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/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 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 %s"), G_STRFUNC);
 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 for 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 %s"),
 648                                            G_STRFUNC);
 649       return;
 650     }
 651
 652   if (!g_output_stream_set_pending (stream, &error))
 653     {
 654       g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
 655                                             callback,
 656                                             user_data,
 657                                             error);
 658       g_error_free (error);
 659       return;
 660     }
 661
 662   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 663
 664   stream->priv->outstanding_callback = callback;
 665   g_object_ref (stream);
 666   class->write_async (stream, buffer, count, io_priority, cancellable,
 667                       async_ready_callback_wrapper, user_data);
 668 }
 669
 670 /**
 671  * g_output_stream_write_finish:
 672  * @stream: a #GOutputStream.
 673  * @result: a #GAsyncResult.
 674  * @error: a #GError location to store the error occuring, or %NULL to
 675  * ignore.
 676  *
 677  * Finishes a stream write operation.
 678  *
 679  * Returns: a #gssize containing the number of bytes written to the stream.
 680  **/
 681 gssize
 682 g_output_stream_write_finish (GOutputStream  *stream,
 683                               GAsyncResult   *result,
 684                               GError        **error)
 685 {
 686   GSimpleAsyncResult *simple;
 687   GOutputStreamClass *class;
 688
 689   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
 690   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), -1);
 691
 692   if (G_IS_SIMPLE_ASYNC_RESULT (result))
 693     {
 694       simple = G_SIMPLE_ASYNC_RESULT (result);
 695       if (g_simple_async_result_propagate_error (simple, error))
 696         return -1;
 697
 698       /* Special case writes of 0 bytes */
 699       if (g_simple_async_result_get_source_tag (simple) == g_output_stream_write_async)
 700         return 0;
 701     }
 702
 703   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 704   return class->write_finish (stream, result, error);
 705 }
 706
 707 typedef struct {
 708   GInputStream *source;
 709   gpointer user_data;
 710   GAsyncReadyCallback callback;
 711 } SpliceUserData;
 712
 713 static void
 714 async_ready_splice_callback_wrapper (GObject      *source_object,
 715                                      GAsyncResult *res,
 716                                      gpointer     _data)
 717 {
 718   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 719   SpliceUserData *data = _data;
 720
 721   g_output_stream_clear_pending (stream);
 722
 723   if (data->callback)
 724     (*data->callback) (source_object, res, data->user_data);
 725
 726   g_object_unref (stream);
 727   g_object_unref (data->source);
 728   g_free (data);
 729 }
 730
 731 /**
 732  * g_output_stream_splice_async:
 733  * @stream: a #GOutputStream.
 734  * @source: a #GInputStream.
 735  * @flags: a set of #GOutputStreamSpliceFlags.
 736  * @io_priority: the io priority of the request.
 737  * @cancellable: optional #GCancellable object, %NULL to ignore.
 738  * @callback: a #GAsyncReadyCallback.
 739  * @user_data: user data passed to @callback.
 740  *
 741  * Splices a stream asynchronously.
 742  * When the operation is finished @callback will be called.
 743  * You can then call g_output_stream_splice_finish() to get the
 744  * result of the operation.
 745  *
 746  * For the synchronous, blocking version of this function, see
 747  * g_output_stream_splice().
 748  **/
 749 void
 750 g_output_stream_splice_async (GOutputStream            *stream,
 751                               GInputStream             *source,
 752                               GOutputStreamSpliceFlags  flags,
 753                               int                       io_priority,
 754                               GCancellable             *cancellable,
 755                               GAsyncReadyCallback       callback,
 756                               gpointer                  user_data)
 757 {
 758   GOutputStreamClass *class;
 759   SpliceUserData *data;
 760   GError *error = NULL;
 761
 762   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 763   g_return_if_fail (G_IS_INPUT_STREAM (source));
 764
 765   if (g_input_stream_is_closed (source))
 766     {
 767       g_simple_async_report_error_in_idle (G_OBJECT (stream),
 768                                            callback,
 769                                            user_data,
 770                                            G_IO_ERROR, G_IO_ERROR_CLOSED,
 771                                            _("Source stream is already closed"));
 772       return;
 773     }
 774
 775   if (!g_output_stream_set_pending (stream, &error))
 776     {
 777       g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
 778                                             callback,
 779                                             user_data,
 780                                             error);
 781       g_error_free (error);
 782       return;
 783     }
 784
 785   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 786
 787   data = g_new0 (SpliceUserData, 1);
 788   data->callback = callback;
 789   data->user_data = user_data;
 790   data->source = g_object_ref (source);
 791
 792   g_object_ref (stream);
 793   class->splice_async (stream, source, flags, io_priority, cancellable,
 794                       async_ready_splice_callback_wrapper, data);
 795 }
 796
 797 /**
 798  * g_output_stream_splice_finish:
 799  * @stream: a #GOutputStream.
 800  * @result: a #GAsyncResult.
 801  * @error: a #GError location to store the error occuring, or %NULL to
 802  * ignore.
 803  *
 804  * Finishes an asynchronous stream splice operation.
 805  *
 806  * Returns: a #gssize of the number of bytes spliced.
 807  **/
 808 gssize
 809 g_output_stream_splice_finish (GOutputStream  *stream,
 810                                GAsyncResult   *result,
 811                                GError        **error)
 812 {
 813   GSimpleAsyncResult *simple;
 814   GOutputStreamClass *class;
 815
 816   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
 817   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), -1);
 818
 819   if (G_IS_SIMPLE_ASYNC_RESULT (result))
 820     {
 821       simple = G_SIMPLE_ASYNC_RESULT (result);
 822       if (g_simple_async_result_propagate_error (simple, error))
 823         return -1;
 824     }
 825
 826   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 827   return class->splice_finish (stream, result, error);
 828 }
 829
 830 /**
 831  * g_output_stream_flush_async:
 832  * @stream: a #GOutputStream.
 833  * @io_priority: the io priority of the request.
 834  * @cancellable: optional #GCancellable object, %NULL to ignore.
 835  * @callback: a #GAsyncReadyCallback to call when the request is satisfied
 836  * @user_data: the data to pass to callback function
 837  *
 838  * Flushes a stream asynchronously.
 839  * For behaviour details see g_output_stream_flush().
 840  *
 841  * When the operation is finished @callback will be
 842  * called. You can then call g_output_stream_flush_finish() to get the
 843  * result of the operation.
 844  **/
 845 void
 846 g_output_stream_flush_async (GOutputStream       *stream,
 847                              int                  io_priority,
 848                              GCancellable        *cancellable,
 849                              GAsyncReadyCallback  callback,
 850                              gpointer             user_data)
 851 {
 852   GOutputStreamClass *class;
 853   GSimpleAsyncResult *simple;
 854   GError *error = NULL;
 855
 856   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 857
 858   if (!g_output_stream_set_pending (stream, &error))
 859     {
 860       g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
 861                                             callback,
 862                                             user_data,
 863                                             error);
 864       g_error_free (error);
 865       return;
 866     }
 867
 868   stream->priv->outstanding_callback = callback;
 869   g_object_ref (stream);
 870
 871   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 872
 873   if (class->flush_async == NULL)
 874     {
 875       simple = g_simple_async_result_new (G_OBJECT (stream),
 876                                           async_ready_callback_wrapper,
 877                                           user_data,
 878                                           g_output_stream_flush_async);
 879       g_simple_async_result_complete_in_idle (simple);
 880       g_object_unref (simple);
 881       return;
 882     }
 883
 884   class->flush_async (stream, io_priority, cancellable,
 885                       async_ready_callback_wrapper, user_data);
 886 }
 887
 888 /**
 889  * g_output_stream_flush_finish:
 890  * @stream: a #GOutputStream.
 891  * @result: a GAsyncResult.
 892  * @error: a #GError location to store the error occuring, or %NULL to
 893  * ignore.
 894  *
 895  * Finishes flushing an output stream.
 896  *
 897  * Returns: %TRUE if flush operation suceeded, %FALSE otherwise.
 898  **/
 899 gboolean
 900 g_output_stream_flush_finish (GOutputStream  *stream,
 901                               GAsyncResult   *result,
 902                               GError        **error)
 903 {
 904   GSimpleAsyncResult *simple;
 905   GOutputStreamClass *klass;
 906
 907   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 908   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), FALSE);
 909
 910   if (G_IS_SIMPLE_ASYNC_RESULT (result))
 911     {
 912       simple = G_SIMPLE_ASYNC_RESULT (result);
 913       if (g_simple_async_result_propagate_error (simple, error))
 914         return FALSE;
 915
 916       /* Special case default implementation */
 917       if (g_simple_async_result_get_source_tag (simple) == g_output_stream_flush_async)
 918         return TRUE;
 919     }
 920
 921   klass = G_OUTPUT_STREAM_GET_CLASS (stream);
 922   return klass->flush_finish (stream, result, error);
 923 }
 924
 925
 926 /**
 927  * g_output_stream_close_async:
 928  * @stream: A #GOutputStream.
 929  * @io_priority: the io priority of the request.
 930  * @callback: callback to call when the request is satisfied
 931  * @user_data: the data to pass to callback function
 932  * @cancellable: optional cancellable object
 933  *
 934  * Requests an asynchronous close of the stream, releasing resources
 935  * related to it. When the operation is finished @callback will be
 936  * called. You can then call g_output_stream_close_finish() to get
 937  * the result of the operation.
 938  *
 939  * For behaviour details see g_output_stream_close().
 940  *
 941  * The asyncronous methods have a default fallback that uses threads
 942  * to implement asynchronicity, so they are optional for inheriting
 943  * classes. However, if you override one you must override all.
 944  **/
 945 void
 946 g_output_stream_close_async (GOutputStream       *stream,
 947                              int                  io_priority,
 948                              GCancellable        *cancellable,
 949                              GAsyncReadyCallback  callback,
 950                              gpointer             user_data)
 951 {
 952   GOutputStreamClass *class;
 953   GSimpleAsyncResult *simple;
 954   GError *error = NULL;
 955
 956   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 957
 958   if (stream->priv->closed)
 959     {
 960       simple = g_simple_async_result_new (G_OBJECT (stream),
 961                                           callback,
 962                                           user_data,
 963                                           g_output_stream_close_async);
 964       g_simple_async_result_complete_in_idle (simple);
 965       g_object_unref (simple);
 966       return;
 967     }
 968
 969   if (!g_output_stream_set_pending (stream, &error))
 970     {
 971       g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
 972                                             callback,
 973                                             user_data,
 974                                             error);
 975       g_error_free (error);
 976       return;
 977     }
 978
 979   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 980   stream->priv->outstanding_callback = callback;
 981   g_object_ref (stream);
 982   class->close_async (stream, io_priority, cancellable,
 983                       async_ready_close_callback_wrapper, user_data);
 984 }
 985
 986 /**
 987  * g_output_stream_close_finish:
 988  * @stream: a #GOutputStream.
 989  * @result: a #GAsyncResult.
 990  * @error: a #GError location to store the error occuring, or %NULL to
 991  * ignore.
 992  *
 993  * Closes an output stream.
 994  *
 995  * Returns: %TRUE if stream was successfully closed, %FALSE otherwise.
 996  **/
 997 gboolean
 998 g_output_stream_close_finish (GOutputStream  *stream,
 999                               GAsyncResult   *result,
1000                               GError        **error)
1001 {
1002   GSimpleAsyncResult *simple;
1003   GOutputStreamClass *class;
1004
1005   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1006   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), FALSE);
1007
1008   if (G_IS_SIMPLE_ASYNC_RESULT (result))
1009     {
1010       simple = G_SIMPLE_ASYNC_RESULT (result);
1011       if (g_simple_async_result_propagate_error (simple, error))
1012         return FALSE;
1013
1014       /* Special case already closed */
1015       if (g_simple_async_result_get_source_tag (simple) == g_output_stream_close_async)
1016         return TRUE;
1017     }
1018
1019   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1020   return class->close_finish (stream, result, error);
1021 }
1022
1023 /**
1024  * g_output_stream_is_closed:
1025  * @stream: a #GOutputStream.
1026  *
1027  * Checks if an output stream has already been closed.
1028  *
1029  * Returns: %TRUE if @stream is closed. %FALSE otherwise.
1030  **/
1031 gboolean
1032 g_output_stream_is_closed (GOutputStream *stream)
1033 {
1034   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), TRUE);
1035
1036   return stream->priv->closed;
1037 }
1038
1039 /**
1040  * g_output_stream_has_pending:
1041  * @stream: a #GOutputStream.
1042  *
1043  * Checks if an ouput stream has pending actions.
1044  *
1045  * Returns: %TRUE if @stream has pending actions.
1046  **/
1047 gboolean
1048 g_output_stream_has_pending (GOutputStream *stream)
1049 {
1050   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1051
1052   return stream->priv->pending;
1053 }
1054
1055 /**
1056  * g_output_stream_set_pending:
1057  * @stream: a #GOutputStream.
1058  * @error: a #GError location to store the error occuring, or %NULL to
1059  * ignore.
1060  *
1061  * Sets @stream to have actions pending. If the pending flag is
1062  * already set or @stream is closed, it will return %FALSE and set
1063  * @error.
1064  *
1065  * Return value: %TRUE if pending was previously unset and is now set.
1066  **/
1067 gboolean
1068 g_output_stream_set_pending (GOutputStream *stream,
1069                              GError **error)
1070 {
1071   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1072
1073   if (stream->priv->closed)
1074     {
1075       g_set_error (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
1076                    _("Stream is already closed"));
1077       return FALSE;
1078     }
1079
1080   if (stream->priv->pending)
1081     {
1082       g_set_error (error, G_IO_ERROR, G_IO_ERROR_PENDING,
1083                       /* Translators: This is an error you get if there is
1084                        * already an operation running against this stream when
1085                        * you try to start one */
1086                       _("Stream has outstanding operation"));
1087       return FALSE;
1088     }
1089
1090   stream->priv->pending = TRUE;
1091   return TRUE;
1092 }
1093
1094 /**
1095  * g_output_stream_clear_pending:
1096  * @stream: output stream
1097  *
1098  * Clears the pending flag on @stream.
1099  **/
1100 void
1101 g_output_stream_clear_pending (GOutputStream *stream)
1102 {
1103   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
1104
1105   stream->priv->pending = FALSE;
1106 }
1107
1108
1109 /********************************************
1110  *   Default implementation of async ops    *
1111  ********************************************/
1112
1113 typedef struct {
1114   const void         *buffer;
1115   gsize               count_requested;
1116   gssize              count_written;
1117 } WriteData;
1118
1119 static void
1120 write_async_thread (GSimpleAsyncResult *res,
1121                     GObject            *object,
1122                     GCancellable       *cancellable)
1123 {
1124   WriteData *op;
1125   GOutputStreamClass *class;
1126   GError *error = NULL;
1127
1128   class = G_OUTPUT_STREAM_GET_CLASS (object);
1129   op = g_simple_async_result_get_op_res_gpointer (res);
1130   op->count_written = class->write_fn (G_OUTPUT_STREAM (object), op->buffer, op->count_requested,
1131                                        cancellable, &error);
1132   if (op->count_written == -1)
1133     {
1134       g_simple_async_result_set_from_error (res, error);
1135       g_error_free (error);
1136     }
1137 }
1138
1139 static void
1140 g_output_stream_real_write_async (GOutputStream       *stream,
1141                                   const void          *buffer,
1142                                   gsize                count,
1143                                   int                  io_priority,
1144                                   GCancellable        *cancellable,
1145                                   GAsyncReadyCallback  callback,
1146                                   gpointer             user_data)
1147 {
1148   GSimpleAsyncResult *res;
1149   WriteData *op;
1150
1151   op = g_new0 (WriteData, 1);
1152   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_write_async);
1153   g_simple_async_result_set_op_res_gpointer (res, op, g_free);
1154   op->buffer = buffer;
1155   op->count_requested = count;
1156
1157   g_simple_async_result_run_in_thread (res, write_async_thread, io_priority, cancellable);
1158   g_object_unref (res);
1159 }
1160
1161 static gssize
1162 g_output_stream_real_write_finish (GOutputStream  *stream,
1163                                    GAsyncResult   *result,
1164                                    GError        **error)
1165 {
1166   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
1167   WriteData *op;
1168
1169   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_output_stream_real_write_async);
1170   op = g_simple_async_result_get_op_res_gpointer (simple);
1171   return op->count_written;
1172 }
1173
1174 typedef struct {
1175   GInputStream *source;
1176   GOutputStreamSpliceFlags flags;
1177   gssize bytes_copied;
1178 } SpliceData;
1179
1180 static void
1181 splice_async_thread (GSimpleAsyncResult *result,
1182                      GObject            *object,
1183                      GCancellable       *cancellable)
1184 {
1185   SpliceData *op;
1186   GOutputStreamClass *class;
1187   GError *error = NULL;
1188   GOutputStream *stream;
1189
1190   stream = G_OUTPUT_STREAM (object);
1191   class = G_OUTPUT_STREAM_GET_CLASS (object);
1192   op = g_simple_async_result_get_op_res_gpointer (result);
1193
1194   op->bytes_copied = class->splice (stream,
1195                                     op->source,
1196                                     op->flags,
1197                                     cancellable,
1198                                     &error);
1199   if (op->bytes_copied == -1)
1200     {
1201       g_simple_async_result_set_from_error (result, error);
1202       g_error_free (error);
1203     }
1204 }
1205
1206 static void
1207 g_output_stream_real_splice_async (GOutputStream             *stream,
1208                                    GInputStream              *source,
1209                                    GOutputStreamSpliceFlags   flags,
1210                                    int                        io_priority,
1211                                    GCancellable              *cancellable,
1212                                    GAsyncReadyCallback        callback,
1213                                    gpointer                   user_data)
1214 {
1215   GSimpleAsyncResult *res;
1216   SpliceData *op;
1217
1218   op = g_new0 (SpliceData, 1);
1219   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_splice_async);
1220   g_simple_async_result_set_op_res_gpointer (res, op, g_free);
1221   op->flags = flags;
1222   op->source = source;
1223
1224   /* TODO: In the case where both source and destintion have
1225      non-threadbased async calls we can use a true async copy here */
1226
1227   g_simple_async_result_run_in_thread (res, splice_async_thread, io_priority, cancellable);
1228   g_object_unref (res);
1229 }
1230
1231 static gssize
1232 g_output_stream_real_splice_finish (GOutputStream  *stream,
1233                                     GAsyncResult   *result,
1234                                     GError        **error)
1235 {
1236   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
1237   SpliceData *op;
1238
1239   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_output_stream_real_splice_async);
1240   op = g_simple_async_result_get_op_res_gpointer (simple);
1241   return op->bytes_copied;
1242 }
1243
1244
1245 static void
1246 flush_async_thread (GSimpleAsyncResult *res,
1247                     GObject            *object,
1248                     GCancellable       *cancellable)
1249 {
1250   GOutputStreamClass *class;
1251   gboolean result;
1252   GError *error = NULL;
1253
1254   class = G_OUTPUT_STREAM_GET_CLASS (object);
1255   result = TRUE;
1256   if (class->flush)
1257     result = class->flush (G_OUTPUT_STREAM (object), cancellable, &error);
1258
1259   if (!result)
1260     {
1261       g_simple_async_result_set_from_error (res, error);
1262       g_error_free (error);
1263     }
1264 }
1265
1266 static void
1267 g_output_stream_real_flush_async (GOutputStream       *stream,
1268                                   int                  io_priority,
1269                                   GCancellable        *cancellable,
1270                                   GAsyncReadyCallback  callback,
1271                                   gpointer             user_data)
1272 {
1273   GSimpleAsyncResult *res;
1274
1275   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_write_async);
1276
1277   g_simple_async_result_run_in_thread (res, flush_async_thread, io_priority, cancellable);
1278   g_object_unref (res);
1279 }
1280
1281 static gboolean
1282 g_output_stream_real_flush_finish (GOutputStream  *stream,
1283                                    GAsyncResult   *result,
1284                                    GError        **error)
1285 {
1286   return TRUE;
1287 }
1288
1289 static void
1290 close_async_thread (GSimpleAsyncResult *res,
1291                     GObject            *object,
1292                     GCancellable       *cancellable)
1293 {
1294   GOutputStreamClass *class;
1295   GError *error = NULL;
1296   gboolean result;
1297
1298   /* Auto handling of cancelation disabled, and ignore
1299      cancellation, since we want to close things anyway, although
1300      possibly in a quick-n-dirty way. At least we never want to leak
1301      open handles */
1302
1303   class = G_OUTPUT_STREAM_GET_CLASS (object);
1304   result = class->close_fn (G_OUTPUT_STREAM (object), cancellable, &error);
1305   if (!result)
1306     {
1307       g_simple_async_result_set_from_error (res, error);
1308       g_error_free (error);
1309     }
1310 }
1311
1312 static void
1313 g_output_stream_real_close_async (GOutputStream       *stream,
1314                                   int                  io_priority,
1315                                   GCancellable        *cancellable,
1316                                   GAsyncReadyCallback  callback,
1317                                   gpointer             user_data)
1318 {
1319   GSimpleAsyncResult *res;
1320
1321   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_close_async);
1322
1323   g_simple_async_result_set_handle_cancellation (res, FALSE);
1324
1325   g_simple_async_result_run_in_thread (res, close_async_thread, io_priority, cancellable);
1326   g_object_unref (res);
1327 }
1328
1329 static gboolean
1330 g_output_stream_real_close_finish (GOutputStream  *stream,
1331                                    GAsyncResult   *result,
1332                                    GError        **error)
1333 {
1334   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
1335   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_output_stream_real_close_async);
1336   return TRUE;
1337 }
1338
1339 #define __G_OUTPUT_STREAM_C__
1340 #include "gioaliasdef.c"