gio/goutputstream.c

   1 /* GIO - GLib Input, Output and Streaming Library
   2  *
   3  * Copyright (C) 2006-2007 Red Hat, Inc.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General
  16  * Public License along with this library; if not, write to the
  17  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  18  * Boston, MA 02111-1307, USA.
  19  *
  20  * Author: Alexander Larsson <alexl@redhat.com>
  21  */
  22
  23 #include "config.h"
  24 #include "goutputstream.h"
  25 #include "gcancellable.h"
  26 #include "gasyncresult.h"
  27 #include "gsimpleasyncresult.h"
  28 #include "ginputstream.h"
  29 #include "gioerror.h"
  30 #include "glibintl.h"
  31
  32 #include "gioalias.h"
  33
  34 /**
  35  * SECTION:goutputstream
  36  * @short_description: Base class for implementing streaming output
  37  * @include: gio/gio.h
  38  *
  39  * GOutputStream has functions to write to a stream (g_output_stream_write()),
  40  * to close a stream (g_output_stream_close()) and to flush pending writes
  41  * (g_output_stream_flush()).
  42  *
  43  * To copy the content of an input stream to an output stream without
  44  * manually handling the reads and writes, use g_output_stream_splice().
  45  *
  46  * All of these functions have async variants too.
  47  **/
  48
  49 G_DEFINE_TYPE (GOutputStream, g_output_stream, G_TYPE_OBJECT);
  50
  51 struct _GOutputStreamPrivate {
  52   guint closed : 1;
  53   guint pending : 1;
  54   GAsyncReadyCallback outstanding_callback;
  55 };
  56
  57 static gssize   g_output_stream_real_splice        (GOutputStream             *stream,
  58                                                     GInputStream              *source,
  59                                                     GOutputStreamSpliceFlags   flags,
  60                                                     GCancellable              *cancellable,
  61                                                     GError                   **error);
  62 static void     g_output_stream_real_write_async   (GOutputStream             *stream,
  63                                                     const void                *buffer,
  64                                                     gsize                      count,
  65                                                     int                        io_priority,
  66                                                     GCancellable              *cancellable,
  67                                                     GAsyncReadyCallback        callback,
  68                                                     gpointer                   data);
  69 static gssize   g_output_stream_real_write_finish  (GOutputStream             *stream,
  70                                                     GAsyncResult              *result,
  71                                                     GError                   **error);
  72 static void     g_output_stream_real_splice_async  (GOutputStream             *stream,
  73                                                     GInputStream              *source,
  74                                                     GOutputStreamSpliceFlags   flags,
  75                                                     int                        io_priority,
  76                                                     GCancellable              *cancellable,
  77                                                     GAsyncReadyCallback        callback,
  78                                                     gpointer                   data);
  79 static gssize   g_output_stream_real_splice_finish (GOutputStream             *stream,
  80                                                     GAsyncResult              *result,
  81                                                     GError                   **error);
  82 static void     g_output_stream_real_flush_async   (GOutputStream             *stream,
  83                                                     int                        io_priority,
  84                                                     GCancellable              *cancellable,
  85                                                     GAsyncReadyCallback        callback,
  86                                                     gpointer                   data);
  87 static gboolean g_output_stream_real_flush_finish  (GOutputStream             *stream,
  88                                                     GAsyncResult              *result,
  89                                                     GError                   **error);
  90 static void     g_output_stream_real_close_async   (GOutputStream             *stream,
  91                                                     int                        io_priority,
  92                                                     GCancellable              *cancellable,
  93                                                     GAsyncReadyCallback        callback,
  94                                                     gpointer                   data);
  95 static gboolean g_output_stream_real_close_finish  (GOutputStream             *stream,
  96                                                     GAsyncResult              *result,
  97                                                     GError                   **error);
  98
  99 static void
 100 g_output_stream_finalize (GObject *object)
 101 {
 102   G_OBJECT_CLASS (g_output_stream_parent_class)->finalize (object);
 103 }
 104
 105 static void
 106 g_output_stream_dispose (GObject *object)
 107 {
 108   GOutputStream *stream;
 109
 110   stream = G_OUTPUT_STREAM (object);
 111
 112   if (!stream->priv->closed)
 113     g_output_stream_close (stream, NULL, NULL);
 114
 115   G_OBJECT_CLASS (g_output_stream_parent_class)->dispose (object);
 116 }
 117
 118 static void
 119 g_output_stream_class_init (GOutputStreamClass *klass)
 120 {
 121   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 122
 123   g_type_class_add_private (klass, sizeof (GOutputStreamPrivate));
 124
 125   gobject_class->finalize = g_output_stream_finalize;
 126   gobject_class->dispose = g_output_stream_dispose;
 127
 128   klass->splice = g_output_stream_real_splice;
 129
 130   klass->write_async = g_output_stream_real_write_async;
 131   klass->write_finish = g_output_stream_real_write_finish;
 132   klass->splice_async = g_output_stream_real_splice_async;
 133   klass->splice_finish = g_output_stream_real_splice_finish;
 134   klass->flush_async = g_output_stream_real_flush_async;
 135   klass->flush_finish = g_output_stream_real_flush_finish;
 136   klass->close_async = g_output_stream_real_close_async;
 137   klass->close_finish = g_output_stream_real_close_finish;
 138 }
 139
 140 static void
 141 g_output_stream_init (GOutputStream *stream)
 142 {
 143   stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (stream,
 144                                               G_TYPE_OUTPUT_STREAM,
 145                                               GOutputStreamPrivate);
 146 }
 147
 148 /**
 149  * g_output_stream_write:
 150  * @stream: a #GOutputStream.
 151  * @buffer: the buffer containing the data to write.
 152  * @count: the number of bytes to write
 153  * @cancellable: optional cancellable object
 154  * @error: location to store the error occuring, or %NULL to ignore
 155  *
 156  * Tries to write @count bytes from @buffer into the stream. Will block
 157  * during the operation.
 158  *
 159  * If count is zero returns zero and does nothing. A value of @count
 160  * larger than %G_MAXSSIZE will cause a %G_IO_ERROR_INVALID_ARGUMENT error.
 161  *
 162  * On success, the number of bytes written to the stream is returned.
 163  * It is not an error if this is not the same as the requested size, as it
 164  * can happen e.g. on a partial i/o error, or if there is not enough
 165  * storage in the stream. All writes either block until at least one byte
 166  * is written, so zero is never returned (unless @count is zero).
 167  *
 168  * If @cancellable is not NULL, then the operation can be cancelled by
 169  * triggering the cancellable object from another thread. If the operation
 170  * was cancelled, the error G_IO_ERROR_CANCELLED will be returned. If an
 171  * operation was partially finished when the operation was cancelled the
 172  * partial result will be returned, without an error.
 173  *
 174  * On error -1 is returned and @error is set accordingly.
 175  *
 176  * Return value: Number of bytes written, or -1 on error
 177  **/
 178 gssize
 179 g_output_stream_write (GOutputStream  *stream,
 180                        const void     *buffer,
 181                        gsize           count,
 182                        GCancellable   *cancellable,
 183                        GError        **error)
 184 {
 185   GOutputStreamClass *class;
 186   gssize res;
 187
 188   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
 189   g_return_val_if_fail (buffer != NULL, 0);
 190
 191   if (count == 0)
 192     return 0;
 193
 194   if (((gssize) count) < 0)
 195     {
 196       g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
 197                    _("Too large count value passed to %s"), G_STRFUNC);
 198       return -1;
 199     }
 200
 201   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 202
 203   if (class->write_fn == NULL)
 204     {
 205       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
 206                            _("Output stream doesn't implement write"));
 207       return -1;
 208     }
 209
 210   if (!g_output_stream_set_pending (stream, error))
 211     return -1;
 212
 213   if (cancellable)
 214     g_cancellable_push_current (cancellable);
 215
 216   res = class->write_fn (stream, buffer, count, cancellable, error);
 217
 218   if (cancellable)
 219     g_cancellable_pop_current (cancellable);
 220
 221   g_output_stream_clear_pending (stream);
 222
 223   return res;
 224 }
 225
 226 /**
 227  * g_output_stream_write_all:
 228  * @stream: a #GOutputStream.
 229  * @buffer: the buffer containing the data to write.
 230  * @count: the number of bytes to write
 231  * @bytes_written: location to store the number of bytes that was
 232  *     written to the stream
 233  * @cancellable: optional #GCancellable object, %NULL to ignore.
 234  * @error: location to store the error occuring, or %NULL to ignore
 235  *
 236  * Tries to write @count bytes from @buffer into the stream. Will block
 237  * during the operation.
 238  *
 239  * This function is similar to g_output_stream_write(), except it tries to
 240  * write as many bytes as requested, only stopping on an error.
 241  *
 242  * On a successful write of @count bytes, %TRUE is returned, and @bytes_written
 243  * is set to @count.
 244  *
 245  * If there is an error during the operation FALSE is returned and @error
 246  * is set to indicate the error status, @bytes_written is updated to contain
 247  * the number of bytes written into the stream before the error occurred.
 248  *
 249  * Return value: %TRUE on success, %FALSE if there was an error
 250  **/
 251 gboolean
 252 g_output_stream_write_all (GOutputStream  *stream,
 253                            const void     *buffer,
 254                            gsize           count,
 255                            gsize          *bytes_written,
 256                            GCancellable   *cancellable,
 257                            GError        **error)
 258 {
 259   gsize _bytes_written;
 260   gssize res;
 261
 262   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 263   g_return_val_if_fail (buffer != NULL, FALSE);
 264
 265   _bytes_written = 0;
 266   while (_bytes_written < count)
 267     {
 268       res = g_output_stream_write (stream, (char *)buffer + _bytes_written, count - _bytes_written,
 269                                    cancellable, error);
 270       if (res == -1)
 271         {
 272           if (bytes_written)
 273             *bytes_written = _bytes_written;
 274           return FALSE;
 275         }
 276
 277       if (res == 0)
 278         g_warning ("Write returned zero without error");
 279
 280       _bytes_written += res;
 281     }
 282
 283   if (bytes_written)
 284     *bytes_written = _bytes_written;
 285
 286   return TRUE;
 287 }
 288
 289 /**
 290  * g_output_stream_flush:
 291  * @stream: a #GOutputStream.
 292  * @cancellable: optional cancellable object
 293  * @error: location to store the error occuring, or %NULL to ignore
 294  *
 295  * Flushed any outstanding buffers in the stream. Will block during
 296  * the operation. Closing the stream will implicitly cause a flush.
 297  *
 298  * This function is optional for inherited classes.
 299  *
 300  * If @cancellable is not %NULL, then the operation can be cancelled by
 301  * triggering the cancellable object from another thread. If the operation
 302  * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned.
 303  *
 304  * Return value: %TRUE on success, %FALSE on error
 305  **/
 306 gboolean
 307 g_output_stream_flush (GOutputStream  *stream,
 308                        GCancellable   *cancellable,
 309                        GError        **error)
 310 {
 311   GOutputStreamClass *class;
 312   gboolean res;
 313
 314   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 315
 316   if (!g_output_stream_set_pending (stream, error))
 317     return FALSE;
 318
 319   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 320
 321   res = TRUE;
 322   if (class->flush)
 323     {
 324       if (cancellable)
 325         g_cancellable_push_current (cancellable);
 326
 327       res = class->flush (stream, cancellable, error);
 328
 329       if (cancellable)
 330         g_cancellable_pop_current (cancellable);
 331     }
 332
 333   g_output_stream_clear_pending (stream);
 334
 335   return res;
 336 }
 337
 338 /**
 339  * g_output_stream_splice:
 340  * @stream: a #GOutputStream.
 341  * @source: a #GInputStream.
 342  * @flags: a set of #GOutputStreamSpliceFlags.
 343  * @cancellable: optional #GCancellable object, %NULL to ignore.
 344  * @error: a #GError location to store the error occuring, or %NULL to
 345  * ignore.
 346  *
 347  * Splices an input stream into an output stream.
 348  *
 349  * Returns: a #gssize containing the size of the data spliced, or
 350  *     -1 if an error occurred.
 351  **/
 352 gssize
 353 g_output_stream_splice (GOutputStream             *stream,
 354                         GInputStream              *source,
 355                         GOutputStreamSpliceFlags   flags,
 356                         GCancellable              *cancellable,
 357                         GError                   **error)
 358 {
 359   GOutputStreamClass *class;
 360   gssize bytes_copied;
 361
 362   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
 363   g_return_val_if_fail (G_IS_INPUT_STREAM (source), -1);
 364
 365   if (g_input_stream_is_closed (source))
 366     {
 367       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
 368                            _("Source stream is already closed"));
 369       return -1;
 370     }
 371
 372   if (!g_output_stream_set_pending (stream, error))
 373     return -1;
 374
 375   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 376
 377   if (cancellable)
 378     g_cancellable_push_current (cancellable);
 379
 380   bytes_copied = class->splice (stream, source, flags, cancellable, error);
 381
 382   if (cancellable)
 383     g_cancellable_pop_current (cancellable);
 384
 385   g_output_stream_clear_pending (stream);
 386
 387   return bytes_copied;
 388 }
 389
 390 static gssize
 391 g_output_stream_real_splice (GOutputStream             *stream,
 392                              GInputStream              *source,
 393                              GOutputStreamSpliceFlags   flags,
 394                              GCancellable              *cancellable,
 395                              GError                   **error)
 396 {
 397   GOutputStreamClass *class = G_OUTPUT_STREAM_GET_CLASS (stream);
 398   gssize n_read, n_written;
 399   gssize bytes_copied;
 400   char buffer[8192], *p;
 401   gboolean res;
 402
 403   bytes_copied = 0;
 404   if (class->write_fn == NULL)
 405     {
 406       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
 407                            _("Output stream doesn't implement write"));
 408       res = FALSE;
 409       goto notsupported;
 410     }
 411
 412   res = TRUE;
 413   do
 414     {
 415       n_read = g_input_stream_read (source, buffer, sizeof (buffer), cancellable, error);
 416       if (n_read == -1)
 417         {
 418           res = FALSE;
 419           break;
 420         }
 421
 422       if (n_read == 0)
 423         break;
 424
 425       p = buffer;
 426       while (n_read > 0)
 427         {
 428           n_written = class->write_fn (stream, p, n_read, cancellable, error);
 429           if (n_written == -1)
 430             {
 431               res = FALSE;
 432               break;
 433             }
 434
 435           p += n_written;
 436           n_read -= n_written;
 437           bytes_copied += n_written;
 438         }
 439     }
 440   while (res);
 441
 442  notsupported:
 443   if (!res)
 444     error = NULL; /* Ignore further errors */
 445
 446   if (flags & G_OUTPUT_STREAM_SPLICE_CLOSE_SOURCE)
 447     {
 448       /* Don't care about errors in source here */
 449       g_input_stream_close (source, cancellable, NULL);
 450     }
 451
 452   if (flags & G_OUTPUT_STREAM_SPLICE_CLOSE_TARGET)
 453     {
 454       /* But write errors on close are bad! */
 455       if (class->close_fn &&
 456           !class->close_fn (stream, cancellable, error))
 457         res = FALSE;
 458     }
 459
 460   if (res)
 461     return bytes_copied;
 462
 463   return -1;
 464 }
 465
 466
 467 /**
 468  * g_output_stream_close:
 469  * @stream: A #GOutputStream.
 470  * @cancellable: optional cancellable object
 471  * @error: location to store the error occuring, or %NULL to ignore
 472  *
 473  * Closes the stream, releasing resources related to it.
 474  *
 475  * Once the stream is closed, all other operations will return %G_IO_ERROR_CLOSED.
 476  * Closing a stream multiple times will not return an error.
 477  *
 478  * Closing a stream will automatically flush any outstanding buffers in the
 479  * stream.
 480  *
 481  * Streams will be automatically closed when the last reference
 482  * is dropped, but you might want to call this function to make sure
 483  * resources are released as early as possible.
 484  *
 485  * Some streams might keep the backing store of the stream (e.g. a file descriptor)
 486  * open after the stream is closed. See the documentation for the individual
 487  * stream for details.
 488  *
 489  * On failure the first error that happened will be reported, but the close
 490  * operation will finish as much as possible. A stream that failed to
 491  * close will still return %G_IO_ERROR_CLOSED for all operations. Still, it
 492  * is important to check and report the error to the user, otherwise
 493  * there might be a loss of data as all data might not be written.
 494  *
 495  * If @cancellable is not NULL, then the operation can be cancelled by
 496  * triggering the cancellable object from another thread. If the operation
 497  * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned.
 498  * Cancelling a close will still leave the stream closed, but there some streams
 499  * can use a faster close that doesn't block to e.g. check errors. On
 500  * cancellation (as with any error) there is no guarantee that all written
 501  * data will reach the target.
 502  *
 503  * Return value: %TRUE on success, %FALSE on failure
 504  **/
 505 gboolean
 506 g_output_stream_close (GOutputStream  *stream,
 507                        GCancellable   *cancellable,
 508                        GError        **error)
 509 {
 510   GOutputStreamClass *class;
 511   gboolean res;
 512
 513   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 514
 515   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 516
 517   if (stream->priv->closed)
 518     return TRUE;
 519
 520   if (!g_output_stream_set_pending (stream, error))
 521     return FALSE;
 522
 523   if (cancellable)
 524     g_cancellable_push_current (cancellable);
 525
 526   if (class->flush)
 527     res = class->flush (stream, cancellable, error);
 528   else
 529     res = TRUE;
 530
 531   if (!res)
 532     {
 533       /* flushing caused the error that we want to return,
 534        * but we still want to close the underlying stream if possible
 535        */
 536       if (class->close_fn)
 537         class->close_fn (stream, cancellable, NULL);
 538     }
 539   else
 540     {
 541       res = TRUE;
 542       if (class->close_fn)
 543         res = class->close_fn (stream, cancellable, error);
 544     }
 545
 546   if (cancellable)
 547     g_cancellable_pop_current (cancellable);
 548
 549   stream->priv->closed = TRUE;
 550   g_output_stream_clear_pending (stream);
 551
 552   return res;
 553 }
 554
 555 static void
 556 async_ready_callback_wrapper (GObject      *source_object,
 557                               GAsyncResult *res,
 558                               gpointer      user_data)
 559 {
 560   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 561
 562   g_output_stream_clear_pending (stream);
 563   if (stream->priv->outstanding_callback)
 564     (*stream->priv->outstanding_callback) (source_object, res, user_data);
 565   g_object_unref (stream);
 566 }
 567
 568 static void
 569 async_ready_close_callback_wrapper (GObject      *source_object,
 570                                     GAsyncResult *res,
 571                                     gpointer      user_data)
 572 {
 573   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 574
 575   stream->priv->closed = TRUE;
 576   g_output_stream_clear_pending (stream);
 577   if (stream->priv->outstanding_callback)
 578     (*stream->priv->outstanding_callback) (source_object, res, user_data);
 579   g_object_unref (stream);
 580 }
 581
 582 /**
 583  * g_output_stream_write_async:
 584  * @stream: A #GOutputStream.
 585  * @buffer: the buffer containing the data to write.
 586  * @count: the number of bytes to write
 587  * @io_priority: the io priority of the request.
 588  * @cancellable: optional #GCancellable object, %NULL to ignore.
 589  * @callback: callback to call when the request is satisfied
 590  * @user_data: the data to pass to callback function
 591  *
 592  * Request an asynchronous write of @count bytes from @buffer into
 593  * the stream. When the operation is finished @callback will be called.
 594  * You can then call g_output_stream_write_finish() to get the result of the
 595  * operation.
 596  *
 597  * During an async request no other sync and async calls are allowed,
 598  * and will result in %G_IO_ERROR_PENDING errors.
 599  *
 600  * A value of @count larger than %G_MAXSSIZE will cause a
 601  * %G_IO_ERROR_INVALID_ARGUMENT error.
 602  *
 603  * On success, the number of bytes written will be passed to the
 604  * @callback. It is not an error if this is not the same as the
 605  * requested size, as it can happen e.g. on a partial I/O error,
 606  * but generally we try to write as many bytes as requested.
 607  *
 608  * Any outstanding I/O request with higher priority (lower numerical
 609  * value) will be executed before an outstanding request with lower
 610  * priority. Default priority is %G_PRIORITY_DEFAULT.
 611  *
 612  * The asyncronous methods have a default fallback that uses threads
 613  * to implement asynchronicity, so they are optional for inheriting
 614  * classes. However, if you override one you must override all.
 615  *
 616  * For the synchronous, blocking version of this function, see
 617  * g_output_stream_write().
 618  **/
 619 void
 620 g_output_stream_write_async (GOutputStream       *stream,
 621                              const void          *buffer,
 622                              gsize                count,
 623                              int                  io_priority,
 624                              GCancellable        *cancellable,
 625                              GAsyncReadyCallback  callback,
 626                              gpointer             user_data)
 627 {
 628   GOutputStreamClass *class;
 629   GSimpleAsyncResult *simple;
 630   GError *error = NULL;
 631
 632   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 633   g_return_if_fail (buffer != NULL);
 634
 635   if (count == 0)
 636     {
 637       simple = g_simple_async_result_new (G_OBJECT (stream),
 638                                           callback,
 639                                           user_data,
 640                                           g_output_stream_write_async);
 641       g_simple_async_result_complete_in_idle (simple);
 642       g_object_unref (simple);
 643       return;
 644     }
 645
 646   if (((gssize) count) < 0)
 647     {
 648       g_simple_async_report_error_in_idle (G_OBJECT (stream),
 649                                            callback,
 650                                            user_data,
 651                                            G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
 652                                            _("Too large count value passed to %s"),
 653                                            G_STRFUNC);
 654       return;
 655     }
 656
 657   if (!g_output_stream_set_pending (stream, &error))
 658     {
 659       g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
 660                                             callback,
 661                                             user_data,
 662                                             error);
 663       g_error_free (error);
 664       return;
 665     }
 666
 667   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 668
 669   stream->priv->outstanding_callback = callback;
 670   g_object_ref (stream);
 671   class->write_async (stream, buffer, count, io_priority, cancellable,
 672                       async_ready_callback_wrapper, user_data);
 673 }
 674
 675 /**
 676  * g_output_stream_write_finish:
 677  * @stream: a #GOutputStream.
 678  * @result: a #GAsyncResult.
 679  * @error: a #GError location to store the error occuring, or %NULL to
 680  * ignore.
 681  *
 682  * Finishes a stream write operation.
 683  *
 684  * Returns: a #gssize containing the number of bytes written to the stream.
 685  **/
 686 gssize
 687 g_output_stream_write_finish (GOutputStream  *stream,
 688                               GAsyncResult   *result,
 689                               GError        **error)
 690 {
 691   GSimpleAsyncResult *simple;
 692   GOutputStreamClass *class;
 693
 694   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
 695   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), -1);
 696
 697   if (G_IS_SIMPLE_ASYNC_RESULT (result))
 698     {
 699       simple = G_SIMPLE_ASYNC_RESULT (result);
 700       if (g_simple_async_result_propagate_error (simple, error))
 701         return -1;
 702
 703       /* Special case writes of 0 bytes */
 704       if (g_simple_async_result_get_source_tag (simple) == g_output_stream_write_async)
 705         return 0;
 706     }
 707
 708   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 709   return class->write_finish (stream, result, error);
 710 }
 711
 712 typedef struct {
 713   GInputStream *source;
 714   gpointer user_data;
 715   GAsyncReadyCallback callback;
 716 } SpliceUserData;
 717
 718 static void
 719 async_ready_splice_callback_wrapper (GObject      *source_object,
 720                                      GAsyncResult *res,
 721                                      gpointer     _data)
 722 {
 723   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 724   SpliceUserData *data = _data;
 725
 726   g_output_stream_clear_pending (stream);
 727
 728   if (data->callback)
 729     (*data->callback) (source_object, res, data->user_data);
 730
 731   g_object_unref (stream);
 732   g_object_unref (data->source);
 733   g_free (data);
 734 }
 735
 736 /**
 737  * g_output_stream_splice_async:
 738  * @stream: a #GOutputStream.
 739  * @source: a #GInputStream.
 740  * @flags: a set of #GOutputStreamSpliceFlags.
 741  * @io_priority: the io priority of the request.
 742  * @cancellable: optional #GCancellable object, %NULL to ignore.
 743  * @callback: a #GAsyncReadyCallback.
 744  * @user_data: user data passed to @callback.
 745  *
 746  * Splices a stream asynchronously.
 747  * When the operation is finished @callback will be called.
 748  * You can then call g_output_stream_splice_finish() to get the
 749  * result of the operation.
 750  *
 751  * For the synchronous, blocking version of this function, see
 752  * g_output_stream_splice().
 753  **/
 754 void
 755 g_output_stream_splice_async (GOutputStream            *stream,
 756                               GInputStream             *source,
 757                               GOutputStreamSpliceFlags  flags,
 758                               int                       io_priority,
 759                               GCancellable             *cancellable,
 760                               GAsyncReadyCallback       callback,
 761                               gpointer                  user_data)
 762 {
 763   GOutputStreamClass *class;
 764   SpliceUserData *data;
 765   GError *error = NULL;
 766
 767   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 768   g_return_if_fail (G_IS_INPUT_STREAM (source));
 769
 770   if (g_input_stream_is_closed (source))
 771     {
 772       g_simple_async_report_error_in_idle (G_OBJECT (stream),
 773                                            callback,
 774                                            user_data,
 775                                            G_IO_ERROR, G_IO_ERROR_CLOSED,
 776                                            _("Source stream is already closed"));
 777       return;
 778     }
 779
 780   if (!g_output_stream_set_pending (stream, &error))
 781     {
 782       g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
 783                                             callback,
 784                                             user_data,
 785                                             error);
 786       g_error_free (error);
 787       return;
 788     }
 789
 790   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 791
 792   data = g_new0 (SpliceUserData, 1);
 793   data->callback = callback;
 794   data->user_data = user_data;
 795   data->source = g_object_ref (source);
 796
 797   g_object_ref (stream);
 798   class->splice_async (stream, source, flags, io_priority, cancellable,
 799                       async_ready_splice_callback_wrapper, data);
 800 }
 801
 802 /**
 803  * g_output_stream_splice_finish:
 804  * @stream: a #GOutputStream.
 805  * @result: a #GAsyncResult.
 806  * @error: a #GError location to store the error occuring, or %NULL to
 807  * ignore.
 808  *
 809  * Finishes an asynchronous stream splice operation.
 810  *
 811  * Returns: a #gssize of the number of bytes spliced.
 812  **/
 813 gssize
 814 g_output_stream_splice_finish (GOutputStream  *stream,
 815                                GAsyncResult   *result,
 816                                GError        **error)
 817 {
 818   GSimpleAsyncResult *simple;
 819   GOutputStreamClass *class;
 820
 821   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
 822   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), -1);
 823
 824   if (G_IS_SIMPLE_ASYNC_RESULT (result))
 825     {
 826       simple = G_SIMPLE_ASYNC_RESULT (result);
 827       if (g_simple_async_result_propagate_error (simple, error))
 828         return -1;
 829     }
 830
 831   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 832   return class->splice_finish (stream, result, error);
 833 }
 834
 835 /**
 836  * g_output_stream_flush_async:
 837  * @stream: a #GOutputStream.
 838  * @io_priority: the io priority of the request.
 839  * @cancellable: optional #GCancellable object, %NULL to ignore.
 840  * @callback: a #GAsyncReadyCallback to call when the request is satisfied
 841  * @user_data: the data to pass to callback function
 842  *
 843  * Flushes a stream asynchronously.
 844  * For behaviour details see g_output_stream_flush().
 845  *
 846  * When the operation is finished @callback will be
 847  * called. You can then call g_output_stream_flush_finish() to get the
 848  * result of the operation.
 849  **/
 850 void
 851 g_output_stream_flush_async (GOutputStream       *stream,
 852                              int                  io_priority,
 853                              GCancellable        *cancellable,
 854                              GAsyncReadyCallback  callback,
 855                              gpointer             user_data)
 856 {
 857   GOutputStreamClass *class;
 858   GSimpleAsyncResult *simple;
 859   GError *error = NULL;
 860
 861   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 862
 863   if (!g_output_stream_set_pending (stream, &error))
 864     {
 865       g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
 866                                             callback,
 867                                             user_data,
 868                                             error);
 869       g_error_free (error);
 870       return;
 871     }
 872
 873   stream->priv->outstanding_callback = callback;
 874   g_object_ref (stream);
 875
 876   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 877
 878   if (class->flush_async == NULL)
 879     {
 880       simple = g_simple_async_result_new (G_OBJECT (stream),
 881                                           async_ready_callback_wrapper,
 882                                           user_data,
 883                                           g_output_stream_flush_async);
 884       g_simple_async_result_complete_in_idle (simple);
 885       g_object_unref (simple);
 886       return;
 887     }
 888
 889   class->flush_async (stream, io_priority, cancellable,
 890                       async_ready_callback_wrapper, user_data);
 891 }
 892
 893 /**
 894  * g_output_stream_flush_finish:
 895  * @stream: a #GOutputStream.
 896  * @result: a GAsyncResult.
 897  * @error: a #GError location to store the error occuring, or %NULL to
 898  * ignore.
 899  *
 900  * Finishes flushing an output stream.
 901  *
 902  * Returns: %TRUE if flush operation suceeded, %FALSE otherwise.
 903  **/
 904 gboolean
 905 g_output_stream_flush_finish (GOutputStream  *stream,
 906                               GAsyncResult   *result,
 907                               GError        **error)
 908 {
 909   GSimpleAsyncResult *simple;
 910   GOutputStreamClass *klass;
 911
 912   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 913   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), FALSE);
 914
 915   if (G_IS_SIMPLE_ASYNC_RESULT (result))
 916     {
 917       simple = G_SIMPLE_ASYNC_RESULT (result);
 918       if (g_simple_async_result_propagate_error (simple, error))
 919         return FALSE;
 920
 921       /* Special case default implementation */
 922       if (g_simple_async_result_get_source_tag (simple) == g_output_stream_flush_async)
 923         return TRUE;
 924     }
 925
 926   klass = G_OUTPUT_STREAM_GET_CLASS (stream);
 927   return klass->flush_finish (stream, result, error);
 928 }
 929
 930
 931 /**
 932  * g_output_stream_close_async:
 933  * @stream: A #GOutputStream.
 934  * @io_priority: the io priority of the request.
 935  * @callback: callback to call when the request is satisfied
 936  * @user_data: the data to pass to callback function
 937  * @cancellable: optional cancellable object
 938  *
 939  * Requests an asynchronous close of the stream, releasing resources
 940  * related to it. When the operation is finished @callback will be
 941  * called. You can then call g_output_stream_close_finish() to get
 942  * the result of the operation.
 943  *
 944  * For behaviour details see g_output_stream_close().
 945  *
 946  * The asyncronous methods have a default fallback that uses threads
 947  * to implement asynchronicity, so they are optional for inheriting
 948  * classes. However, if you override one you must override all.
 949  **/
 950 void
 951 g_output_stream_close_async (GOutputStream       *stream,
 952                              int                  io_priority,
 953                              GCancellable        *cancellable,
 954                              GAsyncReadyCallback  callback,
 955                              gpointer             user_data)
 956 {
 957   GOutputStreamClass *class;
 958   GSimpleAsyncResult *simple;
 959   GError *error = NULL;
 960
 961   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 962
 963   if (stream->priv->closed)
 964     {
 965       simple = g_simple_async_result_new (G_OBJECT (stream),
 966                                           callback,
 967                                           user_data,
 968                                           g_output_stream_close_async);
 969       g_simple_async_result_complete_in_idle (simple);
 970       g_object_unref (simple);
 971       return;
 972     }
 973
 974   if (!g_output_stream_set_pending (stream, &error))
 975     {
 976       g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
 977                                             callback,
 978                                             user_data,
 979                                             error);
 980       g_error_free (error);
 981       return;
 982     }
 983
 984   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 985   stream->priv->outstanding_callback = callback;
 986   g_object_ref (stream);
 987   class->close_async (stream, io_priority, cancellable,
 988                       async_ready_close_callback_wrapper, user_data);
 989 }
 990
 991 /**
 992  * g_output_stream_close_finish:
 993  * @stream: a #GOutputStream.
 994  * @result: a #GAsyncResult.
 995  * @error: a #GError location to store the error occuring, or %NULL to
 996  * ignore.
 997  *
 998  * Closes an output stream.
 999  *
1000  * Returns: %TRUE if stream was successfully closed, %FALSE otherwise.
1001  **/
1002 gboolean
1003 g_output_stream_close_finish (GOutputStream  *stream,
1004                               GAsyncResult   *result,
1005                               GError        **error)
1006 {
1007   GSimpleAsyncResult *simple;
1008   GOutputStreamClass *class;
1009
1010   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1011   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), FALSE);
1012
1013   if (G_IS_SIMPLE_ASYNC_RESULT (result))
1014     {
1015       simple = G_SIMPLE_ASYNC_RESULT (result);
1016       if (g_simple_async_result_propagate_error (simple, error))
1017         return FALSE;
1018
1019       /* Special case already closed */
1020       if (g_simple_async_result_get_source_tag (simple) == g_output_stream_close_async)
1021         return TRUE;
1022     }
1023
1024   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1025   return class->close_finish (stream, result, error);
1026 }
1027
1028 /**
1029  * g_output_stream_is_closed:
1030  * @stream: a #GOutputStream.
1031  *
1032  * Checks if an output stream has already been closed.
1033  *
1034  * Returns: %TRUE if @stream is closed. %FALSE otherwise.
1035  **/
1036 gboolean
1037 g_output_stream_is_closed (GOutputStream *stream)
1038 {
1039   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), TRUE);
1040
1041   return stream->priv->closed;
1042 }
1043
1044 /**
1045  * g_output_stream_has_pending:
1046  * @stream: a #GOutputStream.
1047  *
1048  * Checks if an ouput stream has pending actions.
1049  *
1050  * Returns: %TRUE if @stream has pending actions.
1051  **/
1052 gboolean
1053 g_output_stream_has_pending (GOutputStream *stream)
1054 {
1055   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1056
1057   return stream->priv->pending;
1058 }
1059
1060 /**
1061  * g_output_stream_set_pending:
1062  * @stream: a #GOutputStream.
1063  * @error: a #GError location to store the error occuring, or %NULL to
1064  * ignore.
1065  *
1066  * Sets @stream to have actions pending. If the pending flag is
1067  * already set or @stream is closed, it will return %FALSE and set
1068  * @error.
1069  *
1070  * Return value: %TRUE if pending was previously unset and is now set.
1071  **/
1072 gboolean
1073 g_output_stream_set_pending (GOutputStream *stream,
1074                              GError **error)
1075 {
1076   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1077
1078   if (stream->priv->closed)
1079     {
1080       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
1081                            _("Stream is already closed"));
1082       return FALSE;
1083     }
1084
1085   if (stream->priv->pending)
1086     {
1087       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PENDING,
1088                            /* Translators: This is an error you get if there is
1089                             * already an operation running against this stream when
1090                             * you try to start one */
1091                            _("Stream has outstanding operation"));
1092       return FALSE;
1093     }
1094
1095   stream->priv->pending = TRUE;
1096   return TRUE;
1097 }
1098
1099 /**
1100  * g_output_stream_clear_pending:
1101  * @stream: output stream
1102  *
1103  * Clears the pending flag on @stream.
1104  **/
1105 void
1106 g_output_stream_clear_pending (GOutputStream *stream)
1107 {
1108   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
1109
1110   stream->priv->pending = FALSE;
1111 }
1112
1113
1114 /********************************************
1115  *   Default implementation of async ops    *
1116  ********************************************/
1117
1118 typedef struct {
1119   const void         *buffer;
1120   gsize               count_requested;
1121   gssize              count_written;
1122 } WriteData;
1123
1124 static void
1125 write_async_thread (GSimpleAsyncResult *res,
1126                     GObject            *object,
1127                     GCancellable       *cancellable)
1128 {
1129   WriteData *op;
1130   GOutputStreamClass *class;
1131   GError *error = NULL;
1132
1133   class = G_OUTPUT_STREAM_GET_CLASS (object);
1134   op = g_simple_async_result_get_op_res_gpointer (res);
1135   op->count_written = class->write_fn (G_OUTPUT_STREAM (object), op->buffer, op->count_requested,
1136                                        cancellable, &error);
1137   if (op->count_written == -1)
1138     {
1139       g_simple_async_result_set_from_error (res, error);
1140       g_error_free (error);
1141     }
1142 }
1143
1144 static void
1145 g_output_stream_real_write_async (GOutputStream       *stream,
1146                                   const void          *buffer,
1147                                   gsize                count,
1148                                   int                  io_priority,
1149                                   GCancellable        *cancellable,
1150                                   GAsyncReadyCallback  callback,
1151                                   gpointer             user_data)
1152 {
1153   GSimpleAsyncResult *res;
1154   WriteData *op;
1155
1156   op = g_new0 (WriteData, 1);
1157   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_write_async);
1158   g_simple_async_result_set_op_res_gpointer (res, op, g_free);
1159   op->buffer = buffer;
1160   op->count_requested = count;
1161
1162   g_simple_async_result_run_in_thread (res, write_async_thread, io_priority, cancellable);
1163   g_object_unref (res);
1164 }
1165
1166 static gssize
1167 g_output_stream_real_write_finish (GOutputStream  *stream,
1168                                    GAsyncResult   *result,
1169                                    GError        **error)
1170 {
1171   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
1172   WriteData *op;
1173
1174   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_output_stream_real_write_async);
1175   op = g_simple_async_result_get_op_res_gpointer (simple);
1176   return op->count_written;
1177 }
1178
1179 typedef struct {
1180   GInputStream *source;
1181   GOutputStreamSpliceFlags flags;
1182   gssize bytes_copied;
1183 } SpliceData;
1184
1185 static void
1186 splice_async_thread (GSimpleAsyncResult *result,
1187                      GObject            *object,
1188                      GCancellable       *cancellable)
1189 {
1190   SpliceData *op;
1191   GOutputStreamClass *class;
1192   GError *error = NULL;
1193   GOutputStream *stream;
1194
1195   stream = G_OUTPUT_STREAM (object);
1196   class = G_OUTPUT_STREAM_GET_CLASS (object);
1197   op = g_simple_async_result_get_op_res_gpointer (result);
1198
1199   op->bytes_copied = class->splice (stream,
1200                                     op->source,
1201                                     op->flags,
1202                                     cancellable,
1203                                     &error);
1204   if (op->bytes_copied == -1)
1205     {
1206       g_simple_async_result_set_from_error (result, error);
1207       g_error_free (error);
1208     }
1209 }
1210
1211 static void
1212 g_output_stream_real_splice_async (GOutputStream             *stream,
1213                                    GInputStream              *source,
1214                                    GOutputStreamSpliceFlags   flags,
1215                                    int                        io_priority,
1216                                    GCancellable              *cancellable,
1217                                    GAsyncReadyCallback        callback,
1218                                    gpointer                   user_data)
1219 {
1220   GSimpleAsyncResult *res;
1221   SpliceData *op;
1222
1223   op = g_new0 (SpliceData, 1);
1224   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_splice_async);
1225   g_simple_async_result_set_op_res_gpointer (res, op, g_free);
1226   op->flags = flags;
1227   op->source = source;
1228
1229   /* TODO: In the case where both source and destintion have
1230      non-threadbased async calls we can use a true async copy here */
1231
1232   g_simple_async_result_run_in_thread (res, splice_async_thread, io_priority, cancellable);
1233   g_object_unref (res);
1234 }
1235
1236 static gssize
1237 g_output_stream_real_splice_finish (GOutputStream  *stream,
1238                                     GAsyncResult   *result,
1239                                     GError        **error)
1240 {
1241   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
1242   SpliceData *op;
1243
1244   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_output_stream_real_splice_async);
1245   op = g_simple_async_result_get_op_res_gpointer (simple);
1246   return op->bytes_copied;
1247 }
1248
1249
1250 static void
1251 flush_async_thread (GSimpleAsyncResult *res,
1252                     GObject            *object,
1253                     GCancellable       *cancellable)
1254 {
1255   GOutputStreamClass *class;
1256   gboolean result;
1257   GError *error = NULL;
1258
1259   class = G_OUTPUT_STREAM_GET_CLASS (object);
1260   result = TRUE;
1261   if (class->flush)
1262     result = class->flush (G_OUTPUT_STREAM (object), cancellable, &error);
1263
1264   if (!result)
1265     {
1266       g_simple_async_result_set_from_error (res, error);
1267       g_error_free (error);
1268     }
1269 }
1270
1271 static void
1272 g_output_stream_real_flush_async (GOutputStream       *stream,
1273                                   int                  io_priority,
1274                                   GCancellable        *cancellable,
1275                                   GAsyncReadyCallback  callback,
1276                                   gpointer             user_data)
1277 {
1278   GSimpleAsyncResult *res;
1279
1280   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_write_async);
1281
1282   g_simple_async_result_run_in_thread (res, flush_async_thread, io_priority, cancellable);
1283   g_object_unref (res);
1284 }
1285
1286 static gboolean
1287 g_output_stream_real_flush_finish (GOutputStream  *stream,
1288                                    GAsyncResult   *result,
1289                                    GError        **error)
1290 {
1291   return TRUE;
1292 }
1293
1294 static void
1295 close_async_thread (GSimpleAsyncResult *res,
1296                     GObject            *object,
1297                     GCancellable       *cancellable)
1298 {
1299   GOutputStreamClass *class;
1300   GError *error = NULL;
1301   gboolean result;
1302
1303   /* Auto handling of cancelation disabled, and ignore
1304      cancellation, since we want to close things anyway, although
1305      possibly in a quick-n-dirty way. At least we never want to leak
1306      open handles */
1307
1308   class = G_OUTPUT_STREAM_GET_CLASS (object);
1309   if (class->close_fn)
1310     {
1311       result = class->close_fn (G_OUTPUT_STREAM (object), cancellable, &error);
1312       if (!result)
1313         {
1314           g_simple_async_result_set_from_error (res, error);
1315           g_error_free (error);
1316         }
1317     }
1318 }
1319
1320 static void
1321 g_output_stream_real_close_async (GOutputStream       *stream,
1322                                   int                  io_priority,
1323                                   GCancellable        *cancellable,
1324                                   GAsyncReadyCallback  callback,
1325                                   gpointer             user_data)
1326 {
1327   GSimpleAsyncResult *res;
1328
1329   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_close_async);
1330
1331   g_simple_async_result_set_handle_cancellation (res, FALSE);
1332
1333   g_simple_async_result_run_in_thread (res, close_async_thread, io_priority, cancellable);
1334   g_object_unref (res);
1335 }
1336
1337 static gboolean
1338 g_output_stream_real_close_finish (GOutputStream  *stream,
1339                                    GAsyncResult   *result,
1340                                    GError        **error)
1341 {
1342   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
1343   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_output_stream_real_close_async);
1344   return TRUE;
1345 }
1346
1347 #define __G_OUTPUT_STREAM_C__
1348 #include "gioaliasdef.c"