so_magic.data.features.phi.PhiFunctionRegistry.get_instance() - Code Metrics - Inspection of "Automate Operations" - boromir674/so-magic - Measure and Improve Code Quality continuously with Scrutinizer

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Pull Request — dev (#32)

by Konstantinos

created 2021-06-22 23:25 UTC

ce() A

↳ Parent: so_magic.data.features.phi.PhiFunctionMetaclass.__new__()

Complexity

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Size

Total Lines	8
Code Lines	3

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
cc	1
eloc	3
nop	0
dl	0
loc	8
rs	10
c	0
b	0
f	0

"""This module is responsible to provide a formal way of registering phi functions
at runtime. See the 'PhiFunctionRegistrator' class and its 'register' decorator method
"""
import logging
import inspect
from typing import Callable
from so_magic.utils import Subject

logger = logging.getLogger(__name__)


class PhiFunctionMetaclass(type):
    """Class type with a single broadcasting (notifies listeners) facility.

    Classes using this class as metaclass, obtain a single broadcasting facility
    as a class attribute. The class attribute is called 'subject' can be referenced
    as any class attribute.

    Example:
        class MyExampleClass(metaclass=PhiFunctionMetaclass):
            pass

        instance_object_1 = MyExampleClass()
        instance_object_2 = MyExampleClass()
        assert id(MyExampleClass.subject) == id(instance_object_1.subject) == id(instance_object_2.subject)
    """
    def __new__(mcs, *args, **kwargs):
        """Create a new class type object and set the 'subject' attribute to a new Subject instance; the broadcaster.

        Returns:
            PhiFunctionMetaclass: the new class type object
        """
        phi_function_class = super().__new__(mcs, *args, **kwargs)
        phi_function_class.subject = Subject([])
        return phi_function_class


class PhiFunctionRegistrator(metaclass=PhiFunctionMetaclass):
    """Add phi functions to the registry and notify observers/listeners.

    This class provides the 'register' decorator, that client can use to decorate either functions (defined with the
    def python special word), or classes (defined with the python class special word).
    """

    # NICE TO HAVE: make the decorator work without parenthesis
    @classmethod
    def register(cls, phi_name=''):
        r"""Add a new phi function to phi function registry and notify listeners/observers.

        Use this decorator around either a callable function (defined with the 'def' python special word) or a class
        with a takes-no-arguments (or all-optional-arguments) constructor and a __call__ magic method.

        All phi functions are expected to be registered with a __name__ and a __doc__ attribute.

        You can select your custom phi_name under which to register the phi function or default to an automatic
        determination of the phi_name to use.

        Automatic determination of phi_name is done by examining either the __name__ attribute of the function or the
        class name of the class.

        Example:

            >>> from so_magic.data.features.phi import PhiFunctionRegistry, PhiFunctionRegistrator

            >>> registered_phis = PhiFunctionRegistry()

            >>> @PhiFunctionRegistrator.register()
            ... def f1(x):
            ...  '''Multiply by 2.'''
            ...  return x * 2
            Registering input function f1 as phi function, at key f1.

            >>> registered_phis.get('f1').__doc__
            'Multiply by 2.'

            >>> input_value = 5
            >>> print(f"{input_value} * 2 = {registered_phis.get('f1')(input_value)}")
            5 * 2 = 10

            >>> @PhiFunctionRegistrator.register()
            ... class f2:
            ...  def __call__(self, data, **kwargs):
            ...   return data + 5
            Registering input class f2 instance as phi function, at key f2.

            >>> input_value = 1
            >>> print(f"{input_value} + 5 = {registered_phis.get('f2')(input_value)}")
            1 + 5 = 6

            >>> @PhiFunctionRegistrator.register('f3')
            ... class MyCustomClass:
            ...  def __call__(self, data, **kwargs):
            ...   return data + 1
            Registering input class MyCustomClass instance as phi function, at key f3.

            >>> input_value = 3
            >>> print(f"{input_value} + 1 = {registered_phis.get('f3')(input_value)}")
            3 + 1 = 4

        Args:
            phi_name (str, optional): custom name to register the phi function. Defaults to automatic computation.
        """
        def wrapper(a_callable):
            """Add a callable object to the phi function registry and preserve info for __name__ and __doc__ attributes.

            The callable object should either be function (defined with def) or a class (defined with class). In case of
            a class the class must have a constructor that takes no arguments (or all arguments are optional) and a
            __call__ magic method.

            Registers the callable as a phi function under the given or automatically computed name, makes sure the
            __name__ and __doc__ attributes preserve information and notifies potential listeners/observers.

            Args:
                a_callable (Callable): the object (function or class) to register as phi function
            """
            if hasattr(a_callable, '__code__'):  # it is a function (def func_name ..)
                logging.info("Registering input function %s as phi function.", a_callable.__code__.co_name)
                key = phi_name if phi_name else cls.get_name(a_callable)
                print(f"Registering input function {a_callable.__code__.co_name} as phi function, at key {key}.")
                cls._register(a_callable, key)
            else:
                if not hasattr(a_callable, '__call__'):
                    raise RuntimeError("Expected an class definition with a '__call__' instance method defined 1."
                                       f" Got {type(a_callable)}")
                members = inspect.getmembers(a_callable)
                if ('__call__', a_callable.__call__) not in members:
                    raise RuntimeError("Expected an class definition with a '__call__' instance method defined 2."
                                       f" Got {type(a_callable)}")
                instance = a_callable()
                instance.__name__ = a_callable.__name__
                instance.__doc__ = a_callable.__call__.__doc__
                key = phi_name if phi_name else cls.get_name(instance)
                print(f"Registering input class {a_callable.__name__} instance as phi function, at key {key}.")
                cls._register(instance, key)
            return a_callable
        return wrapper

    @classmethod
    def _register(cls, a_callable, key_name):
        """Register a callable as phi function and notify potential listeners/observers.

        The phi function is registered under the given key_name or in case of None the name is automatically computed
        based on the input callable.

        Args:
            a_callable (Callable): the callable that holds the business logic of the phi function
            key_name (str, optional): custom phi name. Defaults to None, which means automatic determination of the name
        """
        cls.subject.name = key_name
        cls.subject.state = a_callable
        cls.subject.notify()

    @staticmethod
    def get_name(a_callable: Callable):
        """Get the 'name' of the input callable object

        Args:
            a_callable (Callable): a callable object to get its name

        Returns:
            str: the name of the callable object
        """
        if hasattr(a_callable, 'name'):
            return a_callable.name
        if hasattr(a_callable, '__code__') and hasattr(a_callable.__code__, 'co_name'):
            return a_callable.__code__.co_name
        if hasattr(type(a_callable), 'name'):
            return type(a_callable).name
        if hasattr(type(a_callable), '__name__'):
            return type(a_callable).__name__
        raise PhiFunctionNameDeterminationError()


class PhiFunctionNameDeterminationError(Exception): pass


1			"""This module is responsible to provide a formal way of registering phi functions
2			at runtime. See the 'PhiFunctionRegistrator' class and its 'register' decorator method
3			"""
4			import logging
5			import inspect
6			from typing import Callable
7			from so_magic.utils import Subject
8
9			logger = logging.getLogger(__name__)
10
11
12			class PhiFunctionMetaclass(type):
13			"""Class type with a single broadcasting (notifies listeners) facility.
14
15			Classes using this class as metaclass, obtain a single broadcasting facility
16			as a class attribute. The class attribute is called 'subject' can be referenced
17			as any class attribute.
18
19			Example:
20			class MyExampleClass(metaclass=PhiFunctionMetaclass):
21			pass
22
23			instance_object_1 = MyExampleClass()
24			instance_object_2 = MyExampleClass()
25			assert id(MyExampleClass.subject) == id(instance_object_1.subject) == id(instance_object_2.subject)
26			"""
27			def __new__(mcs, args, *kwargs):
28			"""Create a new class type object and set the 'subject' attribute to a new Subject instance; the broadcaster.
29
30			Returns:
31			PhiFunctionMetaclass: the new class type object
32			"""
33			phi_function_class = super().__new__(mcs, args, *kwargs)
34			phi_function_class.subject = Subject([])
35			return phi_function_class
36
37
38			class PhiFunctionRegistrator(metaclass=PhiFunctionMetaclass):
39			"""Add phi functions to the registry and notify observers/listeners.
40
41			This class provides the 'register' decorator, that client can use to decorate either functions (defined with the
42			def python special word), or classes (defined with the python class special word).
43			"""
44
45			# NICE TO HAVE: make the decorator work without parenthesis
46			@classmethod
47			def register(cls, phi_name=''):
48			r"""Add a new phi function to phi function registry and notify listeners/observers.
49
50			Use this decorator around either a callable function (defined with the 'def' python special word) or a class
51			with a takes-no-arguments (or all-optional-arguments) constructor and a __call__ magic method.
52
53			All phi functions are expected to be registered with a __name__ and a __doc__ attribute.
54
55			You can select your custom phi_name under which to register the phi function or default to an automatic
56			determination of the phi_name to use.
57
58			Automatic determination of phi_name is done by examining either the __name__ attribute of the function or the
59			class name of the class.
60
61			Example:
62
63			>>> from so_magic.data.features.phi import PhiFunctionRegistry, PhiFunctionRegistrator
64
65			>>> registered_phis = PhiFunctionRegistry()
66
67			>>> @PhiFunctionRegistrator.register()
68			... def f1(x):
69			... '''Multiply by 2.'''
70			... return x * 2
71			Registering input function f1 as phi function, at key f1.
72
73			>>> registered_phis.get('f1').__doc__
74			'Multiply by 2.'
75
76			>>> input_value = 5
77			>>> print(f"{input_value} * 2 = {registered_phis.get('f1')(input_value)}")
78			5 * 2 = 10
79
80			>>> @PhiFunctionRegistrator.register()
81			... class f2:
82			... def __call__(self, data, **kwargs):
83			... return data + 5
84			Registering input class f2 instance as phi function, at key f2.
85
86			>>> input_value = 1
87			>>> print(f"{input_value} + 5 = {registered_phis.get('f2')(input_value)}")
88			1 + 5 = 6
89
90			>>> @PhiFunctionRegistrator.register('f3')
91			... class MyCustomClass:
92			... def __call__(self, data, **kwargs):
93			... return data + 1
94			Registering input class MyCustomClass instance as phi function, at key f3.
95
96			>>> input_value = 3
97			>>> print(f"{input_value} + 1 = {registered_phis.get('f3')(input_value)}")
98			3 + 1 = 4
99
100			Args:
101			phi_name (str, optional): custom name to register the phi function. Defaults to automatic computation.
102			"""
103			def wrapper(a_callable):
104			"""Add a callable object to the phi function registry and preserve info for __name__ and __doc__ attributes.
105
106			The callable object should either be function (defined with def) or a class (defined with class). In case of
107			a class the class must have a constructor that takes no arguments (or all arguments are optional) and a
108			__call__ magic method.
109
110			Registers the callable as a phi function under the given or automatically computed name, makes sure the
111			__name__ and __doc__ attributes preserve information and notifies potential listeners/observers.
112
113			Args:
114			a_callable (Callable): the object (function or class) to register as phi function
115			"""
116			if hasattr(a_callable, '__code__'): # it is a function (def func_name ..)
117			logging.info("Registering input function %s as phi function.", a_callable.__code__.co_name)
118			key = phi_name if phi_name else cls.get_name(a_callable)
119			print(f"Registering input function {a_callable.__code__.co_name} as phi function, at key {key}.")
120			cls._register(a_callable, key)
121			else:
122			if not hasattr(a_callable, '__call__'):
123			raise RuntimeError("Expected an class definition with a '__call__' instance method defined 1."
124			f" Got {type(a_callable)}")
125			members = inspect.getmembers(a_callable)
126			if ('__call__', a_callable.__call__) not in members:
127			raise RuntimeError("Expected an class definition with a '__call__' instance method defined 2."
128			f" Got {type(a_callable)}")
129			instance = a_callable()
130			instance.__name__ = a_callable.__name__
131			instance.__doc__ = a_callable.__call__.__doc__
132			key = phi_name if phi_name else cls.get_name(instance)
133			print(f"Registering input class {a_callable.__name__} instance as phi function, at key {key}.")
134			cls._register(instance, key)
135			return a_callable
136			return wrapper
137
138			@classmethod
139			def _register(cls, a_callable, key_name):
140			"""Register a callable as phi function and notify potential listeners/observers.
141
142			The phi function is registered under the given key_name or in case of None the name is automatically computed
143			based on the input callable.
144
145			Args:
146			a_callable (Callable): the callable that holds the business logic of the phi function
147			key_name (str, optional): custom phi name. Defaults to None, which means automatic determination of the name
148			"""
149			cls.subject.name = key_name
150			cls.subject.state = a_callable
151			cls.subject.notify()
152
153			@staticmethod
154			def get_name(a_callable: Callable):
155			"""Get the 'name' of the input callable object
156
157			Args:
158			a_callable (Callable): a callable object to get its name
159
160			Returns:
161			str: the name of the callable object
162			"""
163			if hasattr(a_callable, 'name'):
164			return a_callable.name
165			if hasattr(a_callable, '__code__') and hasattr(a_callable.__code__, 'co_name'):
166			return a_callable.__code__.co_name
167			if hasattr(type(a_callable), 'name'):
168			return type(a_callable).name
169			if hasattr(type(a_callable), '__name__'):
170			return type(a_callable).__name__
171			raise PhiFunctionNameDeterminationError()
172
173
174			class PhiFunctionNameDeterminationError(Exception): pass
175

boromir674 / so-magic

Pull Request — dev (#32)

ce() A

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