glib/gio/gkeyfilesettingsbackend.c
Ryan Lortie 6c3ae976e6 Bug 621266 - GSettings "context" clarification
Remove the concept of "context" in favour of dealing with
GSettingsBackend directly.
2010-06-17 14:05:40 -04:00

544 lines
17 KiB
C

/*
* Copyright © 2010 Codethink Limited
* Copyright © 2010 Novell, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the licence, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*
* Authors: Vincent Untz <vuntz@gnome.org>
* Ryan Lortie <desrt@desrt.ca>
*/
#include "config.h"
#include "gkeyfilesettingsbackend.h"
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include "gioerror.h"
#include "giomodule.h"
#include "gfile.h"
#include "gfileinfo.h"
#include "gfilemonitor.h"
#include "gsimplepermission.h"
#include "gioalias.h"
G_DEFINE_TYPE (GKeyfileSettingsBackend,
g_keyfile_settings_backend,
G_TYPE_SETTINGS_BACKEND)
struct _GKeyfileSettingsBackendPrivate
{
GHashTable *table;
GKeyFile *keyfile;
gboolean writable;
gchar *file_path;
gchar *checksum;
GFileMonitor *monitor;
};
static GVariant *
g_keyfile_settings_backend_read (GSettingsBackend *backend,
const gchar *key,
const GVariantType *expected_type,
gboolean default_value)
{
GKeyfileSettingsBackend *kf_backend = G_KEYFILE_SETTINGS_BACKEND (backend);
GVariant *value;
if (default_value)
return NULL;
value = g_hash_table_lookup (kf_backend->priv->table, key);
if (value != NULL)
g_variant_ref (value);
return value;
}
static gboolean
g_keyfile_settings_backend_write_one (const gchar *key,
GVariant *value,
GKeyfileSettingsBackend *kf_backend)
{
const gchar *slash;
const gchar *base_key;
gchar *path;
g_hash_table_replace (kf_backend->priv->table,
g_strdup (key), g_variant_ref (value));
slash = strrchr (key, '/');
g_assert (slash != NULL);
base_key = (slash + 1);
path = g_strndup (key, slash - key + 1);
g_key_file_set_string (kf_backend->priv->keyfile,
path, base_key, g_variant_print (value, TRUE));
g_free (path);
return FALSE;
}
static void
g_keyfile_settings_backend_keyfile_write (GKeyfileSettingsBackend *kf_backend)
{
gchar *dirname;
gchar *contents;
gsize length;
GFile *file;
dirname = g_path_get_dirname (kf_backend->priv->file_path);
if (!g_file_test (dirname, G_FILE_TEST_IS_DIR))
g_mkdir_with_parents (dirname, 0700);
g_free (dirname);
contents = g_key_file_to_data (kf_backend->priv->keyfile, &length, NULL);
file = g_file_new_for_path (kf_backend->priv->file_path);
g_file_replace_contents (file, contents, length,
NULL, FALSE, G_FILE_CREATE_REPLACE_DESTINATION,
NULL, NULL, NULL);
g_object_unref (file);
g_free (kf_backend->priv->checksum);
kf_backend->priv->checksum = g_compute_checksum_for_string (G_CHECKSUM_SHA256, contents, length);
g_free (contents);
}
static gboolean
g_keyfile_settings_backend_write (GSettingsBackend *backend,
const gchar *key,
GVariant *value,
gpointer origin_tag)
{
GKeyfileSettingsBackend *kf_backend = G_KEYFILE_SETTINGS_BACKEND (backend);
g_keyfile_settings_backend_write_one (key, value, kf_backend);
g_keyfile_settings_backend_keyfile_write (kf_backend);
g_settings_backend_changed (backend, key, origin_tag);
return TRUE;
}
static gboolean
g_keyfile_settings_backend_write_keys (GSettingsBackend *backend,
GTree *tree,
gpointer origin_tag)
{
GKeyfileSettingsBackend *kf_backend = G_KEYFILE_SETTINGS_BACKEND (backend);
g_tree_foreach (tree, (GTraverseFunc) g_keyfile_settings_backend_write_one, backend);
g_keyfile_settings_backend_keyfile_write (kf_backend);
g_settings_backend_changed_tree (backend, tree, origin_tag);
return TRUE;
}
static void
g_keyfile_settings_backend_reset_path (GSettingsBackend *backend,
const gchar *path,
gpointer origin_tag)
{
GKeyfileSettingsBackend *kf_backend = G_KEYFILE_SETTINGS_BACKEND (backend);
GPtrArray *reset_array;
GList *hash_keys;
GList *l;
gboolean changed;
gchar **groups = NULL;
gsize groups_nb = 0;
int i;
reset_array = g_ptr_array_new_with_free_func (g_free);
hash_keys = g_hash_table_get_keys (kf_backend->priv->table);
for (l = hash_keys; l != NULL; l = l->next)
{
if (g_str_has_prefix (l->data, path))
{
g_hash_table_remove (kf_backend->priv->table, l->data);
g_ptr_array_add (reset_array, g_strdup (l->data));
}
}
g_list_free (hash_keys);
changed = FALSE;
groups = g_key_file_get_groups (kf_backend->priv->keyfile, &groups_nb);
for (i = 0; i < groups_nb; i++)
{
if (g_str_has_prefix (groups[i], path))
changed = g_key_file_remove_group (kf_backend->priv->keyfile, groups[i], NULL) || changed;
}
g_strfreev (groups);
if (changed)
g_keyfile_settings_backend_keyfile_write (kf_backend);
if (reset_array->len > 0)
{
/* the array has to be NULL-terminated */
g_ptr_array_add (reset_array, NULL);
g_settings_backend_keys_changed (G_SETTINGS_BACKEND (kf_backend),
"",
(const gchar **) reset_array->pdata,
origin_tag);
}
g_ptr_array_free (reset_array, TRUE);
}
static void
g_keyfile_settings_backend_reset (GSettingsBackend *backend,
const gchar *key,
gpointer origin_tag)
{
GKeyfileSettingsBackend *kf_backend = G_KEYFILE_SETTINGS_BACKEND (backend);
gboolean had_key;
const gchar *slash;
const gchar *base_key;
gchar *path;
had_key = g_hash_table_lookup_extended (kf_backend->priv->table, key, NULL, NULL);
if (had_key)
g_hash_table_remove (kf_backend->priv->table, key);
slash = strrchr (key, '/');
g_assert (slash != NULL);
base_key = (slash + 1);
path = g_strndup (key, slash - key + 1);
if (g_key_file_remove_key (kf_backend->priv->keyfile, path, base_key, NULL))
g_keyfile_settings_backend_keyfile_write (kf_backend);
g_free (path);
if (had_key)
g_settings_backend_changed (G_SETTINGS_BACKEND (kf_backend), key, origin_tag);
}
static gboolean
g_keyfile_settings_backend_get_writable (GSettingsBackend *backend,
const gchar *name)
{
GKeyfileSettingsBackend *kf_backend = G_KEYFILE_SETTINGS_BACKEND (backend);
return kf_backend->priv->writable;
}
static GPermission *
g_keyfile_settings_backend_get_permission (GSettingsBackend *backend,
const gchar *path)
{
return g_simple_permission_new (TRUE);
}
static void
g_keyfile_settings_backend_keyfile_reload (GKeyfileSettingsBackend *kf_backend)
{
gchar *contents = NULL;
gsize length = 0;
gchar *new_checksum;
GHashTable *loaded_keys;
GPtrArray *changed_array;
gchar **groups = NULL;
gsize groups_nb = 0;
int i;
GList *keys_l = NULL;
GList *l;
if (!g_file_get_contents (kf_backend->priv->file_path,
&contents, &length, NULL))
{
contents = g_strdup ("");
length = 0;
}
new_checksum = g_compute_checksum_for_string (G_CHECKSUM_SHA256, contents, length);
if (g_strcmp0 (kf_backend->priv->checksum, new_checksum) == 0)
{
g_free (new_checksum);
return;
}
if (kf_backend->priv->checksum != NULL)
g_free (kf_backend->priv->checksum);
kf_backend->priv->checksum = new_checksum;
if (kf_backend->priv->keyfile != NULL)
g_key_file_free (kf_backend->priv->keyfile);
kf_backend->priv->keyfile = g_key_file_new ();
/* we just silently ignore errors: there's not much we can do about them */
if (length > 0)
g_key_file_load_from_data (kf_backend->priv->keyfile, contents, length,
G_KEY_FILE_KEEP_COMMENTS|G_KEY_FILE_KEEP_TRANSLATIONS, NULL);
loaded_keys = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
changed_array = g_ptr_array_new_with_free_func (g_free);
/* Load keys from the keyfile */
groups = g_key_file_get_groups (kf_backend->priv->keyfile, &groups_nb);
for (i = 0; i < groups_nb; i++)
{
gchar **keys = NULL;
gsize keys_nb = 0;
int j;
keys = g_key_file_get_keys (kf_backend->priv->keyfile, groups[i], &keys_nb, NULL);
if (keys == NULL)
continue;
for (j = 0; j < keys_nb; j++)
{
gchar *value;
gchar *full_key;
GVariant *old_variant;
GVariant *variant;
value = g_key_file_get_string (kf_backend->priv->keyfile, groups[i], keys[j], NULL);
if (value == NULL)
continue;
variant = g_variant_new_parsed (value);
g_free (value);
if (variant == NULL)
continue;
full_key = g_strjoin ("", groups[i], keys[j], NULL),
g_hash_table_insert (loaded_keys, full_key, GINT_TO_POINTER(TRUE));
old_variant = g_hash_table_lookup (kf_backend->priv->table, full_key);
if (old_variant == NULL || !g_variant_equal (old_variant, variant))
{
g_ptr_array_add (changed_array, g_strdup (full_key));
g_hash_table_replace (kf_backend->priv->table,
g_strdup (full_key),
g_variant_ref_sink (variant));
}
else
g_variant_unref (variant);
}
g_strfreev (keys);
}
g_strfreev (groups);
/* Remove keys that were in the hashtable but not in the keyfile */
keys_l = g_hash_table_get_keys (kf_backend->priv->table);
for (l = keys_l; l != NULL; l = l->next)
{
gchar *key = l->data;
if (g_hash_table_lookup_extended (loaded_keys, key, NULL, NULL))
continue;
g_ptr_array_add (changed_array, g_strdup (key));
g_hash_table_remove (kf_backend->priv->table, key);
}
g_list_free (keys_l);
if (changed_array->len > 0)
{
/* the array has to be NULL-terminated */
g_ptr_array_add (changed_array, NULL);
g_settings_backend_keys_changed (G_SETTINGS_BACKEND (kf_backend),
"",
(const gchar **) changed_array->pdata,
NULL);
}
g_hash_table_unref (loaded_keys);
g_ptr_array_free (changed_array, TRUE);
}
static gboolean
g_keyfile_settings_backend_keyfile_writable (GFile *file)
{
GFileInfo *fileinfo;
GError *error;
gboolean writable = FALSE;
error = NULL;
fileinfo = g_file_query_info (file, "access::*",
G_FILE_QUERY_INFO_NONE, NULL, &error);
if (fileinfo == NULL)
{
if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_NOT_FOUND))
{
GFile *parent;
parent = g_file_get_parent (file);
if (parent)
{
writable = g_keyfile_settings_backend_keyfile_writable (parent);
g_object_unref (parent);
}
}
g_error_free (error);
return writable;
}
/* We don't want to mark the backend as writable if the file is not readable,
* since it means we won't be able to load the content of the file, and we'll
* lose data. */
writable =
g_file_info_get_attribute_boolean (fileinfo, G_FILE_ATTRIBUTE_ACCESS_CAN_READ) &&
g_file_info_get_attribute_boolean (fileinfo, G_FILE_ATTRIBUTE_ACCESS_CAN_WRITE);
g_object_unref (fileinfo);
return writable;
}
static void
g_keyfile_settings_backend_keyfile_changed (GFileMonitor *monitor,
GFile *file,
GFile *other_file,
GFileMonitorEvent event_type,
gpointer user_data)
{
GKeyfileSettingsBackend *kf_backend;
if (event_type != G_FILE_MONITOR_EVENT_CHANGED &&
event_type != G_FILE_MONITOR_EVENT_CREATED &&
event_type != G_FILE_MONITOR_EVENT_DELETED &&
event_type != G_FILE_MONITOR_EVENT_ATTRIBUTE_CHANGED)
return;
kf_backend = G_KEYFILE_SETTINGS_BACKEND (user_data);
if (event_type == G_FILE_MONITOR_EVENT_ATTRIBUTE_CHANGED)
{
gboolean writable;
writable = g_keyfile_settings_backend_keyfile_writable (file);
if (kf_backend->priv->writable == writable)
return;
kf_backend->priv->writable = writable;
if (!writable)
return;
/* else: reload the file since it was possibly not readable before */
}
g_keyfile_settings_backend_keyfile_reload (kf_backend);
}
static void
g_keyfile_settings_backend_finalize (GObject *object)
{
GKeyfileSettingsBackend *kf_backend = G_KEYFILE_SETTINGS_BACKEND (object);
g_hash_table_unref (kf_backend->priv->table);
kf_backend->priv->table = NULL;
g_key_file_free (kf_backend->priv->keyfile);
kf_backend->priv->keyfile = NULL;
g_free (kf_backend->priv->file_path);
kf_backend->priv->file_path = NULL;
g_free (kf_backend->priv->checksum);
kf_backend->priv->checksum = NULL;
g_file_monitor_cancel (kf_backend->priv->monitor);
g_object_unref (kf_backend->priv->monitor);
kf_backend->priv->monitor = NULL;
G_OBJECT_CLASS (g_keyfile_settings_backend_parent_class)
->finalize (object);
}
static void
g_keyfile_settings_backend_init (GKeyfileSettingsBackend *kf_backend)
{
kf_backend->priv = G_TYPE_INSTANCE_GET_PRIVATE (kf_backend,
G_TYPE_KEYFILE_SETTINGS_BACKEND,
GKeyfileSettingsBackendPrivate);
kf_backend->priv->table =
g_hash_table_new_full (g_str_hash, g_str_equal, g_free,
(GDestroyNotify) g_variant_unref);
kf_backend->priv->keyfile = NULL;
kf_backend->priv->writable = FALSE;
kf_backend->priv->file_path = NULL;
kf_backend->priv->checksum = NULL;
kf_backend->priv->monitor = NULL;
}
static void
g_keyfile_settings_backend_class_init (GKeyfileSettingsBackendClass *class)
{
GSettingsBackendClass *backend_class = G_SETTINGS_BACKEND_CLASS (class);
GObjectClass *object_class = G_OBJECT_CLASS (class);
object_class->finalize = g_keyfile_settings_backend_finalize;
backend_class->read = g_keyfile_settings_backend_read;
backend_class->write = g_keyfile_settings_backend_write;
backend_class->write_keys = g_keyfile_settings_backend_write_keys;
backend_class->reset = g_keyfile_settings_backend_reset;
backend_class->reset_path = g_keyfile_settings_backend_reset_path;
backend_class->get_writable = g_keyfile_settings_backend_get_writable;
backend_class->get_permission = g_keyfile_settings_backend_get_permission;
/* No need to implement subscribed/unsubscribe: the only point would be to
* stop monitoring the file when there's no GSettings anymore, which is no
* big win. */
g_type_class_add_private (class, sizeof (GKeyfileSettingsBackendPrivate));
}
GSettingsBackend *
g_keyfile_settings_backend_new (const gchar *filename)
{
GKeyfileSettingsBackend *kf_backend;
GFile *file;
kf_backend = g_object_new (G_TYPE_KEYFILE_SETTINGS_BACKEND, NULL);
kf_backend->priv->file_path = g_strdup (filename);
file = g_file_new_for_path (kf_backend->priv->file_path);
kf_backend->priv->writable = g_keyfile_settings_backend_keyfile_writable (file);
kf_backend->priv->monitor = g_file_monitor_file (file, G_FILE_MONITOR_SEND_MOVED, NULL, NULL);
g_signal_connect (kf_backend->priv->monitor, "changed",
(GCallback)g_keyfile_settings_backend_keyfile_changed, kf_backend);
g_object_unref (file);
g_keyfile_settings_backend_keyfile_reload (kf_backend);
return G_SETTINGS_BACKEND (kf_backend);
}
#define __G_KEYFILE_SETTINGS_BACKEND_C__
#include "gioaliasdef.c"