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