gio/goutputstream.c

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