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 "gcancellable.h"
  28 #include "gasyncresult.h"
  29 #include "gsimpleasyncresult.h"
  30 #include "gioerror.h"
  31 #include <string.h>
  32 #include "glibintl.h"
  33
  34 #include "gioalias.h"
  35
  36 /**
  37  * SECTION:gbufferedinputstream
  38  * @short_description: Buffered Input Stream
  39  * @include: gio/gio.h
  40  * @see_also: #GFilterInputStream, #GInputStream
  41  *
  42  * Buffered input stream implements #GFilterInputStream and provides
  43  * for buffered reads.
  44  *
  45  * By default, #GBufferedInputStream's buffer size is set at 4 kilobytes.
  46  *
  47  * To create a buffered input stream, use g_buffered_input_stream_new(),
  48  * or g_buffered_input_stream_new_sized() to specify the buffer's size at
  49  * construction.
  50  *
  51  * To get the size of a buffer within a buffered input stream, use
  52  * g_buffered_input_stream_get_buffer_size(). To change the size of a
  53  * buffered input stream's buffer, use
  54  * g_buffered_input_stream_set_buffer_size(). Note that the buffer's size
  55  * cannot be reduced below the size of the data within the buffer.
  56  */
  57
  58
  59 #define DEFAULT_BUFFER_SIZE 4096
  60
  61 struct _GBufferedInputStreamPrivate {
  62   guint8 *buffer;
  63   gsize   len;
  64   gsize   pos;
  65   gsize   end;
  66   GAsyncReadyCallback outstanding_callback;
  67 };
  68
  69 enum {
  70   PROP_0,
  71   PROP_BUFSIZE
  72 };
  73
  74 static void g_buffered_input_stream_set_property  (GObject      *object,
  75                                                    guint         prop_id,
  76                                                    const GValue *value,
  77                                                    GParamSpec   *pspec);
  78
  79 static void g_buffered_input_stream_get_property  (GObject      *object,
  80                                                    guint         prop_id,
  81                                                    GValue       *value,
  82                                                    GParamSpec   *pspec);
  83 static void g_buffered_input_stream_finalize      (GObject *object);
  84
  85
  86 static gssize g_buffered_input_stream_skip             (GInputStream          *stream,
  87                                                         gsize                  count,
  88                                                         GCancellable          *cancellable,
  89                                                         GError               **error);
  90 static void   g_buffered_input_stream_skip_async       (GInputStream          *stream,
  91                                                         gsize                  count,
  92                                                         int                    io_priority,
  93                                                         GCancellable          *cancellable,
  94                                                         GAsyncReadyCallback    callback,
  95                                                         gpointer               user_data);
  96 static gssize g_buffered_input_stream_skip_finish      (GInputStream          *stream,
  97                                                         GAsyncResult          *result,
  98                                                         GError               **error);
  99 static gssize g_buffered_input_stream_read             (GInputStream          *stream,
 100                                                         void                  *buffer,
 101                                                         gsize                  count,
 102                                                         GCancellable          *cancellable,
 103                                                         GError               **error);
 104 static void   g_buffered_input_stream_read_async       (GInputStream          *stream,
 105                                                         void                  *buffer,
 106                                                         gsize                  count,
 107                                                         int                    io_priority,
 108                                                         GCancellable          *cancellable,
 109                                                         GAsyncReadyCallback    callback,
 110                                                         gpointer               user_data);
 111 static gssize g_buffered_input_stream_read_finish      (GInputStream          *stream,
 112                                                         GAsyncResult          *result,
 113                                                         GError               **error);
 114 static gssize g_buffered_input_stream_real_fill        (GBufferedInputStream  *stream,
 115                                                         gssize                 count,
 116                                                         GCancellable          *cancellable,
 117                                                         GError               **error);
 118 static void   g_buffered_input_stream_real_fill_async  (GBufferedInputStream  *stream,
 119                                                         gssize                 count,
 120                                                         int                    io_priority,
 121                                                         GCancellable          *cancellable,
 122                                                         GAsyncReadyCallback    callback,
 123                                                         gpointer               user_data);
 124 static gssize g_buffered_input_stream_real_fill_finish (GBufferedInputStream  *stream,
 125                                                         GAsyncResult          *result,
 126                                                         GError               **error);
 127
 128 static void compact_buffer (GBufferedInputStream *stream);
 129
 130 G_DEFINE_TYPE (GBufferedInputStream,
 131                g_buffered_input_stream,
 132                G_TYPE_FILTER_INPUT_STREAM)
 133
 134
 135 static void
 136 g_buffered_input_stream_class_init (GBufferedInputStreamClass *klass)
 137 {
 138   GObjectClass *object_class;
 139   GInputStreamClass *istream_class;
 140   GBufferedInputStreamClass *bstream_class;
 141
 142   g_type_class_add_private (klass, sizeof (GBufferedInputStreamPrivate));
 143
 144   object_class = G_OBJECT_CLASS (klass);
 145   object_class->get_property = g_buffered_input_stream_get_property;
 146   object_class->set_property = g_buffered_input_stream_set_property;
 147   object_class->finalize     = g_buffered_input_stream_finalize;
 148
 149   istream_class = G_INPUT_STREAM_CLASS (klass);
 150   istream_class->skip = g_buffered_input_stream_skip;
 151   istream_class->skip_async  = g_buffered_input_stream_skip_async;
 152   istream_class->skip_finish = g_buffered_input_stream_skip_finish;
 153   istream_class->read_fn = g_buffered_input_stream_read;
 154   istream_class->read_async  = g_buffered_input_stream_read_async;
 155   istream_class->read_finish = g_buffered_input_stream_read_finish;
 156
 157   bstream_class = G_BUFFERED_INPUT_STREAM_CLASS (klass);
 158   bstream_class->fill = g_buffered_input_stream_real_fill;
 159   bstream_class->fill_async = g_buffered_input_stream_real_fill_async;
 160   bstream_class->fill_finish = g_buffered_input_stream_real_fill_finish;
 161
 162   g_object_class_install_property (object_class,
 163                                    PROP_BUFSIZE,
 164                                    g_param_spec_uint ("buffer-size",
 165                                                       P_("Buffer Size"),
 166                                                       P_("The size of the backend buffer"),
 167                                                       1,
 168                                                       G_MAXUINT,
 169                                                       DEFAULT_BUFFER_SIZE,
 170                                                       G_PARAM_READWRITE | G_PARAM_CONSTRUCT |
 171                                                       G_PARAM_STATIC_NAME|G_PARAM_STATIC_NICK|G_PARAM_STATIC_BLURB));
 172
 173
 174 }
 175
 176 /**
 177  * g_buffered_input_stream_get_buffer_size:
 178  * @stream: a #GBufferedInputStream
 179  *
 180  * Gets the size of the input buffer.
 181  *
 182  * Returns: the current buffer size.
 183  */
 184 gsize
 185 g_buffered_input_stream_get_buffer_size (GBufferedInputStream  *stream)
 186 {
 187   g_return_val_if_fail (G_IS_BUFFERED_INPUT_STREAM (stream), 0);
 188
 189   return stream->priv->len;
 190 }
 191
 192 /**
 193  * g_buffered_input_stream_set_buffer_size:
 194  * @stream: a #GBufferedInputStream
 195  * @size: a #gsize
 196  *
 197  * Sets the size of the internal buffer of @stream to @size, or to the
 198  * size of the contents of the buffer. The buffer can never be resized
 199  * smaller than its current contents.
 200  */
 201 void
 202 g_buffered_input_stream_set_buffer_size (GBufferedInputStream *stream,
 203                                          gsize                 size)
 204 {
 205   GBufferedInputStreamPrivate *priv;
 206   gsize in_buffer;
 207   guint8 *buffer;
 208
 209   g_return_if_fail (G_IS_BUFFERED_INPUT_STREAM (stream));
 210
 211   priv = stream->priv;
 212
 213   if (priv->len == size)
 214     return;
 215
 216   if (priv->buffer)
 217     {
 218       in_buffer = priv->end - priv->pos;
 219
 220       /* Never resize smaller than current buffer contents */
 221       size = MAX (size, in_buffer);
 222
 223       buffer = g_malloc (size);
 224       memcpy (buffer, priv->buffer + priv->pos, in_buffer);
 225       priv->len = size;
 226       priv->pos = 0;
 227       priv->end = in_buffer;
 228       g_free (priv->buffer);
 229       priv->buffer = buffer;
 230     }
 231   else
 232     {
 233       priv->len = size;
 234       priv->pos = 0;
 235       priv->end = 0;
 236       priv->buffer = g_malloc (size);
 237     }
 238
 239   g_object_notify (G_OBJECT (stream), "buffer-size");
 240 }
 241
 242 static void
 243 g_buffered_input_stream_set_property (GObject      *object,
 244                                       guint         prop_id,
 245                                       const GValue *value,
 246                                       GParamSpec   *pspec)
 247 {
 248   GBufferedInputStream        *bstream;
 249
 250   bstream = G_BUFFERED_INPUT_STREAM (object);
 251
 252   switch (prop_id)
 253     {
 254     case PROP_BUFSIZE:
 255       g_buffered_input_stream_set_buffer_size (bstream, g_value_get_uint (value));
 256       break;
 257
 258     default:
 259       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 260       break;
 261     }
 262 }
 263
 264 static void
 265 g_buffered_input_stream_get_property (GObject    *object,
 266                                       guint       prop_id,
 267                                       GValue     *value,
 268                                       GParamSpec *pspec)
 269 {
 270   GBufferedInputStreamPrivate *priv;
 271   GBufferedInputStream        *bstream;
 272
 273   bstream = G_BUFFERED_INPUT_STREAM (object);
 274   priv = bstream->priv;
 275
 276   switch (prop_id)
 277     {
 278     case PROP_BUFSIZE:
 279       g_value_set_uint (value, priv->len);
 280       break;
 281
 282     default:
 283       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 284       break;
 285     }
 286 }
 287
 288 static void
 289 g_buffered_input_stream_finalize (GObject *object)
 290 {
 291   GBufferedInputStreamPrivate *priv;
 292   GBufferedInputStream        *stream;
 293
 294   stream = G_BUFFERED_INPUT_STREAM (object);
 295   priv = stream->priv;
 296
 297   g_free (priv->buffer);
 298
 299   G_OBJECT_CLASS (g_buffered_input_stream_parent_class)->finalize (object);
 300 }
 301
 302 static void
 303 g_buffered_input_stream_init (GBufferedInputStream *stream)
 304 {
 305   stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (stream,
 306                                               G_TYPE_BUFFERED_INPUT_STREAM,
 307                                               GBufferedInputStreamPrivate);
 308 }
 309
 310
 311 /**
 312  * g_buffered_input_stream_new:
 313  * @base_stream: a #GInputStream
 314  *
 315  * Creates a new #GInputStream from the given @base_stream, with
 316  * a buffer set to the default size (4 kilobytes).
 317  *
 318  * Returns: a #GInputStream for the given @base_stream.
 319  */
 320 GInputStream *
 321 g_buffered_input_stream_new (GInputStream *base_stream)
 322 {
 323   GInputStream *stream;
 324
 325   g_return_val_if_fail (G_IS_INPUT_STREAM (base_stream), NULL);
 326
 327   stream = g_object_new (G_TYPE_BUFFERED_INPUT_STREAM,
 328                          "base-stream", base_stream,
 329                          NULL);
 330
 331   return stream;
 332 }
 333
 334 /**
 335  * g_buffered_input_stream_new_sized:
 336  * @base_stream: a #GInputStream
 337  * @size: a #gsize
 338  *
 339  * Creates a new #GBufferedInputStream from the given @base_stream,
 340  * with a buffer set to @size.
 341  *
 342  * Returns: a #GInputStream.
 343  */
 344 GInputStream *
 345 g_buffered_input_stream_new_sized (GInputStream *base_stream,
 346                                    gsize         size)
 347 {
 348   GInputStream *stream;
 349
 350   g_return_val_if_fail (G_IS_INPUT_STREAM (base_stream), NULL);
 351
 352   stream = g_object_new (G_TYPE_BUFFERED_INPUT_STREAM,
 353                          "base-stream", base_stream,
 354                          "buffer-size", (guint)size,
 355                          NULL);
 356
 357   return stream;
 358 }
 359
 360 /**
 361  * g_buffered_input_stream_fill:
 362  * @stream: a #GBufferedInputStream
 363  * @count: the number of bytes that will be read from the stream
 364  * @cancellable: optional #GCancellable object, %NULL to ignore
 365  * @error: location to store the error occuring, or %NULL to ignore
 366  *
 367  * Tries to read @count bytes from the stream into the buffer.
 368  * Will block during this read.
 369  *
 370  * If @count is zero, returns zero and does nothing. A value of @count
 371  * larger than %G_MAXSSIZE will cause a %G_IO_ERROR_INVALID_ARGUMENT error.
 372  *
 373  * On success, the number of bytes read into the buffer is returned.
 374  * It is not an error if this is not the same as the requested size, as it
 375  * can happen e.g. near the end of a file. Zero is returned on end of file
 376  * (or if @count is zero),  but never otherwise.
 377  *
 378  * If @count is -1 then the attempted read size is equal to the number of
 379  * bytes that are required to fill the buffer.
 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 (count < -1)
 410     {
 411       g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
 412                    _("Too large count value passed to %s"), G_STRFUNC);
 413       return -1;
 414     }
 415
 416   if (!g_input_stream_set_pending (input_stream, error))
 417     return -1;
 418
 419   if (cancellable)
 420     g_cancellable_push_current (cancellable);
 421
 422   class = G_BUFFERED_INPUT_STREAM_GET_CLASS (stream);
 423   res = class->fill (stream, count, cancellable, error);
 424
 425   if (cancellable)
 426     g_cancellable_pop_current (cancellable);
 427
 428   g_input_stream_clear_pending (input_stream);
 429
 430   return res;
 431 }
 432
 433 static void
 434 async_fill_callback_wrapper (GObject      *source_object,
 435                              GAsyncResult *res,
 436                              gpointer      user_data)
 437 {
 438   GBufferedInputStream *stream = G_BUFFERED_INPUT_STREAM (source_object);
 439
 440   g_input_stream_clear_pending (G_INPUT_STREAM (stream));
 441   (*stream->priv->outstanding_callback) (source_object, res, user_data);
 442   g_object_unref (stream);
 443 }
 444
 445 /**
 446  * g_buffered_input_stream_fill_async:
 447  * @stream: a #GBufferedInputStream
 448  * @count: the number of bytes that will be read from the stream
 449  * @io_priority: the <link linkend="io-priority">I/O priority</link>
 450  *     of the request
 451  * @cancellable: optional #GCancellable object
 452  * @callback: a #GAsyncReadyCallback
 453  * @user_data: a #gpointer
 454  *
 455  * Reads data into @stream's buffer asynchronously, up to @count size.
 456  * @io_priority can be used to prioritize reads. For the synchronous
 457  * version of this function, see g_buffered_input_stream_fill().
 458  *
 459  * If @count is -1 then the attempted read size is equal to the number
 460  * of bytes that are required to fill the buffer.
 461  */
 462 void
 463 g_buffered_input_stream_fill_async (GBufferedInputStream *stream,
 464                                     gssize                count,
 465                                     int                   io_priority,
 466                                     GCancellable         *cancellable,
 467                                     GAsyncReadyCallback   callback,
 468                                     gpointer              user_data)
 469 {
 470   GBufferedInputStreamClass *class;
 471   GSimpleAsyncResult *simple;
 472   GError *error = NULL;
 473
 474   g_return_if_fail (G_IS_BUFFERED_INPUT_STREAM (stream));
 475
 476   if (count == 0)
 477     {
 478       simple = g_simple_async_result_new (G_OBJECT (stream),
 479                                           callback,
 480                                           user_data,
 481                                           g_buffered_input_stream_fill_async);
 482       g_simple_async_result_complete_in_idle (simple);
 483       g_object_unref (simple);
 484       return;
 485     }
 486
 487   if (count < -1)
 488     {
 489       g_simple_async_report_error_in_idle (G_OBJECT (stream),
 490                                            callback,
 491                                            user_data,
 492                                            G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
 493                                            _("Too large count value passed to %s"),
 494                                            G_STRFUNC);
 495       return;
 496     }
 497
 498   if (!g_input_stream_set_pending (G_INPUT_STREAM (stream), &error))
 499     {
 500       g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
 501                                             callback,
 502                                             user_data,
 503                                             error);
 504       g_error_free (error);
 505       return;
 506     }
 507
 508   class = G_BUFFERED_INPUT_STREAM_GET_CLASS (stream);
 509
 510   stream->priv->outstanding_callback = callback;
 511   g_object_ref (stream);
 512   class->fill_async (stream, count, io_priority, cancellable,
 513                      async_fill_callback_wrapper, user_data);
 514 }
 515
 516 /**
 517  * g_buffered_input_stream_fill_finish:
 518  * @stream: a #GBufferedInputStream
 519  * @result: a #GAsyncResult
 520  * @error: a #GError
 521  *
 522  * Finishes an asynchronous read.
 523  *
 524  * Returns: a #gssize of the read stream, or %-1 on an error.
 525  */
 526 gssize
 527 g_buffered_input_stream_fill_finish (GBufferedInputStream  *stream,
 528                                      GAsyncResult          *result,
 529                                      GError               **error)
 530 {
 531   GSimpleAsyncResult *simple;
 532   GBufferedInputStreamClass *class;
 533
 534   g_return_val_if_fail (G_IS_BUFFERED_INPUT_STREAM (stream), -1);
 535   g_return_val_if_fail (G_IS_ASYNC_RESULT (result), -1);
 536
 537   if (G_IS_SIMPLE_ASYNC_RESULT (result))
 538     {
 539       simple = G_SIMPLE_ASYNC_RESULT (result);
 540       if (g_simple_async_result_propagate_error (simple, error))
 541         return -1;
 542
 543       /* Special case read of 0 bytes */
 544       if (g_simple_async_result_get_source_tag (simple) == g_buffered_input_stream_fill_async)
 545         return 0;
 546     }
 547
 548   class = G_BUFFERED_INPUT_STREAM_GET_CLASS (stream);
 549   return class->fill_finish (stream, result, error);
 550 }
 551
 552 /**
 553  * g_buffered_input_stream_get_available:
 554  * @stream: #GBufferedInputStream
 555  *
 556  * Gets the size of the available data within the stream.
 557  *
 558  * Returns: size of the available stream.
 559  */
 560 gsize
 561 g_buffered_input_stream_get_available (GBufferedInputStream *stream)
 562 {
 563   g_return_val_if_fail (G_IS_BUFFERED_INPUT_STREAM (stream), -1);
 564
 565   return stream->priv->end - stream->priv->pos;
 566 }
 567
 568 /**
 569  * g_buffered_input_stream_peek:
 570  * @stream: a #GBufferedInputStream
 571  * @buffer: a pointer to an allocated chunk of memory
 572  * @offset: a #gsize
 573  * @count: a #gsize
 574  *
 575  * Peeks in the buffer, copying data of size @count into @buffer,
 576  * offset @offset bytes.
 577  *
 578  * Returns: a #gsize of the number of bytes peeked, or -1 on error.
 579  */
 580 gsize
 581 g_buffered_input_stream_peek (GBufferedInputStream *stream,
 582                               void                 *buffer,
 583                               gsize                 offset,
 584                               gsize                 count)
 585 {
 586   gsize available;
 587   gsize end;
 588
 589   g_return_val_if_fail (G_IS_BUFFERED_INPUT_STREAM (stream), -1);
 590   g_return_val_if_fail (buffer != NULL, -1);
 591
 592   available = g_buffered_input_stream_get_available (stream);
 593
 594   if (offset > available)
 595     return 0;
 596
 597   end = MIN (offset + count, available);
 598   count = end - offset;
 599
 600   memcpy (buffer, stream->priv->buffer + stream->priv->pos + offset, count);
 601   return count;
 602 }
 603
 604 /**
 605  * g_buffered_input_stream_peek_buffer:
 606  * @stream: a #GBufferedInputStream
 607  * @count: a #gsize to get the number of bytes available in the buffer
 608  *
 609  * Returns the buffer with the currently available bytes. The returned
 610  * buffer must not be modified and will become invalid when reading from
 611  * the stream or filling the buffer.
 612  *
 613  * Returns: read-only buffer
 614  */
 615 const void*
 616 g_buffered_input_stream_peek_buffer (GBufferedInputStream *stream,
 617                                      gsize                *count)
 618 {
 619   GBufferedInputStreamPrivate *priv;
 620
 621   g_return_val_if_fail (G_IS_BUFFERED_INPUT_STREAM (stream), NULL);
 622
 623   priv = stream->priv;
 624
 625   if (count)
 626     *count = priv->end - priv->pos;
 627
 628   return priv->buffer + priv->pos;
 629 }
 630
 631 static void
 632 compact_buffer (GBufferedInputStream *stream)
 633 {
 634   GBufferedInputStreamPrivate *priv;
 635   gsize current_size;
 636
 637   priv = stream->priv;
 638
 639   current_size = priv->end - priv->pos;
 640
 641   g_memmove (priv->buffer, priv->buffer + priv->pos, current_size);
 642
 643   priv->pos = 0;
 644   priv->end = current_size;
 645 }
 646
 647 static gssize
 648 g_buffered_input_stream_real_fill (GBufferedInputStream  *stream,
 649                                    gssize                 count,
 650                                    GCancellable          *cancellable,
 651                                    GError               **error)
 652 {
 653   GBufferedInputStreamPrivate *priv;
 654   GInputStream *base_stream;
 655   gssize nread;
 656   gsize in_buffer;
 657
 658   priv = stream->priv;
 659
 660   if (count == -1)
 661     count = priv->len;
 662
 663   in_buffer = priv->end - priv->pos;
 664
 665   /* Never fill more than can fit in the buffer */
 666   count = MIN (count, priv->len - in_buffer);
 667
 668   /* If requested length does not fit at end, compact */
 669   if (priv->len - priv->end < count)
 670     compact_buffer (stream);
 671
 672   base_stream = G_FILTER_INPUT_STREAM (stream)->base_stream;
 673   nread = g_input_stream_read (base_stream,
 674                                priv->buffer + priv->end,
 675                                count,
 676                                cancellable,
 677                                error);
 678
 679   if (nread > 0)
 680     priv->end += nread;
 681
 682   return nread;
 683 }
 684
 685 static gssize
 686 g_buffered_input_stream_skip (GInputStream  *stream,
 687                               gsize          count,
 688                               GCancellable  *cancellable,
 689                               GError       **error)
 690 {
 691   GBufferedInputStream        *bstream;
 692   GBufferedInputStreamPrivate *priv;
 693   GBufferedInputStreamClass *class;
 694   GInputStream *base_stream;
 695   gsize available, bytes_skipped;
 696   gssize nread;
 697
 698   bstream = G_BUFFERED_INPUT_STREAM (stream);
 699   priv = bstream->priv;
 700
 701   available = priv->end - priv->pos;
 702
 703   if (count <= available)
 704     {
 705       priv->pos += count;
 706       return count;
 707     }
 708
 709   /* Full request not available, skip all currently available and
 710    * request refill for more
 711    */
 712
 713   priv->pos = 0;
 714   priv->end = 0;
 715   bytes_skipped = available;
 716   count -= available;
 717
 718   if (bytes_skipped > 0)
 719     error = NULL; /* Ignore further errors if we already read some data */
 720
 721   if (count > priv->len)
 722     {
 723       /* Large request, shortcut buffer */
 724
 725       base_stream = G_FILTER_INPUT_STREAM (stream)->base_stream;
 726
 727       nread = g_input_stream_skip (base_stream,
 728                                    count,
 729                                    cancellable,
 730                                    error);
 731
 732       if (nread < 0 && bytes_skipped == 0)
 733         return -1;
 734
 735       if (nread > 0)
 736         bytes_skipped += nread;
 737
 738       return bytes_skipped;
 739     }
 740
 741   class = G_BUFFERED_INPUT_STREAM_GET_CLASS (stream);
 742   nread = class->fill (bstream, priv->len, cancellable, error);
 743
 744   if (nread < 0)
 745     {
 746       if (bytes_skipped == 0)
 747         return -1;
 748       else
 749         return bytes_skipped;
 750     }
 751
 752   available = priv->end - priv->pos;
 753   count = MIN (count, available);
 754
 755   bytes_skipped += count;
 756   priv->pos += count;
 757
 758   return bytes_skipped;
 759 }
 760
 761 static gssize
 762 g_buffered_input_stream_read (GInputStream *stream,
 763                               void         *buffer,
 764                               gsize         count,
 765                               GCancellable *cancellable,
 766                               GError      **error)
 767 {
 768   GBufferedInputStream        *bstream;
 769   GBufferedInputStreamPrivate *priv;
 770   GBufferedInputStreamClass *class;
 771   GInputStream *base_stream;
 772   gsize available, bytes_read;
 773   gssize nread;
 774
 775   bstream = G_BUFFERED_INPUT_STREAM (stream);
 776   priv = bstream->priv;
 777
 778   available = priv->end - priv->pos;
 779
 780   if (count <= available)
 781     {
 782       memcpy (buffer, priv->buffer + priv->pos, count);
 783       priv->pos += count;
 784       return count;
 785     }
 786
 787   /* Full request not available, read all currently available and
 788    * request refill for more
 789    */
 790
 791   memcpy (buffer, priv->buffer + priv->pos, available);
 792   priv->pos = 0;
 793   priv->end = 0;
 794   bytes_read = available;
 795   count -= available;
 796
 797   if (bytes_read > 0)
 798     error = NULL; /* Ignore further errors if we already read some data */
 799
 800   if (count > priv->len)
 801     {
 802       /* Large request, shortcut buffer */
 803
 804       base_stream = G_FILTER_INPUT_STREAM (stream)->base_stream;
 805
 806       nread = g_input_stream_read (base_stream,
 807                                    (char *)buffer + bytes_read,
 808                                    count,
 809                                    cancellable,
 810                                    error);
 811
 812       if (nread < 0 && bytes_read == 0)
 813         return -1;
 814
 815       if (nread > 0)
 816         bytes_read += nread;
 817
 818       return bytes_read;
 819     }
 820
 821   class = G_BUFFERED_INPUT_STREAM_GET_CLASS (stream);
 822   nread = class->fill (bstream, priv->len, cancellable, error);
 823   if (nread < 0)
 824     {
 825       if (bytes_read == 0)
 826         return -1;
 827       else
 828         return bytes_read;
 829     }
 830
 831   available = priv->end - priv->pos;
 832   count = MIN (count, available);
 833
 834   memcpy ((char *)buffer + bytes_read, (char *)priv->buffer + priv->pos, count);
 835   bytes_read += count;
 836   priv->pos += count;
 837
 838   return bytes_read;
 839 }
 840
 841 /**
 842  * g_buffered_input_stream_read_byte:
 843  * @stream: a #GBufferedInputStream
 844  * @cancellable: optional #GCancellable object, %NULL to ignore
 845  * @error: location to store the error occuring, or %NULL to ignore
 846  *
 847  * Tries to read a single byte from the stream or the buffer. Will block
 848  * during this read.
 849  *
 850  * On success, the byte read from the stream is returned. On end of stream
 851  * -1 is returned but it's not an exceptional error and @error is not set.
 852  *
 853  * If @cancellable is not %NULL, then the operation can be cancelled by
 854  * triggering the cancellable object from another thread. If the operation
 855  * was cancelled, the error %G_IO_ERROR_CANCELLED will be returned. If an
 856  * operation was partially finished when the operation was cancelled the
 857  * partial result will be returned, without an error.
 858  *
 859  * On error -1 is returned and @error is set accordingly.
 860  *
 861  * Returns: the byte read from the @stream, or -1 on end of stream or error.
 862  */
 863 int
 864 g_buffered_input_stream_read_byte (GBufferedInputStream  *stream,
 865                                    GCancellable          *cancellable,
 866                                    GError               **error)
 867 {
 868   GBufferedInputStreamPrivate *priv;
 869   GBufferedInputStreamClass *class;
 870   GInputStream *input_stream;
 871   gsize available;
 872   gssize nread;
 873
 874   g_return_val_if_fail (G_IS_BUFFERED_INPUT_STREAM (stream), -1);
 875
 876   priv = stream->priv;
 877   input_stream = G_INPUT_STREAM (stream);
 878
 879   if (g_input_stream_is_closed (input_stream))
 880     {
 881       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
 882                            _("Stream is already closed"));
 883       return -1;
 884     }
 885
 886   if (!g_input_stream_set_pending (input_stream, error))
 887     return -1;
 888
 889   available = priv->end - priv->pos;
 890
 891   if (available != 0)
 892     {
 893       g_input_stream_clear_pending (input_stream);
 894       return priv->buffer[priv->pos++];
 895     }
 896
 897   /* Byte not available, request refill for more */
 898
 899   if (cancellable)
 900     g_cancellable_push_current (cancellable);
 901
 902   priv->pos = 0;
 903   priv->end = 0;
 904
 905   class = G_BUFFERED_INPUT_STREAM_GET_CLASS (stream);
 906   nread = class->fill (stream, priv->len, cancellable, error);
 907
 908   if (cancellable)
 909     g_cancellable_pop_current (cancellable);
 910
 911   g_input_stream_clear_pending (input_stream);
 912
 913   if (nread <= 0)
 914     return -1; /* error or end of stream */
 915
 916   return priv->buffer[priv->pos++];
 917 }
 918
 919 /* ************************** */
 920 /* Async stuff implementation */
 921 /* ************************** */
 922
 923 static void
 924 fill_async_callback (GObject      *source_object,
 925                      GAsyncResult *result,
 926                      gpointer      user_data)
 927 {
 928   GError *error;
 929   gssize res;
 930   GSimpleAsyncResult *simple;
 931
 932   simple = user_data;
 933
 934   error = NULL;
 935   res = g_input_stream_read_finish (G_INPUT_STREAM (source_object),
 936                                     result, &error);
 937
 938   g_simple_async_result_set_op_res_gssize (simple, res);
 939   if (res == -1)
 940     {
 941       g_simple_async_result_set_from_error (simple, error);
 942       g_error_free (error);
 943     }
 944   else
 945     {
 946       GBufferedInputStreamPrivate *priv;
 947       GObject *object;
 948
 949       object = g_async_result_get_source_object (G_ASYNC_RESULT (simple));
 950       priv = G_BUFFERED_INPUT_STREAM (object)->priv;
 951
 952       g_assert_cmpint (priv->end + res, <=, priv->len);
 953       priv->end += res;
 954
 955       g_object_unref (object);
 956     }
 957
 958   /* Complete immediately, not in idle, since we're already
 959    * in a mainloop callout
 960    */
 961   g_simple_async_result_complete (simple);
 962   g_object_unref (simple);
 963 }
 964
 965 static void
 966 g_buffered_input_stream_real_fill_async (GBufferedInputStream *stream,
 967                                          gssize                count,
 968                                          int                   io_priority,
 969                                          GCancellable         *cancellable,
 970                                          GAsyncReadyCallback   callback,
 971                                          gpointer              user_data)
 972 {
 973   GBufferedInputStreamPrivate *priv;
 974   GInputStream *base_stream;
 975   GSimpleAsyncResult *simple;
 976   gsize in_buffer;
 977
 978   priv = stream->priv;
 979
 980   if (count == -1)
 981     count = priv->len;
 982
 983   in_buffer = priv->end - priv->pos;
 984
 985   /* Never fill more than can fit in the buffer */
 986   count = MIN (count, priv->len - in_buffer);
 987
 988   /* If requested length does not fit at end, compact */
 989   if (priv->len - priv->end < count)
 990     compact_buffer (stream);
 991
 992   simple = g_simple_async_result_new (G_OBJECT (stream),
 993                                       callback, user_data,
 994                                       g_buffered_input_stream_real_fill_async);
 995
 996   base_stream = G_FILTER_INPUT_STREAM (stream)->base_stream;
 997   g_input_stream_read_async (base_stream,
 998                              priv->buffer + priv->end,
 999                              count,
1000                              io_priority,
1001                              cancellable,
1002                              fill_async_callback,
1003                              simple);
1004 }
1005
1006 static gssize
1007 g_buffered_input_stream_real_fill_finish (GBufferedInputStream *stream,
1008                                           GAsyncResult         *result,
1009                                           GError              **error)
1010 {
1011   GSimpleAsyncResult *simple;
1012   gssize nread;
1013
1014   simple = G_SIMPLE_ASYNC_RESULT (result);
1015   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_buffered_input_stream_real_fill_async);
1016
1017   nread = g_simple_async_result_get_op_res_gssize (simple);
1018   return nread;
1019 }
1020
1021 typedef struct
1022 {
1023   gssize bytes_read;
1024   gssize count;
1025   void *buffer;
1026 } ReadAsyncData;
1027
1028 static void
1029 free_read_async_data (gpointer _data)
1030 {
1031   ReadAsyncData *data = _data;
1032   g_slice_free (ReadAsyncData, data);
1033 }
1034
1035 static void
1036 large_read_callback (GObject *source_object,
1037                      GAsyncResult *result,
1038                      gpointer user_data)
1039 {
1040   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (user_data);
1041   ReadAsyncData *data;
1042   GError *error;
1043   gssize nread;
1044
1045   data = g_simple_async_result_get_op_res_gpointer (simple);
1046
1047   error = NULL;
1048   nread = g_input_stream_read_finish (G_INPUT_STREAM (source_object),
1049                                       result, &error);
1050
1051   /* Only report the error if we've not already read some data */
1052   if (nread < 0 && data->bytes_read == 0)
1053     g_simple_async_result_set_from_error (simple, error);
1054
1055   if (nread > 0)
1056     data->bytes_read += nread;
1057
1058   if (error)
1059     g_error_free (error);
1060
1061   /* Complete immediately, not in idle, since we're already
1062    * in a mainloop callout
1063    */
1064   g_simple_async_result_complete (simple);
1065   g_object_unref (simple);
1066 }
1067
1068 static void
1069 read_fill_buffer_callback (GObject      *source_object,
1070                            GAsyncResult *result,
1071                            gpointer      user_data)
1072 {
1073   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (user_data);
1074   GBufferedInputStream *bstream;
1075   GBufferedInputStreamPrivate *priv;
1076   ReadAsyncData *data;
1077   GError *error;
1078   gssize nread;
1079   gsize available;
1080
1081   bstream = G_BUFFERED_INPUT_STREAM (source_object);
1082   priv = bstream->priv;
1083
1084   data = g_simple_async_result_get_op_res_gpointer (simple);
1085
1086   error = NULL;
1087   nread = g_buffered_input_stream_fill_finish (bstream,
1088                                                result, &error);
1089
1090   if (nread < 0 && data->bytes_read == 0)
1091     g_simple_async_result_set_from_error (simple, error);
1092
1093
1094   if (nread > 0)
1095     {
1096       available = priv->end - priv->pos;
1097       data->count = MIN (data->count, available);
1098
1099       memcpy ((char *)data->buffer + data->bytes_read, (char *)priv->buffer + priv->pos, data->count);
1100       data->bytes_read += data->count;
1101       priv->pos += data->count;
1102     }
1103
1104   if (error)
1105     g_error_free (error);
1106
1107   /* Complete immediately, not in idle, since we're already
1108    * in a mainloop callout
1109    */
1110   g_simple_async_result_complete (simple);
1111   g_object_unref (simple);
1112 }
1113
1114 static void
1115 g_buffered_input_stream_read_async (GInputStream        *stream,
1116                                     void                *buffer,
1117                                     gsize                count,
1118                                     int                  io_priority,
1119                                     GCancellable        *cancellable,
1120                                     GAsyncReadyCallback  callback,
1121                                     gpointer             user_data)
1122 {
1123   GBufferedInputStream *bstream;
1124   GBufferedInputStreamPrivate *priv;
1125   GBufferedInputStreamClass *class;
1126   GInputStream *base_stream;
1127   gsize available;
1128   GSimpleAsyncResult *simple;
1129   ReadAsyncData *data;
1130
1131   bstream = G_BUFFERED_INPUT_STREAM (stream);
1132   priv = bstream->priv;
1133
1134   data = g_slice_new (ReadAsyncData);
1135   data->buffer = buffer;
1136   data->bytes_read = 0;
1137   simple = g_simple_async_result_new (G_OBJECT (stream),
1138                                       callback, user_data,
1139                                       g_buffered_input_stream_read_async);
1140   g_simple_async_result_set_op_res_gpointer (simple, data, free_read_async_data);
1141
1142   available = priv->end - priv->pos;
1143
1144   if (count <= available)
1145     {
1146       memcpy (buffer, priv->buffer + priv->pos, count);
1147       priv->pos += count;
1148       data->bytes_read = count;
1149
1150       g_simple_async_result_complete_in_idle (simple);
1151       g_object_unref (simple);
1152       return;
1153     }
1154
1155
1156   /* Full request not available, read all currently available
1157    * and request refill for more
1158    */
1159
1160   memcpy (buffer, priv->buffer + priv->pos, available);
1161   priv->pos = 0;
1162   priv->end = 0;
1163
1164   count -= available;
1165
1166   data->bytes_read = available;
1167   data->count = count;
1168
1169   if (count > priv->len)
1170     {
1171       /* Large request, shortcut buffer */
1172
1173       base_stream = G_FILTER_INPUT_STREAM (stream)->base_stream;
1174
1175       g_input_stream_read_async (base_stream,
1176                                  (char *)buffer + data->bytes_read,
1177                                  count,
1178                                  io_priority, cancellable,
1179                                  large_read_callback,
1180                                  simple);
1181     }
1182   else
1183     {
1184       class = G_BUFFERED_INPUT_STREAM_GET_CLASS (stream);
1185       class->fill_async (bstream, priv->len, io_priority, cancellable,
1186                          read_fill_buffer_callback, simple);
1187     }
1188 }
1189
1190 static gssize
1191 g_buffered_input_stream_read_finish (GInputStream   *stream,
1192                                      GAsyncResult   *result,
1193                                      GError        **error)
1194 {
1195   GSimpleAsyncResult *simple;
1196   ReadAsyncData *data;
1197
1198   simple = G_SIMPLE_ASYNC_RESULT (result);
1199
1200   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_buffered_input_stream_read_async);
1201
1202   data = g_simple_async_result_get_op_res_gpointer (simple);
1203
1204   return data->bytes_read;
1205 }
1206
1207 typedef struct
1208 {
1209   gssize bytes_skipped;
1210   gssize count;
1211 } SkipAsyncData;
1212
1213 static void
1214 free_skip_async_data (gpointer _data)
1215 {
1216   SkipAsyncData *data = _data;
1217   g_slice_free (SkipAsyncData, data);
1218 }
1219
1220 static void
1221 large_skip_callback (GObject      *source_object,
1222                      GAsyncResult *result,
1223                      gpointer      user_data)
1224 {
1225   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (user_data);
1226   SkipAsyncData *data;
1227   GError *error;
1228   gssize nread;
1229
1230   data = g_simple_async_result_get_op_res_gpointer (simple);
1231
1232   error = NULL;
1233   nread = g_input_stream_skip_finish (G_INPUT_STREAM (source_object),
1234                                       result, &error);
1235
1236   /* Only report the error if we've not already read some data */
1237   if (nread < 0 && data->bytes_skipped == 0)
1238     g_simple_async_result_set_from_error (simple, error);
1239
1240   if (nread > 0)
1241     data->bytes_skipped += nread;
1242
1243   if (error)
1244     g_error_free (error);
1245
1246   /* Complete immediately, not in idle, since we're already
1247    * in a mainloop callout
1248    */
1249   g_simple_async_result_complete (simple);
1250   g_object_unref (simple);
1251 }
1252
1253 static void
1254 skip_fill_buffer_callback (GObject      *source_object,
1255                            GAsyncResult *result,
1256                            gpointer      user_data)
1257 {
1258   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (user_data);
1259   GBufferedInputStream *bstream;
1260   GBufferedInputStreamPrivate *priv;
1261   SkipAsyncData *data;
1262   GError *error;
1263   gssize nread;
1264   gsize available;
1265
1266   bstream = G_BUFFERED_INPUT_STREAM (source_object);
1267   priv = bstream->priv;
1268
1269   data = g_simple_async_result_get_op_res_gpointer (simple);
1270
1271   error = NULL;
1272   nread = g_buffered_input_stream_fill_finish (bstream,
1273                                                result, &error);
1274
1275   if (nread < 0 && data->bytes_skipped == 0)
1276     g_simple_async_result_set_from_error (simple, error);
1277
1278   if (nread > 0)
1279     {
1280       available = priv->end - priv->pos;
1281       data->count = MIN (data->count, available);
1282
1283       data->bytes_skipped += data->count;
1284       priv->pos += data->count;
1285     }
1286
1287   if (error)
1288     g_error_free (error);
1289
1290   /* Complete immediately, not in idle, since we're already
1291    * in a mainloop callout
1292    */
1293   g_simple_async_result_complete (simple);
1294   g_object_unref (simple);
1295 }
1296
1297 static void
1298 g_buffered_input_stream_skip_async (GInputStream        *stream,
1299                                     gsize                count,
1300                                     int                  io_priority,
1301                                     GCancellable        *cancellable,
1302                                     GAsyncReadyCallback  callback,
1303                                     gpointer             user_data)
1304 {
1305   GBufferedInputStream *bstream;
1306   GBufferedInputStreamPrivate *priv;
1307   GBufferedInputStreamClass *class;
1308   GInputStream *base_stream;
1309   gsize available;
1310   GSimpleAsyncResult *simple;
1311   SkipAsyncData *data;
1312
1313   bstream = G_BUFFERED_INPUT_STREAM (stream);
1314   priv = bstream->priv;
1315
1316   data = g_slice_new (SkipAsyncData);
1317   data->bytes_skipped = 0;
1318   simple = g_simple_async_result_new (G_OBJECT (stream),
1319                                       callback, user_data,
1320                                       g_buffered_input_stream_skip_async);
1321   g_simple_async_result_set_op_res_gpointer (simple, data, free_skip_async_data);
1322
1323   available = priv->end - priv->pos;
1324
1325   if (count <= available)
1326     {
1327       priv->pos += count;
1328       data->bytes_skipped = count;
1329
1330       g_simple_async_result_complete_in_idle (simple);
1331       g_object_unref (simple);
1332       return;
1333     }
1334
1335   /* Full request not available, skip all currently available
1336    * and request refill for more
1337    */
1338
1339   priv->pos = 0;
1340   priv->end = 0;
1341
1342   count -= available;
1343
1344   data->bytes_skipped = available;
1345   data->count = count;
1346
1347   if (count > priv->len)
1348     {
1349       /* Large request, shortcut buffer */
1350
1351       base_stream = G_FILTER_INPUT_STREAM (stream)->base_stream;
1352
1353       g_input_stream_skip_async (base_stream,
1354                                  count,
1355                                  io_priority, cancellable,
1356                                  large_skip_callback,
1357                                  simple);
1358     }
1359   else
1360     {
1361       class = G_BUFFERED_INPUT_STREAM_GET_CLASS (stream);
1362       class->fill_async (bstream, priv->len, io_priority, cancellable,
1363                          skip_fill_buffer_callback, simple);
1364     }
1365 }
1366
1367 static gssize
1368 g_buffered_input_stream_skip_finish (GInputStream   *stream,
1369                                      GAsyncResult   *result,
1370                                      GError        **error)
1371 {
1372   GSimpleAsyncResult *simple;
1373   SkipAsyncData *data;
1374
1375   simple = G_SIMPLE_ASYNC_RESULT (result);
1376
1377   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_buffered_input_stream_skip_async);
1378
1379   data = g_simple_async_result_get_op_res_gpointer (simple);
1380
1381   return data->bytes_skipped;
1382 }
1383
1384
1385 #define __G_BUFFERED_INPUT_STREAM_C__
1386 #include "gioaliasdef.c"