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 "ginputstream.h"
  26 #include "gseekable.h"
  27 #include "string.h"
  28 #include "gsimpleasyncresult.h"
  29 #include "glibintl.h"
  30
  31 #include "gioalias.h"
  32
  33 /**
  34  * SECTION:gmemoryinputstream
  35  * @short_description: Streaming input operations on memory chunks
  36  * @see_also: #GMemoryOutputStream
  37  *
  38  * #GMemoryInputStream is a class for using arbitrary
  39  * memory chunks as input for GIO streaming input operations.
  40  *
  41  */
  42
  43 struct _GMemoryInputStreamPrivate {
  44   guint8 *buffer;
  45   gsize   pos;
  46   gsize   len;
  47   gboolean free_data;
  48 };
  49
  50 static gssize   g_memory_input_stream_read         (GInputStream         *stream,
  51                                                     void                 *buffer,
  52                                                     gsize                 count,
  53                                                     GCancellable         *cancellable,
  54                                                     GError              **error);
  55 static gssize   g_memory_input_stream_skip         (GInputStream         *stream,
  56                                                     gsize                 count,
  57                                                     GCancellable         *cancellable,
  58                                                     GError              **error);
  59 static gboolean g_memory_input_stream_close        (GInputStream         *stream,
  60                                                     GCancellable         *cancellable,
  61                                                     GError              **error);
  62 static void     g_memory_input_stream_read_async   (GInputStream         *stream,
  63                                                     void                 *buffer,
  64                                                     gsize                 count,
  65                                                     int                   io_priority,
  66                                                     GCancellable         *cancellable,
  67                                                     GAsyncReadyCallback   callback,
  68                                                     gpointer              user_data);
  69 static gssize   g_memory_input_stream_read_finish  (GInputStream         *stream,
  70                                                     GAsyncResult         *result,
  71                                                     GError              **error);
  72 static void     g_memory_input_stream_skip_async   (GInputStream         *stream,
  73                                                     gsize                 count,
  74                                                     int                   io_priority,
  75                                                     GCancellable         *cancellabl,
  76                                                     GAsyncReadyCallback   callback,
  77                                                     gpointer              datae);
  78 static gssize   g_memory_input_stream_skip_finish  (GInputStream         *stream,
  79                                                     GAsyncResult         *result,
  80                                                     GError              **error);
  81 static void     g_memory_input_stream_close_async  (GInputStream         *stream,
  82                                                     int                   io_priority,
  83                                                     GCancellable         *cancellabl,
  84                                                     GAsyncReadyCallback   callback,
  85                                                     gpointer              data);
  86 static gboolean g_memory_input_stream_close_finish (GInputStream         *stream,
  87                                                     GAsyncResult         *result,
  88                                                     GError              **error);
  89
  90 static void     g_memory_input_stream_seekable_iface_init (GSeekableIface  *iface);
  91 static goffset  g_memory_input_stream_tell                (GSeekable       *seekable);
  92 static gboolean g_memory_input_stream_can_seek            (GSeekable       *seekable);
  93 static gboolean g_memory_input_stream_seek                (GSeekable       *seekable,
  94                                                            goffset          offset,
  95                                                            GSeekType        type,
  96                                                            GCancellable    *cancellable,
  97                                                            GError         **error);
  98 static gboolean g_memory_input_stream_can_truncate        (GSeekable       *seekable);
  99 static gboolean g_memory_input_stream_truncate            (GSeekable       *seekable,
 100                                                            goffset          offset,
 101                                                            GCancellable    *cancellable,
 102                                                            GError         **error);
 103 static void     g_memory_input_stream_finalize            (GObject         *object);
 104
 105 G_DEFINE_TYPE_WITH_CODE (GMemoryInputStream, g_memory_input_stream, G_TYPE_INPUT_STREAM,
 106                          G_IMPLEMENT_INTERFACE (G_TYPE_SEEKABLE,
 107                                                 g_memory_input_stream_seekable_iface_init))
 108
 109
 110 static void
 111 g_memory_input_stream_class_init (GMemoryInputStreamClass *klass)
 112 {
 113   GObjectClass *object_class;
 114   GInputStreamClass *istream_class;
 115
 116   g_type_class_add_private (klass, sizeof (GMemoryInputStreamPrivate));
 117
 118   object_class = G_OBJECT_CLASS (klass);
 119   object_class->finalize     = g_memory_input_stream_finalize;
 120
 121   istream_class = G_INPUT_STREAM_CLASS (klass);
 122   istream_class->read_fn  = g_memory_input_stream_read;
 123   istream_class->skip  = g_memory_input_stream_skip;
 124   istream_class->close_fn = g_memory_input_stream_close;
 125
 126   istream_class->read_async  = g_memory_input_stream_read_async;
 127   istream_class->read_finish  = g_memory_input_stream_read_finish;
 128   istream_class->skip_async  = g_memory_input_stream_skip_async;
 129   istream_class->skip_finish  = g_memory_input_stream_skip_finish;
 130   istream_class->close_async = g_memory_input_stream_close_async;
 131   istream_class->close_finish = g_memory_input_stream_close_finish;
 132 }
 133
 134 static void
 135 g_memory_input_stream_finalize (GObject *object)
 136 {
 137   GMemoryInputStream        *stream;
 138
 139   stream = G_MEMORY_INPUT_STREAM (object);
 140
 141   if (stream->priv->free_data)
 142     g_free (stream->priv->buffer);
 143
 144   if (G_OBJECT_CLASS (g_memory_input_stream_parent_class)->finalize)
 145     (*G_OBJECT_CLASS (g_memory_input_stream_parent_class)->finalize) (object);
 146 }
 147
 148 static void
 149 g_memory_input_stream_seekable_iface_init (GSeekableIface *iface)
 150 {
 151   iface->tell         = g_memory_input_stream_tell;
 152   iface->can_seek     = g_memory_input_stream_can_seek;
 153   iface->seek         = g_memory_input_stream_seek;
 154   iface->can_truncate = g_memory_input_stream_can_truncate;
 155   iface->truncate_fn  = g_memory_input_stream_truncate;
 156 }
 157
 158 static void
 159 g_memory_input_stream_init (GMemoryInputStream *stream)
 160 {
 161   stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (stream,
 162                                               G_TYPE_MEMORY_INPUT_STREAM,
 163                                               GMemoryInputStreamPrivate);
 164 }
 165
 166 /**
 167  * g_memory_input_stream_set_free_data:
 168  * @stream: a #GMemoryInputStream.
 169  * @free_data: a #gboolean. If %TRUE, frees the data within @stream.
 170  *
 171  * Sets if the data within the @stream should be freed when the stream
 172  * is freed.
 173  **/
 174 void
 175 g_memory_input_stream_set_free_data (GMemoryInputStream *stream,
 176                                      gboolean            free_data)
 177 {
 178   g_return_if_fail (G_IS_MEMORY_INPUT_STREAM (stream));
 179
 180   stream->priv->free_data = free_data;
 181 }
 182
 183 /**
 184  * g_memory_input_stream_from_data:
 185  * @data: input data.
 186  * @len: length of the data.
 187  *
 188  * Creates a new #GMemoryInputStream with data in memory of a given size.
 189  *
 190  * Returns: new #GInputStream read from @data of @len bytes.
 191  **/
 192 GInputStream *
 193 g_memory_input_stream_from_data (const void *data,
 194                                  gssize      len)
 195 {
 196   GInputStream *stream;
 197   GMemoryInputStream *memory_stream;
 198
 199   g_return_val_if_fail (data != NULL, NULL);
 200
 201   stream = g_object_new (G_TYPE_MEMORY_INPUT_STREAM, NULL);
 202   memory_stream = G_MEMORY_INPUT_STREAM (stream);
 203
 204   if (len == -1)
 205     len = strlen (data);
 206
 207   memory_stream->priv->buffer = (guint8 *)data;
 208   memory_stream->priv->len = len;
 209
 210   return stream;
 211 }
 212
 213 static gssize
 214 g_memory_input_stream_read (GInputStream  *stream,
 215                             void          *buffer,
 216                             gsize          count,
 217                             GCancellable  *cancellable,
 218                             GError       **error)
 219 {
 220   GMemoryInputStream *memory_stream;
 221   GMemoryInputStreamPrivate * priv;
 222
 223   memory_stream = G_MEMORY_INPUT_STREAM (stream);
 224   priv = memory_stream->priv;
 225
 226   count = MIN (count, priv->len - priv->pos);
 227   memcpy (buffer, priv->buffer + priv->pos, count);
 228   priv->pos += count;
 229
 230   return count;
 231 }
 232
 233 /**
 234  * g_memory_input_stream_get_data:
 235  * @stream: a #GMemoryInputStream
 236  *
 237  * Gets a pointer to the data within the #GMemoryInputStream.
 238  *
 239  * Returns: a pointer to the memory in the @stream.
 240  **/
 241 const void *
 242 g_memory_input_stream_get_data (GMemoryInputStream *stream)
 243 {
 244   g_return_val_if_fail (G_IS_MEMORY_INPUT_STREAM (stream), NULL);
 245
 246   return stream->priv->buffer;
 247 }
 248
 249 /**
 250  * g_memory_input_stream_get_data_size:
 251  * @stream: a #GMemoryInputStream
 252  *
 253  * Gets the size of the data within the #GMemoryInputStream.
 254  *
 255  * Returns: a gsize with the size of the data in @stream, or -1
 256  *     on error.
 257  **/
 258 gsize
 259 g_memory_input_stream_get_data_size (GMemoryInputStream *stream)
 260 {
 261   g_return_val_if_fail (G_IS_MEMORY_INPUT_STREAM (stream), -1);
 262
 263   return stream->priv->len;
 264 }
 265
 266 static gssize
 267 g_memory_input_stream_skip (GInputStream  *stream,
 268                             gsize          count,
 269                             GCancellable  *cancellable,
 270                             GError       **error)
 271 {
 272   GMemoryInputStream *memory_stream;
 273   GMemoryInputStreamPrivate *priv;
 274
 275   memory_stream = G_MEMORY_INPUT_STREAM (stream);
 276   priv = memory_stream->priv;
 277
 278   count = MIN (count, priv->len - priv->pos);
 279   priv->pos += count;
 280
 281   return count;
 282
 283
 284 }
 285
 286 static gboolean
 287 g_memory_input_stream_close (GInputStream  *stream,
 288                              GCancellable  *cancellable,
 289                              GError       **error)
 290 {
 291   return TRUE;
 292 }
 293
 294 static void
 295 g_memory_input_stream_read_async (GInputStream        *stream,
 296                                   void                *buffer,
 297                                   gsize                count,
 298                                   int                  io_priority,
 299                                   GCancellable        *cancellable,
 300                                   GAsyncReadyCallback  callback,
 301                                   gpointer             user_data)
 302 {
 303   GSimpleAsyncResult *simple;
 304   gssize nread;
 305
 306   nread =  g_memory_input_stream_read (stream,  buffer, count, cancellable, NULL);
 307   simple = g_simple_async_result_new (G_OBJECT (stream),
 308                                       callback,
 309                                       user_data,
 310                                       g_memory_input_stream_read_async);
 311   g_simple_async_result_set_op_res_gssize (simple, nread);
 312   g_simple_async_result_complete_in_idle (simple);
 313   g_object_unref (simple);
 314 }
 315
 316 static gssize
 317 g_memory_input_stream_read_finish (GInputStream  *stream,
 318                                    GAsyncResult  *result,
 319                                    GError       **error)
 320 {
 321   GSimpleAsyncResult *simple;
 322   gssize nread;
 323
 324   simple = G_SIMPLE_ASYNC_RESULT (result);
 325   g_assert (g_simple_async_result_get_source_tag (simple) == g_memory_input_stream_read_async);
 326
 327   nread = g_simple_async_result_get_op_res_gssize (simple);
 328   return nread;
 329 }
 330
 331 static void
 332 g_memory_input_stream_skip_async (GInputStream        *stream,
 333                                   gsize                count,
 334                                   int                  io_priority,
 335                                   GCancellable        *cancellable,
 336                                   GAsyncReadyCallback  callback,
 337                                   gpointer             user_data)
 338 {
 339   GSimpleAsyncResult *simple;
 340   gssize nskipped;
 341
 342   nskipped = g_memory_input_stream_skip (stream, count, cancellable, NULL);
 343   simple = g_simple_async_result_new (G_OBJECT (stream),
 344                                       callback,
 345                                       user_data,
 346                                       g_memory_input_stream_skip_async);
 347   g_simple_async_result_set_op_res_gssize (simple, nskipped);
 348   g_simple_async_result_complete_in_idle (simple);
 349   g_object_unref (simple);
 350 }
 351
 352 static gssize
 353 g_memory_input_stream_skip_finish (GInputStream  *stream,
 354                                    GAsyncResult  *result,
 355                                    GError       **error)
 356 {
 357   GSimpleAsyncResult *simple;
 358   gssize nskipped;
 359
 360   simple = G_SIMPLE_ASYNC_RESULT (result);
 361   g_assert (g_simple_async_result_get_source_tag (simple) == g_memory_input_stream_skip_async);
 362
 363   nskipped = g_simple_async_result_get_op_res_gssize (simple);
 364   return nskipped;
 365 }
 366
 367 static void
 368 g_memory_input_stream_close_async (GInputStream        *stream,
 369                                    int                  io_priority,
 370                                    GCancellable        *cancellable,
 371                                    GAsyncReadyCallback  callback,
 372                                    gpointer             user_data)
 373 {
 374   GSimpleAsyncResult *simple;
 375
 376   simple = g_simple_async_result_new (G_OBJECT (stream),
 377                                       callback,
 378                                       user_data,
 379                                       g_memory_input_stream_close_async);
 380   g_simple_async_result_complete_in_idle (simple);
 381   g_object_unref (simple);
 382 }
 383
 384 static gboolean
 385 g_memory_input_stream_close_finish (GInputStream  *stream,
 386                                     GAsyncResult  *result,
 387                                     GError       **error)
 388 {
 389   return TRUE;
 390 }
 391
 392 static goffset
 393 g_memory_input_stream_tell (GSeekable *seekable)
 394 {
 395   GMemoryInputStream *memory_stream;
 396   GMemoryInputStreamPrivate * priv;
 397
 398   memory_stream = G_MEMORY_INPUT_STREAM (seekable);
 399   priv = memory_stream->priv;
 400
 401   return priv->pos;
 402 }
 403
 404 static
 405 gboolean g_memory_input_stream_can_seek (GSeekable *seekable)
 406 {
 407   return TRUE;
 408 }
 409
 410 static gboolean
 411 g_memory_input_stream_seek (GSeekable     *seekable,
 412                             goffset        offset,
 413                             GSeekType      type,
 414                             GCancellable  *cancellable,
 415                             GError       **error)
 416 {
 417   GMemoryInputStream *memory_stream;
 418   GMemoryInputStreamPrivate * priv;
 419   goffset absolute;
 420
 421   memory_stream = G_MEMORY_INPUT_STREAM (seekable);
 422   priv = memory_stream->priv;
 423
 424   switch (type)
 425     {
 426     case G_SEEK_CUR:
 427       absolute = priv->pos + offset;
 428       break;
 429
 430     case G_SEEK_SET:
 431       absolute = offset;
 432       break;
 433
 434     case G_SEEK_END:
 435       absolute = priv->len + offset;
 436       break;
 437
 438     default:
 439       g_set_error (error,
 440                    G_IO_ERROR,
 441                    G_IO_ERROR_INVALID_ARGUMENT,
 442                    "Invalid GSeekType supplied");
 443
 444       return FALSE;
 445     }
 446
 447   if (absolute < 0 || absolute > priv->len)
 448     {
 449       g_set_error (error,
 450                    G_IO_ERROR,
 451                    G_IO_ERROR_INVALID_ARGUMENT,
 452                    "Invalid seek request");
 453       return FALSE;
 454     }
 455
 456   priv->pos = absolute;
 457
 458   return TRUE;
 459 }
 460
 461 static gboolean
 462 g_memory_input_stream_can_truncate (GSeekable *seekable)
 463 {
 464   return FALSE;
 465 }
 466
 467 static gboolean
 468 g_memory_input_stream_truncate (GSeekable     *seekable,
 469                                 goffset        offset,
 470                                 GCancellable  *cancellable,
 471                                 GError       **error)
 472 {
 473   g_set_error (error,
 474                G_IO_ERROR,
 475                G_IO_ERROR_NOT_SUPPORTED,
 476                "Cannot seek on GMemoryInputStream");
 477   return FALSE;
 478 }
 479
 480 #define __G_MEMORY_INPUT_STREAM_C__
 481 #include "gioaliasdef.c"