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  = g_memory_input_stream_read;
 123   istream_class->skip  = g_memory_input_stream_skip;
 124   istream_class->close = 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     = 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:
 169  * @free_data:
 170  *
 171  **/
 172 void
 173 g_memory_input_stream_set_free_data (GMemoryInputStream *stream,
 174                                      gboolean            free_data)
 175 {
 176   g_return_if_fail (G_IS_MEMORY_INPUT_STREAM (stream));
 177
 178   stream->priv->free_data = free_data;
 179 }
 180
 181 /**
 182  * g_memory_input_stream_from_data:
 183  * @data: input data.
 184  * @len: length of the data.
 185  *
 186  * Returns: new #GInputStream read from @data of @len bytes.
 187  **/
 188 GInputStream *
 189 g_memory_input_stream_from_data (const void *data,
 190                                  gssize      len)
 191 {
 192   GInputStream *stream;
 193   GMemoryInputStream *memory_stream;
 194
 195   g_return_val_if_fail (data != NULL, NULL);
 196
 197   stream = g_object_new (G_TYPE_MEMORY_INPUT_STREAM, NULL);
 198   memory_stream = G_MEMORY_INPUT_STREAM (stream);
 199
 200   if (len == -1)
 201     len = strlen (data);
 202
 203   memory_stream->priv->buffer = (guint8 *)data;
 204   memory_stream->priv->len = len;
 205
 206   return stream;
 207 }
 208
 209 static gssize
 210 g_memory_input_stream_read (GInputStream  *stream,
 211                             void          *buffer,
 212                             gsize          count,
 213                             GCancellable  *cancellable,
 214                             GError       **error)
 215 {
 216   GMemoryInputStream *memory_stream;
 217   GMemoryInputStreamPrivate * priv;
 218
 219   memory_stream = G_MEMORY_INPUT_STREAM (stream);
 220   priv = memory_stream->priv;
 221
 222   count = MIN (count, priv->len - priv->pos);
 223   memcpy (buffer, priv->buffer + priv->pos, count);
 224   priv->pos += count;
 225
 226   return count;
 227 }
 228
 229 /**
 230  * g_memory_input_stream_get_data:
 231  * @stream:
 232  *
 233  * Returns:
 234  **/
 235 const void *
 236 g_memory_input_stream_get_data (GMemoryInputStream *stream)
 237 {
 238   g_return_val_if_fail (G_IS_MEMORY_INPUT_STREAM (stream), NULL);
 239
 240   return stream->priv->buffer;
 241 }
 242
 243 /**
 244  * g_memory_input_stream_get_data_size:
 245  * @stream:
 246  *
 247  * Returns:
 248  **/
 249 gsize
 250 g_memory_input_stream_get_data_size (GMemoryInputStream *stream)
 251 {
 252   g_return_val_if_fail (G_IS_MEMORY_INPUT_STREAM (stream), -1);
 253
 254   return stream->priv->len;
 255 }
 256
 257 static gssize
 258 g_memory_input_stream_skip (GInputStream  *stream,
 259                             gsize          count,
 260                             GCancellable  *cancellable,
 261                             GError       **error)
 262 {
 263   GMemoryInputStream *memory_stream;
 264   GMemoryInputStreamPrivate *priv;
 265
 266   memory_stream = G_MEMORY_INPUT_STREAM (stream);
 267   priv = memory_stream->priv;
 268
 269   count = MIN (count, priv->len - priv->pos);
 270   priv->pos += count;
 271
 272   return count;
 273
 274
 275 }
 276
 277 static gboolean
 278 g_memory_input_stream_close (GInputStream  *stream,
 279                              GCancellable  *cancellable,
 280                              GError       **error)
 281 {
 282   return TRUE;
 283 }
 284
 285 static void
 286 g_memory_input_stream_read_async (GInputStream        *stream,
 287                                   void                *buffer,
 288                                   gsize                count,
 289                                   int                  io_priority,
 290                                   GCancellable        *cancellable,
 291                                   GAsyncReadyCallback  callback,
 292                                   gpointer             user_data)
 293 {
 294   GSimpleAsyncResult *simple;
 295   gssize nread;
 296
 297   nread =  g_memory_input_stream_read (stream,  buffer, count, cancellable, NULL);
 298   simple = g_simple_async_result_new (G_OBJECT (stream),
 299                                       callback,
 300                                       user_data,
 301                                       g_memory_input_stream_read_async);
 302   g_simple_async_result_set_op_res_gssize (simple, nread);
 303   g_simple_async_result_complete_in_idle (simple);
 304   g_object_unref (simple);
 305 }
 306
 307 static gssize
 308 g_memory_input_stream_read_finish (GInputStream  *stream,
 309                                    GAsyncResult  *result,
 310                                    GError       **error)
 311 {
 312   GSimpleAsyncResult *simple;
 313   gssize nread;
 314
 315   simple = G_SIMPLE_ASYNC_RESULT (result);
 316   g_assert (g_simple_async_result_get_source_tag (simple) == g_memory_input_stream_read_async);
 317
 318   nread = g_simple_async_result_get_op_res_gssize (simple);
 319   return nread;
 320 }
 321
 322 static void
 323 g_memory_input_stream_skip_async (GInputStream        *stream,
 324                                   gsize                count,
 325                                   int                  io_priority,
 326                                   GCancellable        *cancellable,
 327                                   GAsyncReadyCallback  callback,
 328                                   gpointer             user_data)
 329 {
 330   GSimpleAsyncResult *simple;
 331   gssize nskipped;
 332
 333   nskipped = g_memory_input_stream_skip (stream, count, cancellable, NULL);
 334   simple = g_simple_async_result_new (G_OBJECT (stream),
 335                                       callback,
 336                                       user_data,
 337                                       g_memory_input_stream_skip_async);
 338   g_simple_async_result_set_op_res_gssize (simple, nskipped);
 339   g_simple_async_result_complete_in_idle (simple);
 340   g_object_unref (simple);
 341 }
 342
 343 static gssize
 344 g_memory_input_stream_skip_finish (GInputStream  *stream,
 345                                    GAsyncResult  *result,
 346                                    GError       **error)
 347 {
 348   GSimpleAsyncResult *simple;
 349   gssize nskipped;
 350
 351   simple = G_SIMPLE_ASYNC_RESULT (result);
 352   g_assert (g_simple_async_result_get_source_tag (simple) == g_memory_input_stream_skip_async);
 353
 354   nskipped = g_simple_async_result_get_op_res_gssize (simple);
 355   return nskipped;
 356 }
 357
 358 static void
 359 g_memory_input_stream_close_async (GInputStream        *stream,
 360                                    int                  io_priority,
 361                                    GCancellable        *cancellable,
 362                                    GAsyncReadyCallback  callback,
 363                                    gpointer             user_data)
 364 {
 365   GSimpleAsyncResult *simple;
 366
 367   simple = g_simple_async_result_new (G_OBJECT (stream),
 368                                       callback,
 369                                       user_data,
 370                                       g_memory_input_stream_close_async);
 371   g_simple_async_result_complete_in_idle (simple);
 372   g_object_unref (simple);
 373 }
 374
 375 static gboolean
 376 g_memory_input_stream_close_finish (GInputStream  *stream,
 377                                     GAsyncResult  *result,
 378                                     GError       **error)
 379 {
 380   return TRUE;
 381 }
 382
 383 static goffset
 384 g_memory_input_stream_tell (GSeekable *seekable)
 385 {
 386   GMemoryInputStream *memory_stream;
 387   GMemoryInputStreamPrivate * priv;
 388
 389   memory_stream = G_MEMORY_INPUT_STREAM (seekable);
 390   priv = memory_stream->priv;
 391
 392   return priv->pos;
 393 }
 394
 395 static
 396 gboolean g_memory_input_stream_can_seek (GSeekable *seekable)
 397 {
 398   return TRUE;
 399 }
 400
 401 static gboolean
 402 g_memory_input_stream_seek (GSeekable     *seekable,
 403                             goffset        offset,
 404                             GSeekType      type,
 405                             GCancellable  *cancellable,
 406                             GError       **error)
 407 {
 408   GMemoryInputStream *memory_stream;
 409   GMemoryInputStreamPrivate * priv;
 410   goffset absolute;
 411
 412   memory_stream = G_MEMORY_INPUT_STREAM (seekable);
 413   priv = memory_stream->priv;
 414
 415   switch (type)
 416     {
 417     case G_SEEK_CUR:
 418       absolute = priv->pos + offset;
 419       break;
 420
 421     case G_SEEK_SET:
 422       absolute = offset;
 423       break;
 424
 425     case G_SEEK_END:
 426       absolute = priv->len + offset;
 427       break;
 428
 429     default:
 430       g_set_error (error,
 431                    G_IO_ERROR,
 432                    G_IO_ERROR_INVALID_ARGUMENT,
 433                    "Invalid GSeekType supplied");
 434
 435       return FALSE;
 436     }
 437
 438   if (absolute < 0 || absolute > priv->len)
 439     {
 440       g_set_error (error,
 441                    G_IO_ERROR,
 442                    G_IO_ERROR_INVALID_ARGUMENT,
 443                    "Invalid seek request");
 444       return FALSE;
 445     }
 446
 447   priv->pos = absolute;
 448
 449   return TRUE;
 450 }
 451
 452 static gboolean
 453 g_memory_input_stream_can_truncate (GSeekable *seekable)
 454 {
 455   return FALSE;
 456 }
 457
 458 static gboolean
 459 g_memory_input_stream_truncate (GSeekable     *seekable,
 460                                 goffset        offset,
 461                                 GCancellable  *cancellable,
 462                                 GError       **error)
 463 {
 464   g_set_error (error,
 465                G_IO_ERROR,
 466                G_IO_ERROR_NOT_SUPPORTED,
 467                "Cannot seek on GMemoryInputStream");
 468   return FALSE;
 469 }
 470
 471 #define __G_MEMORY_INPUT_STREAM_C__
 472 #include "gioaliasdef.c"