gio/goutputstream.c

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