable,
1018                               GAsyncReadyCallback       callback,
1019                               gpointer                  user_data)
1020 {
1021   GOutputStreamClass *class;
1022   SpliceUserData *data;
1023   GError *error = NULL;
1024
1025   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
1026   g_return_if_fail (G_IS_INPUT_STREAM (source));
1027
1028   if (g_input_stream_is_closed (source))
1029     {
1030       g_simple_async_report_error_in_idle (G_OBJECT (stream),
1031                                            callback,
1032                                            user_data,
1033                                            G_IO_ERROR, G_IO_ERROR_CLOSED,
1034                                            _("Source stream is already closed"));
1035       return;
1036     }
1037
1038   if (!g_output_stream_set_pending (stream, &error))
1039     {
1040       g_simple_async_report_take_gerror_in_idle (G_OBJECT (stream),
1041                                             callback,
1042                                             user_data,
1043                                             error);
1044       return;
1045     }
1046
1047   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1048
1049   data = g_new0 (SpliceUserData, 1);
1050   data->callback = callback;
1051   data->user_data = user_data;
1052   data->source = g_object_ref (source);
1053
1054   g_object_ref (stream);
1055   class->splice_async (stream, source, flags, io_priority, cancellable,
1056                       async_ready_splice_callback_wrapper, data);
1057 }
1058
1059 /**
1060  * g_output_stream_splice_finish:
1061  * @stream: a #GOutputStream.
1062  * @result: a #GAsyncResult.
1063  * @error: a #GError location to store the error occurring, or %NULL to
1064  * ignore.
1065  *
1066  * Finishes an asynchronous stream splice operation.
1067  *
1068  * Returns: a #gssize of the number of bytes spliced. Note that if the
1069  *     number of bytes spliced is greater than %G_MAXSSIZE, then that
1070  *     will be returned, and there is no way to determine the actual
1071  *     number of bytes spliced.
1072  **/
1073 gssize
1074 g_output_stream_splice_finish (GOutputStream  *stream,
1075                                GAsyncResult   *result,
1076                                GError        **error)
1077 {
1078   GOutputStreamClass *class;
1079
1080   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
1081   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), -1);
1082
1083   if (g_async_result_legacy_propagate_error (result, error))
1084     return -1;
1085
1086   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1087   return class->splice_finish (stream, result, error);
1088 }
1089
1090 /**
1091  * g_output_stream_flush_async:
1092  * @stream: a #GOutputStream.
1093  * @io_priority: the io priority of the request.
1094  * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
1095  * @callback: (scope async): a #GAsyncReadyCallback to call when the request is satisfied
1096  * @user_data: (closure): the data to pass to callback function
1097  *
1098  * Forces an asynchronous write of all user-space buffered data for
1099  * the given @stream.
1100  * For behaviour details see g_output_stream_flush().
1101  *
1102  * When the operation is finished @callback will be
1103  * called. You can then call g_output_stream_flush_finish() to get the
1104  * result of the operation.
1105  **/
1106 void
1107 g_output_stream_flush_async (GOutputStream       *stream,
1108                              int                  io_priority,
1109                              GCancellable        *cancellable,
1110                              GAsyncReadyCallback  callback,
1111                              gpointer             user_data)
1112 {
1113   GOutputStreamClass *class;
1114   GSimpleAsyncResult *simple;
1115   GError *error = NULL;
1116
1117   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
1118
1119   if (!g_output_stream_set_pending (stream, &error))
1120     {
1121       g_simple_async_report_take_gerror_in_idle (G_OBJECT (stream),
1122                                             callback,
1123                                             user_data,
1124                                             error);
1125       return;
1126     }
1127
1128   stream->priv->outstanding_callback = callback;
1129   g_object_ref (stream);
1130
1131   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1132
1133   if (class->flush_async == NULL)
1134     {
1135       simple = g_simple_async_result_new (G_OBJECT (stream),
1136                                           async_ready_callback_wrapper,
1137                                           user_data,
1138                                           g_output_stream_flush_async);
1139       g_simple_async_result_complete_in_idle (simple);
1140       g_object_unref (simple);
1141       return;
1142     }
1143
1144   class->flush_async (stream, io_priority, cancellable,
1145                       async_ready_callback_wrapper, user_data);
1146 }
1147
1148 /**
1149  * g_output_stream_flush_finish:
1150  * @stream: a #GOutputStream.
1151  * @result: a GAsyncResult.
1152  * @error: a #GError location to store the error occurring, or %NULL to
1153  * ignore.
1154  *
1155  * Finishes flushing an output stream.
1156  *
1157  * Returns: %TRUE if flush operation succeeded, %FALSE otherwise.
1158  **/
1159 gboolean
1160 g_output_stream_flush_finish (GOutputStream  *stream,
1161                               GAsyncResult   *result,
1162                               GError        **error)
1163 {
1164   GSimpleAsyncResult *simple;
1165   GOutputStreamClass *klass;
1166
1167   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1168   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), FALSE);
1169
1170   if (g_async_result_legacy_propagate_error (result, error))
1171     return FALSE;
1172
1173   if (G_IS_SIMPLE_ASYNC_RESULT (result))
1174     {
1175       simple = G_SIMPLE_ASYNC_RESULT (result);
1176
1177       /* Special case default implementation */
1178       if (g_simple_async_result_get_source_tag (simple) == g_output_stream_flush_async)
1179         return TRUE;
1180     }
1181
1182   klass = G_OUTPUT_STREAM_GET_CLASS (stream);
1183   return klass->flush_finish (stream, result, error);
1184 }
1185
1186
1187 /**
1188  * g_output_stream_close_async:
1189  * @stream: A #GOutputStream.
1190  * @io_priority: the io priority of the request.
1191  * @cancellable: (allow-none): optional cancellable object
1192  * @callback: (scope async): callback to call when the request is satisfied
1193  * @user_data: (closure): the data to pass to callback function
1194  *
1195  * Requests an asynchronous close of the stream, releasing resources
1196  * related to it. When the operation is finished @callback will be
1197  * called. You can then call g_output_stream_close_finish() to get
1198  * the result of the operation.
1199  *
1200  * For behaviour details see g_output_stream_close().
1201  *
1202  * The asyncronous methods have a default fallback that uses threads
1203  * to implement asynchronicity, so they are optional for inheriting
1204  * classes. However, if you override one you must override all.
1205  **/
1206 void
1207 g_output_stream_close_async (GOutputStream       *stream,
1208                              int                  io_priority,
1209                              GCancellable        *cancellable,
1210                              GAsyncReadyCallback  callback,
1211                              gpointer             user_data)
1212 {
1213   GOutputStreamClass *class;
1214   GSimpleAsyncResult *simple;
1215   GError *error = NULL;
1216   CloseUserData *data;
1217
1218   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
1219
1220   if (stream->priv->closed)
1221     {
1222       simple = g_simple_async_result_new (G_OBJECT (stream),
1223                                           callback,
1224                                           user_data,
1225                                           g_output_stream_close_async);
1226       g_simple_async_result_complete_in_idle (simple);
1227       g_object_unref (simple);
1228       return;
1229     }
1230
1231   if (!g_output_stream_set_pending (stream, &error))
1232     {
1233       g_simple_async_report_take_gerror_in_idle (G_OBJECT (stream),
1234                                             callback,
1235                                             user_data,
1236                                             error);
1237       return;
1238     }
1239
1240   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1241   stream->priv->closing = TRUE;
1242   stream->priv->outstanding_callback = callback;
1243   g_object_ref (stream);
1244
1245   data = g_slice_new0 (CloseUserData);
1246
1247   if (cancellable != NULL)
1248     data->cancellable = g_object_ref (cancellable);
1249
1250   data->io_priority = io_priority;
1251   data->user_data = user_data;
1252
1253   /* Call close_async directly if there is no need to flush, or if the flush
1254      can be done sync (in the output stream async close thread) */
1255   if (class->flush_async == NULL ||
1256       (class->flush_async == g_output_stream_real_flush_async &&
1257        (class->flush == NULL || class->close_async == g_output_stream_real_close_async)))
1258     {
1259       class->close_async (stream, io_priority, cancellable,
1260                           async_ready_close_callback_wrapper, data);
1261     }
1262   else
1263     {
1264       /* First do an async flush, then do the async close in the callback
1265          wrapper (see async_ready_close_flushed_callback_wrapper) */
1266       class->flush_async (stream, io_priority, cancellable,
1267                           async_ready_close_flushed_callback_wrapper, data);
1268     }
1269 }
1270
1271 /**
1272  * g_output_stream_close_finish:
1273  * @stream: a #GOutputStream.
1274  * @result: a #GAsyncResult.
1275  * @error: a #GError location to store the error occurring, or %NULL to
1276  * ignore.
1277  *
1278  * Closes an output stream.
1279  *
1280  * Returns: %TRUE if stream was successfully closed, %FALSE otherwise.
1281  **/
1282 gboolean
1283 g_output_stream_close_finish (GOutputStream  *stream,
1284                               GAsyncResult   *result,
1285                               GError        **error)
1286 {
1287   GSimpleAsyncResult *simple;
1288   GOutputStreamClass *class;
1289
1290   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1291   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), FALSE);
1292
1293   if (g_async_result_legacy_propagate_error (result, error))
1294     return FALSE;
1295
1296   if (G_IS_SIMPLE_ASYNC_RESULT (result))
1297     {
1298       simple = G_SIMPLE_ASYNC_RESULT (result);
1299
1300       /* Special case already closed */
1301       if (g_simple_async_result_get_source_tag (simple) == g_output_stream_close_async)
1302         return TRUE;
1303     }
1304
1305   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1306   return class->close_finish (stream, result, error);
1307 }
1308
1309 /**
1310  * g_output_stream_is_closed:
1311  * @stream: a #GOutputStream.
1312  *
1313  * Checks if an output stream has already been closed.
1314  *
1315  * Returns: %TRUE if @stream is closed. %FALSE otherwise.
1316  **/
1317 gboolean
1318 g_output_stream_is_closed (GOutputStream *stream)
1319 {
1320   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), TRUE);
1321
1322   return stream->priv->closed;
1323 }
1324
1325 /**
1326  * g_output_stream_is_closing:
1327  * @stream: a #GOutputStream.
1328  *
1329  * Checks if an output stream is being closed. This can be
1330  * used inside e.g. a flush implementation to see if the
1331  * flush (or other i/o operation) is called from within
1332  * the closing operation.
1333  *
1334  * Returns: %TRUE if @stream is being closed. %FALSE otherwise.
1335  *
1336  * Since: 2.24
1337  **/
1338 gboolean
1339 g_output_stream_is_closing (GOutputStream *stream)
1340 {
1341   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), TRUE);
1342
1343   return stream->priv->closing;
1344 }
1345
1346 /**
1347  * g_output_stream_has_pending:
1348  * @stream: a #GOutputStream.
1349  *
1350  * Checks if an ouput stream has pending actions.
1351  *
1352  * Returns: %TRUE if @stream has pending actions.
1353  **/
1354 gboolean
1355 g_output_stream_has_pending (GOutputStream *stream)
1356 {
1357   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1358
1359   return stream->priv->pending;
1360 }
1361
1362 /**
1363  * g_output_stream_set_pending:
1364  * @stream: a #GOutputStream.
1365  * @error: a #GError location to store the error occurring, or %NULL to
1366  * ignore.
1367  *
1368  * Sets @stream to have actions pending. If the pending flag is
1369  * already set or @stream is closed, it will return %FALSE and set
1370  * @error.
1371  *
1372  * Return value: %TRUE if pending was previously unset and is now set.
1373  **/
1374 gboolean
1375 g_output_stream_set_pending (GOutputStream *stream,
1376                              GError **error)
1377 {
1378   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1379
1380   if (stream->priv->closed)
1381     {
1382       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
1383                            _("Stream is already closed"));
1384       return FALSE;
1385     }
1386
1387   if (stream->priv->pending)
1388     {
1389       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PENDING,
1390                            /* Translators: This is an error you get if there is
1391                             * already an operation running against this stream when
1392                             * you try to start one */
1393                            _("Stream has outstanding operation"));
1394       return FALSE;
1395     }
1396
1397   stream->priv->pending = TRUE;
1398   return TRUE;
1399 }
1400
1401 /**
1402  * g_output_stream_clear_pending:
1403  * @stream: output stream
1404  *
1405  * Clears the pending flag on @stream.
1406  **/
1407 void
1408 g_output_stream_clear_pending (GOutputStream *stream)
1409 {
1410   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
1411
1412   stream->priv->pending = FALSE;
1413 }
1414
1415
1416 /********************************************
1417  *   Default implementation of async ops    *
1418  ********************************************/
1419
1420 typedef struct {
1421   const void         *buffer;
1422   gsize               count_requested;
1423   gssize              count_written;
1424
1425   GCancellable       *cancellable;
1426   gint                io_priority;
1427   gboolean            need_idle;
1428 } WriteData;
1429
1430 static void
1431 free_write_data (WriteData *op)
1432 {
1433   if (op->cancellable)
1434     g_object_unref (op->cancellable);
1435   g_slice_free (WriteData, op);
1436 }
1437
1438 static void
1439 write_async_thread (GSimpleAsyncResult *res,
1440                     GObject            *object,
1441                     GCancellable       *cancellable)
1442 {
1443   WriteData *op;
1444   GOutputStreamClass *class;
1445   GError *error = NULL;
1446
1447   class = G_OUTPUT_STREAM_GET_CLASS (object);
1448   op = g_simple_async_result_get_op_res_gpointer (res);
1449   op->count_written = class->write_fn (G_OUTPUT_STREAM (object), op->buffer, op->count_requested,
1450                                        cancellable, &error);
1451   if (op->count_written == -1)
1452     g_simple_async_result_take_error (res, error);
1453 }
1454
1455 static void write_async_pollable (GPollableOutputStream *stream,
1456                                   GSimpleAsyncResult    *result);
1457
1458 static gboolean
1459 write_async_pollable_ready (GPollableOutputStream *stream,
1460                             gpointer               user_data)
1461 {
1462   GSimpleAsyncResult *result = user_data;
1463
1464   write_async_pollable (stream, result);
1465   return FALSE;
1466 }
1467
1468 static void
1469 write_async_pollable (GPollableOutputStream *stream,
1470                       GSimpleAsyncResult    *result)
1471 {
1472   GError *error = NULL;
1473   WriteData *op = g_simple_async_result_get_op_res_gpointer (result);
1474
1475   if (g_cancellable_set_error_if_cancelled (op->cancellable, &error))
1476     op->count_written = -1;
1477   else
1478     {
1479       op->count_written = G_POLLABLE_OUTPUT_STREAM_GET_INTERFACE (stream)->
1480         write_nonblocking (stream, op->buffer, op->count_requested, &error);
1481     }
1482
1483   if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_WOULD_BLOCK))
1484     {
1485       GSource *source;
1486
1487       g_error_free (error);
1488       op->need_idle = FALSE;
1489
1490       source = g_pollable_output_stream_create_source (stream, op->cancellable);
1491       g_source_set_callback (source,
1492                              (GSourceFunc) write_async_pollable_ready,
1493                              g_object_ref (result), g_object_unref);
1494       g_source_set_priority (source, op->io_priority);
1495       g_source_attach (source, g_main_context_get_thread_default ());
1496       g_source_unref (source);
1497       return;
1498     }
1499
1500   if (op->count_written == -1)
1501     g_simple_async_result_take_error (result, error);
1502
1503   if (op->need_idle)
1504     g_simple_async_result_complete_in_idle (result);
1505   else
1506     g_simple_async_result_complete (result);
1507 }
1508
1509 static void
1510 g_output_stream_real_write_async (GOutputStream       *stream,
1511                                   const void          *buffer,
1512                                   gsize                count,
1513                                   int                  io_priority,
1514                                   GCancellable        *cancellable,
1515                                   GAsyncReadyCallback  callback,
1516                                   gpointer             user_data)
1517 {
1518   GSimpleAsyncResult *res;
1519   WriteData *op;
1520
1521   op = g_slice_new0 (WriteData);
1522   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_write_async);
1523   g_simple_async_result_set_op_res_gpointer (res, op, (GDestroyNotify) free_write_data);
1524   op->buffer = buffer;
1525   op->count_requested = count;
1526   op->cancellable = cancellable ? g_object_ref (cancellable) : NULL;
1527   op->io_priority = io_priority;
1528   op->need_idle = TRUE;
1529
1530   if (G_IS_POLLABLE_OUTPUT_STREAM (stream) &&
1531       g_pollable_output_stream_can_poll (G_POLLABLE_OUTPUT_STREAM (stream)))
1532     write_async_pollable (G_POLLABLE_OUTPUT_STREAM (stream), res);
1533   else
1534     g_simple_async_result_run_in_thread (res, write_async_thread, io_priority, cancellable);
1535   g_object_unref (res);
1536 }
1537
1538 static gssize
1539 g_output_stream_real_write_finish (GOutputStream  *stream,
1540                                    GAsyncResult   *result,
1541                                    GError        **error)
1542 {
1543   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
1544   WriteData *op;
1545
1546   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_output_stream_real_write_async);
1547
1548   if (g_simple_async_result_propagate_error (simple, error))
1549     return -1;
1550
1551   op = g_simple_async_result_get_op_res_gpointer (simple);
1552   return op->count_written;
1553 }
1554
1555 typedef struct {
1556   GInputStream *source;
1557   GOutputStreamSpliceFlags flags;
1558   gssize bytes_copied;
1559 } SpliceData;
1560
1561 static void
1562 splice_async_thread (GSimpleAsyncResult *result,
1563                      GObject            *object,
1564                      GCancellable       *cancellable)
1565 {
1566   SpliceData *op;
1567   GOutputStreamClass *class;
1568   GError *error = NULL;
1569   GOutputStream *stream;
1570
1571   stream = G_OUTPUT_STREAM (object);
1572   class = G_OUTPUT_STREAM_GET_CLASS (object);
1573   op = g_simple_async_result_get_op_res_gpointer (result);
1574
1575   op->bytes_copied = class->splice (stream,
1576                                     op->source,
1577                                     op->flags,
1578                                     cancellable,
1579                                     &error);
1580   if (op->bytes_copied == -1)
1581     g_simple_async_result_take_error (result, error);
1582 }
1583
1584 static void
1585 g_output_stream_real_splice_async (GOutputStream             *stream,
1586                                    GInputStream              *source,
1587                                    GOutputStreamSpliceFlags   flags,
1588                                    int                        io_priority,
1589                                    GCancellable              *cancellable,
1590                                    GAsyncReadyCallback        callback,
1591                                    gpointer                   user_data)
1592 {
1593   GSimpleAsyncResult *res;
1594   SpliceData *op;
1595
1596   op = g_new0 (SpliceData, 1);
1597   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_splice_async);
1598   g_simple_async_result_set_op_res_gpointer (res, op, g_free);
1599   op->flags = flags;
1600   op->source = source;
1601
1602   /* TODO: In the case where both source and destintion have
1603      non-threadbased async calls we can use a true async copy here */
1604
1605   g_simple_async_result_run_in_thread (res, splice_async_thread, io_priority, cancellable);
1606   g_object_unref (res);
1607 }
1608
1609 static gssize
1610 g_output_stream_real_splice_finish (GOutputStream  *stream,
1611                                     GAsyncResult   *result,
1612                                     GError        **error)
1613 {
1614   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
1615   SpliceData *op;
1616
1617   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_output_stream_real_splice_async);
1618
1619   if (g_simple_async_result_propagate_error (simple, error))
1620     return -1;
1621
1622   op = g_simple_async_result_get_op_res_gpointer (simple);
1623   return op->bytes_copied;
1624 }
1625
1626
1627 static void
1628 flush_async_thread (GSimpleAsyncResult *res,
1629                     GObject            *object,
1630                     GCancellable       *cancellable)
1631 {
1632   GOutputStreamClass *class;
1633   gboolean result;
1634   GError *error = NULL;
1635
1636   class = G_OUTPUT_STREAM_GET_CLASS (object);
1637   result = TRUE;
1638   if (class->flush)
1639     result = class->flush (G_OUTPUT_STREAM (object), cancellable, &error);
1640
1641   if (!result)
1642     g_simple_async_result_take_error (res, error);
1643 }
1644
1645 static void
1646 g_output_stream_real_flush_async (GOutputStream       *stream,
1647                                   int                  io_priority,
1648                                   GCancellable        *cancellable,
1649                                   GAsyncReadyCallback  callback,
1650                                   gpointer             user_data)
1651 {
1652   GSimpleAsyncResult *res;
1653
1654   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_write_async);
1655
1656   g_simple_async_result_run_in_thread (res, flush_async_thread, io_priority, cancellable);
1657   g_object_unref (res);
1658 }
1659
1660 static gboolean
1661 g_output_stream_real_flush_finish (GOutputStream  *stream,
1662                                    GAsyncResult   *result,
1663                                    GError        **error)
1664 {
1665   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
1666
1667   if (g_simple_async_result_propagate_error (simple, error))
1668     return FALSE;
1669   return TRUE;
1670 }
1671
1672 static void
1673 close_async_thread (GSimpleAsyncResult *res,
1674                     GObject            *object,
1675                     GCancellable       *cancellable)
1676 {
1677   GOutputStreamClass *class;
1678   GError *error = NULL;
1679   gboolean result = TRUE;
1680
1681   class = G_OUTPUT_STREAM_GET_CLASS (object);
1682
1683   /* Do a flush here if there is a flush function, and we did not have to do
1684      an async flush before (see g_output_stream_close_async) */
1685   if (class->flush != NULL &&
1686       (class->flush_async == NULL ||
1687        class->flush_async == g_output_stream_real_flush_async))
1688     {
1689       result = class->flush (G_OUTPUT_STREAM (object), cancellable, &error);
1690     }
1691
1692   /* Auto handling of cancelation disabled, and ignore
1693      cancellation, since we want to close things anyway, although
1694      possibly in a quick-n-dirty way. At least we never want to leak
1695      open handles */
1696
1697   if (class->close_fn)
1698     {
1699       /* Make sure to close, even if the flush failed (see sync close) */
1700       if (!result)
1701         class->close_fn (G_OUTPUT_STREAM (object), cancellable, NULL);
1702       else
1703         result = class->close_fn (G_OUTPUT_STREAM (object), cancellable, &error);
1704
1705       if (!result)
1706         g_simple_async_result_take_error (res, error);
1707     }
1708 }
1709
1710 static void
1711 g_output_stream_real_close_async (GOutputStream       *stream,
1712                                   int                  io_priority,
1713                                   GCancellable        *cancellable,
1714                                   GAsyncReadyCallback  callback,
1715                                   gpointer             user_data)
1716 {
1717   GSimpleAsyncResult *res;
1718
1719   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_close_async);
1720
1721   g_simple_async_result_set_handle_cancellation (res, FALSE);
1722
1723   g_simple_async_result_run_in_thread (res, close_async_thread, io_priority, cancellable);
1724   g_object_unref (res);
1725 }
1726
1727 static gboolean
1728 g_output_stream_real_close_finish (GOutputStream  *stream,
1729                                    GAsyncResult   *result,
1730                                    GError        **error)
1731 {
1732   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
1733
1734   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_output_stream_real_close_async);
1735
1736   if (g_simple_async_result_propagate_error (simple, error))
1737     return FALSE;
1738   return TRUE;
1739 }