gio/gfilterinputstream.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 "gfilterinputstream.h"
  25 #include "ginputstream.h"
  26 #include "glibintl.h"
  27
  28
  29 /**
  30  * SECTION:gfilterinputstream
  31  * @short_description: Filter Input Stream
  32  * @include: gio/gio.h
  33  *
  34  * Base class for input stream implementations that perform some
  35  * kind of filtering operation on a base stream. Typical examples
  36  * of filtering operations are character set conversion, compression
  37  * and byte order flipping.
  38  **/
  39
  40 enum {
  41   PROP_0,
  42   PROP_BASE_STREAM,
  43   PROP_CLOSE_BASE
  44 };
  45
  46 static void     g_filter_input_stream_set_property (GObject      *object,
  47                                                     guint         prop_id,
  48                                                     const GValue *value,
  49                                                     GParamSpec   *pspec);
  50
  51 static void     g_filter_input_stream_get_property (GObject      *object,
  52                                                     guint         prop_id,
  53                                                     GValue       *value,
  54                                                     GParamSpec   *pspec);
  55 static void     g_filter_input_stream_finalize     (GObject *object);
  56
  57
  58 static gssize   g_filter_input_stream_read         (GInputStream         *stream,
  59                                                     void                 *buffer,
  60                                                     gsize                 count,
  61                                                     GCancellable         *cancellable,
  62                                                     GError              **error);
  63 static gssize   g_filter_input_stream_skip         (GInputStream         *stream,
  64                                                     gsize                 count,
  65                                                     GCancellable         *cancellable,
  66                                                     GError              **error);
  67 static gboolean g_filter_input_stream_close        (GInputStream         *stream,
  68                                                     GCancellable         *cancellable,
  69                                                     GError              **error);
  70
  71 G_DEFINE_ABSTRACT_TYPE (GFilterInputStream, g_filter_input_stream, G_TYPE_INPUT_STREAM)
  72
  73 #define GET_PRIVATE(inst) G_TYPE_INSTANCE_GET_PRIVATE (inst, \
  74   G_TYPE_FILTER_INPUT_STREAM, GFilterInputStreamPrivate)
  75
  76 typedef struct
  77 {
  78   gboolean close_base;
  79 } GFilterInputStreamPrivate;
  80
  81 static void
  82 g_filter_input_stream_class_init (GFilterInputStreamClass *klass)
  83 {
  84   GObjectClass *object_class;
  85   GInputStreamClass *istream_class;
  86
  87   object_class = G_OBJECT_CLASS (klass);
  88   object_class->get_property = g_filter_input_stream_get_property;
  89   object_class->set_property = g_filter_input_stream_set_property;
  90   object_class->finalize     = g_filter_input_stream_finalize;
  91
  92   istream_class = G_INPUT_STREAM_CLASS (klass);
  93   istream_class->read_fn  = g_filter_input_stream_read;
  94   istream_class->skip  = g_filter_input_stream_skip;
  95   istream_class->close_fn = g_filter_input_stream_close;
  96
  97   g_type_class_add_private (klass, sizeof (GFilterInputStreamPrivate));
  98
  99   g_object_class_install_property (object_class,
 100                                    PROP_BASE_STREAM,
 101                                    g_param_spec_object ("base-stream",
 102                                                          P_("The Filter Base Stream"),
 103                                                          P_("The underlying base stream on which the io ops will be done."),
 104                                                          G_TYPE_INPUT_STREAM,
 105                                                          G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY |
 106                                                          G_PARAM_STATIC_NAME|G_PARAM_STATIC_NICK|G_PARAM_STATIC_BLURB));
 107
 108   g_object_class_install_property (object_class,
 109                                    PROP_CLOSE_BASE,
 110                                    g_param_spec_boolean ("close-base-stream",
 111                                                          P_("Close Base Stream"),
 112                                                          P_("If the base stream should be closed when the filter stream is closed."),
 113                                                          TRUE, G_PARAM_READWRITE | G_PARAM_CONSTRUCT |
 114                                                          G_PARAM_STATIC_NAME|G_PARAM_STATIC_NICK|G_PARAM_STATIC_BLURB));
 115 }
 116
 117 static void
 118 g_filter_input_stream_set_property (GObject         *object,
 119                                     guint            prop_id,
 120                                     const GValue    *value,
 121                                     GParamSpec      *pspec)
 122 {
 123   GFilterInputStream *filter_stream;
 124   GObject *obj;
 125
 126   filter_stream = G_FILTER_INPUT_STREAM (object);
 127
 128   switch (prop_id)
 129     {
 130     case PROP_BASE_STREAM:
 131       obj = g_value_dup_object (value);
 132       filter_stream->base_stream = G_INPUT_STREAM (obj);
 133       break;
 134
 135     case PROP_CLOSE_BASE:
 136       g_filter_input_stream_set_close_base_stream (filter_stream,
 137                                                    g_value_get_boolean (value));
 138       break;
 139
 140     default:
 141       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 142       break;
 143     }
 144
 145 }
 146
 147 static void
 148 g_filter_input_stream_get_property (GObject    *object,
 149                                     guint       prop_id,
 150                                     GValue     *value,
 151                                     GParamSpec *pspec)
 152 {
 153   GFilterInputStream *filter_stream;
 154
 155   filter_stream = G_FILTER_INPUT_STREAM (object);
 156
 157   switch (prop_id)
 158     {
 159     case PROP_BASE_STREAM:
 160       g_value_set_object (value, filter_stream->base_stream);
 161       break;
 162
 163     case PROP_CLOSE_BASE:
 164       g_value_set_boolean (value, GET_PRIVATE (filter_stream)->close_base);
 165       break;
 166
 167     default:
 168       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 169       break;
 170     }
 171
 172 }
 173
 174 static void
 175 g_filter_input_stream_finalize (GObject *object)
 176 {
 177   GFilterInputStream *stream;
 178
 179   stream = G_FILTER_INPUT_STREAM (object);
 180
 181   g_object_unref (stream->base_stream);
 182
 183   G_OBJECT_CLASS (g_filter_input_stream_parent_class)->finalize (object);
 184 }
 185
 186 static void
 187 g_filter_input_stream_init (GFilterInputStream *stream)
 188 {
 189
 190 }
 191
 192 /**
 193  * g_filter_input_stream_get_base_stream:
 194  * @stream: a #GFilterInputStream.
 195  *
 196  * Gets the base stream for the filter stream.
 197  *
 198  * Returns: (transfer none): a #GInputStream.
 199  **/
 200 GInputStream *
 201 g_filter_input_stream_get_base_stream (GFilterInputStream *stream)
 202 {
 203   g_return_val_if_fail (G_IS_FILTER_INPUT_STREAM (stream), NULL);
 204
 205   return stream->base_stream;
 206 }
 207
 208 /**
 209  * g_filter_input_stream_get_close_base_stream:
 210  * @stream: a #GFilterInputStream.
 211  *
 212  * Returns whether the base stream will be closed when @stream is
 213  * closed.
 214  *
 215  * Return value: %TRUE if the base stream will be closed.
 216  **/
 217 gboolean
 218 g_filter_input_stream_get_close_base_stream (GFilterInputStream *stream)
 219 {
 220   g_return_val_if_fail (G_IS_FILTER_INPUT_STREAM (stream), FALSE);
 221
 222   return GET_PRIVATE (stream)->close_base;
 223 }
 224
 225 /**
 226  * g_filter_input_stream_set_close_base_stream:
 227  * @stream: a #GFilterInputStream.
 228  * @close_base: %TRUE to close the base stream.
 229  *
 230  * Sets whether the base stream will be closed when @stream is closed.
 231  **/
 232 void
 233 g_filter_input_stream_set_close_base_stream (GFilterInputStream *stream,
 234                                              gboolean            close_base)
 235 {
 236   GFilterInputStreamPrivate *priv;
 237
 238   g_return_if_fail (G_IS_FILTER_INPUT_STREAM (stream));
 239
 240   close_base = !!close_base;
 241
 242   priv = GET_PRIVATE (stream);
 243
 244   if (priv->close_base != close_base)
 245     {
 246       priv->close_base = close_base;
 247       g_object_notify (G_OBJECT (stream), "close-base-stream");
 248     }
 249 }
 250
 251 static gssize
 252 g_filter_input_stream_read (GInputStream  *stream,
 253                             void          *buffer,
 254                             gsize          count,
 255                             GCancellable  *cancellable,
 256                             GError       **error)
 257 {
 258   GFilterInputStream *filter_stream;
 259   GInputStream       *base_stream;
 260   gssize              nread;
 261
 262   filter_stream = G_FILTER_INPUT_STREAM (stream);
 263   base_stream = filter_stream->base_stream;
 264
 265   nread = g_input_stream_read (base_stream,
 266                                buffer,
 267                                count,
 268                                cancellable,
 269                                error);
 270
 271   return nread;
 272 }
 273
 274 static gssize
 275 g_filter_input_stream_skip (GInputStream  *stream,
 276                             gsize          count,
 277                             GCancellable  *cancellable,
 278                             GError       **error)
 279 {
 280   GFilterInputStream *filter_stream;
 281   GInputStream       *base_stream;
 282   gssize              nskipped;
 283
 284   filter_stream = G_FILTER_INPUT_STREAM (stream);
 285   base_stream = filter_stream->base_stream;
 286
 287   nskipped = g_input_stream_skip (base_stream,
 288                                   count,
 289                                   cancellable,
 290                                   error);
 291   return nskipped;
 292 }
 293
 294 static gboolean
 295 g_filter_input_stream_close (GInputStream  *stream,
 296                              GCancellable  *cancellable,
 297                              GError       **error)
 298 {
 299   gboolean res = TRUE;
 300
 301   if (GET_PRIVATE (stream)->close_base)
 302     {
 303       GFilterInputStream *filter_stream;
 304       GInputStream       *base_stream;
 305
 306       filter_stream = G_FILTER_INPUT_STREAM (stream);
 307       base_stream = filter_stream->base_stream;
 308
 309       res = g_input_stream_close (base_stream,
 310                                   cancellable,
 311                                   error);
 312     }
 313
 314   return res;
 315 }