From 2ed34f69d4400f863835c4149be4ecb82ffe1c72 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Fri, 7 Aug 2009 01:19:18 +0200
Subject: consolekit: cache ckit database file

Speed up ckit database checks a little by keeping the parsed database
in memory and mantaining an extra hashtable-based cache.
---
 dbus/dbus-userdb-util.c | 107 ++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 98 insertions(+), 9 deletions(-)

(limited to 'dbus/dbus-userdb-util.c')

diff --git a/dbus/dbus-userdb-util.c b/dbus/dbus-userdb-util.c
index 8361fcf3..f4d1f0c9 100644
--- a/dbus/dbus-userdb-util.c
+++ b/dbus/dbus-userdb-util.c
@@ -35,6 +35,28 @@
  * @{
  */
 
+#if defined(HAVE_CONSOLEKIT_DATABASE)
+static DBusDesktopFile *ckit_database = NULL;
+static DBusHashTable *ckit_cache = NULL;
+
+static void
+ckit_cleanup(void *data)
+{
+  if (ckit_database)
+    {
+      _dbus_desktop_file_free(ckit_database);
+      ckit_database = NULL;
+    }
+
+  if (ckit_cache)
+    {
+      _dbus_hash_table_unref(ckit_cache);
+      ckit_cache = NULL;
+    }
+}
+
+#endif
+
 /**
  * Checks to see if the UID sent in is the console user
  *
@@ -49,19 +71,68 @@ _dbus_is_console_user (dbus_uid_t uid,
 
 #if defined(HAVE_CONSOLEKIT_DATABASE)
 
-  DBusDesktopFile *f;
+
   const char *section;
   dbus_bool_t found = FALSE;
   DBusString fn;
   unsigned i = 0;
+  void *e;
 
   _dbus_string_init_const(&fn, DBUS_CONSOLEKIT_DATABASE);
 
-  f = _dbus_desktop_file_load(&fn, error);
-  if (!f)
-    return FALSE;
+  _dbus_user_database_lock_system ();
+
+  /* Flush database if it changed */
+  if (ckit_database &&
+      _dbus_desktop_file_changed(ckit_database, &fn))
+    {
+      _dbus_desktop_file_free(ckit_database);
+      ckit_database = NULL;
+
+      if (ckit_cache)
+        _dbus_hash_table_remove_all(ckit_cache);
+    }
+
+  /* Initialize cache */
+  if (!ckit_cache)
+    {
+      ckit_cache = _dbus_hash_table_new(DBUS_HASH_ULONG, NULL, NULL);
+      if (!ckit_cache)
+        {
+          _dbus_user_database_unlock_system ();
+          _DBUS_SET_OOM(error);
+          return FALSE;
+        }
+
+      if (!_dbus_register_shutdown_func(ckit_cleanup, NULL))
+        {
+          ckit_cleanup(NULL);
+          _dbus_user_database_unlock_system ();
+          _DBUS_SET_OOM(error);
+          return FALSE;
+        }
+    }
+
+  /* Load database */
+  if (!ckit_database)
+    {
+      ckit_database = _dbus_desktop_file_load(&fn, error);
+      if (!ckit_database)
+        {
+          _dbus_user_database_unlock_system ();
+          return FALSE;
+        }
+    }
+
+  /* Check cache first */
+  e = _dbus_hash_table_lookup_ulong(ckit_cache, (unsigned long) uid);
+  if (e)
+    {
+      _dbus_user_database_unlock_system ();
+      return _DBUS_POINTER_TO_INT(e) > 0;
+    }
 
-  while ((section = _dbus_desktop_file_get_section(f, i++)))
+  while ((section = _dbus_desktop_file_get_section(ckit_database, i++)))
     {
       const char *val;
       char *e = NULL;
@@ -70,7 +141,7 @@ _dbus_is_console_user (dbus_uid_t uid,
       if (strncmp(section, "Session ", 8))
         continue;
 
-      if (!_dbus_desktop_file_get_raw(f, section, "uid", &val))
+      if (!_dbus_desktop_file_get_raw(ckit_database, section, "uid", &val))
         continue;
 
       errno = 0;
@@ -85,7 +156,11 @@ _dbus_is_console_user (dbus_uid_t uid,
         }
     }
 
-  _dbus_desktop_file_free(f);
+  /* Cache for later. We don't care if that worked. If it didn't the
+     only price we pay is that we have to recheck next time */
+  _dbus_hash_table_insert_ulong(ckit_cache, (unsigned long) uid, _DBUS_INT_TO_POINTER(found ? 1 : -1));
+
+  _dbus_user_database_unlock_system ();
   return found;
 
 #elif defined(HAVE_CONSOLE_OWNER_FILE)
@@ -486,8 +561,22 @@ _dbus_userdb_test (const char *test_data_dir)
   printf ("\n");
 
   dbus_error_init(&error);
-  printf ("Is Console user: %i\n",
-          _dbus_is_console_user(uid, &error));
+  printf ("1000 is Console user: %i\n", _dbus_is_console_user(1000, &error));
+  printf ("Invocation was OK: %s\n", error.message ? error.message : "yes");
+  dbus_error_free(&error);
+
+  dbus_error_init(&error);
+  printf ("0 is Console user: %i\n", _dbus_is_console_user(0, &error));
+  printf ("Invocation was OK: %s\n", error.message ? error.message : "yes");
+  dbus_error_free(&error);
+
+  dbus_error_init(&error);
+  printf ("1001 is Console user: %i\n", _dbus_is_console_user(1001, &error));
+  printf ("Invocation was OK: %s\n", error.message ? error.message : "yes");
+  dbus_error_free(&error);
+
+  dbus_error_init(&error);
+  printf ("1000 is Console user: %i\n", _dbus_is_console_user(1000, &error));
   printf ("Invocation was OK: %s\n", error.message ? error.message : "yes");
   dbus_error_free(&error);
 
-- 
cgit