| # coding: utf-8 |
| # pylint: disable=no-member |
| |
| """Registry for serializable objects.""" |
| from __future__ import absolute_import |
| |
| import warnings |
| |
| from .base import string_types |
| |
| _REGISTRY = {} |
| |
| |
| def get_register_func(base_class, nickname): |
| """Get registrator function. |
| |
| Parameters |
| ---------- |
| base_class : type |
| base class for classes that will be reigstered |
| nickname : str |
| nickname of base_class for logging |
| |
| Returns |
| ------- |
| a registrator function |
| """ |
| if base_class not in _REGISTRY: |
| _REGISTRY[base_class] = {} |
| registry = _REGISTRY[base_class] |
| |
| def register(klass, name=None): |
| """Register functions""" |
| assert issubclass(klass, base_class), \ |
| "Can only register subclass of %s"%base_class.__name__ |
| if name is None: |
| name = klass.__name__.lower() |
| if name in registry: |
| warnings.warn( |
| "\033[91mNew %s %s.%s registered with name %s is" |
| "overriding existing %s %s.%s\033[0m"%( |
| nickname, klass.__module__, klass.__name__, name, |
| nickname, registry[name].__module__, registry[name].__name__), |
| UserWarning, stacklevel=2) |
| registry[name] = klass |
| return klass |
| |
| register.__doc__ = "Register %s to the %s factory"%(nickname, nickname) |
| return register |
| |
| |
| def get_alias_func(base_class, nickname): |
| """Get registrator function that allow aliases. |
| |
| Parameters |
| ---------- |
| base_class : type |
| base class for classes that will be reigstered |
| nickname : str |
| nickname of base_class for logging |
| |
| Returns |
| ------- |
| a registrator function |
| """ |
| register = get_register_func(base_class, nickname) |
| |
| def alias(*aliases): |
| """alias registrator""" |
| def reg(klass): |
| """registrator function""" |
| for name in aliases: |
| register(klass, name) |
| return klass |
| return reg |
| return alias |
| |
| |
| def get_create_func(base_class, nickname): |
| """Get creator function |
| |
| Parameters |
| ---------- |
| base_class : type |
| base class for classes that will be reigstered |
| nickname : str |
| nickname of base_class for logging |
| |
| Returns |
| ------- |
| a creator function |
| """ |
| if base_class not in _REGISTRY: |
| _REGISTRY[base_class] = {} |
| registry = _REGISTRY[base_class] |
| |
| def create(*args, **kwargs): |
| """Create instance from config""" |
| if len(args): |
| name = args[0] |
| args = args[1:] |
| else: |
| name = kwargs.pop(nickname) |
| |
| if isinstance(name, base_class): |
| assert len(args) == 0 and len(kwargs) == 0, \ |
| "%s is already an instance. Additional arguments are invalid"%(nickname) |
| return name |
| |
| assert isinstance(name, string_types), "%s must be of string type"%nickname |
| name = name.lower() |
| assert name in registry, \ |
| "%s is not registered. Please register with %s.register first"%( |
| str(name), nickname) |
| return registry[name](*args, **kwargs) |
| |
| create.__doc__ = """Create a %s instance from config. |
| |
| Parameters |
| ---------- |
| %s : str or %s instance |
| class name of desired instance. If is a instance, |
| it will be returned directly. |
| **kwargs : dict |
| arguments to be passed to constructor"""%(nickname, nickname, base_class.__name__) |
| |
| return create |
