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