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  *
  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 == 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_push_current_cancellable (cancellable);
 211
 212   res = class->write (stream, buffer, count, cancellable, error);
 213
 214   if (cancellable)
 215     g_pop_current_cancellable (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 occured.
 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_push_current_cancellable (cancellable);
 322
 323       res = class->flush (stream, cancellable, error);
 324
 325       if (cancellable)
 326         g_pop_current_cancellable (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 containig 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_push_current_cancellable (cancellable);
 375
 376   res = class->splice (stream, source, flags, cancellable, error);
 377
 378   if (cancellable)
 379     g_pop_current_cancellable (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   if (class->write == NULL)
 400     {
 401       g_set_error (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
 402                    _("Output stream doesn't implement write"));
 403       res = FALSE;
 404       goto notsupported;
 405     }
 406
 407   bytes_copied = 0;
 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 (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_FLAGS_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_FLAGS_CLOSE_TARGET)
 449     {
 450       /* But write errors on close are bad! */
 451       if (!class->close (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 make sure resources
 478  * 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_push_current_cancellable (cancellable);
 520
 521   res = class->flush (stream, cancellable, error);
 522
 523   if (!res)
 524     {
 525       /* flushing caused the error that we want to return,
 526        * but we still want to close the underlying stream if possible
 527        */
 528       if (class->close)
 529         class->close (stream, cancellable, NULL);
 530     }
 531   else
 532     {
 533       res = TRUE;
 534       if (class->close)
 535         res = class->close (stream, cancellable, error);
 536     }
 537
 538   if (cancellable)
 539     g_pop_current_cancellable (cancellable);
 540
 541   stream->priv->closed = TRUE;
 542   g_output_stream_clear_pending (stream);
 543
 544   return res;
 545 }
 546
 547 static void
 548 async_ready_callback_wrapper (GObject      *source_object,
 549                               GAsyncResult *res,
 550                               gpointer      user_data)
 551 {
 552   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 553
 554   g_output_stream_clear_pending (stream);
 555   if (stream->priv->outstanding_callback)
 556     (*stream->priv->outstanding_callback) (source_object, res, user_data);
 557   g_object_unref (stream);
 558 }
 559
 560 static void
 561 async_ready_close_callback_wrapper (GObject      *source_object,
 562                                     GAsyncResult *res,
 563                                     gpointer      user_data)
 564 {
 565   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 566
 567   stream->priv->closed = TRUE;
 568   g_output_stream_clear_pending (stream);
 569   if (stream->priv->outstanding_callback)
 570     (*stream->priv->outstanding_callback) (source_object, res, user_data);
 571   g_object_unref (stream);
 572 }
 573
 574 /**
 575  * g_output_stream_write_async:
 576  * @stream: A #GOutputStream.
 577  * @buffer: the buffer containing the data to write.
 578  * @count: the number of bytes to write
 579  * @io_priority: the io priority of the request.
 580  * @cancellable: optional #GCancellable object, %NULL to ignore.
 581  * @callback: callback to call when the request is satisfied
 582  * @user_data: the data to pass to callback function
 583  *
 584  * Request an asynchronous write of @count bytes from @buffer into
 585  * the stream. When the operation is finished @callback will be called,
 586  * giving the results.
 587  *
 588  * During an async request no other sync and async calls are allowed,
 589  * and will result in %G_IO_ERROR_PENDING errors.
 590  *
 591  * A value of @count larger than %G_MAXSSIZE will cause a
 592  * %G_IO_ERROR_INVALID_ARGUMENT error.
 593  *
 594  * On success, the number of bytes written will be passed to the
 595  * @callback. It is not an error if this is not the same as the
 596  * requested size, as it can happen e.g. on a partial I/O error,
 597  * but generally we try to write as many bytes as requested.
 598  *
 599  * Any outstanding I/O request with higher priority (lower numerical
 600  * value) will be executed before an outstanding request with lower
 601  * priority. Default priority is %G_PRIORITY_DEFAULT.
 602  *
 603  * The asyncronous methods have a default fallback that uses threads
 604  * to implement asynchronicity, so they are optional for inheriting
 605  * classes. However, if you override one you must override all.
 606  *
 607  * For the synchronous, blocking version of this function, see
 608  * g_output_stream_write().
 609  **/
 610 void
 611 g_output_stream_write_async (GOutputStream       *stream,
 612                              const void          *buffer,
 613                              gsize                count,
 614                              int                  io_priority,
 615                              GCancellable        *cancellable,
 616                              GAsyncReadyCallback  callback,
 617                              gpointer             user_data)
 618 {
 619   GOutputStreamClass *class;
 620   GSimpleAsyncResult *simple;
 621   GError *error = NULL;
 622
 623   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 624   g_return_if_fail (buffer != NULL);
 625
 626   if (count == 0)
 627     {
 628       simple = g_simple_async_result_new (G_OBJECT (stream),
 629                                           callback,
 630                                           user_data,
 631                                           g_output_stream_write_async);
 632       g_simple_async_result_complete_in_idle (simple);
 633       g_object_unref (simple);
 634       return;
 635     }
 636
 637   if (((gssize) count) < 0)
 638     {
 639       g_simple_async_report_error_in_idle (G_OBJECT (stream),
 640                                            callback,
 641                                            user_data,
 642                                            G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
 643                                            _("Too large count value passed to g_output_stream_write_async"));
 644       return;
 645     }
 646
 647   if (!g_output_stream_set_pending (stream, &error))
 648     {
 649       g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
 650                                             callback,
 651                                             user_data,
 652                                             error);
 653       g_error_free (error);
 654       return;
 655     }
 656
 657   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 658
 659   stream->priv->outstanding_callback = callback;
 660   g_object_ref (stream);
 661   class->write_async (stream, buffer, count, io_priority, cancellable,
 662                       async_ready_callback_wrapper, user_data);
 663 }
 664
 665 /**
 666  * g_output_stream_write_finish:
 667  * @stream: a #GOutputStream.
 668  * @result: a #GAsyncResult.
 669  * @error: a #GError location to store the error occuring, or %NULL to
 670  * ignore.
 671  *
 672  * Finishes a stream write operation.
 673  *
 674  * Returns: a #gssize containing the number of bytes written to the stream.
 675  **/
 676 gssize
 677 g_output_stream_write_finish (GOutputStream  *stream,
 678                               GAsyncResult   *result,
 679                               GError        **error)
 680 {
 681   GSimpleAsyncResult *simple;
 682   GOutputStreamClass *class;
 683
 684   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
 685   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), -1);
 686
 687   if (G_IS_SIMPLE_ASYNC_RESULT (result))
 688     {
 689       simple = G_SIMPLE_ASYNC_RESULT (result);
 690       if (g_simple_async_result_propagate_error (simple, error))
 691         return -1;
 692
 693       /* Special case writes of 0 bytes */
 694       if (g_simple_async_result_get_source_tag (simple) == g_output_stream_write_async)
 695         return 0;
 696     }
 697
 698   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 699   return class->write_finish (stream, result, error);
 700 }
 701
 702 typedef struct {
 703   GInputStream *source;
 704   gpointer user_data;
 705   GAsyncReadyCallback callback;
 706 } SpliceUserData;
 707
 708 static void
 709 async_ready_splice_callback_wrapper (GObject      *source_object,
 710                                      GAsyncResult *res,
 711                                      gpointer     _data)
 712 {
 713   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 714   SpliceUserData *data = _data;
 715
 716   g_output_stream_clear_pending (stream);
 717
 718   if (data->callback)
 719     (*data->callback) (source_object, res, data->user_data);
 720
 721   g_object_unref (stream);
 722   g_object_unref (data->source);
 723   g_free (data);
 724 }
 725
 726 /**
 727  * g_output_stream_splice_async:
 728  * @stream: a #GOutputStream.
 729  * @source: a #GInputStream.
 730  * @flags: a set of #GOutputStreamSpliceFlags.
 731  * @io_priority: the io priority of the request.
 732  * @cancellable: optional #GCancellable object, %NULL to ignore.
 733  * @callback: a #GAsyncReadyCallback.
 734  * @user_data: user data passed to @callback.
 735  *
 736  * Splices a stream asynchronously.
 737  *
 738  **/
 739 void
 740 g_output_stream_splice_async (GOutputStream            *stream,
 741                               GInputStream             *source,
 742                               GOutputStreamSpliceFlags  flags,
 743                               int                       io_priority,
 744                               GCancellable             *cancellable,
 745                               GAsyncReadyCallback       callback,
 746                               gpointer                  user_data)
 747 {
 748   GOutputStreamClass *class;
 749   SpliceUserData *data;
 750   GError *error = NULL;
 751
 752   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 753   g_return_if_fail (G_IS_INPUT_STREAM (source));
 754
 755   if (g_input_stream_is_closed (source))
 756     {
 757       g_simple_async_report_error_in_idle (G_OBJECT (stream),
 758                                            callback,
 759                                            user_data,
 760                                            G_IO_ERROR, G_IO_ERROR_CLOSED,
 761                                            _("Source stream is already closed"));
 762       return;
 763     }
 764
 765   if (!g_output_stream_set_pending (stream, &error))
 766     {
 767       g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
 768                                             callback,
 769                                             user_data,
 770                                             error);
 771       g_error_free (error);
 772       return;
 773     }
 774
 775   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 776
 777   data = g_new0 (SpliceUserData, 1);
 778   data->callback = callback;
 779   data->user_data = user_data;
 780   data->source = g_object_ref (source);
 781
 782   g_object_ref (stream);
 783   class->splice_async (stream, source, flags, io_priority, cancellable,
 784                       async_ready_splice_callback_wrapper, data);
 785 }
 786
 787 /**
 788  * g_output_stream_splice_finish:
 789  * @stream: a #GOutputStream.
 790  * @result: a #GAsyncResult.
 791  * @error: a #GError location to store the error occuring, or %NULL to
 792  * ignore.
 793  *
 794  * Finishes an asynchronous stream splice operation.
 795  *
 796  * Returns: a #gssize of the number of bytes spliced.
 797  **/
 798 gssize
 799 g_output_stream_splice_finish (GOutputStream  *stream,
 800                                GAsyncResult   *result,
 801                                GError        **error)
 802 {
 803   GSimpleAsyncResult *simple;
 804   GOutputStreamClass *class;
 805
 806   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
 807   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), -1);
 808
 809   if (G_IS_SIMPLE_ASYNC_RESULT (result))
 810     {
 811       simple = G_SIMPLE_ASYNC_RESULT (result);
 812       if (g_simple_async_result_propagate_error (simple, error))
 813         return -1;
 814     }
 815
 816   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 817   return class->splice_finish (stream, result, error);
 818 }
 819
 820 /**
 821  * g_output_stream_flush_async:
 822  * @stream: a #GOutputStream.
 823  * @io_priority: the io priority of the request.
 824  * @cancellable: optional #GCancellable object, %NULL to ignore.
 825  * @callback: a #GAsyncReadyCallback to call when the request is satisfied
 826  * @user_data: the data to pass to callback function
 827  *
 828  * Flushes a stream asynchronously.
 829  *
 830  **/
 831 void
 832 g_output_stream_flush_async (GOutputStream       *stream,
 833                              int                  io_priority,
 834                              GCancellable        *cancellable,
 835                              GAsyncReadyCallback  callback,
 836                              gpointer             user_data)
 837 {
 838   GOutputStreamClass *class;
 839   GSimpleAsyncResult *simple;
 840   GError *error = NULL;
 841
 842   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 843
 844   if (!g_output_stream_set_pending (stream, &error))
 845     {
 846       g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
 847                                             callback,
 848                                             user_data,
 849                                             error);
 850       g_error_free (error);
 851       return;
 852     }
 853
 854   stream->priv->outstanding_callback = callback;
 855   g_object_ref (stream);
 856
 857   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 858
 859   if (class->flush_async == NULL)
 860     {
 861       simple = g_simple_async_result_new (G_OBJECT (stream),
 862                                           async_ready_callback_wrapper,
 863                                           user_data,
 864                                           g_output_stream_flush_async);
 865       g_simple_async_result_complete_in_idle (simple);
 866       g_object_unref (simple);
 867       return;
 868     }
 869
 870   class->flush_async (stream, io_priority, cancellable,
 871                       async_ready_callback_wrapper, user_data);
 872 }
 873
 874 /**
 875  * g_output_stream_flush_finish:
 876  * @stream: a #GOutputStream.
 877  * @result: a GAsyncResult.
 878  * @error: a #GError location to store the error occuring, or %NULL to
 879  * ignore.
 880  *
 881  * Finishes flushing an output stream.
 882  *
 883  * Returns: %TRUE if flush operation suceeded, %FALSE otherwise.
 884  **/
 885 gboolean
 886 g_output_stream_flush_finish (GOutputStream  *stream,
 887                               GAsyncResult   *result,
 888                               GError        **error)
 889 {
 890   GSimpleAsyncResult *simple;
 891   GOutputStreamClass *klass;
 892
 893   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 894   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), FALSE);
 895
 896   if (G_IS_SIMPLE_ASYNC_RESULT (result))
 897     {
 898       simple = G_SIMPLE_ASYNC_RESULT (result);
 899       if (g_simple_async_result_propagate_error (simple, error))
 900         return FALSE;
 901
 902       /* Special case default implementation */
 903       if (g_simple_async_result_get_source_tag (simple) == g_output_stream_flush_async)
 904         return TRUE;
 905     }
 906
 907   klass = G_OUTPUT_STREAM_GET_CLASS (stream);
 908   return klass->flush_finish (stream, result, error);
 909 }
 910
 911
 912 /**
 913  * g_output_stream_close_async:
 914  * @stream: A #GOutputStream.
 915  * @io_priority: the io priority of the request.
 916  * @callback: callback to call when the request is satisfied
 917  * @user_data: the data to pass to callback function
 918  * @cancellable: optional cancellable object
 919  *
 920  * Requests an asynchronous close of the stream, releasing resources
 921  * related to it. When the operation is finished @callback will be
 922  * called, giving the results.
 923  *
 924  * For behaviour details see g_output_stream_close().
 925  *
 926  * The asyncronous methods have a default fallback that uses threads
 927  * to implement asynchronicity, so they are optional for inheriting
 928  * classes. However, if you override one you must override all.
 929  **/
 930 void
 931 g_output_stream_close_async (GOutputStream       *stream,
 932                              int                  io_priority,
 933                              GCancellable        *cancellable,
 934                              GAsyncReadyCallback  callback,
 935                              gpointer             user_data)
 936 {
 937   GOutputStreamClass *class;
 938   GSimpleAsyncResult *simple;
 939   GError *error = NULL;
 940
 941   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 942
 943   if (stream->priv->closed)
 944     {
 945       simple = g_simple_async_result_new (G_OBJECT (stream),
 946                                           callback,
 947                                           user_data,
 948                                           g_output_stream_close_async);
 949       g_simple_async_result_complete_in_idle (simple);
 950       g_object_unref (simple);
 951       return;
 952     }
 953
 954   if (!g_output_stream_set_pending (stream, &error))
 955     {
 956       g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
 957                                             callback,
 958                                             user_data,
 959                                             error);
 960       g_error_free (error);
 961       return;
 962     }
 963
 964   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 965   stream->priv->outstanding_callback = callback;
 966   g_object_ref (stream);
 967   class->close_async (stream, io_priority, cancellable,
 968                       async_ready_close_callback_wrapper, user_data);
 969 }
 970
 971 /**
 972  * g_output_stream_close_finish:
 973  * @stream: a #GOutputStream.
 974  * @result: a #GAsyncResult.
 975  * @error: a #GError location to store the error occuring, or %NULL to
 976  * ignore.
 977  *
 978  * Closes an output stream.
 979  *
 980  * Returns: %TRUE if stream was successfully closed, %FALSE otherwise.
 981  **/
 982 gboolean
 983 g_output_stream_close_finish (GOutputStream  *stream,
 984                               GAsyncResult   *result,
 985                               GError        **error)
 986 {
 987   GSimpleAsyncResult *simple;
 988   GOutputStreamClass *class;
 989
 990   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 991   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), FALSE);
 992
 993   if (G_IS_SIMPLE_ASYNC_RESULT (result))
 994     {
 995       simple = G_SIMPLE_ASYNC_RESULT (result);
 996       if (g_simple_async_result_propagate_error (simple, error))
 997         return FALSE;
 998
 999       /* Special case already closed */
1000       if (g_simple_async_result_get_source_tag (simple) == g_output_stream_close_async)
1001         return TRUE;
1002     }
1003
1004   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1005   return class->close_finish (stream, result, error);
1006 }
1007
1008 /**
1009  * g_output_stream_is_closed:
1010  * @stream: a #GOutputStream.
1011  *
1012  * Checks if an output stream has already been closed.
1013  *
1014  * Returns: %TRUE if @stream is closed. %FALSE otherwise.
1015  **/
1016 gboolean
1017 g_output_stream_is_closed (GOutputStream *stream)
1018 {
1019   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), TRUE);
1020
1021   return stream->priv->closed;
1022 }
1023
1024 /**
1025  * g_output_stream_has_pending:
1026  * @stream: a #GOutputStream.
1027  *
1028  * Checks if an ouput stream has pending actions.
1029  *
1030  * Returns: %TRUE if @stream has pending actions.
1031  **/
1032 gboolean
1033 g_output_stream_has_pending (GOutputStream *stream)
1034 {
1035   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1036
1037   return stream->priv->pending;
1038 }
1039
1040 /**
1041  * g_output_stream_set_pending:
1042  * @stream: a #GOutputStream.
1043  * @error: a #GError location to store the error occuring, or %NULL to
1044  * ignore.
1045  *
1046  * Sets @stream to have actions pending. If the pending flag is
1047  * already set or @stream is closed, it will return %FALSE and set
1048  * @error.
1049  *
1050  * Return value: %TRUE if pending was previously unset and is now set.
1051  **/
1052 gboolean
1053 g_output_stream_set_pending (GOutputStream *stream,
1054                              GError **error)
1055 {
1056   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1057
1058   if (stream->priv->closed)
1059     {
1060       g_set_error (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
1061                    _("Stream is already closed"));
1062       return FALSE;
1063     }
1064
1065   if (stream->priv->pending)
1066     {
1067       g_set_error (error, G_IO_ERROR, G_IO_ERROR_PENDING,
1068                    _("Stream has outstanding operation"));
1069       return FALSE;
1070     }
1071
1072   stream->priv->pending = TRUE;
1073   return TRUE;
1074 }
1075
1076 /**
1077  * g_output_stream_clear_pending:
1078  * @stream: output stream
1079  *
1080  * Clears the pending flag on @stream.
1081  **/
1082 void
1083 g_output_stream_clear_pending (GOutputStream *stream)
1084 {
1085   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
1086
1087   stream->priv->pending = FALSE;
1088 }
1089
1090
1091 /********************************************
1092  *   Default implementation of async ops    *
1093  ********************************************/
1094
1095 typedef struct {
1096   const void         *buffer;
1097   gsize               count_requested;
1098   gssize              count_written;
1099 } WriteData;
1100
1101 static void
1102 write_async_thread (GSimpleAsyncResult *res,
1103                     GObject            *object,
1104                     GCancellable       *cancellable)
1105 {
1106   WriteData *op;
1107   GOutputStreamClass *class;
1108   GError *error = NULL;
1109
1110   class = G_OUTPUT_STREAM_GET_CLASS (object);
1111   op = g_simple_async_result_get_op_res_gpointer (res);
1112   op->count_written = class->write (G_OUTPUT_STREAM (object), op->buffer, op->count_requested,
1113                                     cancellable, &error);
1114   if (op->count_written == -1)
1115     {
1116       g_simple_async_result_set_from_error (res, error);
1117       g_error_free (error);
1118     }
1119 }
1120
1121 static void
1122 g_output_stream_real_write_async (GOutputStream       *stream,
1123                                   const void          *buffer,
1124                                   gsize                count,
1125                                   int                  io_priority,
1126                                   GCancellable        *cancellable,
1127                                   GAsyncReadyCallback  callback,
1128                                   gpointer             user_data)
1129 {
1130   GSimpleAsyncResult *res;
1131   WriteData *op;
1132
1133   op = g_new0 (WriteData, 1);
1134   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_write_async);
1135   g_simple_async_result_set_op_res_gpointer (res, op, g_free);
1136   op->buffer = buffer;
1137   op->count_requested = count;
1138
1139   g_simple_async_result_run_in_thread (res, write_async_thread, io_priority, cancellable);
1140   g_object_unref (res);
1141 }
1142
1143 static gssize
1144 g_output_stream_real_write_finish (GOutputStream  *stream,
1145                                    GAsyncResult   *result,
1146                                    GError        **error)
1147 {
1148   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
1149   WriteData *op;
1150
1151   g_assert (g_simple_async_result_get_source_tag (simple) == g_output_stream_real_write_async);
1152   op = g_simple_async_result_get_op_res_gpointer (simple);
1153   return op->count_written;
1154 }
1155
1156 typedef struct {
1157   GInputStream *source;
1158   GOutputStreamSpliceFlags flags;
1159   gssize bytes_copied;
1160 } SpliceData;
1161
1162 static void
1163 splice_async_thread (GSimpleAsyncResult *result,
1164                      GObject            *object,
1165                      GCancellable       *cancellable)
1166 {
1167   SpliceData *op;
1168   GOutputStreamClass *class;
1169   GError *error = NULL;
1170   GOutputStream *stream;
1171
1172   stream = G_OUTPUT_STREAM (object);
1173   class = G_OUTPUT_STREAM_GET_CLASS (object);
1174   op = g_simple_async_result_get_op_res_gpointer (result);
1175
1176   op->bytes_copied = class->splice (stream,
1177                                     op->source,
1178                                     op->flags,
1179                                     cancellable,
1180                                     &error);
1181   if (op->bytes_copied == -1)
1182     {
1183       g_simple_async_result_set_from_error (result, error);
1184       g_error_free (error);
1185     }
1186 }
1187
1188 static void
1189 g_output_stream_real_splice_async (GOutputStream             *stream,
1190                                    GInputStream              *source,
1191                                    GOutputStreamSpliceFlags   flags,
1192                                    int                        io_priority,
1193                                    GCancellable              *cancellable,
1194                                    GAsyncReadyCallback        callback,
1195                                    gpointer                   user_data)
1196 {
1197   GSimpleAsyncResult *res;
1198   SpliceData *op;
1199
1200   op = g_new0 (SpliceData, 1);
1201   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_splice_async);
1202   g_simple_async_result_set_op_res_gpointer (res, op, g_free);
1203   op->flags = flags;
1204   op->source = source;
1205
1206   /* TODO: In the case where both source and destintion have
1207      non-threadbased async calls we can use a true async copy here */
1208
1209   g_simple_async_result_run_in_thread (res, splice_async_thread, io_priority, cancellable);
1210   g_object_unref (res);
1211 }
1212
1213 static gssize
1214 g_output_stream_real_splice_finish (GOutputStream  *stream,
1215                                     GAsyncResult   *result,
1216                                     GError        **error)
1217 {
1218   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
1219   SpliceData *op;
1220
1221   g_assert (g_simple_async_result_get_source_tag (simple) == g_output_stream_real_splice_async);
1222   op = g_simple_async_result_get_op_res_gpointer (simple);
1223   return op->bytes_copied;
1224 }
1225
1226
1227 static void
1228 flush_async_thread (GSimpleAsyncResult *res,
1229                     GObject            *object,
1230                     GCancellable       *cancellable)
1231 {
1232   GOutputStreamClass *class;
1233   gboolean result;
1234   GError *error = NULL;
1235
1236   class = G_OUTPUT_STREAM_GET_CLASS (object);
1237   result = TRUE;
1238   if (class->flush)
1239     result = class->flush (G_OUTPUT_STREAM (object), cancellable, &error);
1240
1241   if (!result)
1242     {
1243       g_simple_async_result_set_from_error (res, error);
1244       g_error_free (error);
1245     }
1246 }
1247
1248 static void
1249 g_output_stream_real_flush_async (GOutputStream       *stream,
1250                                   int                  io_priority,
1251                                   GCancellable        *cancellable,
1252                                   GAsyncReadyCallback  callback,
1253                                   gpointer             user_data)
1254 {
1255   GSimpleAsyncResult *res;
1256
1257   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_write_async);
1258
1259   g_simple_async_result_run_in_thread (res, flush_async_thread, io_priority, cancellable);
1260   g_object_unref (res);
1261 }
1262
1263 static gboolean
1264 g_output_stream_real_flush_finish (GOutputStream  *stream,
1265                                    GAsyncResult   *result,
1266                                    GError        **error)
1267 {
1268   return TRUE;
1269 }
1270
1271 static void
1272 close_async_thread (GSimpleAsyncResult *res,
1273                     GObject            *object,
1274                     GCancellable       *cancellable)
1275 {
1276   GOutputStreamClass *class;
1277   GError *error = NULL;
1278   gboolean result;
1279
1280   /* Auto handling of cancelation disabled, and ignore
1281      cancellation, since we want to close things anyway, although
1282      possibly in a quick-n-dirty way. At least we never want to leak
1283      open handles */
1284
1285   class = G_OUTPUT_STREAM_GET_CLASS (object);
1286   result = class->close (G_OUTPUT_STREAM (object), cancellable, &error);
1287   if (!result)
1288     {
1289       g_simple_async_result_set_from_error (res, error);
1290       g_error_free (error);
1291     }
1292 }
1293
1294 static void
1295 g_output_stream_real_close_async (GOutputStream       *stream,
1296                                   int                  io_priority,
1297                                   GCancellable        *cancellable,
1298                                   GAsyncReadyCallback  callback,
1299                                   gpointer             user_data)
1300 {
1301   GSimpleAsyncResult *res;
1302
1303   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_close_async);
1304
1305   g_simple_async_result_set_handle_cancellation (res, FALSE);
1306
1307   g_simple_async_result_run_in_thread (res, close_async_thread, io_priority, cancellable);
1308   g_object_unref (res);
1309 }
1310
1311 static gboolean
1312 g_output_stream_real_close_finish (GOutputStream  *stream,
1313                                    GAsyncResult   *result,
1314                                    GError        **error)
1315 {
1316   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
1317   g_assert (g_simple_async_result_get_source_tag (simple) == g_output_stream_real_close_async);
1318   return TRUE;
1319 }
1320
1321 #define __G_OUTPUT_STREAM_C__
1322 #include "gioaliasdef.c"