gio/gfilteroutputstream.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 "gfilteroutputstream.h"
  25 #include "goutputstream.h"
  26 #include "glibintl.h"
  27
  28
  29 /**
  30  * SECTION:gfilteroutputstream
  31  * @short_description: Filter Output Stream
  32  * @include: gio/gio.h
  33  *
  34  * Base class for output 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_output_stream_set_property (GObject      *object,
  47                                                      guint         prop_id,
  48                                                      const GValue *value,
  49                                                      GParamSpec   *pspec);
  50
  51 static void     g_filter_output_stream_get_property (GObject    *object,
  52                                                      guint       prop_id,
  53                                                      GValue     *value,
  54                                                      GParamSpec *pspec);
  55 static void     g_filter_output_stream_dispose      (GObject *object);
  56
  57
  58 static gssize   g_filter_output_stream_write        (GOutputStream *stream,
  59                                                      const void    *buffer,
  60                                                      gsize          count,
  61                                                      GCancellable  *cancellable,
  62                                                      GError       **error);
  63 static gboolean g_filter_output_stream_flush        (GOutputStream    *stream,
  64                                                      GCancellable  *cancellable,
  65                                                      GError          **error);
  66 static gboolean g_filter_output_stream_close        (GOutputStream  *stream,
  67                                                      GCancellable   *cancellable,
  68                                                      GError        **error);
  69
  70 G_DEFINE_ABSTRACT_TYPE (GFilterOutputStream, g_filter_output_stream, G_TYPE_OUTPUT_STREAM)
  71
  72 #define GET_PRIVATE(inst) G_TYPE_INSTANCE_GET_PRIVATE (inst, \
  73   G_TYPE_FILTER_OUTPUT_STREAM, GFilterOutputStreamPrivate)
  74
  75 typedef struct
  76 {
  77   gboolean close_base;
  78 } GFilterOutputStreamPrivate;
  79
  80 static void
  81 g_filter_output_stream_class_init (GFilterOutputStreamClass *klass)
  82 {
  83   GObjectClass *object_class;
  84   GOutputStreamClass *ostream_class;
  85
  86   object_class = G_OBJECT_CLASS (klass);
  87   object_class->get_property = g_filter_output_stream_get_property;
  88   object_class->set_property = g_filter_output_stream_set_property;
  89   object_class->dispose      = g_filter_output_stream_dispose;
  90
  91   ostream_class = G_OUTPUT_STREAM_CLASS (klass);
  92   ostream_class->write_fn = g_filter_output_stream_write;
  93   ostream_class->flush = g_filter_output_stream_flush;
  94   ostream_class->close_fn = g_filter_output_stream_close;
  95
  96   g_type_class_add_private (klass, sizeof (GFilterOutputStreamPrivate));
  97
  98   g_object_class_install_property (object_class,
  99                                    PROP_BASE_STREAM,
 100                                    g_param_spec_object ("base-stream",
 101                                                          P_("The Filter Base Stream"),
 102                                                          P_("The underlying base stream on which the io ops will be done."),
 103                                                          G_TYPE_OUTPUT_STREAM,
 104                                                          G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY |
 105                                                          G_PARAM_STATIC_NAME|G_PARAM_STATIC_NICK|G_PARAM_STATIC_BLURB));
 106
 107   g_object_class_install_property (object_class,
 108                                    PROP_CLOSE_BASE,
 109                                    g_param_spec_boolean ("close-base-stream",
 110                                                          P_("Close Base Stream"),
 111                                                          P_("If the base stream should be closed when the filter stream is closed."),
 112                                                          TRUE, G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY |
 113                                                          G_PARAM_STATIC_NAME|G_PARAM_STATIC_NICK|G_PARAM_STATIC_BLURB));
 114 }
 115
 116 static void
 117 g_filter_output_stream_set_property (GObject      *object,
 118                                      guint         prop_id,
 119                                      const GValue *value,
 120                                      GParamSpec   *pspec)
 121 {
 122   GFilterOutputStream *filter_stream;
 123   GObject *obj;
 124
 125   filter_stream = G_FILTER_OUTPUT_STREAM (object);
 126
 127   switch (prop_id)
 128     {
 129     case PROP_BASE_STREAM:
 130       obj = g_value_dup_object (value);
 131       filter_stream->base_stream = G_OUTPUT_STREAM (obj);
 132       break;
 133
 134     case PROP_CLOSE_BASE:
 135       g_filter_output_stream_set_close_base_stream (filter_stream,
 136                                                     g_value_get_boolean (value));
 137       break;
 138
 139     default:
 140       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 141       break;
 142     }
 143
 144 }
 145
 146 static void
 147 g_filter_output_stream_get_property (GObject    *object,
 148                                      guint       prop_id,
 149                                      GValue     *value,
 150                                      GParamSpec *pspec)
 151 {
 152   GFilterOutputStream *filter_stream;
 153
 154   filter_stream = G_FILTER_OUTPUT_STREAM (object);
 155
 156   switch (prop_id)
 157     {
 158     case PROP_BASE_STREAM:
 159       g_value_set_object (value, filter_stream->base_stream);
 160       break;
 161
 162     case PROP_CLOSE_BASE:
 163       g_value_set_boolean (value, GET_PRIVATE (filter_stream)->close_base);
 164       break;
 165
 166     default:
 167       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 168       break;
 169     }
 170
 171 }
 172
 173 static void
 174 g_filter_output_stream_dispose (GObject *object)
 175 {
 176   GFilterOutputStream *stream;
 177
 178   stream = G_FILTER_OUTPUT_STREAM (object);
 179
 180   G_OBJECT_CLASS (g_filter_output_stream_parent_class)->dispose (object);
 181
 182   if (stream->base_stream)
 183     {
 184       g_object_unref (stream->base_stream);
 185       stream->base_stream = NULL;
 186     }
 187 }
 188
 189
 190 static void
 191 g_filter_output_stream_init (GFilterOutputStream *stream)
 192 {
 193 }
 194
 195 /**
 196  * g_filter_output_stream_get_base_stream:
 197  * @stream: a #GFilterOutputStream.
 198  *
 199  * Gets the base stream for the filter stream.
 200  *
 201  * Returns: (transfer none): a #GOutputStream.
 202  **/
 203 GOutputStream *
 204 g_filter_output_stream_get_base_stream (GFilterOutputStream *stream)
 205 {
 206   g_return_val_if_fail (G_IS_FILTER_OUTPUT_STREAM (stream), NULL);
 207
 208   return stream->base_stream;
 209 }
 210
 211 /**
 212  * g_filter_output_stream_get_close_base_stream:
 213  * @stream: a #GFilterOutputStream.
 214  *
 215  * Returns whether the base stream will be closed when @stream is
 216  * closed.
 217  *
 218  * Return value: %TRUE if the base stream will be closed.
 219  **/
 220 gboolean
 221 g_filter_output_stream_get_close_base_stream (GFilterOutputStream *stream)
 222 {
 223   g_return_val_if_fail (G_IS_FILTER_OUTPUT_STREAM (stream), FALSE);
 224
 225   return GET_PRIVATE (stream)->close_base;
 226 }
 227
 228 /**
 229  * g_filter_output_stream_set_close_base_stream:
 230  * @stream: a #GFilterOutputStream.
 231  * @close_base: %TRUE to close the base stream.
 232  *
 233  * Sets whether the base stream will be closed when @stream is closed.
 234  **/
 235 void
 236 g_filter_output_stream_set_close_base_stream (GFilterOutputStream *stream,
 237                                               gboolean             close_base)
 238 {
 239   GFilterOutputStreamPrivate *priv;
 240
 241   g_return_if_fail (G_IS_FILTER_OUTPUT_STREAM (stream));
 242
 243   close_base = !!close_base;
 244
 245   priv = GET_PRIVATE (stream);
 246
 247   if (priv->close_base != close_base)
 248     {
 249       priv->close_base = close_base;
 250       g_object_notify (G_OBJECT (stream), "close-base-stream");
 251     }
 252 }
 253
 254 static gssize
 255 g_filter_output_stream_write (GOutputStream  *stream,
 256                               const void     *buffer,
 257                               gsize           count,
 258                               GCancellable   *cancellable,
 259                               GError        **error)
 260 {
 261   GFilterOutputStream *filter_stream;
 262   gssize nwritten;
 263
 264   filter_stream = G_FILTER_OUTPUT_STREAM (stream);
 265
 266   nwritten = g_output_stream_write (filter_stream->base_stream,
 267                                     buffer,
 268                                     count,
 269                                     cancellable,
 270                                     error);
 271
 272   return nwritten;
 273 }
 274
 275 static gboolean
 276 g_filter_output_stream_flush (GOutputStream  *stream,
 277                               GCancellable   *cancellable,
 278                               GError        **error)
 279 {
 280   GFilterOutputStream *filter_stream;
 281   gboolean res;
 282
 283   filter_stream = G_FILTER_OUTPUT_STREAM (stream);
 284
 285   res = g_output_stream_flush (filter_stream->base_stream,
 286                                cancellable,
 287                                error);
 288
 289   return res;
 290 }
 291
 292 static gboolean
 293 g_filter_output_stream_close (GOutputStream  *stream,
 294                               GCancellable   *cancellable,
 295                               GError        **error)
 296 {
 297   gboolean res = TRUE;
 298
 299   if (GET_PRIVATE (stream)->close_base)
 300     {
 301       GFilterOutputStream *filter_stream;
 302
 303       filter_stream = G_FILTER_OUTPUT_STREAM (stream);
 304
 305       res = g_output_stream_close (filter_stream->base_stream,
 306                                    cancellable,
 307                                    error);
 308     }
 309
 310   return res;
 311 }