service/dconf-writer.c

   1 /*
   2  * Copyright © 2010 Codethink Limited
   3  * Copyright © 2012 Canonical Limited
   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 licence, 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 Public
  16  * 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: Ryan Lortie <desrt@desrt.ca>
  21  */
  22
  23 #include "dconf-writer.h"
  24
  25 #include "../shm/dconf-shm.h"
  26 #include "dconf-gvdb-utils.h"
  27 #include "dconf-generated.h"
  28 #include "dconf-blame.h"
  29
  30 #include <stdlib.h>
  31 #include <unistd.h>
  32 #include <string.h>
  33 #include <fcntl.h>
  34 #include <errno.h>
  35 #include <stdio.h>
  36
  37 struct _DConfWriterPrivate
  38 {
  39   gchar *filename;
  40   gboolean native;
  41   gchar *basepath;
  42   gchar *name;
  43   guint64 tag;
  44
  45   DConfChangeset *uncommited_values;
  46   DConfChangeset *commited_values;
  47
  48   GQueue uncommited_changes;
  49   GQueue commited_changes;
  50 };
  51
  52 typedef struct
  53 {
  54   DConfChangeset *changeset;
  55   gchar          *tag;
  56 } TaggedChange;
  57
  58 static void dconf_writer_iface_init (DConfDBusWriterIface *iface);
  59
  60 G_DEFINE_TYPE_WITH_CODE (DConfWriter, dconf_writer, DCONF_DBUS_TYPE_WRITER_SKELETON,
  61                          G_IMPLEMENT_INTERFACE (DCONF_DBUS_TYPE_WRITER, dconf_writer_iface_init))
  62
  63 static void
  64 dconf_writer_real_list (GHashTable *set)
  65 {
  66   const gchar *name;
  67   gchar *dirname;
  68   GDir *dir;
  69
  70   dirname = g_build_filename (g_get_user_config_dir (), "dconf", NULL);
  71   dir = g_dir_open (dirname, 0, NULL);
  72
  73   if (!dir)
  74     return;
  75
  76   while ((name = g_dir_read_name (dir)))
  77     g_hash_table_add (set, g_strdup (name));
  78
  79   g_dir_close (dir);
  80 }
  81
  82 static gchar *
  83 dconf_writer_get_tag (DConfWriter *writer)
  84 {
  85   GDBusConnection *connection;
  86
  87   connection = g_dbus_interface_skeleton_get_connection (G_DBUS_INTERFACE_SKELETON (writer));
  88
  89   return g_strdup_printf ("%s:%s:%" G_GUINT64_FORMAT,
  90                           g_dbus_connection_get_unique_name (connection),
  91                           writer->priv->name, writer->priv->tag++);
  92 }
  93
  94 static gboolean
  95 dconf_writer_real_begin (DConfWriter  *writer,
  96                          GError      **error)
  97 {
  98   /* If this is the first time, populate the value table with the
  99    * existing values.
 100    */
 101   if (writer->priv->commited_values == NULL)
 102     {
 103       writer->priv->commited_values = dconf_gvdb_utils_read_file (writer->priv->filename, error);
 104
 105       if (!writer->priv->commited_values)
 106         return FALSE;
 107     }
 108
 109   writer->priv->uncommited_values = dconf_changeset_new_database (writer->priv->commited_values);
 110
 111   return TRUE;
 112 }
 113
 114 static void
 115 dconf_writer_real_change (DConfWriter    *writer,
 116                           DConfChangeset *changeset,
 117                           const gchar    *tag)
 118 {
 119   g_return_if_fail (writer->priv->uncommited_values != NULL);
 120
 121   dconf_changeset_change (writer->priv->uncommited_values, changeset);
 122
 123   if (tag)
 124     {
 125       TaggedChange *change;
 126
 127       change = g_slice_new (TaggedChange);
 128       change->changeset = dconf_changeset_ref (changeset);
 129       change->tag = g_strdup (tag);
 130
 131       g_queue_push_tail (&writer->priv->uncommited_changes, change);
 132     }
 133 }
 134
 135 static gboolean
 136 dconf_writer_real_commit (DConfWriter  *writer,
 137                           GError      **error)
 138 {
 139   gint invalidate_fd = -1;
 140
 141   if (!writer->priv->native)
 142     /* If it fails, it doesn't matter... */
 143     invalidate_fd = open (writer->priv->filename, O_WRONLY);
 144
 145   if (!dconf_gvdb_utils_write_file (writer->priv->filename, writer->priv->uncommited_values, error))
 146     return FALSE;
 147
 148   if (writer->priv->native)
 149     dconf_shm_flag (writer->priv->name);
 150
 151   if (invalidate_fd != -1)
 152     {
 153       write (invalidate_fd, "\0\0\0\0\0\0\0\0", 8);
 154       close (invalidate_fd);
 155     }
 156
 157   if (writer->priv->commited_values)
 158     dconf_changeset_unref (writer->priv->commited_values);
 159   writer->priv->commited_values = writer->priv->uncommited_values;
 160   writer->priv->uncommited_values = NULL;
 161
 162   {
 163     GQueue empty_queue = G_QUEUE_INIT;
 164
 165     g_assert (g_queue_is_empty (&writer->priv->commited_changes));
 166     writer->priv->commited_changes = writer->priv->uncommited_changes;
 167     writer->priv->uncommited_changes = empty_queue;
 168   }
 169
 170   return TRUE;
 171 }
 172
 173 static void
 174 dconf_writer_real_end (DConfWriter *writer)
 175 {
 176   while (!g_queue_is_empty (&writer->priv->uncommited_changes))
 177     {
 178       TaggedChange *change = g_queue_pop_head (&writer->priv->uncommited_changes);
 179       g_free (change->tag);
 180       g_slice_free (TaggedChange, change);
 181     }
 182
 183   while (!g_queue_is_empty (&writer->priv->commited_changes))
 184     {
 185       TaggedChange *change = g_queue_pop_head (&writer->priv->commited_changes);
 186       const gchar *prefix;
 187       const gchar * const *paths;
 188
 189       dconf_changeset_describe (change->changeset, &prefix, &paths, NULL);
 190       dconf_dbus_writer_emit_notify_signal (DCONF_DBUS_WRITER (writer), prefix, paths, change->tag);
 191       dconf_changeset_unref (change->changeset);
 192       g_free (change->tag);
 193       g_slice_free (TaggedChange, change);
 194     }
 195
 196   g_clear_pointer (&writer->priv->uncommited_values, dconf_changeset_unref);
 197 }
 198
 199 gboolean
 200 dconf_writer_begin (DConfWriter  *writer,
 201                     GError      **error)
 202 {
 203   return DCONF_WRITER_GET_CLASS (writer)->begin (writer, error);
 204 }
 205
 206 void
 207 dconf_writer_change (DConfWriter    *writer,
 208                      DConfChangeset *changeset,
 209                      const gchar    *tag)
 210 {
 211   DCONF_WRITER_GET_CLASS (writer)->change (writer, changeset, tag);
 212 }
 213
 214 gboolean
 215 dconf_writer_commit (DConfWriter  *writer,
 216                      GError      **error)
 217 {
 218   return DCONF_WRITER_GET_CLASS (writer)->commit (writer, error);
 219 }
 220
 221 void
 222 dconf_writer_end (DConfWriter *writer)
 223 {
 224   return DCONF_WRITER_GET_CLASS (writer)->end (writer);
 225 }
 226
 227 static gboolean
 228 dconf_writer_handle_init (DConfDBusWriter       *dbus_writer,
 229                           GDBusMethodInvocation *invocation)
 230 {
 231   DConfWriter *writer = DCONF_WRITER (dbus_writer);
 232   GError *error = NULL;
 233
 234   dconf_blame_record (invocation);
 235
 236   dconf_writer_begin (writer, &error) && dconf_writer_commit (writer, &error);
 237
 238   if (error)
 239     {
 240       g_dbus_method_invocation_return_gerror (invocation, error);
 241       g_error_free (error);
 242     }
 243
 244   else
 245     g_dbus_method_invocation_return_value (invocation, NULL);
 246
 247   dconf_writer_end (writer);
 248
 249   return TRUE;
 250 }
 251
 252 static gboolean
 253 dconf_writer_handle_change (DConfDBusWriter       *dbus_writer,
 254                             GDBusMethodInvocation *invocation,
 255                             GVariant              *blob)
 256 {
 257   DConfWriter *writer = DCONF_WRITER (dbus_writer);
 258   DConfChangeset *changeset;
 259   GError *error = NULL;
 260   GVariant *tmp, *args;
 261   gchar *tag;
 262
 263   dconf_blame_record (invocation);
 264
 265   tmp = g_variant_new_from_data (G_VARIANT_TYPE ("a{smv}"),
 266                                  g_variant_get_data (blob), g_variant_get_size (blob), FALSE,
 267                                  (GDestroyNotify) g_variant_unref, g_variant_ref (blob));
 268   g_variant_ref_sink (tmp);
 269   args = g_variant_get_normal_form (tmp);
 270   g_variant_unref (tmp);
 271
 272   changeset = dconf_changeset_deserialise (args);
 273   g_variant_unref (args);
 274
 275   tag = dconf_writer_get_tag (writer);
 276
 277   if (!dconf_writer_begin (writer, &error))
 278     goto out;
 279
 280   dconf_writer_change (writer, changeset, tag);
 281   dconf_changeset_unref (changeset);
 282
 283   if (!dconf_writer_commit (writer, &error))
 284     goto out;
 285
 286 out:
 287   if (error)
 288     {
 289       g_dbus_method_invocation_return_gerror (invocation, error);
 290       g_error_free (error);
 291     }
 292
 293   else
 294     g_dbus_method_invocation_return_value (invocation, g_variant_new ("(s)", tag));
 295
 296   g_free (tag);
 297
 298   dconf_writer_end (writer);
 299
 300   return TRUE;
 301 }
 302
 303 static void
 304 dconf_writer_iface_init (DConfDBusWriterIface *iface)
 305 {
 306   iface->handle_init = dconf_writer_handle_init;
 307   iface->handle_change = dconf_writer_handle_change;
 308 }
 309
 310 static void
 311 dconf_writer_init (DConfWriter *writer)
 312 {
 313   writer->priv = G_TYPE_INSTANCE_GET_PRIVATE (writer, DCONF_TYPE_WRITER, DConfWriterPrivate);
 314   writer->priv->basepath = g_build_filename (g_get_user_config_dir (), "dconf", NULL);
 315   writer->priv->native = TRUE;
 316 }
 317
 318 static void
 319 dconf_writer_set_property (GObject *object, guint prop_id,
 320                            const GValue *value, GParamSpec *pspec)
 321 {
 322   DConfWriter *writer = DCONF_WRITER (object);
 323
 324   g_assert_cmpint (prop_id, ==, 1);
 325
 326   g_assert (!writer->priv->name);
 327   writer->priv->name = g_value_dup_string (value);
 328
 329   writer->priv->filename = g_build_filename (writer->priv->basepath, writer->priv->name, NULL);
 330 }
 331
 332 static void
 333 dconf_writer_class_init (DConfWriterClass *class)
 334 {
 335   GObjectClass *object_class = G_OBJECT_CLASS (class);
 336
 337   object_class->set_property = dconf_writer_set_property;
 338
 339   class->begin = dconf_writer_real_begin;
 340   class->change = dconf_writer_real_change;
 341   class->commit = dconf_writer_real_commit;
 342   class->end = dconf_writer_real_end;
 343   class->list = dconf_writer_real_list;
 344
 345   g_object_class_install_property (object_class, 1,
 346                                    g_param_spec_string ("name", "name", "name", NULL,
 347                                                         G_PARAM_STATIC_STRINGS | G_PARAM_CONSTRUCT_ONLY |
 348                                                         G_PARAM_WRITABLE));
 349
 350   g_type_class_add_private (class, sizeof (DConfWriterPrivate));
 351 }
 352
 353 void
 354 dconf_writer_set_basepath (DConfWriter *writer,
 355                            const gchar *name)
 356 {
 357   g_free (writer->priv->basepath);
 358   writer->priv->basepath = g_build_filename (g_get_user_runtime_dir (), "dconf-service", name, NULL);
 359   writer->priv->native = FALSE;
 360 }
 361
 362 const gchar *
 363 dconf_writer_get_name (DConfWriter *writer)
 364 {
 365   return writer->priv->name;
 366 }
 367
 368 void
 369 dconf_writer_list (GType       type,
 370                    GHashTable *set)
 371 {
 372   DConfWriterClass *class;
 373
 374   g_return_if_fail (g_type_is_a (type, DCONF_TYPE_WRITER));
 375
 376   class = g_type_class_ref (type);
 377   class->list (set);
 378   g_type_class_unref (class);
 379 }
 380
 381 GDBusInterfaceSkeleton *
 382 dconf_writer_new (GType        type,
 383                   const gchar *name)
 384 {
 385   g_return_val_if_fail (g_type_is_a (type, DCONF_TYPE_WRITER), NULL);
 386
 387   return g_object_new (type, "name", name, NULL);
 388 }