Files
odoo_source/odoo/tools/func.py
T
Gorash b376a0deb5 [IMP] base: comparison between two lazy values is possible.
Before this commit, two lazy values could not always be compared. Indeed,
the comparison did indeed use the value for the self, but not the other.
A normally true comparison was returned as false. Inverting the values
causes the code to pass through the lazy functions of the objects. For
example, if we go through `__lt__` the fact of having reversed the
values means that we will necessarily go through the `__gt__` of the
other.

Part-of: odoo/odoo#88276
2022-06-03 16:40:38 +02:00

261 lines
10 KiB
Python

# -*- coding: utf-8 -*-
# Part of Odoo. See LICENSE file for full copyright and licensing details.
__all__ = ['synchronized', 'lazy_classproperty', 'lazy_property',
'classproperty', 'conditional', 'lazy']
from inspect import getsourcefile, Parameter, signature
from functools import wraps
from json import JSONEncoder
from decorator import decorator
class lazy_property(object):
""" Decorator for a lazy property of an object, i.e., an object attribute
that is determined by the result of a method call evaluated once. To
reevaluate the property, simply delete the attribute on the object, and
get it again.
"""
def __init__(self, fget):
assert not fget.__name__.startswith('__'),\
"lazy_property does not support mangled names"
self.fget = fget
def __get__(self, obj, cls):
if obj is None:
return self
value = self.fget(obj)
setattr(obj, self.fget.__name__, value)
return value
@property
def __doc__(self):
return self.fget.__doc__
@staticmethod
def reset_all(obj):
""" Reset all lazy properties on the instance `obj`. """
cls = type(obj)
obj_dict = vars(obj)
for name in list(obj_dict):
if isinstance(getattr(cls, name, None), lazy_property):
obj_dict.pop(name)
class lazy_classproperty(lazy_property):
""" Similar to :class:`lazy_property`, but for classes. """
def __get__(self, obj, cls):
val = self.fget(cls)
setattr(cls, self.fget.__name__, val)
return val
def conditional(condition, decorator):
""" Decorator for a conditionally applied decorator.
Example::
@conditional(get_config('use_cache'), ormcache)
def fn():
pass
"""
if condition:
return decorator
else:
return lambda fn: fn
def filter_kwargs(func, kwargs):
""" Filter the given keyword arguments to only return the kwargs
that binds to the function's signature.
"""
leftovers = set(kwargs)
for p in signature(func).parameters.values():
if p.kind in (Parameter.POSITIONAL_OR_KEYWORD, Parameter.KEYWORD_ONLY):
leftovers.discard(p.name)
elif p.kind == Parameter.VAR_KEYWORD: # **kwargs
leftovers.clear()
break
if not leftovers:
return kwargs
return {key: kwargs[key] for key in kwargs if key not in leftovers}
def synchronized(lock_attr='_lock'):
@decorator
def locked(func, inst, *args, **kwargs):
with getattr(inst, lock_attr):
return func(inst, *args, **kwargs)
return locked
locked = synchronized()
def frame_codeinfo(fframe, back=0):
""" Return a (filename, line) pair for a previous frame .
@return (filename, lineno) where lineno is either int or string==''
"""
try:
if not fframe:
return "<unknown>", ''
for i in range(back):
fframe = fframe.f_back
try:
fname = getsourcefile(fframe)
except TypeError:
fname = '<builtin>'
lineno = fframe.f_lineno or ''
return fname, lineno
except Exception:
return "<unknown>", ''
def compose(a, b):
""" Composes the callables ``a`` and ``b``. ``compose(a, b)(*args)`` is
equivalent to ``a(b(*args))``.
Can be used as a decorator by partially applying ``a``::
@partial(compose, a)
def b():
...
"""
@wraps(b)
def wrapper(*args, **kwargs):
return a(b(*args, **kwargs))
return wrapper
class _ClassProperty(property):
def __get__(self, cls, owner):
return self.fget.__get__(None, owner)()
def classproperty(func):
return _ClassProperty(classmethod(func))
class lazy(object):
""" A proxy to the (memoized) result of a lazy evaluation:
.. code-block::
foo = lazy(func, arg) # func(arg) is not called yet
bar = foo + 1 # eval func(arg) and add 1
baz = foo + 2 # use result of func(arg) and add 2
"""
__slots__ = ['_func', '_args', '_kwargs', '_cached_value']
def __init__(self, func, *args, **kwargs):
# bypass own __setattr__
object.__setattr__(self, '_func', func)
object.__setattr__(self, '_args', args)
object.__setattr__(self, '_kwargs', kwargs)
@property
def _value(self):
if self._func is not None:
value = self._func(*self._args, **self._kwargs)
object.__setattr__(self, '_func', None)
object.__setattr__(self, '_args', None)
object.__setattr__(self, '_kwargs', None)
object.__setattr__(self, '_cached_value', value)
return self._cached_value
def __getattr__(self, name): return getattr(self._value, name)
def __setattr__(self, name, value): return setattr(self._value, name, value)
def __delattr__(self, name): return delattr(self._value, name)
def __repr__(self):
return repr(self._value) if self._func is None else object.__repr__(self)
def __str__(self): return str(self._value)
def __bytes__(self): return bytes(self._value)
def __format__(self, format_spec): return format(self._value, format_spec)
def __lt__(self, other): return other > self._value
def __le__(self, other): return other >= self._value
def __eq__(self, other): return other == self._value
def __ne__(self, other): return other != self._value
def __gt__(self, other): return other < self._value
def __ge__(self, other): return other <= self._value
def __hash__(self): return hash(self._value)
def __bool__(self): return bool(self._value)
def __call__(self, *args, **kwargs): return self._value(*args, **kwargs)
def __len__(self): return len(self._value)
def __getitem__(self, key): return self._value[key]
def __missing__(self, key): return self._value.__missing__(key)
def __setitem__(self, key, value): self._value[key] = value
def __delitem__(self, key): del self._value[key]
def __iter__(self): return iter(self._value)
def __reversed__(self): return reversed(self._value)
def __contains__(self, key): return key in self._value
def __add__(self, other): return self._value.__add__(other)
def __sub__(self, other): return self._value.__sub__(other)
def __mul__(self, other): return self._value.__mul__(other)
def __matmul__(self, other): return self._value.__matmul__(other)
def __truediv__(self, other): return self._value.__truediv__(other)
def __floordiv__(self, other): return self._value.__floordiv__(other)
def __mod__(self, other): return self._value.__mod__(other)
def __divmod__(self, other): return self._value.__divmod__(other)
def __pow__(self, other): return self._value.__pow__(other)
def __lshift__(self, other): return self._value.__lshift__(other)
def __rshift__(self, other): return self._value.__rshift__(other)
def __and__(self, other): return self._value.__and__(other)
def __xor__(self, other): return self._value.__xor__(other)
def __or__(self, other): return self._value.__or__(other)
def __radd__(self, other): return self._value.__radd__(other)
def __rsub__(self, other): return self._value.__rsub__(other)
def __rmul__(self, other): return self._value.__rmul__(other)
def __rmatmul__(self, other): return self._value.__rmatmul__(other)
def __rtruediv__(self, other): return self._value.__rtruediv__(other)
def __rfloordiv__(self, other): return self._value.__rfloordiv__(other)
def __rmod__(self, other): return self._value.__rmod__(other)
def __rdivmod__(self, other): return self._value.__rdivmod__(other)
def __rpow__(self, other): return self._value.__rpow__(other)
def __rlshift__(self, other): return self._value.__rlshift__(other)
def __rrshift__(self, other): return self._value.__rrshift__(other)
def __rand__(self, other): return self._value.__rand__(other)
def __rxor__(self, other): return self._value.__rxor__(other)
def __ror__(self, other): return self._value.__ror__(other)
def __iadd__(self, other): return self._value.__iadd__(other)
def __isub__(self, other): return self._value.__isub__(other)
def __imul__(self, other): return self._value.__imul__(other)
def __imatmul__(self, other): return self._value.__imatmul__(other)
def __itruediv__(self, other): return self._value.__itruediv__(other)
def __ifloordiv__(self, other): return self._value.__ifloordiv__(other)
def __imod__(self, other): return self._value.__imod__(other)
def __ipow__(self, other): return self._value.__ipow__(other)
def __ilshift__(self, other): return self._value.__ilshift__(other)
def __irshift__(self, other): return self._value.__irshift__(other)
def __iand__(self, other): return self._value.__iand__(other)
def __ixor__(self, other): return self._value.__ixor__(other)
def __ior__(self, other): return self._value.__ior__(other)
def __neg__(self): return self._value.__neg__()
def __pos__(self): return self._value.__pos__()
def __abs__(self): return self._value.__abs__()
def __invert__(self): return self._value.__invert__()
def __complex__(self): return complex(self._value)
def __int__(self): return int(self._value)
def __float__(self): return float(self._value)
def __index__(self): return self._value.__index__()
def __round__(self): return self._value.__round__()
def __trunc__(self): return self._value.__trunc__()
def __floor__(self): return self._value.__floor__()
def __ceil__(self): return self._value.__ceil__()
def __enter__(self): return self._value.__enter__()
def __exit__(self, exc_type, exc_value, traceback):
return self._value.__exit__(exc_type, exc_value, traceback)
def __await__(self): return self._value.__await__()
def __aiter__(self): return self._value.__aiter__()
def __anext__(self): return self._value.__anext__()
def __aenter__(self): return self._value.__aenter__()
def __aexit__(self, exc_type, exc_value, traceback):
return self._value.__aexit__(exc_type, exc_value, traceback)