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
 238   return stream;
 239 }
 240
 241 /**
 242  * g_memory_output_stream_set_free_data:
 243  * @ostream:
 244  * @free_data:
 245  *
 246  **/
 247 void
 248 g_memory_output_stream_set_free_data (GMemoryOutputStream *ostream,
 249                                       gboolean free_data)
 250 {
 251   GMemoryOutputStreamPrivate *priv;
 252
 253   g_return_if_fail (G_IS_MEMORY_OUTPUT_STREAM (ostream));
 254
 255   priv = ostream->priv;
 256
 257   priv->free_data = free_data;
 258 }
 259
 260 /**
 261  * g_memory_output_stream_set_max_size:
 262  * @ostream:
 263  * @max_size:
 264  *
 265  **/
 266 void
 267 g_memory_output_stream_set_max_size (GMemoryOutputStream *ostream,
 268                                      guint                max_size)
 269 {
 270   GMemoryOutputStreamPrivate *priv;
 271
 272   g_return_if_fail (G_IS_MEMORY_OUTPUT_STREAM (ostream));
 273
 274   priv = ostream->priv;
 275
 276   priv->max_size = max_size;
 277
 278   if (priv->max_size > 0 &&
 279       priv->max_size < priv->data->len) {
 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
 288   g_object_notify (G_OBJECT (ostream), "size-limit");
 289 }
 290
 291 static void
 292 g_memory_output_stream_set_property (GObject         *object,
 293                                      guint            prop_id,
 294                                      const GValue    *value,
 295                                      GParamSpec      *pspec)
 296 {
 297   GMemoryOutputStream *ostream;
 298   GMemoryOutputStreamPrivate *priv;
 299   GByteArray *data;
 300   guint       max_size;
 301
 302   ostream = G_MEMORY_OUTPUT_STREAM (object);
 303   priv = ostream->priv;
 304
 305   switch (prop_id)
 306     {
 307     case PROP_DATA:
 308
 309       if (priv->data && priv->free_data) {
 310         g_byte_array_free (priv->data, TRUE);
 311       }
 312
 313       data = g_value_get_pointer (value);
 314
 315       if (data == NULL) {
 316         data = g_byte_array_new ();
 317         priv->free_data = TRUE;
 318       } else {
 319         priv->free_data = FALSE;
 320       }
 321
 322       priv->data = data;
 323       priv->pos  = 0;
 324       g_object_notify (G_OBJECT (ostream), "data");
 325       break;
 326
 327     case PROP_FREE_ARRAY:
 328       priv->free_data = g_value_get_boolean (value);
 329       break;
 330
 331     case PROP_SIZE_LIMIT:
 332       max_size = g_value_get_uint (value);
 333       g_memory_output_stream_set_max_size (ostream, max_size);
 334       break;
 335
 336     default:
 337       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 338       break;
 339     }
 340 }
 341
 342 static void
 343 g_memory_output_stream_get_property (GObject    *object,
 344                                      guint       prop_id,
 345                                      GValue     *value,
 346                                      GParamSpec *pspec)
 347 {
 348   GMemoryOutputStream *ostream;
 349   GMemoryOutputStreamPrivate *priv;
 350
 351   ostream = G_MEMORY_OUTPUT_STREAM (object);
 352   priv = ostream->priv;
 353
 354   switch (prop_id)
 355     {
 356     case PROP_DATA:
 357       g_value_set_pointer (value, priv->data);
 358       break;
 359
 360     case PROP_FREE_ARRAY:
 361       g_value_set_boolean (value, priv->free_data);
 362       break;
 363
 364     case PROP_SIZE_LIMIT:
 365       g_value_set_uint (value, priv->max_size);
 366       break;
 367
 368     default:
 369       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 370       break;
 371     }
 372 }
 373
 374 /**
 375  * g_memory_output_stream_get_data:
 376  * @ostream:
 377  *
 378  * Returns: #GByteArray of the stream's data.
 379  **/
 380 GByteArray *
 381 g_memory_output_stream_get_data (GMemoryOutputStream *ostream)
 382 {
 383   g_return_val_if_fail (G_IS_MEMORY_OUTPUT_STREAM (ostream), NULL);
 384
 385   return ostream->priv->data;
 386 }
 387
 388
 389 static gboolean
 390 array_check_boundary (GMemoryOutputStream  *stream,
 391                       goffset               size,
 392                       GError              **error)
 393 {
 394   GMemoryOutputStreamPrivate *priv;
 395
 396   priv = stream->priv;
 397
 398   if (! priv->max_size) {
 399     return TRUE;
 400   }
 401
 402   if (priv->max_size < size || size > G_MAXUINT) {
 403
 404     g_set_error (error,
 405                  G_IO_ERROR,
 406                  G_IO_ERROR_FAILED,
 407                  "Reached maximum data array limit");
 408
 409     return FALSE;
 410   }
 411
 412   return TRUE;
 413 }
 414
 415 static gssize
 416 array_resize (GMemoryOutputStream  *stream,
 417               goffset               size,
 418               GError              **error)
 419 {
 420   GMemoryOutputStreamPrivate *priv;
 421   guint old_len;
 422
 423   priv = stream->priv;
 424
 425   if (! array_check_boundary (stream, size, error))
 426     return -1;
 427
 428
 429   if (priv->data->len == size)
 430     return priv->data->len - priv->pos;
 431
 432
 433   old_len = priv->data->len;
 434   g_byte_array_set_size (priv->data, size);
 435
 436   if (size > old_len && priv->pos > old_len)
 437     memset (priv->data->data + priv->pos, 0, size - old_len);
 438
 439
 440   return priv->data->len - priv->pos;
 441 }
 442
 443 static gssize
 444 g_memory_output_stream_write (GOutputStream *stream,
 445                               const void    *buffer,
 446                               gsize          count,
 447                               GCancellable  *cancellable,
 448                               GError       **error)
 449 {
 450   GMemoryOutputStream        *ostream;
 451   GMemoryOutputStreamPrivate *priv;
 452   gsize     new_size;
 453   gssize    n;
 454   guint8   *dest;
 455
 456   ostream = G_MEMORY_OUTPUT_STREAM (stream);
 457   priv = ostream->priv;
 458
 459   /* count < 0 is ensured by GOutputStream */
 460
 461   n = MIN (count, priv->data->len - priv->pos);
 462
 463   if (n < 1)
 464     {
 465       new_size = priv->pos + count;
 466
 467       if (priv->max_size > 0)
 468         {
 469           new_size = MIN (new_size, priv->max_size);
 470         }
 471
 472       n = array_resize (ostream, new_size, error);
 473
 474       if (n == 0)
 475         {
 476           g_set_error (error,
 477                        G_IO_ERROR,
 478                        G_IO_ERROR_FAILED,
 479                        "Reached maximum data array limit");
 480           return -1;
 481         }
 482       else if (n < 0)
 483         {
 484           return -1;
 485         }
 486     }
 487
 488   dest = priv->data->data + priv->pos;
 489   memcpy (dest, buffer, n);
 490   priv->pos += n;
 491
 492   return n;
 493 }
 494
 495 static gboolean
 496 g_memory_output_stream_close (GOutputStream  *stream,
 497                               GCancellable   *cancellable,
 498                               GError        **error)
 499 {
 500   GMemoryOutputStream        *ostream;
 501   GMemoryOutputStreamPrivate *priv;
 502
 503   ostream = G_MEMORY_OUTPUT_STREAM (stream);
 504   priv = ostream->priv;
 505
 506   return TRUE;
 507 }
 508
 509 static void
 510 g_memory_output_stream_write_async  (GOutputStream        *stream,
 511                                      const void           *buffer,
 512                                      gsize                 count,
 513                                      int                   io_priority,
 514                                      GCancellable         *cancellable,
 515                                      GAsyncReadyCallback   callback,
 516                                      gpointer              data)
 517 {
 518   GSimpleAsyncResult *simple;
 519   gssize nwritten;
 520
 521   nwritten = g_memory_output_stream_write (stream,
 522                                            buffer,
 523                                            count,
 524                                            cancellable,
 525                                            NULL);
 526
 527
 528   simple = g_simple_async_result_new (G_OBJECT (stream),
 529                                       callback,
 530                                       data,
 531                                       g_memory_output_stream_write_async);
 532
 533   g_simple_async_result_set_op_res_gssize (simple, nwritten);
 534   g_simple_async_result_complete_in_idle (simple);
 535   g_object_unref (simple);
 536
 537 }
 538
 539 static gssize
 540 g_memory_output_stream_write_finish (GOutputStream        *stream,
 541                                      GAsyncResult         *result,
 542                                      GError              **error)
 543 {
 544   GSimpleAsyncResult *simple;
 545   gssize nwritten;
 546
 547   simple = G_SIMPLE_ASYNC_RESULT (result);
 548
 549   g_assert (g_simple_async_result_get_source_tag (simple) ==
 550             g_memory_output_stream_write_async);
 551
 552   nwritten = g_simple_async_result_get_op_res_gssize (simple);
 553   return nwritten;
 554 }
 555
 556 static void
 557 g_memory_output_stream_close_async  (GOutputStream        *stream,
 558                                      int                   io_priority,
 559                                      GCancellable         *cancellable,
 560                                      GAsyncReadyCallback   callback,
 561                                      gpointer              data)
 562 {
 563   GSimpleAsyncResult *simple;
 564
 565   simple = g_simple_async_result_new (G_OBJECT (stream),
 566                                       callback,
 567                                       data,
 568                                       g_memory_output_stream_close_async);
 569
 570
 571   /* will always return TRUE */
 572   g_memory_output_stream_close (stream, cancellable, NULL);
 573
 574   g_simple_async_result_complete_in_idle (simple);
 575   g_object_unref (simple);
 576
 577 }
 578
 579 static gboolean
 580 g_memory_output_stream_close_finish (GOutputStream        *stream,
 581                                      GAsyncResult         *result,
 582                                      GError              **error)
 583 {
 584   GSimpleAsyncResult *simple;
 585
 586   simple = G_SIMPLE_ASYNC_RESULT (result);
 587
 588   g_assert (g_simple_async_result_get_source_tag (simple) ==
 589             g_memory_output_stream_close_async);
 590
 591
 592   return TRUE;
 593 }
 594
 595 static goffset
 596 g_memory_output_stream_tell (GSeekable  *seekable)
 597 {
 598   GMemoryOutputStream *stream;
 599   GMemoryOutputStreamPrivate *priv;
 600
 601   stream = G_MEMORY_OUTPUT_STREAM (seekable);
 602   priv = stream->priv;
 603
 604   return priv->pos;
 605 }
 606
 607 static gboolean
 608 g_memory_output_stream_can_seek (GSeekable *seekable)
 609 {
 610   return TRUE;
 611 }
 612
 613 static gboolean
 614 g_memory_output_stream_seek (GSeekable      *seekable,
 615                             goffset          offset,
 616                             GSeekType        type,
 617                             GCancellable    *cancellable,
 618                             GError         **error)
 619 {
 620   GMemoryOutputStream        *stream;
 621   GMemoryOutputStreamPrivate *priv;
 622   goffset absolute;
 623
 624   stream = G_MEMORY_OUTPUT_STREAM (seekable);
 625   priv = stream->priv;
 626
 627   switch (type) {
 628
 629     case G_SEEK_CUR:
 630       absolute = priv->pos + offset;
 631       break;
 632
 633     case G_SEEK_SET:
 634       absolute = offset;
 635       break;
 636
 637     case G_SEEK_END:
 638       absolute = priv->data->len + offset;
 639       break;
 640
 641     default:
 642       g_set_error (error,
 643                    G_IO_ERROR,
 644                    G_IO_ERROR_INVALID_ARGUMENT,
 645                    "Invalid GSeekType supplied");
 646
 647       return FALSE;
 648   }
 649
 650   if (absolute < 0) {
 651     g_set_error (error,
 652                  G_IO_ERROR,
 653                  G_IO_ERROR_INVALID_ARGUMENT,
 654                  "Invalid seek request");
 655     return FALSE;
 656   }
 657
 658   if (! array_check_boundary (stream, absolute, error))
 659     return FALSE;
 660
 661   priv->pos = absolute;
 662
 663   return TRUE;
 664 }
 665
 666 static gboolean
 667 g_memory_output_stream_can_truncate (GSeekable *seekable)
 668 {
 669   return TRUE;
 670 }
 671
 672 static gboolean
 673 g_memory_output_stream_truncate (GSeekable      *seekable,
 674                                  goffset         offset,
 675                                  GCancellable   *cancellable,
 676                                  GError         **error)
 677 {
 678   GMemoryOutputStream *ostream;
 679   GMemoryOutputStreamPrivate *priv;
 680
 681   ostream = G_MEMORY_OUTPUT_STREAM (seekable);
 682   priv = ostream->priv;
 683
 684   if (array_resize (ostream, offset, error) < 0)
 685       return FALSE;
 686
 687   return TRUE;
 688 }
 689
 690 #define __G_MEMORY_OUTPUT_STREAM_C__
 691 #include "gioaliasdef.c"
 692
 693 /* vim: ts=2 sw=2 et */