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Diffstat (limited to 'poky/meta/lib/oe/classutils.py')
-rw-r--r-- | poky/meta/lib/oe/classutils.py | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/poky/meta/lib/oe/classutils.py b/poky/meta/lib/oe/classutils.py new file mode 100644 index 000000000..45cd5249b --- /dev/null +++ b/poky/meta/lib/oe/classutils.py @@ -0,0 +1,44 @@ + +class ClassRegistryMeta(type): + """Give each ClassRegistry their own registry""" + def __init__(cls, name, bases, attrs): + cls.registry = {} + type.__init__(cls, name, bases, attrs) + +class ClassRegistry(type, metaclass=ClassRegistryMeta): + """Maintain a registry of classes, indexed by name. + +Note that this implementation requires that the names be unique, as it uses +a dictionary to hold the classes by name. + +The name in the registry can be overridden via the 'name' attribute of the +class, and the 'priority' attribute controls priority. The prioritized() +method returns the registered classes in priority order. + +Subclasses of ClassRegistry may define an 'implemented' property to exert +control over whether the class will be added to the registry (e.g. to keep +abstract base classes out of the registry).""" + priority = 0 + def __init__(cls, name, bases, attrs): + super(ClassRegistry, cls).__init__(name, bases, attrs) + try: + if not cls.implemented: + return + except AttributeError: + pass + + try: + cls.name + except AttributeError: + cls.name = name + cls.registry[cls.name] = cls + + @classmethod + def prioritized(tcls): + return sorted(list(tcls.registry.values()), + key=lambda v: (v.priority, v.name), reverse=True) + + def unregister(cls): + for key in cls.registry.keys(): + if cls.registry[key] is cls: + del cls.registry[key] |