gio/gmemoryinputstream.c

   1 /* GIO - GLib Input, Output and Streaming Library
   2  *
   3  * Copyright (C) 2006-2007 Red Hat, Inc.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General
  16  * Public License along with this library; if not, write to the
  17  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  18  * Boston, MA 02111-1307, USA.
  19  *
  20  * Author: Christian Kellner <gicmo@gnome.org>
  21  */
  22
  23 #include "config.h"
  24 #include "gmemoryinputstream.h"
  25 #include "gpollableinputstream.h"
  26 #include "ginputstream.h"
  27 #include "gseekable.h"
  28 #include "string.h"
  29 #include "gsimpleasyncresult.h"
  30 #include "gioerror.h"
  31 #include "glibintl.h"
  32
  33
  34 /**
  35  * SECTION:gmemoryinputstream
  36  * @short_description: Streaming input operations on memory chunks
  37  * @include: gio/gio.h
  38  * @see_also: #GMemoryOutputStream
  39  *
  40  * #GMemoryInputStream is a class for using arbitrary
  41  * memory chunks as input for GIO streaming input operations.
  42  *
  43  * As of GLib 2.34, #GMemoryInputStream implements
  44  * #GPollableInputStream.
  45  */
  46
  47 typedef struct _Chunk Chunk;
  48
  49 struct _Chunk {
  50   guint8         *data;
  51   gsize           len;
  52   GDestroyNotify  destroy;
  53 };
  54
  55 struct _GMemoryInputStreamPrivate {
  56   GSList *chunks;
  57   gsize   len;
  58   gsize   pos;
  59 };
  60
  61 static gssize   g_memory_input_stream_read         (GInputStream         *stream,
  62                                                     void                 *buffer,
  63                                                     gsize                 count,
  64                                                     GCancellable         *cancellable,
  65                                                     GError              **error);
  66 static gssize   g_memory_input_stream_skip         (GInputStream         *stream,
  67                                                     gsize                 count,
  68                                                     GCancellable         *cancellable,
  69                                                     GError              **error);
  70 static gboolean g_memory_input_stream_close        (GInputStream         *stream,
  71                                                     GCancellable         *cancellable,
  72                                                     GError              **error);
  73 static void     g_memory_input_stream_read_async   (GInputStream         *stream,
  74                                                     void                 *buffer,
  75                                                     gsize                 count,
  76                                                     int                   io_priority,
  77                                                     GCancellable         *cancellable,
  78                                                     GAsyncReadyCallback   callback,
  79                                                     gpointer              user_data);
  80 static gssize   g_memory_input_stream_read_finish  (GInputStream         *stream,
  81                                                     GAsyncResult         *result,
  82                                                     GError              **error);
  83 static void     g_memory_input_stream_skip_async   (GInputStream         *stream,
  84                                                     gsize                 count,
  85                                                     int                   io_priority,
  86                                                     GCancellable         *cancellabl,
  87                                                     GAsyncReadyCallback   callback,
  88                                                     gpointer              datae);
  89 static gssize   g_memory_input_stream_skip_finish  (GInputStream         *stream,
  90                                                     GAsyncResult         *result,
  91                                                     GError              **error);
  92 static void     g_memory_input_stream_close_async  (GInputStream         *stream,
  93                                                     int                   io_priority,
  94                                                     GCancellable         *cancellabl,
  95                                                     GAsyncReadyCallback   callback,
  96                                                     gpointer              data);
  97 static gboolean g_memory_input_stream_close_finish (GInputStream         *stream,
  98                                                     GAsyncResult         *result,
  99                                                     GError              **error);
 100
 101 static void     g_memory_input_stream_seekable_iface_init (GSeekableIface  *iface);
 102 static goffset  g_memory_input_stream_tell                (GSeekable       *seekable);
 103 static gboolean g_memory_input_stream_can_seek            (GSeekable       *seekable);
 104 static gboolean g_memory_input_stream_seek                (GSeekable       *seekable,
 105                                                            goffset          offset,
 106                                                            GSeekType        type,
 107                                                            GCancellable    *cancellable,
 108                                                            GError         **error);
 109 static gboolean g_memory_input_stream_can_truncate        (GSeekable       *seekable);
 110 static gboolean g_memory_input_stream_truncate            (GSeekable       *seekable,
 111                                                            goffset          offset,
 112                                                            GCancellable    *cancellable,
 113                                                            GError         **error);
 114
 115 static void     g_memory_input_stream_pollable_iface_init (GPollableInputStreamInterface *iface);
 116 static gboolean g_memory_input_stream_is_readable         (GPollableInputStream *stream);
 117 static GSource *g_memory_input_stream_create_source       (GPollableInputStream *stream,
 118                                                            GCancellable          *cancellable);
 119
 120 static void     g_memory_input_stream_finalize            (GObject         *object);
 121
 122 G_DEFINE_TYPE_WITH_CODE (GMemoryInputStream, g_memory_input_stream, G_TYPE_INPUT_STREAM,
 123                          G_IMPLEMENT_INTERFACE (G_TYPE_SEEKABLE,
 124                                                 g_memory_input_stream_seekable_iface_init);
 125                          G_IMPLEMENT_INTERFACE (G_TYPE_POLLABLE_INPUT_STREAM,
 126                                                 g_memory_input_stream_pollable_iface_init);
 127                          )
 128
 129
 130 static void
 131 g_memory_input_stream_class_init (GMemoryInputStreamClass *klass)
 132 {
 133   GObjectClass *object_class;
 134   GInputStreamClass *istream_class;
 135
 136   g_type_class_add_private (klass, sizeof (GMemoryInputStreamPrivate));
 137
 138   object_class = G_OBJECT_CLASS (klass);
 139   object_class->finalize     = g_memory_input_stream_finalize;
 140
 141   istream_class = G_INPUT_STREAM_CLASS (klass);
 142   istream_class->read_fn  = g_memory_input_stream_read;
 143   istream_class->skip  = g_memory_input_stream_skip;
 144   istream_class->close_fn = g_memory_input_stream_close;
 145
 146   istream_class->read_async  = g_memory_input_stream_read_async;
 147   istream_class->read_finish  = g_memory_input_stream_read_finish;
 148   istream_class->skip_async  = g_memory_input_stream_skip_async;
 149   istream_class->skip_finish  = g_memory_input_stream_skip_finish;
 150   istream_class->close_async = g_memory_input_stream_close_async;
 151   istream_class->close_finish = g_memory_input_stream_close_finish;
 152 }
 153
 154 static void
 155 free_chunk (gpointer data)
 156 {
 157   Chunk *chunk = data;
 158
 159   if (chunk->destroy)
 160     chunk->destroy (chunk->data);
 161
 162   g_slice_free (Chunk, chunk);
 163 }
 164
 165 static void
 166 g_memory_input_stream_finalize (GObject *object)
 167 {
 168   GMemoryInputStream        *stream;
 169   GMemoryInputStreamPrivate *priv;
 170
 171   stream = G_MEMORY_INPUT_STREAM (object);
 172   priv = stream->priv;
 173
 174   g_slist_free_full (priv->chunks, free_chunk);
 175
 176   G_OBJECT_CLASS (g_memory_input_stream_parent_class)->finalize (object);
 177 }
 178
 179 static void
 180 g_memory_input_stream_seekable_iface_init (GSeekableIface *iface)
 181 {
 182   iface->tell         = g_memory_input_stream_tell;
 183   iface->can_seek     = g_memory_input_stream_can_seek;
 184   iface->seek         = g_memory_input_stream_seek;
 185   iface->can_truncate = g_memory_input_stream_can_truncate;
 186   iface->truncate_fn  = g_memory_input_stream_truncate;
 187 }
 188
 189 static void
 190 g_memory_input_stream_pollable_iface_init (GPollableInputStreamInterface *iface)
 191 {
 192   iface->is_readable   = g_memory_input_stream_is_readable;
 193   iface->create_source = g_memory_input_stream_create_source;
 194 }
 195
 196 static void
 197 g_memory_input_stream_init (GMemoryInputStream *stream)
 198 {
 199   stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (stream,
 200                                               G_TYPE_MEMORY_INPUT_STREAM,
 201                                               GMemoryInputStreamPrivate);
 202 }
 203
 204 /**
 205  * g_memory_input_stream_new:
 206  *
 207  * Creates a new empty #GMemoryInputStream.
 208  *
 209  * Returns: a new #GInputStream
 210  */
 211 GInputStream *
 212 g_memory_input_stream_new (void)
 213 {
 214   GInputStream *stream;
 215
 216   stream = g_object_new (G_TYPE_MEMORY_INPUT_STREAM, NULL);
 217
 218   return stream;
 219 }
 220
 221 /**
 222  * g_memory_input_stream_new_from_data:
 223  * @data: (array length=len) (element-type guint8) (transfer full): input data
 224  * @len: length of the data, may be -1 if @data is a nul-terminated string
 225  * @destroy: (allow-none): function that is called to free @data, or %NULL
 226  *
 227  * Creates a new #GMemoryInputStream with data in memory of a given size.
 228  *
 229  * Returns: new #GInputStream read from @data of @len bytes.
 230  **/
 231 GInputStream *
 232 g_memory_input_stream_new_from_data (const void     *data,
 233                                      gssize          len,
 234                                      GDestroyNotify  destroy)
 235 {
 236   GInputStream *stream;
 237
 238   stream = g_memory_input_stream_new ();
 239
 240   g_memory_input_stream_add_data (G_MEMORY_INPUT_STREAM (stream),
 241                                   data, len, destroy);
 242
 243   return stream;
 244 }
 245
 246 /**
 247  * g_memory_input_stream_add_data:
 248  * @stream: a #GMemoryInputStream
 249  * @data: (array length=len) (element-type guint8) (transfer full): input data
 250  * @len: length of the data, may be -1 if @data is a nul-terminated string
 251  * @destroy: (allow-none): function that is called to free @data, or %NULL
 252  *
 253  * Appends @data to data that can be read from the input stream
 254  */
 255 void
 256 g_memory_input_stream_add_data (GMemoryInputStream *stream,
 257                                 const void         *data,
 258                                 gssize              len,
 259                                 GDestroyNotify      destroy)
 260 {
 261   GMemoryInputStreamPrivate *priv;
 262   Chunk *chunk;
 263
 264   g_return_if_fail (G_IS_MEMORY_INPUT_STREAM (stream));
 265   g_return_if_fail (data != NULL);
 266
 267   priv = stream->priv;
 268
 269   if (len == -1)
 270     len = strlen (data);
 271
 272   chunk = g_slice_new (Chunk);
 273   chunk->data = (guint8 *)data;
 274   chunk->len = len;
 275   chunk->destroy = destroy;
 276
 277   priv->chunks = g_slist_append (priv->chunks, chunk);
 278   priv->len += chunk->len;
 279 }
 280
 281 static gssize
 282 g_memory_input_stream_read (GInputStream  *stream,
 283                             void          *buffer,
 284                             gsize          count,
 285                             GCancellable  *cancellable,
 286                             GError       **error)
 287 {
 288   GMemoryInputStream *memory_stream;
 289   GMemoryInputStreamPrivate *priv;
 290   GSList *l;
 291   Chunk *chunk;
 292   gsize offset, start, rest, size;
 293
 294   memory_stream = G_MEMORY_INPUT_STREAM (stream);
 295   priv = memory_stream->priv;
 296
 297   count = MIN (count, priv->len - priv->pos);
 298
 299   offset = 0;
 300   for (l = priv->chunks; l; l = l->next)
 301     {
 302       chunk = (Chunk *)l->data;
 303
 304       if (offset + chunk->len > priv->pos)
 305         break;
 306
 307       offset += chunk->len;
 308     }
 309
 310   start = priv->pos - offset;
 311   rest = count;
 312
 313   for (; l && rest > 0; l = l->next)
 314     {
 315       chunk = (Chunk *)l->data;
 316       size = MIN (rest, chunk->len - start);
 317
 318       memcpy ((guint8 *)buffer + (count - rest), chunk->data + start, size);
 319       rest -= size;
 320
 321       start = 0;
 322     }
 323
 324   priv->pos += count;
 325
 326   return count;
 327 }
 328
 329 static gssize
 330 g_memory_input_stream_skip (GInputStream  *stream,
 331                             gsize          count,
 332                             GCancellable  *cancellable,
 333                             GError       **error)
 334 {
 335   GMemoryInputStream *memory_stream;
 336   GMemoryInputStreamPrivate *priv;
 337
 338   memory_stream = G_MEMORY_INPUT_STREAM (stream);
 339   priv = memory_stream->priv;
 340
 341   count = MIN (count, priv->len - priv->pos);
 342   priv->pos += count;
 343
 344   return count;
 345 }
 346
 347 static gboolean
 348 g_memory_input_stream_close (GInputStream  *stream,
 349                              GCancellable  *cancellable,
 350                              GError       **error)
 351 {
 352   return TRUE;
 353 }
 354
 355 static void
 356 g_memory_input_stream_read_async (GInputStream        *stream,
 357                                   void                *buffer,
 358                                   gsize                count,
 359                                   int                  io_priority,
 360                                   GCancellable        *cancellable,
 361                                   GAsyncReadyCallback  callback,
 362                                   gpointer             user_data)
 363 {
 364   GSimpleAsyncResult *simple;
 365   GError *error = NULL;
 366   gssize nread;
 367
 368   nread = G_INPUT_STREAM_GET_CLASS (stream)->read_fn (stream,
 369                                                       buffer,
 370                                                       count,
 371                                                       cancellable,
 372                                                       &error);
 373   simple = g_simple_async_result_new (G_OBJECT (stream),
 374                                       callback,
 375                                       user_data,
 376                                       g_memory_input_stream_read_async);
 377   if (error)
 378     g_simple_async_result_take_error (simple, error);
 379   else
 380     g_simple_async_result_set_op_res_gssize (simple, nread);
 381   g_simple_async_result_complete_in_idle (simple);
 382   g_object_unref (simple);
 383 }
 384
 385 static gssize
 386 g_memory_input_stream_read_finish (GInputStream  *stream,
 387                                    GAsyncResult  *result,
 388                                    GError       **error)
 389 {
 390   GSimpleAsyncResult *simple;
 391   gssize nread;
 392
 393   simple = G_SIMPLE_ASYNC_RESULT (result);
 394   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_memory_input_stream_read_async);
 395
 396   nread = g_simple_async_result_get_op_res_gssize (simple);
 397   return nread;
 398 }
 399
 400 static void
 401 g_memory_input_stream_skip_async (GInputStream        *stream,
 402                                   gsize                count,
 403                                   int                  io_priority,
 404                                   GCancellable        *cancellable,
 405                                   GAsyncReadyCallback  callback,
 406                                   gpointer             user_data)
 407 {
 408   GSimpleAsyncResult *simple;
 409   gssize nskipped;
 410
 411   nskipped = g_input_stream_skip (stream, count, cancellable, NULL);
 412   simple = g_simple_async_result_new (G_OBJECT (stream),
 413                                       callback,
 414                                       user_data,
 415                                       g_memory_input_stream_skip_async);
 416   g_simple_async_result_set_op_res_gssize (simple, nskipped);
 417   g_simple_async_result_complete_in_idle (simple);
 418   g_object_unref (simple);
 419 }
 420
 421 static gssize
 422 g_memory_input_stream_skip_finish (GInputStream  *stream,
 423                                    GAsyncResult  *result,
 424                                    GError       **error)
 425 {
 426   GSimpleAsyncResult *simple;
 427   gssize nskipped;
 428
 429   simple = G_SIMPLE_ASYNC_RESULT (result);
 430   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_memory_input_stream_skip_async);
 431
 432   nskipped = g_simple_async_result_get_op_res_gssize (simple);
 433   return nskipped;
 434 }
 435
 436 static void
 437 g_memory_input_stream_close_async (GInputStream        *stream,
 438                                    int                  io_priority,
 439                                    GCancellable        *cancellable,
 440                                    GAsyncReadyCallback  callback,
 441                                    gpointer             user_data)
 442 {
 443   GSimpleAsyncResult *simple;
 444
 445   simple = g_simple_async_result_new (G_OBJECT (stream),
 446                                       callback,
 447                                       user_data,
 448                                       g_memory_input_stream_close_async);
 449   g_simple_async_result_complete_in_idle (simple);
 450   g_object_unref (simple);
 451 }
 452
 453 static gboolean
 454 g_memory_input_stream_close_finish (GInputStream  *stream,
 455                                     GAsyncResult  *result,
 456                                     GError       **error)
 457 {
 458   return TRUE;
 459 }
 460
 461 static goffset
 462 g_memory_input_stream_tell (GSeekable *seekable)
 463 {
 464   GMemoryInputStream *memory_stream;
 465   GMemoryInputStreamPrivate *priv;
 466
 467   memory_stream = G_MEMORY_INPUT_STREAM (seekable);
 468   priv = memory_stream->priv;
 469
 470   return priv->pos;
 471 }
 472
 473 static
 474 gboolean g_memory_input_stream_can_seek (GSeekable *seekable)
 475 {
 476   return TRUE;
 477 }
 478
 479 static gboolean
 480 g_memory_input_stream_seek (GSeekable     *seekable,
 481                             goffset        offset,
 482                             GSeekType      type,
 483                             GCancellable  *cancellable,
 484                             GError       **error)
 485 {
 486   GMemoryInputStream *memory_stream;
 487   GMemoryInputStreamPrivate *priv;
 488   goffset absolute;
 489
 490   memory_stream = G_MEMORY_INPUT_STREAM (seekable);
 491   priv = memory_stream->priv;
 492
 493   switch (type)
 494     {
 495     case G_SEEK_CUR:
 496       absolute = priv->pos + offset;
 497       break;
 498
 499     case G_SEEK_SET:
 500       absolute = offset;
 501       break;
 502
 503     case G_SEEK_END:
 504       absolute = priv->len + offset;
 505       break;
 506
 507     default:
 508       g_set_error_literal (error,
 509                            G_IO_ERROR,
 510                            G_IO_ERROR_INVALID_ARGUMENT,
 511                            _("Invalid GSeekType supplied"));
 512
 513       return FALSE;
 514     }
 515
 516   if (absolute < 0 || absolute > priv->len)
 517     {
 518       g_set_error_literal (error,
 519                            G_IO_ERROR,
 520                            G_IO_ERROR_INVALID_ARGUMENT,
 521                            _("Invalid seek request"));
 522       return FALSE;
 523     }
 524
 525   priv->pos = absolute;
 526
 527   return TRUE;
 528 }
 529
 530 static gboolean
 531 g_memory_input_stream_can_truncate (GSeekable *seekable)
 532 {
 533   return FALSE;
 534 }
 535
 536 static gboolean
 537 g_memory_input_stream_truncate (GSeekable     *seekable,
 538                                 goffset        offset,
 539                                 GCancellable  *cancellable,
 540                                 GError       **error)
 541 {
 542   g_set_error_literal (error,
 543                        G_IO_ERROR,
 544                        G_IO_ERROR_NOT_SUPPORTED,
 545                        _("Cannot truncate GMemoryInputStream"));
 546   return FALSE;
 547 }
 548
 549 static gboolean
 550 g_memory_input_stream_is_readable (GPollableInputStream *stream)
 551 {
 552   return TRUE;
 553 }
 554
 555 static GSource *
 556 g_memory_input_stream_create_source (GPollableInputStream *stream,
 557                                      GCancellable         *cancellable)
 558 {
 559   GSource *base_source, *pollable_source;
 560
 561   base_source = g_timeout_source_new (0);
 562   pollable_source = g_pollable_source_new_full (stream, base_source,
 563                                                 cancellable);
 564   g_source_unref (base_source);
 565
 566   return pollable_source;
 567 }