X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=gio%2Fgsettingsbackend.c;h=f211e2cbf095f4812916017f6741c7f8d542985f;hb=7a1aaaa1fa02679ecf335a19fffe3f55505921b5;hp=28bdd34cbcba07e2f6d995ad6e396535b4bd698e;hpb=eaaa4d14aa8166b72b4dd7b703b1cca143d725cc;p=platform%2Fupstream%2Fglib.git diff --git a/gio/gsettingsbackend.c b/gio/gsettingsbackend.c index 28bdd34..f211e2c 100644 --- a/gio/gsettingsbackend.c +++ b/gio/gsettingsbackend.c @@ -13,9 +13,7 @@ * 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. + * License along with this library; if not, see . * * Authors: Ryan Lortie * Matthias Clasen @@ -24,37 +22,37 @@ #include "config.h" #include "gsettingsbackendinternal.h" -#include "gnullsettingsbackend.h" +#include "gsimplepermission.h" #include "giomodule-priv.h" -#include "gio-marshal.h" #include #include #include #include -#include "gioalias.h" -G_DEFINE_ABSTRACT_TYPE (GSettingsBackend, g_settings_backend, G_TYPE_OBJECT) - -typedef struct _GSettingsBackendWatch GSettingsBackendWatch; +typedef struct _GSettingsBackendClosure GSettingsBackendClosure; +typedef struct _GSettingsBackendWatch GSettingsBackendWatch; struct _GSettingsBackendPrivate { GSettingsBackendWatch *watches; - gchar *context; + GMutex lock; }; -enum -{ - PROP_0, - PROP_CONTEXT -}; +G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (GSettingsBackend, g_settings_backend, G_TYPE_OBJECT) + +/* For g_settings_backend_sync_default(), we only want to actually do + * the sync if the backend already exists. This avoids us creating an + * entire GSettingsBackend in order to call a do-nothing sync() + * operation on it. This variable lets us avoid that. + */ +static gboolean g_settings_has_backend; /** * SECTION:gsettingsbackend * @title: GSettingsBackend - * @short_description: an interface for settings backend implementations + * @short_description: Interface for settings backend implementations * @include: gio/gsettingsbackend.h * @see_also: #GSettings, #GIOExtensionPoint * @@ -77,106 +75,258 @@ enum * g_settings_backend_create_tree() is a convenience function to create * suitable trees. * - * - * The #GSettingsBackend API is exported to allow third-party + * The GSettingsBackend API is exported to allow third-party * implementations, but does not carry the same stability guarantees * as the public GIO API. For this reason, you have to define the - * C preprocessor symbol #G_SETTINGS_ENABLE_BACKEND before including - * gio/gsettingsbackend.h - * + * C preprocessor symbol %G_SETTINGS_ENABLE_BACKEND before including + * `gio/gsettingsbackend.h`. **/ -struct _GSettingsBackendWatch +static gboolean +is_key (const gchar *key) { - GSettingsBackendChangedFunc changed; - GSettingsBackendPathChangedFunc path_changed; - GSettingsBackendKeysChangedFunc keys_changed; - GSettingsBackendWritableChangedFunc writable_changed; - GSettingsBackendPathWritableChangedFunc path_writable_changed; - gpointer user_data; + gint length; + gint i; - GSettingsBackendWatch *next; -}; + g_return_val_if_fail (key != NULL, FALSE); + g_return_val_if_fail (key[0] == '/', FALSE); -void -g_settings_backend_watch (GSettingsBackend *backend, - GSettingsBackendChangedFunc changed, - GSettingsBackendPathChangedFunc path_changed, - GSettingsBackendKeysChangedFunc keys_changed, - GSettingsBackendWritableChangedFunc writable_changed, - GSettingsBackendPathWritableChangedFunc path_writable_changed, - gpointer user_data) + for (i = 1; key[i]; i++) + g_return_val_if_fail (key[i] != '/' || key[i + 1] != '/', FALSE); + + length = i; + + g_return_val_if_fail (key[length - 1] != '/', FALSE); + + return TRUE; +} + +static gboolean +is_path (const gchar *path) { - GSettingsBackendWatch *watch; + gint length; + gint i; - watch = g_slice_new (GSettingsBackendWatch); - watch->changed = changed; - watch->path_changed = path_changed; - watch->keys_changed = keys_changed; - watch->writable_changed = writable_changed; - watch->path_writable_changed = path_writable_changed; - watch->user_data = user_data; + g_return_val_if_fail (path != NULL, FALSE); + g_return_val_if_fail (path[0] == '/', FALSE); - watch->next = backend->priv->watches; - backend->priv->watches = watch; + for (i = 1; path[i]; i++) + g_return_val_if_fail (path[i] != '/' || path[i + 1] != '/', FALSE); + + length = i; + + g_return_val_if_fail (path[length - 1] == '/', FALSE); + + return TRUE; } -void -g_settings_backend_unwatch (GSettingsBackend *backend, - gpointer user_data) +struct _GSettingsBackendWatch { + GObject *target; + const GSettingsListenerVTable *vtable; + GMainContext *context; + GSettingsBackendWatch *next; +}; + +struct _GSettingsBackendClosure +{ + void (*function) (GObject *target, + GSettingsBackend *backend, + const gchar *name, + gpointer origin_tag, + gchar **names); + + GMainContext *context; + GObject *target; + GSettingsBackend *backend; + gchar *name; + gpointer origin_tag; + gchar **names; +}; + +static void +g_settings_backend_watch_weak_notify (gpointer data, + GObject *where_the_object_was) +{ + GSettingsBackend *backend = data; GSettingsBackendWatch **ptr; + /* search and remove */ + g_mutex_lock (&backend->priv->lock); for (ptr = &backend->priv->watches; *ptr; ptr = &(*ptr)->next) - if ((*ptr)->user_data == user_data) + if ((*ptr)->target == where_the_object_was) { GSettingsBackendWatch *tmp = *ptr; *ptr = tmp->next; g_slice_free (GSettingsBackendWatch, tmp); + g_mutex_unlock (&backend->priv->lock); return; } + /* we didn't find it. that shouldn't happen. */ g_assert_not_reached (); } -static gboolean -is_key (const gchar *key) +/*< private > + * g_settings_backend_watch: + * @backend: a #GSettingsBackend + * @target: the GObject (typically GSettings instance) to call back to + * @context: (allow-none): a #GMainContext, or %NULL + * ...: callbacks... + * + * Registers a new watch on a #GSettingsBackend. + * + * note: %NULL @context does not mean "default main context" but rather, + * "it is okay to dispatch in any context". If the default main context + * is specifically desired then it must be given. + * + * note also: if you want to get meaningful values for the @origin_tag + * that appears as an argument to some of the callbacks, you *must* have + * @context as %NULL. Otherwise, you are subject to cross-thread + * dispatching and whatever owned @origin_tag at the time that the event + * occurred may no longer own it. This is a problem if you consider that + * you may now be the new owner of that address and mistakenly think + * that the event in question originated from yourself. + * + * tl;dr: If you give a non-%NULL @context then you must ignore the + * value of @origin_tag given to any callbacks. + **/ +void +g_settings_backend_watch (GSettingsBackend *backend, + const GSettingsListenerVTable *vtable, + GObject *target, + GMainContext *context) { - gint length; - gint i; - - g_return_val_if_fail (key != NULL, FALSE); - g_return_val_if_fail (key[0] == '/', FALSE); + GSettingsBackendWatch *watch; - for (i = 1; key[i]; i++) - g_return_val_if_fail (key[i] != '/' || key[i + 1] != '/', FALSE); + /* For purposes of discussion, we assume that our target is a + * GSettings instance. + * + * Our strategy to defend against the final reference dropping on the + * GSettings object in a thread other than the one that is doing the + * dispatching is as follows: + * + * 1) hold a GObject reference on the GSettings during an outstanding + * dispatch. This ensures that the delivery is always possible. + * + * 2) hold a weak reference on the GSettings at other times. This + * allows us to receive early notification of pending destruction + * of the object. At this point, it is still safe to obtain a + * reference on the GObject to keep it alive, so #1 will work up + * to that point. After that point, we'll have been able to drop + * the watch from the list. + * + * Note, in particular, that it's not possible to simply have an + * "unwatch" function that gets called from the finalize function of + * the GSettings instance because, by that point it is no longer + * possible to keep the object alive using g_object_ref() and we would + * have no way of knowing this. + * + * Note also that we do not need to hold a reference on the main + * context here since the GSettings instance does that for us and we + * will receive the weak notify long before it is dropped. We don't + * even need to hold it during dispatches because our reference on the + * GSettings will prevent the finalize from running and dropping the + * ref on the context. + * + * All access to the list holds a mutex. We have some strategies to + * avoid some of the pain that would be associated with that. + */ - length = i; + watch = g_slice_new (GSettingsBackendWatch); + watch->context = context; + watch->vtable = vtable; + watch->target = target; + g_object_weak_ref (target, g_settings_backend_watch_weak_notify, backend); - g_return_val_if_fail (key[length - 1] != '/', FALSE); + /* linked list prepend */ + g_mutex_lock (&backend->priv->lock); + watch->next = backend->priv->watches; + backend->priv->watches = watch; + g_mutex_unlock (&backend->priv->lock); +} - return TRUE; +void +g_settings_backend_unwatch (GSettingsBackend *backend, + GObject *target) +{ + /* Our caller surely owns a reference on 'target', so the order of + * these two calls is unimportant. + */ + g_object_weak_unref (target, g_settings_backend_watch_weak_notify, backend); + g_settings_backend_watch_weak_notify (backend, target); } static gboolean -is_path (const gchar *path) +g_settings_backend_invoke_closure (gpointer user_data) { - gint length; - gint i; + GSettingsBackendClosure *closure = user_data; - g_return_val_if_fail (path != NULL, FALSE); - g_return_val_if_fail (path[0] == '/', FALSE); + closure->function (closure->target, closure->backend, closure->name, + closure->origin_tag, closure->names); - for (i = 1; path[i]; i++) - g_return_val_if_fail (path[i] != '/' || path[i + 1] != '/', FALSE); + g_object_unref (closure->backend); + g_object_unref (closure->target); + g_strfreev (closure->names); + g_free (closure->name); - length = i; + g_slice_free (GSettingsBackendClosure, closure); - g_return_val_if_fail (path[length - 1] == '/', FALSE); + return FALSE; +} - return TRUE; +static void +g_settings_backend_dispatch_signal (GSettingsBackend *backend, + gsize function_offset, + const gchar *name, + gpointer origin_tag, + const gchar * const *names) +{ + GSettingsBackendWatch *watch; + GSList *closures = NULL; + + /* We're in a little bit of a tricky situation here. We need to hold + * a lock while traversing the list, but we don't want to hold the + * lock while calling back into user code. + * + * We work around this by creating a bunch of GSettingsBackendClosure + * objects while holding the lock and dispatching them after. We + * never touch the list without holding the lock. + */ + g_mutex_lock (&backend->priv->lock); + for (watch = backend->priv->watches; watch; watch = watch->next) + { + GSettingsBackendClosure *closure; + + closure = g_slice_new (GSettingsBackendClosure); + closure->context = watch->context; + closure->backend = g_object_ref (backend); + closure->target = g_object_ref (watch->target); + closure->function = G_STRUCT_MEMBER (void *, watch->vtable, + function_offset); + closure->name = g_strdup (name); + closure->origin_tag = origin_tag; + closure->names = g_strdupv ((gchar **) names); + + closures = g_slist_prepend (closures, closure); + } + g_mutex_unlock (&backend->priv->lock); + + while (closures) + { + GSettingsBackendClosure *closure = closures->data; + + if (closure->context) + g_main_context_invoke (closure->context, + g_settings_backend_invoke_closure, + closure); + else + g_settings_backend_invoke_closure (closure); + + closures = g_slist_delete_link (closures, closures); + } } /** @@ -189,7 +339,7 @@ is_path (const gchar *path) * implementations should call this if a key has possibly changed its * value. * - * @key must be a valid key (ie: starting with a slash, not containing + * @key must be a valid key (ie starting with a slash, not containing * '//', and not ending with a slash). * * The implementation must call this function during any call to @@ -199,7 +349,7 @@ is_path (const gchar *path) * dispatching the signal later. * * The implementation may call this function at any other time it likes - * in response to other events (such as changes occuring outside of the + * in response to other events (such as changes occurring outside of the * program). These calls may originate from a mainloop or may originate * in response to any other action (including from calls to * g_settings_backend_write()). @@ -215,27 +365,27 @@ g_settings_backend_changed (GSettingsBackend *backend, const gchar *key, gpointer origin_tag) { - GSettingsBackendWatch *watch; - g_return_if_fail (G_IS_SETTINGS_BACKEND (backend)); g_return_if_fail (is_key (key)); - for (watch = backend->priv->watches; watch; watch = watch->next) - watch->changed (backend, key, origin_tag, watch->user_data); + g_settings_backend_dispatch_signal (backend, + G_STRUCT_OFFSET (GSettingsListenerVTable, + changed), + key, origin_tag, NULL); } /** * g_settings_backend_keys_changed: * @backend: a #GSettingsBackend implementation * @path: the path containing the changes - * @items: the %NULL-terminated list of changed keys + * @items: (array zero-terminated=1): the %NULL-terminated list of changed keys * @origin_tag: the origin tag * * Signals that a list of keys have possibly changed. Backend * implementations should call this if keys have possibly changed their * values. * - * @path must be a valid path (ie: starting and ending with a slash and + * @path must be a valid path (ie starting and ending with a slash and * not containing '//'). Each string in @items must form a valid key * name when @path is prefixed to it (ie: each item must not start or * end with '/' and must not contain '//'). @@ -261,14 +411,16 @@ g_settings_backend_keys_changed (GSettingsBackend *backend, gchar const * const *items, gpointer origin_tag) { - GSettingsBackendWatch *watch; - g_return_if_fail (G_IS_SETTINGS_BACKEND (backend)); - g_return_if_fail (path[0] == '\0' || is_path (path)); + g_return_if_fail (is_path (path)); + + /* XXX: should do stricter checking (ie: inspect each item) */ g_return_if_fail (items != NULL); - for (watch = backend->priv->watches; watch; watch = watch->next) - watch->keys_changed (backend, path, items, origin_tag, watch->user_data); + g_settings_backend_dispatch_signal (backend, + G_STRUCT_OFFSET (GSettingsListenerVTable, + keys_changed), + path, origin_tag, items); } /** @@ -281,7 +433,7 @@ g_settings_backend_keys_changed (GSettingsBackend *backend, * Backend implementations should call this if an entire path of keys * have possibly changed their values. * - * @path must be a valid path (ie: starting and ending with a slash and + * @path must be a valid path (ie starting and ending with a slash and * not containing '//'). * * The meaning of this signal is that any of the key which has a name @@ -306,13 +458,13 @@ g_settings_backend_path_changed (GSettingsBackend *backend, const gchar *path, gpointer origin_tag) { - GSettingsBackendWatch *watch; - g_return_if_fail (G_IS_SETTINGS_BACKEND (backend)); g_return_if_fail (is_path (path)); - for (watch = backend->priv->watches; watch; watch = watch->next) - watch->path_changed (backend, path, origin_tag, watch->user_data); + g_settings_backend_dispatch_signal (backend, + G_STRUCT_OFFSET (GSettingsListenerVTable, + path_changed), + path, origin_tag, NULL); } /** @@ -331,13 +483,13 @@ void g_settings_backend_writable_changed (GSettingsBackend *backend, const gchar *key) { - GSettingsBackendWatch *watch; - g_return_if_fail (G_IS_SETTINGS_BACKEND (backend)); g_return_if_fail (is_key (key)); - for (watch = backend->priv->watches; watch; watch = watch->next) - watch->writable_changed (backend, key, watch->user_data); + g_settings_backend_dispatch_signal (backend, + G_STRUCT_OFFSET (GSettingsListenerVTable, + writable_changed), + key, NULL, NULL); } /** @@ -357,28 +509,29 @@ void g_settings_backend_path_writable_changed (GSettingsBackend *backend, const gchar *path) { - GSettingsBackendWatch *watch; - g_return_if_fail (G_IS_SETTINGS_BACKEND (backend)); g_return_if_fail (is_path (path)); - for (watch = backend->priv->watches; watch; watch = watch->next) - watch->path_writable_changed (backend, path, watch->user_data); + g_settings_backend_dispatch_signal (backend, + G_STRUCT_OFFSET (GSettingsListenerVTable, + path_writable_changed), + path, NULL, NULL); } typedef struct { + const gchar **keys; + GVariant **values; gint prefix_len; gchar *prefix; - gchar **items; -} GetKeysState; +} FlattenState; static gboolean -tree_get_keys (gpointer key, - gpointer value, - gpointer user_data) +g_settings_backend_flatten_one (gpointer key, + gpointer value, + gpointer user_data) { - GetKeysState *state = user_data; + FlattenState *state = user_data; const gchar *skey = key; gint i; @@ -419,12 +572,62 @@ tree_get_keys (gpointer key, /* save the entire item into the array. * the prefixes will be removed later. */ - *state->items++ = key; + *state->keys++ = key; + + if (state->values) + *state->values++ = value; return FALSE; } /** + * g_settings_backend_flatten_tree: + * @tree: a #GTree containing the changes + * @path: (out): the location to save the path + * @keys: (out) (transfer container) (array zero-terminated=1): the + * location to save the relative keys + * @values: (out) (allow-none) (transfer container) (array zero-terminated=1): + * the location to save the values, or %NULL + * + * Calculate the longest common prefix of all keys in a tree and write + * out an array of the key names relative to that prefix and, + * optionally, the value to store at each of those keys. + * + * You must free the value returned in @path, @keys and @values using + * g_free(). You should not attempt to free or unref the contents of + * @keys or @values. + * + * Since: 2.26 + **/ +void +g_settings_backend_flatten_tree (GTree *tree, + gchar **path, + const gchar ***keys, + GVariant ***values) +{ + FlattenState state = { 0, }; + gsize nnodes; + + nnodes = g_tree_nnodes (tree); + + *keys = state.keys = g_new (const gchar *, nnodes + 1); + state.keys[nnodes] = NULL; + + if (values != NULL) + { + *values = state.values = g_new (GVariant *, nnodes + 1); + state.values[nnodes] = NULL; + } + + g_tree_foreach (tree, g_settings_backend_flatten_one, &state); + g_return_if_fail (*keys + nnodes == state.keys); + + *path = state.prefix; + while (nnodes--) + *--state.keys += state.prefix_len; +} + +/** * g_settings_backend_changed_tree: * @backend: a #GSettingsBackend implementation * @tree: a #GTree containing the changes @@ -441,54 +644,110 @@ g_settings_backend_changed_tree (GSettingsBackend *backend, GTree *tree, gpointer origin_tag) { - GSettingsBackendWatch *watch; - GetKeysState state = { 0, }; - gchar **list; + const gchar **keys; + gchar *path; - list = g_new (gchar *, g_tree_nnodes (tree) + 1); - state.items = list; + g_return_if_fail (G_IS_SETTINGS_BACKEND (backend)); - g_tree_foreach (tree, tree_get_keys, &state); - g_return_if_fail (list + g_tree_nnodes (tree) == state.items); - *state.items = NULL; + g_settings_backend_flatten_tree (tree, &path, &keys, NULL); - while (state.items-- != list) - *state.items += state.prefix_len; +#ifdef DEBUG_CHANGES + { + gint i; - for (watch = backend->priv->watches; watch; watch = watch->next) - watch->keys_changed (backend, state.prefix, - (const gchar * const *) list, - origin_tag, watch->user_data); + g_print ("----\n"); + g_print ("changed_tree(): prefix %s\n", path); + for (i = 0; keys[i]; i++) + g_print (" %s\n", keys[i]); + g_print ("----\n"); + } +#endif - g_free (list); - g_free (state.prefix); + g_settings_backend_keys_changed (backend, path, keys, origin_tag); + g_free (path); + g_free (keys); } /*< private > * g_settings_backend_read: * @backend: a #GSettingsBackend implementation * @key: the key to read - * @expected_type: a #GVariantType hint - * @returns: the value that was read, or %NULL + * @expected_type: a #GVariantType + * @default_value: if the default value should be returned * * Reads a key. This call will never block. * * If the key exists, the value associated with it will be returned. * If the key does not exist, %NULL will be returned. * - * If @expected_type is given, it serves as a type hint to the backend. - * If you expect a key of a certain type then you should give - * @expected_type to increase your chances of getting it. Some backends - * may ignore this argument and return values of a different type; it is - * mostly used by backends that don't store strong type information. + * The returned value will be of the type given in @expected_type. If + * the backend stored a value of a different type then %NULL will be + * returned. + * + * If @default_value is %TRUE then this gets the default value from the + * backend (ie: the one that the backend would contain if + * g_settings_reset() were called). + * + * Returns: the value that was read, or %NULL */ GVariant * g_settings_backend_read (GSettingsBackend *backend, const gchar *key, - const GVariantType *expected_type) + const GVariantType *expected_type, + gboolean default_value) { - return G_SETTINGS_BACKEND_GET_CLASS (backend) - ->read (backend, key, expected_type); + GVariant *value; + + value = G_SETTINGS_BACKEND_GET_CLASS (backend) + ->read (backend, key, expected_type, default_value); + + if (value != NULL) + value = g_variant_take_ref (value); + + if G_UNLIKELY (value && !g_variant_is_of_type (value, expected_type)) + { + g_variant_unref (value); + value = NULL; + } + + return value; +} + +/*< private > + * g_settings_backend_read_user_value: + * @backend: a #GSettingsBackend implementation + * @key: the key to read + * @expected_type: a #GVariantType + * + * Reads the 'user value' of a key. + * + * This is the value of the key that the user has control over and has + * set for themselves. Put another way: if the user did not set the + * value for themselves, then this will return %NULL (even if the + * sysadmin has provided a default value). + * + * Returns: the value that was read, or %NULL + */ +GVariant * +g_settings_backend_read_user_value (GSettingsBackend *backend, + const gchar *key, + const GVariantType *expected_type) +{ + GVariant *value; + + value = G_SETTINGS_BACKEND_GET_CLASS (backend) + ->read_user_value (backend, key, expected_type); + + if (value != NULL) + value = g_variant_take_ref (value); + + if G_UNLIKELY (value && !g_variant_is_of_type (value, expected_type)) + { + g_variant_unref (value); + value = NULL; + } + + return value; } /*< private > @@ -497,7 +756,6 @@ g_settings_backend_read (GSettingsBackend *backend, * @key: the name of the key * @value: a #GVariant value to write to this key * @origin_tag: the origin tag - * @returns: %TRUE if the write succeeded, %FALSE if the key was not writable * * Writes exactly one key. * @@ -510,6 +768,8 @@ g_settings_backend_read (GSettingsBackend *backend, * to emit a second "changed" signal (either during this call, or later) * to indicate that the affected keys have suddenly "changed back" to their * old values. + * + * Returns: %TRUE if the write succeeded, %FALSE if the key was not writable */ gboolean g_settings_backend_write (GSettingsBackend *backend, @@ -517,14 +777,20 @@ g_settings_backend_write (GSettingsBackend *backend, GVariant *value, gpointer origin_tag) { - return G_SETTINGS_BACKEND_GET_CLASS (backend) + gboolean success; + + g_variant_ref_sink (value); + success = G_SETTINGS_BACKEND_GET_CLASS (backend) ->write (backend, key, value, origin_tag); + g_variant_unref (value); + + return success; } /*< private > - * g_settings_backend_write_keys: + * g_settings_backend_write_tree: * @backend: a #GSettingsBackend implementation - * @values: a #GTree containing key-value pairs to write + * @tree: a #GTree containing key-value pairs to write * @origin_tag: the origin tag * * Writes one or more keys. This call will never block. @@ -545,12 +811,12 @@ g_settings_backend_write (GSettingsBackend *backend, * old values. */ gboolean -g_settings_backend_write_keys (GSettingsBackend *backend, +g_settings_backend_write_tree (GSettingsBackend *backend, GTree *tree, gpointer origin_tag) { return G_SETTINGS_BACKEND_GET_CLASS (backend) - ->write_keys (backend, tree, origin_tag); + ->write_tree (backend, tree, origin_tag); } /*< private > @@ -573,28 +839,9 @@ g_settings_backend_reset (GSettingsBackend *backend, } /*< private > - * g_settings_backend_reset_path: - * @backend: a #GSettingsBackend implementation - * @name: the name of a key or path - * @origin_tag: the origin tag - * - * "Resets" the named path. This means that every key under the path is - * reset. - */ -void -g_settings_backend_reset_path (GSettingsBackend *backend, - const gchar *path, - gpointer origin_tag) -{ - G_SETTINGS_BACKEND_GET_CLASS (backend) - ->reset_path (backend, path, origin_tag); -} - -/*< private > * g_settings_backend_get_writable: * @backend: a #GSettingsBackend implementation * @key: the name of a key - * @returns: %TRUE if the key is writable * * Finds out if a key is available for writing to. This is the * interface through which 'lockdown' is implemented. Locked down @@ -602,6 +849,8 @@ g_settings_backend_reset_path (GSettingsBackend *backend, * * You should not write to locked-down keys, but if you do, the * implementation will deal with it. + * + * Returns: %TRUE if the key is writable */ gboolean g_settings_backend_get_writable (GSettingsBackend *backend, @@ -643,53 +892,14 @@ g_settings_backend_subscribe (GSettingsBackend *backend, } static void -g_settings_backend_set_property (GObject *object, - guint prop_id, - const GValue *value, - GParamSpec *pspec) -{ - GSettingsBackend *backend = G_SETTINGS_BACKEND (object); - - switch (prop_id) - { - case PROP_CONTEXT: - backend->priv->context = g_value_dup_string (value); - break; - - default: - G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); - break; - } -} - -static void -g_settings_backend_get_property (GObject *object, - guint prop_id, - GValue *value, - GParamSpec *pspec) -{ - GSettingsBackend *backend = G_SETTINGS_BACKEND (object); - - switch (prop_id) - { - case PROP_CONTEXT: - g_value_set_string (value, backend->priv->context); - break; - - default: - G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); - break; - } -} - -static void g_settings_backend_finalize (GObject *object) { GSettingsBackend *backend = G_SETTINGS_BACKEND (object); - g_free (backend->priv->context); + g_mutex_clear (&backend->priv->lock); - G_OBJECT_CLASS (g_settings_backend_parent_class)->finalize (object); + G_OBJECT_CLASS (g_settings_backend_parent_class) + ->finalize (object); } static void @@ -698,12 +908,19 @@ ignore_subscription (GSettingsBackend *backend, { } +static GVariant * +g_settings_backend_real_read_user_value (GSettingsBackend *backend, + const gchar *key, + const GVariantType *expected_type) +{ + return g_settings_backend_read (backend, key, expected_type, FALSE); +} + static void g_settings_backend_init (GSettingsBackend *backend) { - backend->priv = G_TYPE_INSTANCE_GET_PRIVATE (backend, - G_TYPE_SETTINGS_BACKEND, - GSettingsBackendPrivate); + backend->priv = g_settings_backend_get_instance_private (backend); + g_mutex_init (&backend->priv->lock); } static void @@ -714,215 +931,116 @@ g_settings_backend_class_init (GSettingsBackendClass *class) class->subscribe = ignore_subscription; class->unsubscribe = ignore_subscription; - gobject_class->get_property = g_settings_backend_get_property; - gobject_class->set_property = g_settings_backend_set_property; - gobject_class->finalize = g_settings_backend_finalize; + class->read_user_value = g_settings_backend_real_read_user_value; - g_type_class_add_private (class, sizeof (GSettingsBackendPrivate)); - - /** - * GSettingsBackend:context: - * - * The "context" property gives a hint to the backend as to - * what storage to use. It is up to the implementation to make - * use of this information. - * - * E.g. DConf supports "user", "system", "defaults" and "login" - * contexts. - * - * If your backend supports different contexts, you should also - * provide an implementation of the supports_context() class - * function in #GSettingsBackendClass. - */ - g_object_class_install_property (gobject_class, PROP_CONTEXT, - g_param_spec_string ("context", P_("Context"), - P_("An identifier to decide which storage to use"), - "", G_PARAM_READWRITE | - G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS)); + gobject_class->finalize = g_settings_backend_finalize; +} +static void +g_settings_backend_variant_unref0 (gpointer data) +{ + if (data != NULL) + g_variant_unref (data); } /*< private > * g_settings_backend_create_tree: - * @returns: a new #GTree * * This is a convenience function for creating a tree that is compatible * with g_settings_backend_write(). It merely calls g_tree_new_full() * with strcmp(), g_free() and g_variant_unref(). + * + * Returns: a new #GTree */ GTree * g_settings_backend_create_tree (void) { return g_tree_new_full ((GCompareDataFunc) strcmp, NULL, - g_free, (GDestroyNotify) g_variant_unref); + g_free, g_settings_backend_variant_unref0); } - -static gpointer -get_default_backend (const gchar *context) +static gboolean +g_settings_backend_verify (gpointer impl) { - GIOExtension *extension = NULL; - GIOExtensionPoint *point; - GList *extensions; - const gchar *env; - GType type; - - _g_io_modules_ensure_loaded (); + GSettingsBackend *backend = impl; - point = g_io_extension_point_lookup (G_SETTINGS_BACKEND_EXTENSION_POINT_NAME); - - if ((env = getenv ("GSETTINGS_BACKEND"))) + if (strcmp (G_OBJECT_TYPE_NAME (backend), "GMemorySettingsBackend") == 0 && + g_strcmp0 (g_getenv ("GSETTINGS_BACKEND"), "memory") != 0) { - extension = g_io_extension_point_get_extension_by_name (point, env); - - if (extension == NULL) - g_warning ("Can't find GSettings backend '%s' given in " - "GSETTINGS_BACKEND environment variable", env); + g_message ("Using the 'memory' GSettings backend. Your settings " + "will not be saved or shared with other applications."); } - if (extension == NULL) - { - extensions = g_io_extension_point_get_extensions (point); - - if (extensions == NULL) - g_error ("No GSettingsBackend implementations exist."); - - extension = extensions->data; - } - - if (context[0] != '\0') /* (context != "") */ - { - GSettingsBackendClass *backend_class; - GTypeClass *class; - - class = g_io_extension_ref_class (extension); - backend_class = G_SETTINGS_BACKEND_CLASS (class); - - if (backend_class->supports_context == NULL || - !backend_class->supports_context (context)) - { - g_type_class_unref (class); - return NULL; - } - - g_type_class_unref (class); - } - - type = g_io_extension_get_type (extension); - - return g_object_new (type, "context", context, NULL); + g_settings_has_backend = TRUE; + return TRUE; } -static GHashTable *g_settings_backends; - -/*< private > - * g_settings_backend_get_with_context: - * @context: a context that might be used by the backend to determine - * which storage to use, or %NULL to use the default storage - * @returns: the default #GSettingsBackend +/** + * g_settings_backend_get_default: * * Returns the default #GSettingsBackend. It is possible to override - * the default by setting the GSETTINGS_BACKEND - * environment variable to the name of a settings backend. + * the default by setting the `GSETTINGS_BACKEND` environment variable + * to the name of a settings backend. * - * The @context parameter can be used to indicate that a different - * than the default storage is desired. E.g. the DConf backend lets - * you use "user", "system", "defaults" and "login" as contexts. + * The user gets a reference to the backend. * - * If @context is not supported by the implementation, this function - * returns an instance of the #GSettingsMemoryBackend. - * See g_settings_backend_supports_context(), + * Returns: (transfer full): the default #GSettingsBackend * - * The user does not own the return value and it must not be freed. + * Since: 2.28 */ GSettingsBackend * -g_settings_backend_get_with_context (const gchar *context) +g_settings_backend_get_default (void) { GSettingsBackend *backend; - g_return_val_if_fail (context != NULL, NULL); - - _g_io_modules_ensure_extension_points_registered (); - - if (g_settings_backends == NULL) - g_settings_backends = g_hash_table_new (g_str_hash, g_str_equal); - - backend = g_hash_table_lookup (g_settings_backends, context); - - if (!backend) - { - backend = get_default_backend (context); - - if (!backend) - backend = g_null_settings_backend_new (); - - g_hash_table_insert (g_settings_backends, g_strdup (context), backend); - } - + backend = _g_io_module_get_default (G_SETTINGS_BACKEND_EXTENSION_POINT_NAME, + "GSETTINGS_BACKEND", + g_settings_backend_verify); return g_object_ref (backend); } /*< private > - * g_settings_backend_supports_context: - * @context: a context string that might be passed to - * g_settings_backend_new_with_context() - * @returns: #TRUE if @context is supported + * g_settings_backend_get_permission: + * @backend: a #GSettingsBackend + * @path: a path + * + * Gets the permission object associated with writing to keys below + * @path on @backend. * - * Determines if the given context is supported by the default - * GSettingsBackend implementation. + * If this is not implemented in the backend, then a %TRUE + * #GSimplePermission is returned. + * + * Returns: a non-%NULL #GPermission. Free with g_object_unref() */ -gboolean -g_settings_backend_supports_context (const gchar *context) +GPermission * +g_settings_backend_get_permission (GSettingsBackend *backend, + const gchar *path) { - GSettingsBackend *backend; - - g_return_val_if_fail (context != NULL, FALSE); + GSettingsBackendClass *class = G_SETTINGS_BACKEND_GET_CLASS (backend); - backend = get_default_backend (context); + if (class->get_permission) + return class->get_permission (backend, path); - if (backend) - { - g_object_unref (backend); - return TRUE; - } - - return FALSE; + return g_simple_permission_new (TRUE); } -/** - * g_settings_backend_setup: - * @context: a context string (not %NULL or "") - * @backend: a #GSettingsBackend - * - * Sets up @backend for use with #GSettings. - * - * If you create a #GSettings with its context property set to @context - * then it will use the backend given to this function. See - * g_settings_new_with_context(). - * - * The backend must be set up before any settings objects are created - * for the named context. - * - * It is not possible to specify a backend for the default context. +/*< private > + * g_settings_backend_sync_default: * - * This function takes a reference on @backend and never releases it. - **/ + * Syncs the default backend. + */ void -g_settings_backend_setup (const gchar *context, - GSettingsBackend *backend) +g_settings_backend_sync_default (void) { - g_return_if_fail (context[0] != '\0'); - - if (g_settings_backends == NULL) - g_settings_backends = g_hash_table_new (g_str_hash, g_str_equal); + if (g_settings_has_backend) + { + GSettingsBackendClass *class; + GSettingsBackend *backend; - if (g_hash_table_lookup (g_settings_backends, context)) - g_error ("A GSettingsBackend already exists for context '%s'", context); + backend = g_settings_backend_get_default (); + class = G_SETTINGS_BACKEND_GET_CLASS (backend); - g_hash_table_insert (g_settings_backends, - g_strdup (context), - g_object_ref (backend)); + if (class->sync) + class->sync (backend); + } } - -#define __G_SETTINGS_BACKEND_C__ -#include "gioaliasdef.c"