Commit 5bcf54b2 authored by David Zeuthen's avatar David Zeuthen

GDBus: Add mechanism to make lookup on interfaces constant-time

This is used both on the service- and client-side and is currently
O(n).
Signed-off-by: default avatarDavid Zeuthen <davidz@redhat.com>
parent 5aa8f135
......@@ -2613,6 +2613,8 @@ g_dbus_annotation_info_lookup
g_dbus_interface_info_lookup_method
g_dbus_interface_info_lookup_signal
g_dbus_interface_info_lookup_property
g_dbus_interface_info_cache_build
g_dbus_interface_info_cache_release
g_dbus_interface_info_generate_xml
g_dbus_node_info_new_for_xml
g_dbus_node_info_lookup_interface
......
......@@ -1868,6 +1868,37 @@ g_dbus_annotation_info_lookup (GDBusAnnotationInfo **annotations,
/* ---------------------------------------------------------------------------------------------------- */
G_LOCK_DEFINE_STATIC (info_cache_lock);
typedef struct
{
gint use_count;
/* gchar* -> GDBusMethodInfo* */
GHashTable *method_name_to_data;
/* gchar* -> GDBusMethodInfo* */
GHashTable *signal_name_to_data;
/* gchar* -> GDBusMethodInfo* */
GHashTable *property_name_to_data;
} InfoCacheEntry;
static void
info_cache_free (InfoCacheEntry *cache)
{
g_assert (cache->use_count == 0);
g_hash_table_unref (cache->method_name_to_data);
g_hash_table_unref (cache->signal_name_to_data);
g_hash_table_unref (cache->property_name_to_data);
g_slice_free (InfoCacheEntry, cache);
}
/* maps from GDBusInterfaceInfo* to InfoCacheEntry* */
static GHashTable *info_cache = NULL;
/* ---------------------------------------------------------------------------------------------------- */
/**
* g_dbus_interface_info_lookup_method:
* @info: A #GDBusInterfaceInfo.
......@@ -1875,7 +1906,8 @@ g_dbus_annotation_info_lookup (GDBusAnnotationInfo **annotations,
*
* Looks up information about a method.
*
* This cost of this function is O(n) in number of methods.
* This cost of this function is O(n) in number of methods unless
* g_dbus_interface_info_cache_build() has been used on @info.
*
* Returns: A #GDBusMethodInfo or %NULL if not found. Do not free, it is owned by @info.
*
......@@ -1888,6 +1920,20 @@ g_dbus_interface_info_lookup_method (GDBusInterfaceInfo *info,
guint n;
GDBusMethodInfo *result;
G_LOCK (info_cache_lock);
if (G_LIKELY (info_cache != NULL))
{
InfoCacheEntry *cache;
cache = g_hash_table_lookup (info_cache, info);
if (G_LIKELY (cache != NULL))
{
result = g_hash_table_lookup (cache->method_name_to_data, name);
G_UNLOCK (info_cache_lock);
goto out;
}
}
G_UNLOCK (info_cache_lock);
for (n = 0; info->methods != NULL && info->methods[n] != NULL; n++)
{
GDBusMethodInfo *i = info->methods[n];
......@@ -1914,7 +1960,8 @@ g_dbus_interface_info_lookup_method (GDBusInterfaceInfo *info,
*
* Looks up information about a signal.
*
* This cost of this function is O(n) in number of signals.
* This cost of this function is O(n) in number of signals unless
* g_dbus_interface_info_cache_build() has been used on @info.
*
* Returns: A #GDBusSignalInfo or %NULL if not found. Do not free, it is owned by @info.
*
......@@ -1927,6 +1974,20 @@ g_dbus_interface_info_lookup_signal (GDBusInterfaceInfo *info,
guint n;
GDBusSignalInfo *result;
G_LOCK (info_cache_lock);
if (G_LIKELY (info_cache != NULL))
{
InfoCacheEntry *cache;
cache = g_hash_table_lookup (info_cache, info);
if (G_LIKELY (cache != NULL))
{
result = g_hash_table_lookup (cache->signal_name_to_data, name);
G_UNLOCK (info_cache_lock);
goto out;
}
}
G_UNLOCK (info_cache_lock);
for (n = 0; info->signals != NULL && info->signals[n] != NULL; n++)
{
GDBusSignalInfo *i = info->signals[n];
......@@ -1953,7 +2014,8 @@ g_dbus_interface_info_lookup_signal (GDBusInterfaceInfo *info,
*
* Looks up information about a property.
*
* This cost of this function is O(n) in number of properties.
* This cost of this function is O(n) in number of properties unless
* g_dbus_interface_info_cache_build() has been used on @info.
*
* Returns: A #GDBusPropertyInfo or %NULL if not found. Do not free, it is owned by @info.
*
......@@ -1966,6 +2028,20 @@ g_dbus_interface_info_lookup_property (GDBusInterfaceInfo *info,
guint n;
GDBusPropertyInfo *result;
G_LOCK (info_cache_lock);
if (G_LIKELY (info_cache != NULL))
{
InfoCacheEntry *cache;
cache = g_hash_table_lookup (info_cache, info);
if (G_LIKELY (cache != NULL))
{
result = g_hash_table_lookup (cache->property_name_to_data, name);
G_UNLOCK (info_cache_lock);
goto out;
}
}
G_UNLOCK (info_cache_lock);
for (n = 0; info->properties != NULL && info->properties[n] != NULL; n++)
{
GDBusPropertyInfo *i = info->properties[n];
......@@ -1983,6 +2059,95 @@ g_dbus_interface_info_lookup_property (GDBusInterfaceInfo *info,
return result;
}
/* ---------------------------------------------------------------------------------------------------- */
/**
* g_dbus_interface_info_cache_build:
* @info: A #GDBusInterfaceInfo.
*
* Builds a lookup-cache to speed up
* g_dbus_interface_info_lookup_method(),
* g_dbus_interface_info_lookup_signal() and
* g_dbus_interface_info_lookup_property().
*
* If this has already been called with @info, the existing cache is
* used and its use count is increased.
*
* Note that @info cannot be modified until
* g_dbus_interface_info_cache_release() is called.
*
* Since: 2.30
*/
void
g_dbus_interface_info_cache_build (GDBusInterfaceInfo *info)
{
InfoCacheEntry *cache;
guint n;
G_LOCK (info_cache_lock);
if (info_cache == NULL)
info_cache = g_hash_table_new_full (g_direct_hash, g_direct_equal, NULL, (GDestroyNotify) info_cache_free);
cache = g_hash_table_lookup (info_cache, info);
if (cache != NULL)
{
cache->use_count += 1;
goto out;
}
cache = g_slice_new0 (InfoCacheEntry);
cache->use_count = 1;
cache->method_name_to_data = g_hash_table_new (g_str_hash, g_str_equal);
cache->signal_name_to_data = g_hash_table_new (g_str_hash, g_str_equal);
cache->property_name_to_data = g_hash_table_new (g_str_hash, g_str_equal);
for (n = 0; info->methods != NULL && info->methods[n] != NULL; n++)
g_hash_table_insert (cache->method_name_to_data, info->methods[n]->name, info->methods[n]);
for (n = 0; info->signals != NULL && info->signals[n] != NULL; n++)
g_hash_table_insert (cache->signal_name_to_data, info->signals[n]->name, info->signals[n]);
for (n = 0; info->properties != NULL && info->properties[n] != NULL; n++)
g_hash_table_insert (cache->property_name_to_data, info->properties[n]->name, info->properties[n]);
g_hash_table_insert (info_cache, info, cache);
out:
G_UNLOCK (info_cache_lock);
}
/**
* g_dbus_interface_info_cache_release:
* @info: A GDBusInterfaceInfo
*
* Decrements the usage count for the cache for @info built by
* g_dbus_interface_info_cache_build() (if any) and frees the
* resources used by the cache if the usage count drops to zero.
*
* Since: 2.30
*/
void
g_dbus_interface_info_cache_release (GDBusInterfaceInfo *info)
{
InfoCacheEntry *cache;
G_LOCK (info_cache_lock);
if (G_UNLIKELY (info_cache == NULL))
{
g_warning ("%s called for interface %s but there is no cache", info->name, G_STRFUNC);
goto out;
}
cache = g_hash_table_lookup (info_cache, info);
if (G_UNLIKELY (cache == NULL))
{
g_warning ("%s called for interface %s but there is no cache entry", info->name, G_STRFUNC);
goto out;
}
cache->use_count -= 1;
if (cache->use_count == 0)
{
g_hash_table_remove (info_cache, info);
/* could nuke info_cache itself if empty */
}
out:
G_UNLOCK (info_cache_lock);
}
/* ---------------------------------------------------------------------------------------------------- */
/**
......
......@@ -182,6 +182,9 @@ GDBusSignalInfo *g_dbus_interface_info_lookup_signal (GDBusInterfaceInfo
const gchar *name);
GDBusPropertyInfo *g_dbus_interface_info_lookup_property (GDBusInterfaceInfo *info,
const gchar *name);
void g_dbus_interface_info_cache_build (GDBusInterfaceInfo *info);
void g_dbus_interface_info_cache_release (GDBusInterfaceInfo *info);
void g_dbus_interface_info_generate_xml (GDBusInterfaceInfo *info,
guint indent,
GString *string_builder);
......
......@@ -1725,6 +1725,8 @@ g_dbus_interface_info_generate_xml
g_dbus_interface_info_lookup_method
g_dbus_interface_info_lookup_property
g_dbus_interface_info_lookup_signal
g_dbus_interface_info_cache_build
g_dbus_interface_info_cache_release
g_dbus_node_info_new_for_xml
g_dbus_node_info_generate_xml
g_dbus_node_info_lookup_interface
......
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