gio/gbufferedinputstream.c

   1 /* GIO - GLib Input, Output and Streaming Library
   2  *
   3  * Copyright (C) 2006-2007 Red Hat, Inc.
   4  * Copyright (C) 2007 Jürg Billeter
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General
  17  * Public License along with this library; if not, write to the
  18  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  19  * Boston, MA 02111-1307, USA.
  20  *
  21  * Author: Christian Kellner <gicmo@gnome.org>
  22  */
  23
  24 #include <config.h>
  25 #include "gbufferedinputstream.h"
  26 #include "ginputstream.h"
  27 #include "gsimpleasyncresult.h"
  28 #include <string.h>
  29 #include "glibintl.h"
  30
  31 #include "gioalias.h"
  32
  33 /**
  34  * SECTION:gbufferedinputstream
  35  * @short_description: Buffered Input Stream
  36  * @include: gio/gio.h
  37  * @see_also: #GFilterInputStream, #GInputStream
  38  *
  39  * Buffered input stream implements #GFilterInputStream and provides
  40  * for buffered reads.
  41  *
  42  * By default, #GBufferedInputStream's buffer size is set at 4 kilobytes.
  43  *
  44  * To create a buffered input stream, use g_buffered_input_stream_new(),
  45  * or g_buffered_input_stream_new_sized() to specify the buffer's size at
  46  * construction.
  47  *
  48  * To get the size of a buffer within a buffered input stream, use
  49  * g_buffered_input_stream_get_buffer_size(). To change the size of a
  50  * buffered input stream's buffer, use
  51  * g_buffered_input_stream_set_buffer_size(). Note that the buffer's size
  52  * cannot be reduced below the size of the data within the buffer.
  53  *
  54  **/
  55
  56
  57
  58 #define DEFAULT_BUFFER_SIZE 4096
  59
  60 struct _GBufferedInputStreamPrivate {
  61   guint8 *buffer;
  62   gsize   len;
  63   gsize   pos;
  64   gsize   end;
  65   GAsyncReadyCallback outstanding_callback;
  66 };
  67
  68 enum {
  69   PROP_0,
  70   PROP_BUFSIZE
  71 };
  72
  73 static void g_buffered_input_stream_set_property  (GObject      *object,
  74                                                    guint         prop_id,
  75                                                    const GValue *value,
  76                                                    GParamSpec   *pspec);
  77
  78 static void g_buffered_input_stream_get_property  (GObject      *object,
  79                                                    guint         prop_id,
  80                                                    GValue       *value,
  81                                                    GParamSpec   *pspec);
  82 static void g_buffered_input_stream_finalize      (GObject *object);
  83
  84
  85 static gssize g_buffered_input_stream_skip             (GInputStream          *stream,
  86                                                         gsize                  count,
  87                                                         GCancellable          *cancellable,
  88                                                         GError               **error);
  89 static void   g_buffered_input_stream_skip_async       (GInputStream          *stream,
  90                                                         gsize                  count,
  91                                                         int                    io_priority,
  92                                                         GCancellable          *cancellable,
  93                                                         GAsyncReadyCallback    callback,
  94                                                         gpointer               user_data);
  95 static gssize g_buffered_input_stream_skip_finish      (GInputStream          *stream,
  96                                                         GAsyncResult          *result,
  97                                                         GError               **error);
  98 static gssize g_buffered_input_stream_read             (GInputStream          *stream,
  99                                                         void                  *buffer,
 100                                                         gsize                  count,
 101                                                         GCancellable          *cancellable,
 102                                                         GError               **error);
 103 static void   g_buffered_input_stream_read_async       (GInputStream          *stream,
 104                                                         void                  *buffer,
 105                                                         gsize                  count,
 106                                                         int                    io_priority,
 107                                                         GCancellable          *cancellable,
 108                                                         GAsyncReadyCallback    callback,
 109                                                         gpointer               user_data);
 110 static gssize g_buffered_input_stream_read_finish      (GInputStream          *stream,
 111                                                         GAsyncResult          *result,
 112                                                         GError               **error);
 113 static gssize g_buffered_input_stream_real_fill        (GBufferedInputStream  *stream,
 114                                                         gssize                 count,
 115                                                         GCancellable          *cancellable,
 116                                                         GError               **error);
 117 static void   g_buffered_input_stream_real_fill_async  (GBufferedInputStream  *stream,
 118                                                         gssize                 count,
 119                                                         int                    io_priority,
 120                                                         GCancellable          *cancellable,
 121                                                         GAsyncReadyCallback    callback,
 122                                                         gpointer               user_data);
 123 static gssize g_buffered_input_stream_real_fill_finish (GBufferedInputStream  *stream,
 124                                                         GAsyncResult          *result,
 125                                                         GError               **error);
 126
 127 static void compact_buffer (GBufferedInputStream *stream);
 128
 129 G_DEFINE_TYPE (GBufferedInputStream,
 130                g_buffered_input_stream,
 131                G_TYPE_FILTER_INPUT_STREAM)
 132
 133
 134 static void
 135 g_buffered_input_stream_class_init (GBufferedInputStreamClass *klass)
 136 {
 137   GObjectClass *object_class;
 138   GInputStreamClass *istream_class;
 139   GBufferedInputStreamClass *bstream_class;
 140
 141   g_type_class_add_private (klass, sizeof (GBufferedInputStreamPrivate));
 142
 143   object_class = G_OBJECT_CLASS (klass);
 144   object_class->get_property = g_buffered_input_stream_get_property;
 145   object_class->set_property = g_buffered_input_stream_set_property;
 146   object_class->finalize     = g_buffered_input_stream_finalize;
 147
 148   istream_class = G_INPUT_STREAM_CLASS (klass);
 149   istream_class->skip = g_buffered_input_stream_skip;
 150   istream_class->skip_async  = g_buffered_input_stream_skip_async;
 151   istream_class->skip_finish = g_buffered_input_stream_skip_finish;
 152   istream_class->read_fn = g_buffered_input_stream_read;
 153   istream_class->read_async  = g_buffered_input_stream_read_async;
 154   istream_class->read_finish = g_buffered_input_stream_read_finish;
 155
 156   bstream_class = G_BUFFERED_INPUT_STREAM_CLASS (klass);
 157   bstream_class->fill = g_buffered_input_stream_real_fill;
 158   bstream_class->fill_async = g_buffered_input_stream_real_fill_async;
 159   bstream_class->fill_finish = g_buffered_input_stream_real_fill_finish;
 160
 161   g_object_class_install_property (object_class,
 162                                    PROP_BUFSIZE,
 163                                    g_param_spec_uint ("buffer-size",
 164                                                       P_("Buffer Size"),
 165                                                       P_("The size of the backend buffer"),
 166                                                       1,
 167                                                       G_MAXUINT,
 168                                                       DEFAULT_BUFFER_SIZE,
 169                                                       G_PARAM_READWRITE | G_PARAM_CONSTRUCT |
 170                                                       G_PARAM_STATIC_NAME|G_PARAM_STATIC_NICK|G_PARAM_STATIC_BLURB));
 171
 172
 173 }
 174
 175 /**
 176  * g_buffered_input_stream_get_buffer_size:
 177  * @stream: #GBufferedInputStream.
 178  *
 179  * Gets the size of the input buffer.
 180  *
 181  * Returns: the current buffer size.
 182  **/
 183 gsize
 184 g_buffered_input_stream_get_buffer_size (GBufferedInputStream  *stream)
 185 {
 186   g_return_val_if_fail (G_IS_BUFFERED_INPUT_STREAM (stream), 0);
 187
 188   return stream->priv->len;
 189 }
 190
 191 /**
 192  * g_buffered_input_stream_set_buffer_size:
 193  * @stream: #GBufferedInputStream.
 194  * @size: a #gsize.
 195  *
 196  * Sets the size of the internal buffer of @stream to @size, or to the
 197  * size of the contents of the buffer. The buffer can never be resized
 198  * smaller than its current contents.
 199  **/
 200 void
 201 g_buffered_input_stream_set_buffer_size (GBufferedInputStream  *stream,
 202                                          gsize                  size)
 203 {
 204   GBufferedInputStreamPrivate *priv;
 205   gsize in_buffer;
 206   guint8 *buffer;
 207
 208   g_return_if_fail (G_IS_BUFFERED_INPUT_STREAM (stream));
 209
 210   priv = stream->priv;
 211
 212   if (priv->len == size)
 213     return;
 214
 215   if (priv->buffer)
 216     {
 217       in_buffer = priv->end - priv->pos;
 218
 219       /* Never resize smaller than current buffer contents */
 220       size = MAX (size, in_buffer);
 221
 222       buffer = g_malloc (size);
 223       memcpy (buffer, priv->buffer + priv->pos, in_buffer);
 224       priv->len = size;
 225       priv->pos = 0;
 226       priv->end = in_buffer;
 227       g_free (priv->buffer);
 228       priv->buffer = buffer;
 229     }
 230   else
 231     {
 232       priv->len = size;
 233       priv->pos = 0;
 234       priv->end = 0;
 235       priv->buffer = g_malloc (size);
 236     }
 237
 238   g_object_notify (G_OBJECT (stream), "buffer-size");
 239 }
 240
 241 static void
 242 g_buffered_input_stream_set_property (GObject      *object,
 243                                       guint         prop_id,
 244                                       const GValue *value,
 245                                       GParamSpec   *pspec)
 246 {
 247   GBufferedInputStreamPrivate *priv;
 248   GBufferedInputStream        *bstream;
 249
 250   bstream = G_BUFFERED_INPUT_STREAM (object);
 251   priv = bstream->priv;
 252
 253   switch (prop_id)
 254     {
 255     case PROP_BUFSIZE:
 256       g_buffered_input_stream_set_buffer_size (bstream, g_value_get_uint (value));
 257       break;
 258
 259     default:
 260       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 261       break;
 262     }
 263
 264 }
 265
 266 static void
 267 g_buffered_input_stream_get_property (GObject    *object,
 268                                       guint       prop_id,
 269                                       GValue     *value,
 270                                       GParamSpec *pspec)
 271 {
 272   GBufferedInputStreamPrivate *priv;
 273   GBufferedInputStream        *bstream;
 274
 275   bstream = G_BUFFERED_INPUT_STREAM (object);
 276   priv = bstream->priv;
 277
 278   switch (prop_id)
 279     {
 280     case PROP_BUFSIZE:
 281       g_value_set_uint (value, priv->len);
 282       break;
 283
 284     default:
 285       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 286       break;
 287     }
 288 }
 289
 290 static void
 291 g_buffered_input_stream_finalize (GObject *object)
 292 {
 293   GBufferedInputStreamPrivate *priv;
 294   GBufferedInputStream        *stream;
 295
 296   stream = G_BUFFERED_INPUT_STREAM (object);
 297   priv = stream->priv;
 298
 299   g_free (priv->buffer);
 300
 301   if (G_OBJECT_CLASS (g_buffered_input_stream_parent_class)->finalize)
 302     (*G_OBJECT_CLASS (g_buffered_input_stream_parent_class)->finalize) (object);
 303 }
 304
 305 static void
 306 g_buffered_input_stream_init (GBufferedInputStream *stream)
 307 {
 308   stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (stream,
 309                                               G_TYPE_BUFFERED_INPUT_STREAM,
 310                                               GBufferedInputStreamPrivate);
 311 }
 312
 313
 314 /**
 315  * g_buffered_input_stream_new:
 316  * @base_stream: a #GInputStream.
 317  *
 318  * Creates a new #GInputStream from the given @base_stream, with
 319  * a buffer set to the default size (4 kilobytes).
 320  *
 321  * Returns: a #GInputStream for the given @base_stream.
 322  **/
 323 GInputStream *
 324 g_buffered_input_stream_new (GInputStream *base_stream)
 325 {
 326   GInputStream *stream;
 327
 328   g_return_val_if_fail (G_IS_INPUT_STREAM (base_stream), NULL);
 329
 330   stream = g_object_new (G_TYPE_BUFFERED_INPUT_STREAM,
 331                          "base-stream", base_stream,
 332                          NULL);
 333
 334   return stream;
 335 }
 336
 337 /**
 338  * g_buffered_input_stream_new_sized:
 339  * @base_stream: a #GInputStream.
 340  * @size: a #gsize.
 341  *
 342  * Creates a new #GBufferedInputStream from the given @base_stream,
 343  * with a buffer set to @size.
 344  *
 345  * Returns: a #GInputStream.
 346  **/
 347 GInputStream *
 348 g_buffered_input_stream_new_sized (GInputStream *base_stream,
 349                                    gsize         size)
 350 {
 351   GInputStream *stream;
 352
 353   g_return_val_if_fail (G_IS_INPUT_STREAM (base_stream), NULL);
 354
 355   stream = g_object_new (G_TYPE_BUFFERED_INPUT_STREAM,
 356                          "base-stream", base_stream,
 357                          "buffer-size", (guint)size,
 358                          NULL);
 359
 360   return stream;
 361 }
 362
 363 /**
 364  * g_buffered_input_stream_fill:
 365  * @stream: #GBufferedInputStream.
 366  * @count: the number of bytes that will be read from the stream.
 367  * @cancellable: optional #GCancellable object, %NULL to ignore.
 368  * @error: location to store the error occuring, or %NULL to ignore.
 369  *
 370  * Tries to read @count bytes from the stream into the buffer.
 371  * Will block during this read.
 372  *
 373  * If @count is zero, returns zero and does nothing. A value of @count
 374  * larger than %G_MAXSSIZE will cause a %G_IO_ERROR_INVALID_ARGUMENT error.
 375  *
 376  * On success, the number of bytes read into the buffer is returned.
 377  * It is not an error if this is not the same as the requested size, as it
 378  * can happen e.g. near the end of a file. Zero is returned on end of file
 379  * (or if @count is zero),  but never otherwise.
 380  *
 381  * If @cancellable is not %NULL, then the operation can be cancelled by
 382  * triggering the cancellable object from another thread. If the operation
 383  * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned. If an
 384  * operation was partially finished when the operation was cancelled the
 385  * partial result will be returned, without an error.
 386  *
 387  * On error -1 is returned and @error is set accordingly.
 388  *
 389  * For the asynchronous, non-blocking, version of this function, see
 390  * g_buffered_input_stream_fill_async().
 391  *
 392  * Returns: the number of bytes read into @stream's buffer, up to @count,
 393  *     or -1 on error.
 394  **/
 395 gssize
 396 g_buffered_input_stream_fill (GBufferedInputStream  *stream,
 397                               gssize                 count,
 398                               GCancellable          *cancellable,
 399                               GError               **error)
 400 {
 401   GBufferedInputStreamClass *class;
 402   GInputStream *input_stream;
 403   gssize res;
 404
 405   g_return_val_if_fail (G_IS_BUFFERED_INPUT_STREAM (stream), -1);
 406
 407   input_stream = G_INPUT_STREAM (stream);
 408
 409   if (!g_input_stream_set_pending (input_stream, error))
 410     return -1;
 411
 412   if (cancellable)
 413     g_cancellable_push_current (cancellable);
 414
 415   class = G_BUFFERED_INPUT_STREAM_GET_CLASS (stream);
 416   res = class->fill (stream, count, cancellable, error);
 417
 418   if (cancellable)
 419     g_cancellable_pop_current (cancellable);
 420
 421   g_input_stream_clear_pending (input_stream);
 422
 423   return res;
 424 }
 425
 426 static void
 427 async_fill_callback_wrapper (GObject      *source_object,
 428                              GAsyncResult *res,
 429                              gpointer      user_data)
 430 {
 431   GBufferedInputStream *stream = G_BUFFERED_INPUT_STREAM (source_object);
 432
 433   g_input_stream_clear_pending (G_INPUT_STREAM (stream));
 434   (*stream->priv->outstanding_callback) (source_object, res, user_data);
 435   g_object_unref (stream);
 436 }
 437
 438 /**
 439  * g_buffered_input_stream_fill_async:
 440  * @stream: #GBufferedInputStream.
 441  * @count: a #gssize.
 442  * @io_priority: the <link linkend="io-priority">I/O priority</link>
 443  *     of the request.
 444  * @cancellable: optional #GCancellable object
 445  * @callback: a #GAsyncReadyCallback.
 446  * @user_data: a #gpointer.
 447  *
 448  * Reads data into @stream's buffer asynchronously, up to @count size.
 449  * @io_priority can be used to prioritize reads. For the synchronous
 450  * version of this function, see g_buffered_input_stream_fill().
 451  **/
 452 void
 453 g_buffered_input_stream_fill_async (GBufferedInputStream *stream,
 454                                     gssize                count,
 455                                     int                   io_priority,
 456                                     GCancellable         *cancellable,
 457                                     GAsyncReadyCallback   callback,
 458                                     gpointer              user_data)
 459 {
 460   GBufferedInputStreamClass *class;
 461   GSimpleAsyncResult *simple;
 462   GError *error = NULL;
 463
 464   g_return_if_fail (G_IS_BUFFERED_INPUT_STREAM (stream));
 465
 466   if (count == 0)
 467     {
 468       simple = g_simple_async_result_new (G_OBJECT (stream),
 469                                           callback,
 470                                           user_data,
 471                                           g_buffered_input_stream_fill_async);
 472       g_simple_async_result_complete_in_idle (simple);
 473       g_object_unref (simple);
 474       return;
 475     }
 476
 477   if (((gssize) count) < 0)
 478     {
 479       g_simple_async_report_error_in_idle (G_OBJECT (stream),
 480                                            callback,
 481                                            user_data,
 482                                            G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
 483                                            _("Too large count value passed to %s"),
 484                                            G_STRFUNC);
 485       return;
 486     }
 487
 488   if (!g_input_stream_set_pending (G_INPUT_STREAM (stream), &error))
 489     {
 490       g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
 491                                             callback,
 492                                             user_data,
 493                                             error);
 494       g_error_free (error);
 495       return;
 496     }
 497
 498   class = G_BUFFERED_INPUT_STREAM_GET_CLASS (stream);
 499
 500   stream->priv->outstanding_callback = callback;
 501   g_object_ref (stream);
 502   class->fill_async (stream, count, io_priority, cancellable,
 503                      async_fill_callback_wrapper, user_data);
 504 }
 505
 506 /**
 507  * g_buffered_input_stream_fill_finish:
 508  * @stream: a #GBufferedInputStream.
 509  * @result: a #GAsyncResult.
 510  * @error: a #GError.
 511  *
 512  * Finishes an asynchronous read.
 513  *
 514  * Returns: a #gssize of the read stream, or %-1 on an error.
 515  **/
 516 gssize
 517 g_buffered_input_stream_fill_finish (GBufferedInputStream  *stream,
 518                                      GAsyncResult          *result,
 519                                      GError               **error)
 520 {
 521   GSimpleAsyncResult *simple;
 522   GBufferedInputStreamClass *class;
 523
 524   g_return_val_if_fail (G_IS_BUFFERED_INPUT_STREAM (stream), -1);
 525   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), -1);
 526
 527   if (G_IS_SIMPLE_ASYNC_RESULT (result))
 528     {
 529       simple = G_SIMPLE_ASYNC_RESULT (result);
 530       if (g_simple_async_result_propagate_error (simple, error))
 531         return -1;
 532
 533       /* Special case read of 0 bytes */
 534       if (g_simple_async_result_get_source_tag (simple) == g_buffered_input_stream_fill_async)
 535         return 0;
 536     }
 537
 538   class = G_BUFFERED_INPUT_STREAM_GET_CLASS (stream);
 539   return class->fill_finish (stream, result, error);
 540 }
 541
 542 /**
 543  * g_buffered_input_stream_get_available:
 544  * @stream: #GBufferedInputStream.
 545  *
 546  * Gets the size of the available data within the stream.
 547  *
 548  * Returns: size of the available stream.
 549  **/
 550 gsize
 551 g_buffered_input_stream_get_available (GBufferedInputStream *stream)
 552 {
 553   g_return_val_if_fail (G_IS_BUFFERED_INPUT_STREAM (stream), -1);
 554
 555   return stream->priv->end - stream->priv->pos;
 556 }
 557
 558 /**
 559  * g_buffered_input_stream_peek:
 560  * @stream: a #GBufferedInputStream.
 561  * @buffer: a pointer to an allocated chunk of memory.
 562  * @offset: a #gsize.
 563  * @count: a #gsize.
 564  *
 565  * Peeks in the buffer, copying data of size @count into @buffer,
 566  * offset @offset bytes.
 567  *
 568  * Returns: a #gsize of the number of bytes peeked, or %-1 on error.
 569  **/
 570 gsize
 571 g_buffered_input_stream_peek (GBufferedInputStream *stream,
 572                               void                 *buffer,
 573                               gsize                 offset,
 574                               gsize                 count)
 575 {
 576   gsize available;
 577   gsize end;
 578
 579   g_return_val_if_fail (G_IS_BUFFERED_INPUT_STREAM (stream), -1);
 580   g_return_val_if_fail (buffer != NULL, -1);
 581
 582   available = g_buffered_input_stream_get_available (stream);
 583
 584   if (offset > available)
 585     return 0;
 586
 587   end = MIN (offset + count, available);
 588   count = end - offset;
 589
 590   memcpy (buffer, stream->priv->buffer + stream->priv->pos + offset, count);
 591   return count;
 592 }
 593
 594 /**
 595  * g_buffered_input_stream_peek_buffer:
 596  * @stream: a #GBufferedInputStream.
 597  * @count: a #gsize to get the number of bytes available in the buffer.
 598  *
 599  * Returns the buffer with the currently available bytes. The returned
 600  * buffer must not be modified and will become invalid when reading from
 601  * the stream or filling the buffer.
 602  *
 603  * Returns: read-only buffer
 604  **/
 605 const void*
 606 g_buffered_input_stream_peek_buffer (GBufferedInputStream *stream,
 607                                      gsize                *count)
 608 {
 609   GBufferedInputStreamPrivate *priv;
 610
 611   g_return_val_if_fail (G_IS_BUFFERED_INPUT_STREAM (stream), NULL);
 612
 613   priv = stream->priv;
 614
 615   if (count)
 616     *count = priv->end - priv->pos;
 617
 618   return priv->buffer + priv->pos;
 619 }
 620
 621 static void
 622 compact_buffer (GBufferedInputStream *stream)
 623 {
 624   GBufferedInputStreamPrivate *priv;
 625   gsize current_size;
 626
 627   priv = stream->priv;
 628
 629   current_size = priv->end - priv->pos;
 630
 631   g_memmove (priv->buffer, priv->buffer + priv->pos, current_size);
 632
 633   priv->pos = 0;
 634   priv->end = current_size;
 635 }
 636
 637 static gssize
 638 g_buffered_input_stream_real_fill (GBufferedInputStream  *stream,
 639                                    gssize                 count,
 640                                    GCancellable          *cancellable,
 641                                    GError               **error)
 642 {
 643   GBufferedInputStreamPrivate *priv;
 644   GInputStream *base_stream;
 645   gssize nread;
 646   gsize in_buffer;
 647
 648   priv = stream->priv;
 649
 650   if (count == -1)
 651     count = priv->len;
 652
 653   in_buffer = priv->end - priv->pos;
 654
 655   /* Never fill more than can fit in the buffer */
 656   count = MIN (count, priv->len - in_buffer);
 657
 658   /* If requested length does not fit at end, compact */
 659   if (priv->len - priv->end < count)
 660     compact_buffer (stream);
 661
 662   base_stream = G_FILTER_INPUT_STREAM (stream)->base_stream;
 663   nread = g_input_stream_read (base_stream,
 664                                priv->buffer + priv->end,
 665                                count,
 666                                cancellable,
 667                                error);
 668
 669   if (nread > 0)
 670     priv->end += nread;
 671
 672   return nread;
 673 }
 674
 675 static gssize
 676 g_buffered_input_stream_skip (GInputStream  *stream,
 677                               gsize          count,
 678                               GCancellable  *cancellable,
 679                               GError       **error)
 680 {
 681   GBufferedInputStream        *bstream;
 682   GBufferedInputStreamPrivate *priv;
 683   GBufferedInputStreamClass *class;
 684   GInputStream *base_stream;
 685   gsize available, bytes_skipped;
 686   gssize nread;
 687
 688   bstream = G_BUFFERED_INPUT_STREAM (stream);
 689   priv = bstream->priv;
 690
 691   available = priv->end - priv->pos;
 692
 693   if (count <= available)
 694     {
 695       priv->pos += count;
 696       return count;
 697     }
 698
 699   /* Full request not available, skip all currently available and
 700    * request refill for more
 701    */
 702
 703   priv->pos = 0;
 704   priv->end = 0;
 705   bytes_skipped = available;
 706   count -= available;
 707
 708   if (bytes_skipped > 0)
 709     error = NULL; /* Ignore further errors if we already read some data */
 710
 711   if (count > priv->len)
 712     {
 713       /* Large request, shortcut buffer */
 714
 715       base_stream = G_FILTER_INPUT_STREAM (stream)->base_stream;
 716
 717       nread = g_input_stream_skip (base_stream,
 718                                    count,
 719                                    cancellable,
 720                                    error);
 721
 722       if (nread < 0 && bytes_skipped == 0)
 723         return -1;
 724
 725       if (nread > 0)
 726         bytes_skipped += nread;
 727
 728       return bytes_skipped;
 729     }
 730
 731   class = G_BUFFERED_INPUT_STREAM_GET_CLASS (stream);
 732   nread = class->fill (bstream, priv->len, cancellable, error);
 733
 734   if (nread < 0)
 735     {
 736       if (bytes_skipped == 0)
 737         return -1;
 738       else
 739         return bytes_skipped;
 740     }
 741
 742   available = priv->end - priv->pos;
 743   count = MIN (count, available);
 744
 745   bytes_skipped += count;
 746   priv->pos += count;
 747
 748   return bytes_skipped;
 749 }
 750
 751 static gssize
 752 g_buffered_input_stream_read (GInputStream *stream,
 753                               void         *buffer,
 754                               gsize         count,
 755                               GCancellable *cancellable,
 756                               GError      **error)
 757 {
 758   GBufferedInputStream        *bstream;
 759   GBufferedInputStreamPrivate *priv;
 760   GBufferedInputStreamClass *class;
 761   GInputStream *base_stream;
 762   gsize available, bytes_read;
 763   gssize nread;
 764
 765   bstream = G_BUFFERED_INPUT_STREAM (stream);
 766   priv = bstream->priv;
 767
 768   available = priv->end - priv->pos;
 769
 770   if (count <= available)
 771     {
 772       memcpy (buffer, priv->buffer + priv->pos, count);
 773       priv->pos += count;
 774       return count;
 775     }
 776
 777   /* Full request not available, read all currently availbile and request refill for more */
 778
 779   memcpy (buffer, priv->buffer + priv->pos, available);
 780   priv->pos = 0;
 781   priv->end = 0;
 782   bytes_read = available;
 783   count -= available;
 784
 785   if (bytes_read > 0)
 786     error = NULL; /* Ignore further errors if we already read some data */
 787
 788   if (count > priv->len)
 789     {
 790       /* Large request, shortcut buffer */
 791
 792       base_stream = G_FILTER_INPUT_STREAM (stream)->base_stream;
 793
 794       nread = g_input_stream_read (base_stream,
 795                                    (char *)buffer + bytes_read,
 796                                    count,
 797                                    cancellable,
 798                                    error);
 799
 800       if (nread < 0 && bytes_read == 0)
 801         return -1;
 802
 803       if (nread > 0)
 804         bytes_read += nread;
 805
 806       return bytes_read;
 807     }
 808
 809   class = G_BUFFERED_INPUT_STREAM_GET_CLASS (stream);
 810   nread = class->fill (bstream, priv->len, cancellable, error);
 811   if (nread < 0)
 812     {
 813       if (bytes_read == 0)
 814         return -1;
 815       else
 816         return bytes_read;
 817     }
 818
 819   available = priv->end - priv->pos;
 820   count = MIN (count, available);
 821
 822   memcpy ((char *)buffer + bytes_read, (char *)priv->buffer + priv->pos, count);
 823   bytes_read += count;
 824   priv->pos += count;
 825
 826   return bytes_read;
 827 }
 828
 829 /**
 830  * g_buffered_input_stream_read_byte:
 831  * @stream: #GBufferedInputStream.
 832  * @cancellable: optional #GCancellable object, %NULL to ignore.
 833  * @error: location to store the error occuring, or %NULL to ignore.
 834  *
 835  * Tries to read a single byte from the stream or the buffer. Will block
 836  * during this read.
 837  *
 838  * On success, the byte read from the stream is returned. On end of stream
 839  * -1 is returned but it's not an exceptional error and @error is not set.
 840  *
 841  * If @cancellable is not %NULL, then the operation can be cancelled by
 842  * triggering the cancellable object from another thread. If the operation
 843  * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned. If an
 844  * operation was partially finished when the operation was cancelled the
 845  * partial result will be returned, without an error.
 846  *
 847  * On error -1 is returned and @error is set accordingly.
 848  *
 849  * Returns: the byte read from the @stream, or -1 on end of stream or error.
 850  **/
 851 int
 852 g_buffered_input_stream_read_byte (GBufferedInputStream  *stream,
 853                                    GCancellable          *cancellable,
 854                                    GError               **error)
 855 {
 856   GBufferedInputStreamPrivate *priv;
 857   GBufferedInputStreamClass *class;
 858   GInputStream *input_stream;
 859   gsize available;
 860   gssize nread;
 861
 862   g_return_val_if_fail (G_IS_BUFFERED_INPUT_STREAM (stream), -1);
 863
 864   priv = stream->priv;
 865   input_stream = G_INPUT_STREAM (stream);
 866
 867   if (g_input_stream_is_closed (input_stream))
 868     {
 869       g_set_error (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
 870        _("Stream is already closed"));
 871       return -1;
 872     }
 873
 874   if (!g_input_stream_set_pending (input_stream, error))
 875     return -1;
 876
 877   available = priv->end - priv->pos;
 878
 879   if (available < 1)
 880     {
 881       g_input_stream_clear_pending (input_stream);
 882       return priv->buffer[priv->pos++];
 883     }
 884
 885   /* Byte not available, request refill for more */
 886
 887   if (cancellable)
 888     g_cancellable_push_current (cancellable);
 889
 890   priv->pos = 0;
 891   priv->end = 0;
 892
 893   class = G_BUFFERED_INPUT_STREAM_GET_CLASS (stream);
 894   nread = class->fill (stream, priv->len, cancellable, error);
 895
 896   if (cancellable)
 897     g_cancellable_pop_current (cancellable);
 898
 899   g_input_stream_clear_pending (input_stream);
 900
 901   if (nread <= 0)
 902     return -1; /* error or end of stream */
 903
 904   return priv->buffer[priv->pos++];
 905 }
 906
 907 /* ************************** */
 908 /* Async stuff implementation */
 909 /* ************************** */
 910
 911 static void
 912 fill_async_callback (GObject      *source_object,
 913                      GAsyncResult *result,
 914                      gpointer      user_data)
 915 {
 916   GError *error;
 917   gssize res;
 918   GSimpleAsyncResult *simple;
 919
 920   simple = user_data;
 921
 922   error = NULL;
 923   res = g_input_stream_read_finish (G_INPUT_STREAM (source_object),
 924                                     result, &error);
 925
 926   g_simple_async_result_set_op_res_gssize (simple, res);
 927   if (res == -1)
 928     {
 929       g_simple_async_result_set_from_error (simple, error);
 930       g_error_free (error);
 931     }
 932
 933   /* Complete immediately, not in idle, since we're already in a mainloop callout */
 934   g_simple_async_result_complete (simple);
 935   g_object_unref (simple);
 936 }
 937
 938 static void
 939 g_buffered_input_stream_real_fill_async (GBufferedInputStream *stream,
 940                                          gssize                count,
 941                                          int                   io_priority,
 942                                          GCancellable         *cancellable,
 943                                          GAsyncReadyCallback   callback,
 944                                          gpointer              user_data)
 945 {
 946   GBufferedInputStreamPrivate *priv;
 947   GInputStream *base_stream;
 948   GSimpleAsyncResult *simple;
 949   gsize in_buffer;
 950
 951   priv = stream->priv;
 952
 953   if (count == -1)
 954     count = priv->len;
 955
 956   in_buffer = priv->end - priv->pos;
 957
 958   /* Never fill more than can fit in the buffer */
 959   count = MIN (count, priv->len - in_buffer);
 960
 961   /* If requested length does not fit at end, compact */
 962   if (priv->len - priv->end < count)
 963     compact_buffer (stream);
 964
 965   simple = g_simple_async_result_new (G_OBJECT (stream),
 966                                       callback, user_data,
 967                                       g_buffered_input_stream_real_fill_async);
 968
 969   base_stream = G_FILTER_INPUT_STREAM (stream)->base_stream;
 970   g_input_stream_read_async (base_stream,
 971                              priv->buffer + priv->end,
 972                              count,
 973                              io_priority,
 974                              cancellable,
 975                              fill_async_callback,
 976                              simple);
 977 }
 978
 979 static gssize
 980 g_buffered_input_stream_real_fill_finish (GBufferedInputStream *stream,
 981                                           GAsyncResult         *result,
 982                                           GError              **error)
 983 {
 984   GSimpleAsyncResult *simple;
 985   gssize nread;
 986
 987   simple = G_SIMPLE_ASYNC_RESULT (result);
 988   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_buffered_input_stream_real_fill_async);
 989
 990   nread = g_simple_async_result_get_op_res_gssize (simple);
 991   return nread;
 992 }
 993
 994 typedef struct {
 995   gssize bytes_read;
 996   gssize count;
 997   void *buffer;
 998 } ReadAsyncData;
 999
1000 static void
1001 free_read_async_data (gpointer _data)
1002 {
1003   ReadAsyncData *data = _data;
1004   g_slice_free (ReadAsyncData, data);
1005 }
1006
1007 static void
1008 large_read_callback (GObject *source_object,
1009                      GAsyncResult *result,
1010                      gpointer user_data)
1011 {
1012   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (user_data);
1013   ReadAsyncData *data;
1014   GError *error;
1015   gssize nread;
1016
1017   data = g_simple_async_result_get_op_res_gpointer (simple);
1018
1019   error = NULL;
1020   nread = g_input_stream_read_finish (G_INPUT_STREAM (source_object),
1021                                       result, &error);
1022
1023   /* Only report the error if we've not already read some data */
1024   if (nread < 0 && data->bytes_read == 0)
1025     g_simple_async_result_set_from_error (simple, error);
1026
1027   if (nread > 0)
1028     data->bytes_read += nread;
1029
1030   if (error)
1031     g_error_free (error);
1032
1033   /* Complete immediately, not in idle, since we're already in a mainloop callout */
1034   g_simple_async_result_complete (simple);
1035   g_object_unref (simple);
1036 }
1037
1038 static void
1039 read_fill_buffer_callback (GObject *source_object,
1040                            GAsyncResult *result,
1041                            gpointer user_data)
1042 {
1043   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (user_data);
1044   GBufferedInputStream *bstream;
1045   GBufferedInputStreamPrivate *priv;
1046   ReadAsyncData *data;
1047   GError *error;
1048   gssize nread;
1049   gsize available;
1050
1051   bstream = G_BUFFERED_INPUT_STREAM (source_object);
1052   priv = bstream->priv;
1053
1054   data = g_simple_async_result_get_op_res_gpointer (simple);
1055
1056   error = NULL;
1057   nread = g_buffered_input_stream_fill_finish (bstream,
1058                                                result, &error);
1059
1060   if (nread < 0 && data->bytes_read == 0)
1061     g_simple_async_result_set_from_error (simple, error);
1062
1063
1064   if (nread > 0)
1065     {
1066       available = priv->end - priv->pos;
1067       data->count = MIN (data->count, available);
1068
1069       memcpy ((char *)data->buffer + data->bytes_read, (char *)priv->buffer + priv->pos, data->count);
1070       data->bytes_read += data->count;
1071       priv->pos += data->count;
1072     }
1073
1074   if (error)
1075     g_error_free (error);
1076
1077   /* Complete immediately, not in idle, since we're already in a mainloop callout */
1078   g_simple_async_result_complete (simple);
1079   g_object_unref (simple);
1080 }
1081
1082 static void
1083 g_buffered_input_stream_read_async (GInputStream              *stream,
1084                                     void                      *buffer,
1085                                     gsize                      count,
1086                                     int                        io_priority,
1087                                     GCancellable              *cancellable,
1088                                     GAsyncReadyCallback        callback,
1089                                     gpointer                   user_data)
1090 {
1091   GBufferedInputStream *bstream;
1092   GBufferedInputStreamPrivate *priv;
1093   GBufferedInputStreamClass *class;
1094   GInputStream *base_stream;
1095   gsize available;
1096   GSimpleAsyncResult *simple;
1097   ReadAsyncData *data;
1098
1099   bstream = G_BUFFERED_INPUT_STREAM (stream);
1100   priv = bstream->priv;
1101
1102   data = g_slice_new (ReadAsyncData);
1103   data->buffer = buffer;
1104   data->bytes_read = 0;
1105   simple = g_simple_async_result_new (G_OBJECT (stream),
1106                                       callback, user_data,
1107                                       g_buffered_input_stream_read_async);
1108   g_simple_async_result_set_op_res_gpointer (simple, data, free_read_async_data);
1109
1110   available = priv->end - priv->pos;
1111
1112   if (count <= available)
1113     {
1114       memcpy (buffer, priv->buffer + priv->pos, count);
1115       priv->pos += count;
1116       data->bytes_read = count;
1117
1118       g_simple_async_result_complete_in_idle (simple);
1119       g_object_unref (simple);
1120       return;
1121     }
1122
1123
1124   /* Full request not available, read all currently availbile and request refill for more */
1125
1126   memcpy (buffer, priv->buffer + priv->pos, available);
1127   priv->pos = 0;
1128   priv->end = 0;
1129
1130   count -= available;
1131
1132   data->bytes_read = available;
1133   data->count = count;
1134
1135   if (count > priv->len)
1136     {
1137       /* Large request, shortcut buffer */
1138
1139       base_stream = G_FILTER_INPUT_STREAM (stream)->base_stream;
1140
1141       g_input_stream_read_async (base_stream,
1142                                  (char *)buffer + data->bytes_read,
1143                                  count,
1144                                  io_priority, cancellable,
1145                                  large_read_callback,
1146                                  simple);
1147     }
1148   else
1149     {
1150       class = G_BUFFERED_INPUT_STREAM_GET_CLASS (stream);
1151       class->fill_async (bstream, priv->len, io_priority, cancellable,
1152                          read_fill_buffer_callback, simple);
1153     }
1154 }
1155
1156 static gssize
1157 g_buffered_input_stream_read_finish (GInputStream   *stream,
1158                                      GAsyncResult   *result,
1159                                      GError        **error)
1160 {
1161   GSimpleAsyncResult *simple;
1162   ReadAsyncData *data;
1163
1164   simple = G_SIMPLE_ASYNC_RESULT (result);
1165
1166   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_buffered_input_stream_read_async);
1167
1168   data = g_simple_async_result_get_op_res_gpointer (simple);
1169
1170   return data->bytes_read;
1171 }
1172
1173 typedef struct {
1174   gssize bytes_skipped;
1175   gssize count;
1176 } SkipAsyncData;
1177
1178 static void
1179 free_skip_async_data (gpointer _data)
1180 {
1181   SkipAsyncData *data = _data;
1182   g_slice_free (SkipAsyncData, data);
1183 }
1184
1185 static void
1186 large_skip_callback (GObject *source_object,
1187                      GAsyncResult *result,
1188                      gpointer user_data)
1189 {
1190   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (user_data);
1191   SkipAsyncData *data;
1192   GError *error;
1193   gssize nread;
1194
1195   data = g_simple_async_result_get_op_res_gpointer (simple);
1196
1197   error = NULL;
1198   nread = g_input_stream_skip_finish (G_INPUT_STREAM (source_object),
1199                                       result, &error);
1200
1201   /* Only report the error if we've not already read some data */
1202   if (nread < 0 && data->bytes_skipped == 0)
1203     g_simple_async_result_set_from_error (simple, error);
1204
1205   if (nread > 0)
1206     data->bytes_skipped += nread;
1207
1208   if (error)
1209     g_error_free (error);
1210
1211   /* Complete immediately, not in idle, since we're already in a mainloop callout */
1212   g_simple_async_result_complete (simple);
1213   g_object_unref (simple);
1214 }
1215
1216 static void
1217 skip_fill_buffer_callback (GObject *source_object,
1218                            GAsyncResult *result,
1219                            gpointer user_data)
1220 {
1221   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (user_data);
1222   GBufferedInputStream *bstream;
1223   GBufferedInputStreamPrivate *priv;
1224   SkipAsyncData *data;
1225   GError *error;
1226   gssize nread;
1227   gsize available;
1228
1229   bstream = G_BUFFERED_INPUT_STREAM (source_object);
1230   priv = bstream->priv;
1231
1232   data = g_simple_async_result_get_op_res_gpointer (simple);
1233
1234   error = NULL;
1235   nread = g_buffered_input_stream_fill_finish (bstream,
1236                                                result, &error);
1237
1238   if (nread < 0 && data->bytes_skipped == 0)
1239     g_simple_async_result_set_from_error (simple, error);
1240
1241
1242   if (nread > 0)
1243     {
1244       available = priv->end - priv->pos;
1245       data->count = MIN (data->count, available);
1246
1247       data->bytes_skipped += data->count;
1248       priv->pos += data->count;
1249     }
1250
1251   if (error)
1252     g_error_free (error);
1253
1254   /* Complete immediately, not in idle, since we're already in a mainloop callout */
1255   g_simple_async_result_complete (simple);
1256   g_object_unref (simple);
1257 }
1258
1259 static void
1260 g_buffered_input_stream_skip_async (GInputStream              *stream,
1261                                     gsize                      count,
1262                                     int                        io_priority,
1263                                     GCancellable              *cancellable,
1264                                     GAsyncReadyCallback        callback,
1265                                     gpointer                   user_data)
1266 {
1267   GBufferedInputStream *bstream;
1268   GBufferedInputStreamPrivate *priv;
1269   GBufferedInputStreamClass *class;
1270   GInputStream *base_stream;
1271   gsize available;
1272   GSimpleAsyncResult *simple;
1273   SkipAsyncData *data;
1274
1275   bstream = G_BUFFERED_INPUT_STREAM (stream);
1276   priv = bstream->priv;
1277
1278   data = g_slice_new (SkipAsyncData);
1279   data->bytes_skipped = 0;
1280   simple = g_simple_async_result_new (G_OBJECT (stream),
1281                                       callback, user_data,
1282                                       g_buffered_input_stream_skip_async);
1283   g_simple_async_result_set_op_res_gpointer (simple, data, free_skip_async_data);
1284
1285   available = priv->end - priv->pos;
1286
1287   if (count <= available)
1288     {
1289       priv->pos += count;
1290       data->bytes_skipped = count;
1291
1292       g_simple_async_result_complete_in_idle (simple);
1293       g_object_unref (simple);
1294       return;
1295     }
1296
1297
1298   /* Full request not available, skip all currently availbile and request refill for more */
1299
1300   priv->pos = 0;
1301   priv->end = 0;
1302
1303   count -= available;
1304
1305   data->bytes_skipped = available;
1306   data->count = count;
1307
1308   if (count > priv->len)
1309     {
1310       /* Large request, shortcut buffer */
1311
1312       base_stream = G_FILTER_INPUT_STREAM (stream)->base_stream;
1313
1314       g_input_stream_skip_async (base_stream,
1315                                  count,
1316                                  io_priority, cancellable,
1317                                  large_skip_callback,
1318                                  simple);
1319     }
1320   else
1321     {
1322       class = G_BUFFERED_INPUT_STREAM_GET_CLASS (stream);
1323       class->fill_async (bstream, priv->len, io_priority, cancellable,
1324                          skip_fill_buffer_callback, simple);
1325     }
1326 }
1327
1328 static gssize
1329 g_buffered_input_stream_skip_finish (GInputStream   *stream,
1330                                      GAsyncResult   *result,
1331                                      GError        **error)
1332 {
1333   GSimpleAsyncResult *simple;
1334   SkipAsyncData *data;
1335
1336   simple = G_SIMPLE_ASYNC_RESULT (result);
1337
1338   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_buffered_input_stream_skip_async);
1339
1340   data = g_simple_async_result_get_op_res_gpointer (simple);
1341
1342   return data->bytes_skipped;
1343 }
1344
1345
1346 #define __G_BUFFERED_INPUT_STREAM_C__
1347 #include "gioaliasdef.c"