gio/gmemoryoutputstream.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 "gmemoryoutputstream.h"
  25 #include "goutputstream.h"
  26 #include "gseekable.h"
  27 #include "gsimpleasyncresult.h"
  28 #include "string.h"
  29 #include "glibintl.h"
  30
  31 #include "gioalias.h"
  32
  33 /**
  34  * SECTION:gmemoryoutputstream
  35  * @short_description: Streaming output operations on memory chunks
  36  * @see_also: #GMemoryInputStream
  37  *
  38  * #GMemoryOutputStream is a class for using arbitrary
  39  * memory chunks as output for GIO streaming output operations.
  40  *
  41  */
  42
  43 struct _GMemoryOutputStreamPrivate {
  44
  45   GByteArray *data;
  46   goffset     pos;
  47
  48   guint       max_size;
  49   guint       free_data : 1;
  50 };
  51
  52 enum {
  53   PROP_0,
  54   PROP_DATA,
  55   PROP_FREE_ARRAY,
  56   PROP_SIZE_LIMIT
  57 };
  58
  59 static void     g_memory_output_stream_finalize     (GObject         *object);
  60
  61 static void     g_memory_output_stream_set_property (GObject      *object,
  62                                                      guint         prop_id,
  63                                                      const GValue *value,
  64                                                      GParamSpec   *pspec);
  65
  66 static void     g_memory_output_stream_get_property (GObject    *object,
  67                                                      guint       prop_id,
  68                                                      GValue     *value,
  69                                                      GParamSpec *pspec);
  70
  71 static gssize   g_memory_output_stream_write       (GOutputStream *stream,
  72                                                     const void    *buffer,
  73                                                     gsize          count,
  74                                                     GCancellable  *cancellable,
  75                                                     GError       **error);
  76
  77 static gboolean g_memory_output_stream_close       (GOutputStream  *stream,
  78                                                     GCancellable   *cancellable,
  79                                                     GError        **error);
  80
  81 static void     g_memory_output_stream_write_async  (GOutputStream        *stream,
  82                                                      const void           *buffer,
  83                                                      gsize                 count,
  84                                                      int                   io_priority,
  85                                                      GCancellable         *cancellable,
  86                                                      GAsyncReadyCallback   callback,
  87                                                      gpointer              data);
  88 static gssize   g_memory_output_stream_write_finish (GOutputStream        *stream,
  89                                                      GAsyncResult         *result,
  90                                                      GError              **error);
  91 static void     g_memory_output_stream_close_async  (GOutputStream        *stream,
  92                                                      int                   io_priority,
  93                                                      GCancellable         *cancellable,
  94                                                      GAsyncReadyCallback   callback,
  95                                                      gpointer              data);
  96 static gboolean g_memory_output_stream_close_finish (GOutputStream        *stream,
  97                                                      GAsyncResult         *result,
  98                                                      GError              **error);
  99
 100 static void     g_memory_output_stream_seekable_iface_init (GSeekableIface  *iface);
 101 static goffset  g_memory_output_stream_tell                (GSeekable       *seekable);
 102 static gboolean g_memory_output_stream_can_seek            (GSeekable       *seekable);
 103 static gboolean g_memory_output_stream_seek                (GSeekable       *seekable,
 104                                                            goffset          offset,
 105                                                            GSeekType        type,
 106                                                            GCancellable    *cancellable,
 107                                                            GError         **error);
 108 static gboolean g_memory_output_stream_can_truncate        (GSeekable       *seekable);
 109 static gboolean g_memory_output_stream_truncate            (GSeekable       *seekable,
 110                                                            goffset          offset,
 111                                                            GCancellable    *cancellable,
 112                                                            GError         **error);
 113
 114 G_DEFINE_TYPE_WITH_CODE (GMemoryOutputStream, g_memory_output_stream, G_TYPE_OUTPUT_STREAM,
 115                          G_IMPLEMENT_INTERFACE (G_TYPE_SEEKABLE,
 116                                                 g_memory_output_stream_seekable_iface_init))
 117
 118
 119 static void
 120 g_memory_output_stream_class_init (GMemoryOutputStreamClass *klass)
 121 {
 122   GOutputStreamClass *ostream_class;
 123   GObjectClass *gobject_class;
 124
 125   g_type_class_add_private (klass, sizeof (GMemoryOutputStreamPrivate));
 126
 127   gobject_class = G_OBJECT_CLASS (klass);
 128   gobject_class->finalize = g_memory_output_stream_finalize;
 129   gobject_class->get_property = g_memory_output_stream_get_property;
 130   gobject_class->set_property = g_memory_output_stream_set_property;
 131
 132   ostream_class = G_OUTPUT_STREAM_CLASS (klass);
 133
 134   ostream_class->write = g_memory_output_stream_write;
 135   ostream_class->close = g_memory_output_stream_close;
 136   ostream_class->write_async  = g_memory_output_stream_write_async;
 137   ostream_class->write_finish = g_memory_output_stream_write_finish;
 138   ostream_class->close_async  = g_memory_output_stream_close_async;
 139   ostream_class->close_finish = g_memory_output_stream_close_finish;
 140
 141   g_object_class_install_property (gobject_class,
 142                                    PROP_DATA,
 143                                    g_param_spec_pointer ("data",
 144                                                          P_("Data byte array"),
 145                                                          P_("The byte array used as internal storage."),
 146                                                          G_PARAM_READWRITE | G_PARAM_CONSTRUCT |
 147                                                          G_PARAM_STATIC_NAME|G_PARAM_STATIC_NICK|G_PARAM_STATIC_BLURB));
 148
 149   g_object_class_install_property (gobject_class,
 150                                    PROP_FREE_ARRAY,
 151                                    g_param_spec_boolean ("free-array",
 152                                                          P_("Free array data"),
 153                                                          P_("Wether or not the interal array should be free on close."),
 154                                                          FALSE,
 155                                                          G_PARAM_READWRITE |
 156                                                          G_PARAM_STATIC_NAME|G_PARAM_STATIC_NICK|G_PARAM_STATIC_BLURB));
 157   g_object_class_install_property (gobject_class,
 158                                    PROP_SIZE_LIMIT,
 159                                    g_param_spec_uint ("size-limit",
 160                                                       P_("Limit"),
 161                                                       P_("Maximum amount of bytes that can be written to the stream."),
 162                                                       0,
 163                                                       G_MAXUINT,
 164                                                       0,
 165                                                       G_PARAM_READWRITE |
 166                                                       G_PARAM_STATIC_NAME|G_PARAM_STATIC_NICK|G_PARAM_STATIC_BLURB));
 167
 168
 169 }
 170
 171 static void
 172 g_memory_output_stream_finalize (GObject *object)
 173 {
 174   GMemoryOutputStream        *stream;
 175
 176   stream = G_MEMORY_OUTPUT_STREAM (object);
 177
 178   if (stream->priv->free_data)
 179     g_byte_array_free (stream->priv->data, TRUE);
 180
 181   if (G_OBJECT_CLASS (g_memory_output_stream_parent_class)->finalize)
 182     (*G_OBJECT_CLASS (g_memory_output_stream_parent_class)->finalize) (object);
 183 }
 184
 185 static void
 186 g_memory_output_stream_seekable_iface_init (GSeekableIface *iface)
 187 {
 188   iface->tell         = g_memory_output_stream_tell;
 189   iface->can_seek     = g_memory_output_stream_can_seek;
 190   iface->seek         = g_memory_output_stream_seek;
 191   iface->can_truncate = g_memory_output_stream_can_truncate;
 192   iface->truncate     = g_memory_output_stream_truncate;
 193 }
 194
 195
 196 static void
 197 g_memory_output_stream_init (GMemoryOutputStream *stream)
 198 {
 199   GMemoryOutputStreamPrivate *priv;
 200
 201   stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (stream,
 202                                               G_TYPE_MEMORY_OUTPUT_STREAM,
 203                                               GMemoryOutputStreamPrivate);
 204
 205   priv = stream->priv;
 206   priv->data = NULL;
 207 }
 208
 209 /**
 210  * g_memory_output_stream_new:
 211  * @data: a #GByteArray.
 212  *
 213  * Creates a new #GMemoryOutputStream. If @data is non-%NULL it will use
 214  * that for its internal storage otherwise it will create a new #GByteArray.
 215  * In both cases the internal #GByteArray can later be accessed through the
 216  * "data" property.
 217  *
 218  * Note: The new stream will not take ownership of the supplied
 219  * @data so you have to free it yourself after use or explicitly
 220  * ask for it be freed on close by setting the "free-array"
 221  * property to $TRUE.
 222  *
 223  * Return value: A newly created #GMemoryOutputStream object.
 224  **/
 225 GOutputStream *
 226 g_memory_output_stream_new (GByteArray *data)
 227 {
 228   GOutputStream *stream;
 229
 230   if (data == NULL)
 231     stream = g_object_new (G_TYPE_MEMORY_OUTPUT_STREAM, NULL);
 232   else
 233     stream = g_object_new (G_TYPE_MEMORY_OUTPUT_STREAM,
 234                            "data", data,
 235                            NULL);
 236
 237   return stream;
 238 }
 239
 240 /**
 241  * g_memory_output_stream_set_free_data:
 242  * @ostream:
 243  * @free_data:
 244  *
 245  **/
 246 void
 247 g_memory_output_stream_set_free_data (GMemoryOutputStream *ostream,
 248                                       gboolean             free_data)
 249 {
 250   GMemoryOutputStreamPrivate *priv;
 251
 252   g_return_if_fail (G_IS_MEMORY_OUTPUT_STREAM (ostream));
 253
 254   priv = ostream->priv;
 255
 256   priv->free_data = free_data;
 257 }
 258
 259 /**
 260  * g_memory_output_stream_set_max_size:
 261  * @ostream:
 262  * @max_size:
 263  *
 264  **/
 265 void
 266 g_memory_output_stream_set_max_size (GMemoryOutputStream *ostream,
 267                                      guint                max_size)
 268 {
 269   GMemoryOutputStreamPrivate *priv;
 270
 271   g_return_if_fail (G_IS_MEMORY_OUTPUT_STREAM (ostream));
 272
 273   priv = ostream->priv;
 274
 275   priv->max_size = max_size;
 276
 277   if (priv->max_size > 0 &&
 278       priv->max_size < priv->data->len)
 279     {
 280
 281       g_byte_array_set_size (priv->data, priv->max_size);
 282
 283       if (priv->pos > priv->max_size)
 284         priv->pos = priv->max_size;
 285     }
 286
 287   g_object_notify (G_OBJECT (ostream), "size-limit");
 288 }
 289
 290 static void
 291 g_memory_output_stream_set_property (GObject      *object,
 292                                      guint         prop_id,
 293                                      const GValue *value,
 294                                      GParamSpec   *pspec)
 295 {
 296   GMemoryOutputStream *ostream;
 297   GMemoryOutputStreamPrivate *priv;
 298   GByteArray *data;
 299   guint       max_size;
 300
 301   ostream = G_MEMORY_OUTPUT_STREAM (object);
 302   priv = ostream->priv;
 303
 304   switch (prop_id)
 305     {
 306     case PROP_DATA:
 307
 308       if (priv->data && priv->free_data)
 309         g_byte_array_free (priv->data, TRUE);
 310
 311       data = g_value_get_pointer (value);
 312
 313       if (data == NULL)
 314         {
 315           data = g_byte_array_new ();
 316           priv->free_data = TRUE;
 317         }
 318       else
 319         priv->free_data = FALSE;
 320
 321       priv->data = data;
 322       priv->pos  = 0;
 323       g_object_notify (G_OBJECT (ostream), "data");
 324       break;
 325
 326     case PROP_FREE_ARRAY:
 327       priv->free_data = g_value_get_boolean (value);
 328       break;
 329
 330     case PROP_SIZE_LIMIT:
 331       max_size = g_value_get_uint (value);
 332       g_memory_output_stream_set_max_size (ostream, max_size);
 333       break;
 334
 335     default:
 336       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 337       break;
 338     }
 339 }
 340
 341 static void
 342 g_memory_output_stream_get_property (GObject    *object,
 343                                      guint       prop_id,
 344                                      GValue     *value,
 345                                      GParamSpec *pspec)
 346 {
 347   GMemoryOutputStream *ostream;
 348   GMemoryOutputStreamPrivate *priv;
 349
 350   ostream = G_MEMORY_OUTPUT_STREAM (object);
 351   priv = ostream->priv;
 352
 353   switch (prop_id)
 354     {
 355     case PROP_DATA:
 356       g_value_set_pointer (value, priv->data);
 357       break;
 358
 359     case PROP_FREE_ARRAY:
 360       g_value_set_boolean (value, priv->free_data);
 361       break;
 362
 363     case PROP_SIZE_LIMIT:
 364       g_value_set_uint (value, priv->max_size);
 365       break;
 366
 367     default:
 368       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 369       break;
 370     }
 371 }
 372
 373 /**
 374  * g_memory_output_stream_get_data:
 375  * @ostream:
 376  *
 377  * Returns: #GByteArray of the stream's data.
 378  **/
 379 GByteArray *
 380 g_memory_output_stream_get_data (GMemoryOutputStream *ostream)
 381 {
 382   g_return_val_if_fail (G_IS_MEMORY_OUTPUT_STREAM (ostream), NULL);
 383
 384   return ostream->priv->data;
 385 }
 386
 387
 388 static gboolean
 389 array_check_boundary (GMemoryOutputStream  *stream,
 390                       goffset               size,
 391                       GError              **error)
 392 {
 393   GMemoryOutputStreamPrivate *priv;
 394
 395   priv = stream->priv;
 396
 397   if (!priv->max_size)
 398     return TRUE;
 399
 400   if (priv->max_size < size || size > G_MAXUINT)
 401     {
 402       g_set_error (error,
 403                    G_IO_ERROR,
 404                    G_IO_ERROR_FAILED,
 405                    "Reached maximum data array limit");
 406
 407       return FALSE;
 408     }
 409
 410   return TRUE;
 411 }
 412
 413 static gssize
 414 array_resize (GMemoryOutputStream  *stream,
 415               goffset               size,
 416               GError              **error)
 417 {
 418   GMemoryOutputStreamPrivate *priv;
 419   guint old_len;
 420
 421   priv = stream->priv;
 422
 423   if (! array_check_boundary (stream, size, error))
 424     return -1;
 425
 426
 427   if (priv->data->len == size)
 428     return priv->data->len - priv->pos;
 429
 430
 431   old_len = priv->data->len;
 432   g_byte_array_set_size (priv->data, size);
 433
 434   if (size > old_len && priv->pos > old_len)
 435     memset (priv->data->data + priv->pos, 0, size - old_len);
 436
 437   return priv->data->len - priv->pos;
 438 }
 439
 440 static gssize
 441 g_memory_output_stream_write (GOutputStream  *stream,
 442                               const void     *buffer,
 443                               gsize           count,
 444                               GCancellable   *cancellable,
 445                               GError        **error)
 446 {
 447   GMemoryOutputStream        *ostream;
 448   GMemoryOutputStreamPrivate *priv;
 449   gsize     new_size;
 450   gssize    n;
 451   guint8   *dest;
 452
 453   ostream = G_MEMORY_OUTPUT_STREAM (stream);
 454   priv = ostream->priv;
 455
 456   /* count < 0 is ensured by GOutputStream */
 457
 458   n = MIN (count, priv->data->len - priv->pos);
 459
 460   if (n < 1)
 461     {
 462       new_size = priv->pos + count;
 463
 464       if (priv->max_size > 0)
 465         new_size = MIN (new_size, priv->max_size);
 466
 467       n = array_resize (ostream, new_size, error);
 468
 469       if (n == 0)
 470         {
 471           g_set_error (error,
 472                        G_IO_ERROR,
 473                        G_IO_ERROR_FAILED,
 474                        "Reached maximum data array limit");
 475           return -1;
 476         }
 477       else if (n < 0)
 478         return -1;
 479     }
 480
 481   dest = priv->data->data + priv->pos;
 482   memcpy (dest, buffer, n);
 483   priv->pos += n;
 484
 485   return n;
 486 }
 487
 488 static gboolean
 489 g_memory_output_stream_close (GOutputStream  *stream,
 490                               GCancellable   *cancellable,
 491                               GError        **error)
 492 {
 493   GMemoryOutputStream        *ostream;
 494   GMemoryOutputStreamPrivate *priv;
 495
 496   ostream = G_MEMORY_OUTPUT_STREAM (stream);
 497   priv = ostream->priv;
 498
 499   return TRUE;
 500 }
 501
 502 static void
 503 g_memory_output_stream_write_async  (GOutputStream       *stream,
 504                                      const void          *buffer,
 505                                      gsize                count,
 506                                      int                  io_priority,
 507                                      GCancellable        *cancellable,
 508                                      GAsyncReadyCallback  callback,
 509                                      gpointer             data)
 510 {
 511   GSimpleAsyncResult *simple;
 512   gssize nwritten;
 513
 514   nwritten = g_memory_output_stream_write (stream,
 515                                            buffer,
 516                                            count,
 517                                            cancellable,
 518                                            NULL);
 519
 520
 521   simple = g_simple_async_result_new (G_OBJECT (stream),
 522                                       callback,
 523                                       data,
 524                                       g_memory_output_stream_write_async);
 525
 526   g_simple_async_result_set_op_res_gssize (simple, nwritten);
 527   g_simple_async_result_complete_in_idle (simple);
 528   g_object_unref (simple);
 529 }
 530
 531 static gssize
 532 g_memory_output_stream_write_finish (GOutputStream  *stream,
 533                                      GAsyncResult   *result,
 534                                      GError        **error)
 535 {
 536   GSimpleAsyncResult *simple;
 537   gssize nwritten;
 538
 539   simple = G_SIMPLE_ASYNC_RESULT (result);
 540
 541   g_assert (g_simple_async_result_get_source_tag (simple) ==
 542             g_memory_output_stream_write_async);
 543
 544   nwritten = g_simple_async_result_get_op_res_gssize (simple);
 545   return nwritten;
 546 }
 547
 548 static void
 549 g_memory_output_stream_close_async  (GOutputStream       *stream,
 550                                      int                  io_priority,
 551                                      GCancellable        *cancellable,
 552                                      GAsyncReadyCallback  callback,
 553                                      gpointer             data)
 554 {
 555   GSimpleAsyncResult *simple;
 556
 557   simple = g_simple_async_result_new (G_OBJECT (stream),
 558                                       callback,
 559                                       data,
 560                                       g_memory_output_stream_close_async);
 561
 562
 563   /* will always return TRUE */
 564   g_memory_output_stream_close (stream, cancellable, NULL);
 565
 566   g_simple_async_result_complete_in_idle (simple);
 567   g_object_unref (simple);
 568 }
 569
 570 static gboolean
 571 g_memory_output_stream_close_finish (GOutputStream  *stream,
 572                                      GAsyncResult   *result,
 573                                      GError        **error)
 574 {
 575   GSimpleAsyncResult *simple;
 576
 577   simple = G_SIMPLE_ASYNC_RESULT (result);
 578
 579   g_assert (g_simple_async_result_get_source_tag (simple) ==
 580             g_memory_output_stream_close_async);
 581
 582   return TRUE;
 583 }
 584
 585 static goffset
 586 g_memory_output_stream_tell (GSeekable *seekable)
 587 {
 588   GMemoryOutputStream *stream;
 589   GMemoryOutputStreamPrivate *priv;
 590
 591   stream = G_MEMORY_OUTPUT_STREAM (seekable);
 592   priv = stream->priv;
 593
 594   return priv->pos;
 595 }
 596
 597 static gboolean
 598 g_memory_output_stream_can_seek (GSeekable *seekable)
 599 {
 600   return TRUE;
 601 }
 602
 603 static gboolean
 604 g_memory_output_stream_seek (GSeekable    *seekable,
 605                             goffset        offset,
 606                             GSeekType      type,
 607                             GCancellable  *cancellable,
 608                             GError       **error)
 609 {
 610   GMemoryOutputStream        *stream;
 611   GMemoryOutputStreamPrivate *priv;
 612   goffset absolute;
 613
 614   stream = G_MEMORY_OUTPUT_STREAM (seekable);
 615   priv = stream->priv;
 616
 617   switch (type)
 618     {
 619     case G_SEEK_CUR:
 620       absolute = priv->pos + offset;
 621       break;
 622
 623     case G_SEEK_SET:
 624       absolute = offset;
 625       break;
 626
 627     case G_SEEK_END:
 628       absolute = priv->data->len + offset;
 629       break;
 630
 631     default:
 632       g_set_error (error,
 633                    G_IO_ERROR,
 634                    G_IO_ERROR_INVALID_ARGUMENT,
 635                    "Invalid GSeekType supplied");
 636
 637       return FALSE;
 638     }
 639
 640   if (absolute < 0)
 641     {
 642       g_set_error (error,
 643                    G_IO_ERROR,
 644                    G_IO_ERROR_INVALID_ARGUMENT,
 645                    "Invalid seek request");
 646       return FALSE;
 647     }
 648
 649   if (!array_check_boundary (stream, absolute, error))
 650     return FALSE;
 651
 652   priv->pos = absolute;
 653
 654   return TRUE;
 655 }
 656
 657 static gboolean
 658 g_memory_output_stream_can_truncate (GSeekable *seekable)
 659 {
 660   return TRUE;
 661 }
 662
 663 static gboolean
 664 g_memory_output_stream_truncate (GSeekable     *seekable,
 665                                  goffset        offset,
 666                                  GCancellable  *cancellable,
 667                                  GError       **error)
 668 {
 669   GMemoryOutputStream *ostream;
 670   GMemoryOutputStreamPrivate *priv;
 671
 672   ostream = G_MEMORY_OUTPUT_STREAM (seekable);
 673   priv = ostream->priv;
 674
 675   if (array_resize (ostream, offset, error) < 0)
 676     return FALSE;
 677
 678   return TRUE;
 679 }
 680
 681 #define __G_MEMORY_OUTPUT_STREAM_C__
 682 #include "gioaliasdef.c"