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, see <http://www.gnu.org/licenses/>.
  17  *
  18  * Author: Christian Kellner <gicmo@gnome.org>
  19  */
  20
  21 #include "config.h"
  22 #include "gfilteroutputstream.h"
  23 #include "goutputstream.h"
  24 #include "glibintl.h"
  25
  26
  27 /**
  28  * SECTION:gfilteroutputstream
  29  * @short_description: Filter Output Stream
  30  * @include: gio/gio.h
  31  *
  32  * Base class for output stream implementations that perform some
  33  * kind of filtering operation on a base stream. Typical examples
  34  * of filtering operations are character set conversion, compression
  35  * and byte order flipping.
  36  */
  37
  38 enum {
  39   PROP_0,
  40   PROP_BASE_STREAM,
  41   PROP_CLOSE_BASE
  42 };
  43
  44 static void     g_filter_output_stream_set_property (GObject      *object,
  45                                                      guint         prop_id,
  46                                                      const GValue *value,
  47                                                      GParamSpec   *pspec);
  48
  49 static void     g_filter_output_stream_get_property (GObject    *object,
  50                                                      guint       prop_id,
  51                                                      GValue     *value,
  52                                                      GParamSpec *pspec);
  53 static void     g_filter_output_stream_dispose      (GObject *object);
  54
  55
  56 static gssize   g_filter_output_stream_write        (GOutputStream *stream,
  57                                                      const void    *buffer,
  58                                                      gsize          count,
  59                                                      GCancellable  *cancellable,
  60                                                      GError       **error);
  61 static gboolean g_filter_output_stream_flush        (GOutputStream    *stream,
  62                                                      GCancellable  *cancellable,
  63                                                      GError          **error);
  64 static gboolean g_filter_output_stream_close        (GOutputStream  *stream,
  65                                                      GCancellable   *cancellable,
  66                                                      GError        **error);
  67
  68 typedef struct
  69 {
  70   gboolean close_base;
  71 } GFilterOutputStreamPrivate;
  72
  73 G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (GFilterOutputStream, g_filter_output_stream, G_TYPE_OUTPUT_STREAM)
  74
  75 static void
  76 g_filter_output_stream_class_init (GFilterOutputStreamClass *klass)
  77 {
  78   GObjectClass *object_class;
  79   GOutputStreamClass *ostream_class;
  80
  81   object_class = G_OBJECT_CLASS (klass);
  82   object_class->get_property = g_filter_output_stream_get_property;
  83   object_class->set_property = g_filter_output_stream_set_property;
  84   object_class->dispose      = g_filter_output_stream_dispose;
  85
  86   ostream_class = G_OUTPUT_STREAM_CLASS (klass);
  87   ostream_class->write_fn = g_filter_output_stream_write;
  88   ostream_class->flush = g_filter_output_stream_flush;
  89   ostream_class->close_fn = g_filter_output_stream_close;
  90
  91   g_object_class_install_property (object_class,
  92                                    PROP_BASE_STREAM,
  93                                    g_param_spec_object ("base-stream",
  94                                                          P_("The Filter Base Stream"),
  95                                                          P_("The underlying base stream on which the io ops will be done."),
  96                                                          G_TYPE_OUTPUT_STREAM,
  97                                                          G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY |
  98                                                          G_PARAM_STATIC_NAME|G_PARAM_STATIC_NICK|G_PARAM_STATIC_BLURB));
  99
 100   g_object_class_install_property (object_class,
 101                                    PROP_CLOSE_BASE,
 102                                    g_param_spec_boolean ("close-base-stream",
 103                                                          P_("Close Base Stream"),
 104                                                          P_("If the base stream should be closed when the filter stream is closed."),
 105                                                          TRUE, G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY |
 106                                                          G_PARAM_STATIC_NAME|G_PARAM_STATIC_NICK|G_PARAM_STATIC_BLURB));
 107 }
 108
 109 static void
 110 g_filter_output_stream_set_property (GObject      *object,
 111                                      guint         prop_id,
 112                                      const GValue *value,
 113                                      GParamSpec   *pspec)
 114 {
 115   GFilterOutputStream *filter_stream;
 116   GObject *obj;
 117
 118   filter_stream = G_FILTER_OUTPUT_STREAM (object);
 119
 120   switch (prop_id)
 121     {
 122     case PROP_BASE_STREAM:
 123       obj = g_value_dup_object (value);
 124       filter_stream->base_stream = G_OUTPUT_STREAM (obj);
 125       break;
 126
 127     case PROP_CLOSE_BASE:
 128       g_filter_output_stream_set_close_base_stream (filter_stream,
 129                                                     g_value_get_boolean (value));
 130       break;
 131
 132     default:
 133       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 134       break;
 135     }
 136
 137 }
 138
 139 static void
 140 g_filter_output_stream_get_property (GObject    *object,
 141                                      guint       prop_id,
 142                                      GValue     *value,
 143                                      GParamSpec *pspec)
 144 {
 145   GFilterOutputStream *filter_stream;
 146   GFilterOutputStreamPrivate *priv;
 147
 148   filter_stream = G_FILTER_OUTPUT_STREAM (object);
 149   priv = g_filter_output_stream_get_instance_private (filter_stream);
 150
 151   switch (prop_id)
 152     {
 153     case PROP_BASE_STREAM:
 154       g_value_set_object (value, filter_stream->base_stream);
 155       break;
 156
 157     case PROP_CLOSE_BASE:
 158       g_value_set_boolean (value, priv->close_base);
 159       break;
 160
 161     default:
 162       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 163       break;
 164     }
 165
 166 }
 167
 168 static void
 169 g_filter_output_stream_dispose (GObject *object)
 170 {
 171   GFilterOutputStream *stream;
 172
 173   stream = G_FILTER_OUTPUT_STREAM (object);
 174
 175   G_OBJECT_CLASS (g_filter_output_stream_parent_class)->dispose (object);
 176
 177   if (stream->base_stream)
 178     {
 179       g_object_unref (stream->base_stream);
 180       stream->base_stream = NULL;
 181     }
 182 }
 183
 184
 185 static void
 186 g_filter_output_stream_init (GFilterOutputStream *stream)
 187 {
 188 }
 189
 190 /**
 191  * g_filter_output_stream_get_base_stream:
 192  * @stream: a #GFilterOutputStream.
 193  *
 194  * Gets the base stream for the filter stream.
 195  *
 196  * Returns: (transfer none): a #GOutputStream.
 197  **/
 198 GOutputStream *
 199 g_filter_output_stream_get_base_stream (GFilterOutputStream *stream)
 200 {
 201   g_return_val_if_fail (G_IS_FILTER_OUTPUT_STREAM (stream), NULL);
 202
 203   return stream->base_stream;
 204 }
 205
 206 /**
 207  * g_filter_output_stream_get_close_base_stream:
 208  * @stream: a #GFilterOutputStream.
 209  *
 210  * Returns whether the base stream will be closed when @stream is
 211  * closed.
 212  *
 213  * Returns: %TRUE if the base stream will be closed.
 214  **/
 215 gboolean
 216 g_filter_output_stream_get_close_base_stream (GFilterOutputStream *stream)
 217 {
 218   GFilterOutputStreamPrivate *priv;
 219
 220   g_return_val_if_fail (G_IS_FILTER_OUTPUT_STREAM (stream), FALSE);
 221
 222   priv = g_filter_output_stream_get_instance_private (stream);
 223
 224   return priv->close_base;
 225 }
 226
 227 /**
 228  * g_filter_output_stream_set_close_base_stream:
 229  * @stream: a #GFilterOutputStream.
 230  * @close_base: %TRUE to close the base stream.
 231  *
 232  * Sets whether the base stream will be closed when @stream is closed.
 233  **/
 234 void
 235 g_filter_output_stream_set_close_base_stream (GFilterOutputStream *stream,
 236                                               gboolean             close_base)
 237 {
 238   GFilterOutputStreamPrivate *priv;
 239
 240   g_return_if_fail (G_IS_FILTER_OUTPUT_STREAM (stream));
 241
 242   close_base = !!close_base;
 243
 244   priv = g_filter_output_stream_get_instance_private (stream);
 245
 246   if (priv->close_base != close_base)
 247     {
 248       priv->close_base = close_base;
 249       g_object_notify (G_OBJECT (stream), "close-base-stream");
 250     }
 251 }
 252
 253 static gssize
 254 g_filter_output_stream_write (GOutputStream  *stream,
 255                               const void     *buffer,
 256                               gsize           count,
 257                               GCancellable   *cancellable,
 258                               GError        **error)
 259 {
 260   GFilterOutputStream *filter_stream;
 261   gssize nwritten;
 262
 263   filter_stream = G_FILTER_OUTPUT_STREAM (stream);
 264
 265   nwritten = g_output_stream_write (filter_stream->base_stream,
 266                                     buffer,
 267                                     count,
 268                                     cancellable,
 269                                     error);
 270
 271   return nwritten;
 272 }
 273
 274 static gboolean
 275 g_filter_output_stream_flush (GOutputStream  *stream,
 276                               GCancellable   *cancellable,
 277                               GError        **error)
 278 {
 279   GFilterOutputStream *filter_stream;
 280   gboolean res;
 281
 282   filter_stream = G_FILTER_OUTPUT_STREAM (stream);
 283
 284   res = g_output_stream_flush (filter_stream->base_stream,
 285                                cancellable,
 286                                error);
 287
 288   return res;
 289 }
 290
 291 static gboolean
 292 g_filter_output_stream_close (GOutputStream  *stream,
 293                               GCancellable   *cancellable,
 294                               GError        **error)
 295 {
 296   GFilterOutputStream *filter_stream = G_FILTER_OUTPUT_STREAM (stream);
 297   GFilterOutputStreamPrivate *priv = g_filter_output_stream_get_instance_private (filter_stream);
 298   gboolean res = TRUE;
 299
 300   if (priv->close_base)
 301     {
 302       res = g_output_stream_close (filter_stream->base_stream,
 303                                    cancellable,
 304                                    error);
 305     }
 306
 307   return res;
 308 }