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 &&
 460           !class->close_fn (stream, cancellable, error))
 461         res = FALSE;
 462     }
 463
 464   if (res)
 465     return bytes_copied;
 466
 467   return -1;
 468 }
 469
 470
 471 /**
 472  * g_output_stream_close:
 473  * @stream: A #GOutputStream.
 474  * @cancellable: optional cancellable object
 475  * @error: location to store the error occuring, or %NULL to ignore
 476  *
 477  * Closes the stream, releasing resources related to it.
 478  *
 479  * Once the stream is closed, all other operations will return %G_IO_ERROR_CLOSED.
 480  * Closing a stream multiple times will not return an error.
 481  *
 482  * Closing a stream will automatically flush any outstanding buffers in the
 483  * stream.
 484  *
 485  * Streams will be automatically closed when the last reference
 486  * is dropped, but you might want to call this function to make sure
 487  * resources are released as early as possible.
 488  *
 489  * Some streams might keep the backing store of the stream (e.g. a file descriptor)
 490  * open after the stream is closed. See the documentation for the individual
 491  * stream for details.
 492  *
 493  * On failure the first error that happened will be reported, but the close
 494  * operation will finish as much as possible. A stream that failed to
 495  * close will still return %G_IO_ERROR_CLOSED for all operations. Still, it
 496  * is important to check and report the error to the user, otherwise
 497  * there might be a loss of data as all data might not be written.
 498  *
 499  * If @cancellable is not NULL, then the operation can be cancelled by
 500  * triggering the cancellable object from another thread. If the operation
 501  * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned.
 502  * Cancelling a close will still leave the stream closed, but there some streams
 503  * can use a faster close that doesn't block to e.g. check errors. On
 504  * cancellation (as with any error) there is no guarantee that all written
 505  * data will reach the target.
 506  *
 507  * Return value: %TRUE on success, %FALSE on failure
 508  **/
 509 gboolean
 510 g_output_stream_close (GOutputStream  *stream,
 511                        GCancellable   *cancellable,
 512                        GError        **error)
 513 {
 514   GOutputStreamClass *class;
 515   gboolean res;
 516
 517   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 518
 519   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 520
 521   if (stream->priv->closed)
 522     return TRUE;
 523
 524   if (!g_output_stream_set_pending (stream, error))
 525     return FALSE;
 526
 527   if (cancellable)
 528     g_cancellable_push_current (cancellable);
 529
 530   if (class->flush)
 531     res = class->flush (stream, cancellable, error);
 532   else
 533     res = TRUE;
 534
 535   if (!res)
 536     {
 537       /* flushing caused the error that we want to return,
 538        * but we still want to close the underlying stream if possible
 539        */
 540       if (class->close_fn)
 541         class->close_fn (stream, cancellable, NULL);
 542     }
 543   else
 544     {
 545       res = TRUE;
 546       if (class->close_fn)
 547         res = class->close_fn (stream, cancellable, error);
 548     }
 549
 550   if (cancellable)
 551     g_cancellable_pop_current (cancellable);
 552
 553   stream->priv->closed = TRUE;
 554   g_output_stream_clear_pending (stream);
 555
 556   return res;
 557 }
 558
 559 static void
 560 async_ready_callback_wrapper (GObject      *source_object,
 561                               GAsyncResult *res,
 562                               gpointer      user_data)
 563 {
 564   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 565
 566   g_output_stream_clear_pending (stream);
 567   if (stream->priv->outstanding_callback)
 568     (*stream->priv->outstanding_callback) (source_object, res, user_data);
 569   g_object_unref (stream);
 570 }
 571
 572 static void
 573 async_ready_close_callback_wrapper (GObject      *source_object,
 574                                     GAsyncResult *res,
 575                                     gpointer      user_data)
 576 {
 577   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 578
 579   stream->priv->closed = TRUE;
 580   g_output_stream_clear_pending (stream);
 581   if (stream->priv->outstanding_callback)
 582     (*stream->priv->outstanding_callback) (source_object, res, user_data);
 583   g_object_unref (stream);
 584 }
 585
 586 /**
 587  * g_output_stream_write_async:
 588  * @stream: A #GOutputStream.
 589  * @buffer: the buffer containing the data to write.
 590  * @count: the number of bytes to write
 591  * @io_priority: the io priority of the request.
 592  * @cancellable: optional #GCancellable object, %NULL to ignore.
 593  * @callback: callback to call when the request is satisfied
 594  * @user_data: the data to pass to callback function
 595  *
 596  * Request an asynchronous write of @count bytes from @buffer into
 597  * the stream. When the operation is finished @callback will be called.
 598  * You can then call g_output_stream_write_finish() to get the result of the
 599  * operation.
 600  *
 601  * During an async request no other sync and async calls are allowed,
 602  * and will result in %G_IO_ERROR_PENDING errors.
 603  *
 604  * A value of @count larger than %G_MAXSSIZE will cause a
 605  * %G_IO_ERROR_INVALID_ARGUMENT error.
 606  *
 607  * On success, the number of bytes written will be passed to the
 608  * @callback. It is not an error if this is not the same as the
 609  * requested size, as it can happen e.g. on a partial I/O error,
 610  * but generally we try to write as many bytes as requested.
 611  *
 612  * Any outstanding I/O request with higher priority (lower numerical
 613  * value) will be executed before an outstanding request with lower
 614  * priority. Default priority is %G_PRIORITY_DEFAULT.
 615  *
 616  * The asyncronous methods have a default fallback that uses threads
 617  * to implement asynchronicity, so they are optional for inheriting
 618  * classes. However, if you override one you must override all.
 619  *
 620  * For the synchronous, blocking version of this function, see
 621  * g_output_stream_write().
 622  **/
 623 void
 624 g_output_stream_write_async (GOutputStream       *stream,
 625                              const void          *buffer,
 626                              gsize                count,
 627                              int                  io_priority,
 628                              GCancellable        *cancellable,
 629                              GAsyncReadyCallback  callback,
 630                              gpointer             user_data)
 631 {
 632   GOutputStreamClass *class;
 633   GSimpleAsyncResult *simple;
 634   GError *error = NULL;
 635
 636   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 637   g_return_if_fail (buffer != NULL);
 638
 639   if (count == 0)
 640     {
 641       simple = g_simple_async_result_new (G_OBJECT (stream),
 642                                           callback,
 643                                           user_data,
 644                                           g_output_stream_write_async);
 645       g_simple_async_result_complete_in_idle (simple);
 646       g_object_unref (simple);
 647       return;
 648     }
 649
 650   if (((gssize) count) < 0)
 651     {
 652       g_simple_async_report_error_in_idle (G_OBJECT (stream),
 653                                            callback,
 654                                            user_data,
 655                                            G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
 656                                            _("Too large count value passed to %s"),
 657                                            G_STRFUNC);
 658       return;
 659     }
 660
 661   if (!g_output_stream_set_pending (stream, &error))
 662     {
 663       g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
 664                                             callback,
 665                                             user_data,
 666                                             error);
 667       g_error_free (error);
 668       return;
 669     }
 670
 671   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 672
 673   stream->priv->outstanding_callback = callback;
 674   g_object_ref (stream);
 675   class->write_async (stream, buffer, count, io_priority, cancellable,
 676                       async_ready_callback_wrapper, user_data);
 677 }
 678
 679 /**
 680  * g_output_stream_write_finish:
 681  * @stream: a #GOutputStream.
 682  * @result: a #GAsyncResult.
 683  * @error: a #GError location to store the error occuring, or %NULL to
 684  * ignore.
 685  *
 686  * Finishes a stream write operation.
 687  *
 688  * Returns: a #gssize containing the number of bytes written to the stream.
 689  **/
 690 gssize
 691 g_output_stream_write_finish (GOutputStream  *stream,
 692                               GAsyncResult   *result,
 693                               GError        **error)
 694 {
 695   GSimpleAsyncResult *simple;
 696   GOutputStreamClass *class;
 697
 698   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
 699   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), -1);
 700
 701   if (G_IS_SIMPLE_ASYNC_RESULT (result))
 702     {
 703       simple = G_SIMPLE_ASYNC_RESULT (result);
 704       if (g_simple_async_result_propagate_error (simple, error))
 705         return -1;
 706
 707       /* Special case writes of 0 bytes */
 708       if (g_simple_async_result_get_source_tag (simple) == g_output_stream_write_async)
 709         return 0;
 710     }
 711
 712   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 713   return class->write_finish (stream, result, error);
 714 }
 715
 716 typedef struct {
 717   GInputStream *source;
 718   gpointer user_data;
 719   GAsyncReadyCallback callback;
 720 } SpliceUserData;
 721
 722 static void
 723 async_ready_splice_callback_wrapper (GObject      *source_object,
 724                                      GAsyncResult *res,
 725                                      gpointer     _data)
 726 {
 727   GOutputStream *stream = G_OUTPUT_STREAM (source_object);
 728   SpliceUserData *data = _data;
 729
 730   g_output_stream_clear_pending (stream);
 731
 732   if (data->callback)
 733     (*data->callback) (source_object, res, data->user_data);
 734
 735   g_object_unref (stream);
 736   g_object_unref (data->source);
 737   g_free (data);
 738 }
 739
 740 /**
 741  * g_output_stream_splice_async:
 742  * @stream: a #GOutputStream.
 743  * @source: a #GInputStream.
 744  * @flags: a set of #GOutputStreamSpliceFlags.
 745  * @io_priority: the io priority of the request.
 746  * @cancellable: optional #GCancellable object, %NULL to ignore.
 747  * @callback: a #GAsyncReadyCallback.
 748  * @user_data: user data passed to @callback.
 749  *
 750  * Splices a stream asynchronously.
 751  * When the operation is finished @callback will be called.
 752  * You can then call g_output_stream_splice_finish() to get the
 753  * result of the operation.
 754  *
 755  * For the synchronous, blocking version of this function, see
 756  * g_output_stream_splice().
 757  **/
 758 void
 759 g_output_stream_splice_async (GOutputStream            *stream,
 760                               GInputStream             *source,
 761                               GOutputStreamSpliceFlags  flags,
 762                               int                       io_priority,
 763                               GCancellable             *cancellable,
 764                               GAsyncReadyCallback       callback,
 765                               gpointer                  user_data)
 766 {
 767   GOutputStreamClass *class;
 768   SpliceUserData *data;
 769   GError *error = NULL;
 770
 771   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 772   g_return_if_fail (G_IS_INPUT_STREAM (source));
 773
 774   if (g_input_stream_is_closed (source))
 775     {
 776       g_simple_async_report_error_in_idle (G_OBJECT (stream),
 777                                            callback,
 778                                            user_data,
 779                                            G_IO_ERROR, G_IO_ERROR_CLOSED,
 780                                            _("Source stream is already closed"));
 781       return;
 782     }
 783
 784   if (!g_output_stream_set_pending (stream, &error))
 785     {
 786       g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
 787                                             callback,
 788                                             user_data,
 789                                             error);
 790       g_error_free (error);
 791       return;
 792     }
 793
 794   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 795
 796   data = g_new0 (SpliceUserData, 1);
 797   data->callback = callback;
 798   data->user_data = user_data;
 799   data->source = g_object_ref (source);
 800
 801   g_object_ref (stream);
 802   class->splice_async (stream, source, flags, io_priority, cancellable,
 803                       async_ready_splice_callback_wrapper, data);
 804 }
 805
 806 /**
 807  * g_output_stream_splice_finish:
 808  * @stream: a #GOutputStream.
 809  * @result: a #GAsyncResult.
 810  * @error: a #GError location to store the error occuring, or %NULL to
 811  * ignore.
 812  *
 813  * Finishes an asynchronous stream splice operation.
 814  *
 815  * Returns: a #gssize of the number of bytes spliced.
 816  **/
 817 gssize
 818 g_output_stream_splice_finish (GOutputStream  *stream,
 819                                GAsyncResult   *result,
 820                                GError        **error)
 821 {
 822   GSimpleAsyncResult *simple;
 823   GOutputStreamClass *class;
 824
 825   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), -1);
 826   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), -1);
 827
 828   if (G_IS_SIMPLE_ASYNC_RESULT (result))
 829     {
 830       simple = G_SIMPLE_ASYNC_RESULT (result);
 831       if (g_simple_async_result_propagate_error (simple, error))
 832         return -1;
 833     }
 834
 835   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 836   return class->splice_finish (stream, result, error);
 837 }
 838
 839 /**
 840  * g_output_stream_flush_async:
 841  * @stream: a #GOutputStream.
 842  * @io_priority: the io priority of the request.
 843  * @cancellable: optional #GCancellable object, %NULL to ignore.
 844  * @callback: a #GAsyncReadyCallback to call when the request is satisfied
 845  * @user_data: the data to pass to callback function
 846  *
 847  * Flushes a stream asynchronously.
 848  * For behaviour details see g_output_stream_flush().
 849  *
 850  * When the operation is finished @callback will be
 851  * called. You can then call g_output_stream_flush_finish() to get the
 852  * result of the operation.
 853  **/
 854 void
 855 g_output_stream_flush_async (GOutputStream       *stream,
 856                              int                  io_priority,
 857                              GCancellable        *cancellable,
 858                              GAsyncReadyCallback  callback,
 859                              gpointer             user_data)
 860 {
 861   GOutputStreamClass *class;
 862   GSimpleAsyncResult *simple;
 863   GError *error = NULL;
 864
 865   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 866
 867   if (!g_output_stream_set_pending (stream, &error))
 868     {
 869       g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
 870                                             callback,
 871                                             user_data,
 872                                             error);
 873       g_error_free (error);
 874       return;
 875     }
 876
 877   stream->priv->outstanding_callback = callback;
 878   g_object_ref (stream);
 879
 880   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 881
 882   if (class->flush_async == NULL)
 883     {
 884       simple = g_simple_async_result_new (G_OBJECT (stream),
 885                                           async_ready_callback_wrapper,
 886                                           user_data,
 887                                           g_output_stream_flush_async);
 888       g_simple_async_result_complete_in_idle (simple);
 889       g_object_unref (simple);
 890       return;
 891     }
 892
 893   class->flush_async (stream, io_priority, cancellable,
 894                       async_ready_callback_wrapper, user_data);
 895 }
 896
 897 /**
 898  * g_output_stream_flush_finish:
 899  * @stream: a #GOutputStream.
 900  * @result: a GAsyncResult.
 901  * @error: a #GError location to store the error occuring, or %NULL to
 902  * ignore.
 903  *
 904  * Finishes flushing an output stream.
 905  *
 906  * Returns: %TRUE if flush operation suceeded, %FALSE otherwise.
 907  **/
 908 gboolean
 909 g_output_stream_flush_finish (GOutputStream  *stream,
 910                               GAsyncResult   *result,
 911                               GError        **error)
 912 {
 913   GSimpleAsyncResult *simple;
 914   GOutputStreamClass *klass;
 915
 916   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
 917   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), FALSE);
 918
 919   if (G_IS_SIMPLE_ASYNC_RESULT (result))
 920     {
 921       simple = G_SIMPLE_ASYNC_RESULT (result);
 922       if (g_simple_async_result_propagate_error (simple, error))
 923         return FALSE;
 924
 925       /* Special case default implementation */
 926       if (g_simple_async_result_get_source_tag (simple) == g_output_stream_flush_async)
 927         return TRUE;
 928     }
 929
 930   klass = G_OUTPUT_STREAM_GET_CLASS (stream);
 931   return klass->flush_finish (stream, result, error);
 932 }
 933
 934
 935 /**
 936  * g_output_stream_close_async:
 937  * @stream: A #GOutputStream.
 938  * @io_priority: the io priority of the request.
 939  * @callback: callback to call when the request is satisfied
 940  * @user_data: the data to pass to callback function
 941  * @cancellable: optional cancellable object
 942  *
 943  * Requests an asynchronous close of the stream, releasing resources
 944  * related to it. When the operation is finished @callback will be
 945  * called. You can then call g_output_stream_close_finish() to get
 946  * the result of the operation.
 947  *
 948  * For behaviour details see g_output_stream_close().
 949  *
 950  * The asyncronous methods have a default fallback that uses threads
 951  * to implement asynchronicity, so they are optional for inheriting
 952  * classes. However, if you override one you must override all.
 953  **/
 954 void
 955 g_output_stream_close_async (GOutputStream       *stream,
 956                              int                  io_priority,
 957                              GCancellable        *cancellable,
 958                              GAsyncReadyCallback  callback,
 959                              gpointer             user_data)
 960 {
 961   GOutputStreamClass *class;
 962   GSimpleAsyncResult *simple;
 963   GError *error = NULL;
 964
 965   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
 966
 967   if (stream->priv->closed)
 968     {
 969       simple = g_simple_async_result_new (G_OBJECT (stream),
 970                                           callback,
 971                                           user_data,
 972                                           g_output_stream_close_async);
 973       g_simple_async_result_complete_in_idle (simple);
 974       g_object_unref (simple);
 975       return;
 976     }
 977
 978   if (!g_output_stream_set_pending (stream, &error))
 979     {
 980       g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
 981                                             callback,
 982                                             user_data,
 983                                             error);
 984       g_error_free (error);
 985       return;
 986     }
 987
 988   class = G_OUTPUT_STREAM_GET_CLASS (stream);
 989   stream->priv->outstanding_callback = callback;
 990   g_object_ref (stream);
 991   class->close_async (stream, io_priority, cancellable,
 992                       async_ready_close_callback_wrapper, user_data);
 993 }
 994
 995 /**
 996  * g_output_stream_close_finish:
 997  * @stream: a #GOutputStream.
 998  * @result: a #GAsyncResult.
 999  * @error: a #GError location to store the error occuring, or %NULL to
1000  * ignore.
1001  *
1002  * Closes an output stream.
1003  *
1004  * Returns: %TRUE if stream was successfully closed, %FALSE otherwise.
1005  **/
1006 gboolean
1007 g_output_stream_close_finish (GOutputStream  *stream,
1008                               GAsyncResult   *result,
1009                               GError        **error)
1010 {
1011   GSimpleAsyncResult *simple;
1012   GOutputStreamClass *class;
1013
1014   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1015   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), FALSE);
1016
1017   if (G_IS_SIMPLE_ASYNC_RESULT (result))
1018     {
1019       simple = G_SIMPLE_ASYNC_RESULT (result);
1020       if (g_simple_async_result_propagate_error (simple, error))
1021         return FALSE;
1022
1023       /* Special case already closed */
1024       if (g_simple_async_result_get_source_tag (simple) == g_output_stream_close_async)
1025         return TRUE;
1026     }
1027
1028   class = G_OUTPUT_STREAM_GET_CLASS (stream);
1029   return class->close_finish (stream, result, error);
1030 }
1031
1032 /**
1033  * g_output_stream_is_closed:
1034  * @stream: a #GOutputStream.
1035  *
1036  * Checks if an output stream has already been closed.
1037  *
1038  * Returns: %TRUE if @stream is closed. %FALSE otherwise.
1039  **/
1040 gboolean
1041 g_output_stream_is_closed (GOutputStream *stream)
1042 {
1043   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), TRUE);
1044
1045   return stream->priv->closed;
1046 }
1047
1048 /**
1049  * g_output_stream_has_pending:
1050  * @stream: a #GOutputStream.
1051  *
1052  * Checks if an ouput stream has pending actions.
1053  *
1054  * Returns: %TRUE if @stream has pending actions.
1055  **/
1056 gboolean
1057 g_output_stream_has_pending (GOutputStream *stream)
1058 {
1059   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1060
1061   return stream->priv->pending;
1062 }
1063
1064 /**
1065  * g_output_stream_set_pending:
1066  * @stream: a #GOutputStream.
1067  * @error: a #GError location to store the error occuring, or %NULL to
1068  * ignore.
1069  *
1070  * Sets @stream to have actions pending. If the pending flag is
1071  * already set or @stream is closed, it will return %FALSE and set
1072  * @error.
1073  *
1074  * Return value: %TRUE if pending was previously unset and is now set.
1075  **/
1076 gboolean
1077 g_output_stream_set_pending (GOutputStream *stream,
1078                              GError **error)
1079 {
1080   g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
1081
1082   if (stream->priv->closed)
1083     {
1084       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
1085                            _("Stream is already closed"));
1086       return FALSE;
1087     }
1088
1089   if (stream->priv->pending)
1090     {
1091       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PENDING,
1092                            /* Translators: This is an error you get if there is
1093                             * already an operation running against this stream when
1094                             * you try to start one */
1095                            _("Stream has outstanding operation"));
1096       return FALSE;
1097     }
1098
1099   stream->priv->pending = TRUE;
1100   return TRUE;
1101 }
1102
1103 /**
1104  * g_output_stream_clear_pending:
1105  * @stream: output stream
1106  *
1107  * Clears the pending flag on @stream.
1108  **/
1109 void
1110 g_output_stream_clear_pending (GOutputStream *stream)
1111 {
1112   g_return_if_fail (G_IS_OUTPUT_STREAM (stream));
1113
1114   stream->priv->pending = FALSE;
1115 }
1116
1117
1118 /********************************************
1119  *   Default implementation of async ops    *
1120  ********************************************/
1121
1122 typedef struct {
1123   const void         *buffer;
1124   gsize               count_requested;
1125   gssize              count_written;
1126 } WriteData;
1127
1128 static void
1129 write_async_thread (GSimpleAsyncResult *res,
1130                     GObject            *object,
1131                     GCancellable       *cancellable)
1132 {
1133   WriteData *op;
1134   GOutputStreamClass *class;
1135   GError *error = NULL;
1136
1137   class = G_OUTPUT_STREAM_GET_CLASS (object);
1138   op = g_simple_async_result_get_op_res_gpointer (res);
1139   op->count_written = class->write_fn (G_OUTPUT_STREAM (object), op->buffer, op->count_requested,
1140                                        cancellable, &error);
1141   if (op->count_written == -1)
1142     {
1143       g_simple_async_result_set_from_error (res, error);
1144       g_error_free (error);
1145     }
1146 }
1147
1148 static void
1149 g_output_stream_real_write_async (GOutputStream       *stream,
1150                                   const void          *buffer,
1151                                   gsize                count,
1152                                   int                  io_priority,
1153                                   GCancellable        *cancellable,
1154                                   GAsyncReadyCallback  callback,
1155                                   gpointer             user_data)
1156 {
1157   GSimpleAsyncResult *res;
1158   WriteData *op;
1159
1160   op = g_new0 (WriteData, 1);
1161   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_write_async);
1162   g_simple_async_result_set_op_res_gpointer (res, op, g_free);
1163   op->buffer = buffer;
1164   op->count_requested = count;
1165
1166   g_simple_async_result_run_in_thread (res, write_async_thread, io_priority, cancellable);
1167   g_object_unref (res);
1168 }
1169
1170 static gssize
1171 g_output_stream_real_write_finish (GOutputStream  *stream,
1172                                    GAsyncResult   *result,
1173                                    GError        **error)
1174 {
1175   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
1176   WriteData *op;
1177
1178   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_output_stream_real_write_async);
1179   op = g_simple_async_result_get_op_res_gpointer (simple);
1180   return op->count_written;
1181 }
1182
1183 typedef struct {
1184   GInputStream *source;
1185   GOutputStreamSpliceFlags flags;
1186   gssize bytes_copied;
1187 } SpliceData;
1188
1189 static void
1190 splice_async_thread (GSimpleAsyncResult *result,
1191                      GObject            *object,
1192                      GCancellable       *cancellable)
1193 {
1194   SpliceData *op;
1195   GOutputStreamClass *class;
1196   GError *error = NULL;
1197   GOutputStream *stream;
1198
1199   stream = G_OUTPUT_STREAM (object);
1200   class = G_OUTPUT_STREAM_GET_CLASS (object);
1201   op = g_simple_async_result_get_op_res_gpointer (result);
1202
1203   op->bytes_copied = class->splice (stream,
1204                                     op->source,
1205                                     op->flags,
1206                                     cancellable,
1207                                     &error);
1208   if (op->bytes_copied == -1)
1209     {
1210       g_simple_async_result_set_from_error (result, error);
1211       g_error_free (error);
1212     }
1213 }
1214
1215 static void
1216 g_output_stream_real_splice_async (GOutputStream             *stream,
1217                                    GInputStream              *source,
1218                                    GOutputStreamSpliceFlags   flags,
1219                                    int                        io_priority,
1220                                    GCancellable              *cancellable,
1221                                    GAsyncReadyCallback        callback,
1222                                    gpointer                   user_data)
1223 {
1224   GSimpleAsyncResult *res;
1225   SpliceData *op;
1226
1227   op = g_new0 (SpliceData, 1);
1228   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_splice_async);
1229   g_simple_async_result_set_op_res_gpointer (res, op, g_free);
1230   op->flags = flags;
1231   op->source = source;
1232
1233   /* TODO: In the case where both source and destintion have
1234      non-threadbased async calls we can use a true async copy here */
1235
1236   g_simple_async_result_run_in_thread (res, splice_async_thread, io_priority, cancellable);
1237   g_object_unref (res);
1238 }
1239
1240 static gssize
1241 g_output_stream_real_splice_finish (GOutputStream  *stream,
1242                                     GAsyncResult   *result,
1243                                     GError        **error)
1244 {
1245   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
1246   SpliceData *op;
1247
1248   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_output_stream_real_splice_async);
1249   op = g_simple_async_result_get_op_res_gpointer (simple);
1250   return op->bytes_copied;
1251 }
1252
1253
1254 static void
1255 flush_async_thread (GSimpleAsyncResult *res,
1256                     GObject            *object,
1257                     GCancellable       *cancellable)
1258 {
1259   GOutputStreamClass *class;
1260   gboolean result;
1261   GError *error = NULL;
1262
1263   class = G_OUTPUT_STREAM_GET_CLASS (object);
1264   result = TRUE;
1265   if (class->flush)
1266     result = class->flush (G_OUTPUT_STREAM (object), cancellable, &error);
1267
1268   if (!result)
1269     {
1270       g_simple_async_result_set_from_error (res, error);
1271       g_error_free (error);
1272     }
1273 }
1274
1275 static void
1276 g_output_stream_real_flush_async (GOutputStream       *stream,
1277                                   int                  io_priority,
1278                                   GCancellable        *cancellable,
1279                                   GAsyncReadyCallback  callback,
1280                                   gpointer             user_data)
1281 {
1282   GSimpleAsyncResult *res;
1283
1284   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_write_async);
1285
1286   g_simple_async_result_run_in_thread (res, flush_async_thread, io_priority, cancellable);
1287   g_object_unref (res);
1288 }
1289
1290 static gboolean
1291 g_output_stream_real_flush_finish (GOutputStream  *stream,
1292                                    GAsyncResult   *result,
1293                                    GError        **error)
1294 {
1295   return TRUE;
1296 }
1297
1298 static void
1299 close_async_thread (GSimpleAsyncResult *res,
1300                     GObject            *object,
1301                     GCancellable       *cancellable)
1302 {
1303   GOutputStreamClass *class;
1304   GError *error = NULL;
1305   gboolean result;
1306
1307   /* Auto handling of cancelation disabled, and ignore
1308      cancellation, since we want to close things anyway, although
1309      possibly in a quick-n-dirty way. At least we never want to leak
1310      open handles */
1311
1312   class = G_OUTPUT_STREAM_GET_CLASS (object);
1313   if (class->close_fn)
1314     {
1315       result = class->close_fn (G_OUTPUT_STREAM (object), cancellable, &error);
1316       if (!result)
1317         {
1318           g_simple_async_result_set_from_error (res, error);
1319           g_error_free (error);
1320         }
1321     }
1322 }
1323
1324 static void
1325 g_output_stream_real_close_async (GOutputStream       *stream,
1326                                   int                  io_priority,
1327                                   GCancellable        *cancellable,
1328                                   GAsyncReadyCallback  callback,
1329                                   gpointer             user_data)
1330 {
1331   GSimpleAsyncResult *res;
1332
1333   res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_output_stream_real_close_async);
1334
1335   g_simple_async_result_set_handle_cancellation (res, FALSE);
1336
1337   g_simple_async_result_run_in_thread (res, close_async_thread, io_priority, cancellable);
1338   g_object_unref (res);
1339 }
1340
1341 static gboolean
1342 g_output_stream_real_close_finish (GOutputStream  *stream,
1343                                    GAsyncResult   *result,
1344                                    GError        **error)
1345 {
1346   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
1347   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_output_stream_real_close_async);
1348   return TRUE;
1349 }
1350
1351 #define __G_OUTPUT_STREAM_C__
1352 #include "gioaliasdef.c"