123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454 |
- # ######################### LICENSE ############################ #
- # Copyright (c) 2005-2018, Michele Simionato
- # All rights reserved.
- # Redistribution and use in source and binary forms, with or without
- # modification, are permitted provided that the following conditions are
- # met:
- # Redistributions of source code must retain the above copyright
- # notice, this list of conditions and the following disclaimer.
- # Redistributions in bytecode form must reproduce the above copyright
- # notice, this list of conditions and the following disclaimer in
- # the documentation and/or other materials provided with the
- # distribution.
- # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- # HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
- # INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
- # BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
- # OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
- # ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
- # TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
- # USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
- # DAMAGE.
- """
- Decorator module, see http://pypi.python.org/pypi/decorator
- for the documentation.
- """
- from __future__ import print_function
- import re
- import sys
- import inspect
- import operator
- import itertools
- import collections
- __version__ = '4.4.2'
- if sys.version_info >= (3,):
- from inspect import getfullargspec
- def get_init(cls):
- return cls.__init__
- else:
- FullArgSpec = collections.namedtuple(
- 'FullArgSpec', 'args varargs varkw defaults '
- 'kwonlyargs kwonlydefaults annotations')
- def getfullargspec(f):
- "A quick and dirty replacement for getfullargspec for Python 2.X"
- return FullArgSpec._make(inspect.getargspec(f) + ([], None, {}))
- def get_init(cls):
- return cls.__init__.__func__
- try:
- iscoroutinefunction = inspect.iscoroutinefunction
- except AttributeError:
- # let's assume there are no coroutine functions in old Python
- def iscoroutinefunction(f):
- return False
- try:
- from inspect import isgeneratorfunction
- except ImportError:
- # assume no generator function in old Python versions
- def isgeneratorfunction(caller):
- return False
- DEF = re.compile(r'\s*def\s*([_\w][_\w\d]*)\s*\(')
- # basic functionality
- class FunctionMaker(object):
- """
- An object with the ability to create functions with a given signature.
- It has attributes name, doc, module, signature, defaults, dict and
- methods update and make.
- """
- # Atomic get-and-increment provided by the GIL
- _compile_count = itertools.count()
- # make pylint happy
- args = varargs = varkw = defaults = kwonlyargs = kwonlydefaults = ()
- def __init__(self, func=None, name=None, signature=None,
- defaults=None, doc=None, module=None, funcdict=None):
- self.shortsignature = signature
- if func:
- # func can be a class or a callable, but not an instance method
- self.name = func.__name__
- if self.name == '<lambda>': # small hack for lambda functions
- self.name = '_lambda_'
- self.doc = func.__doc__
- self.module = func.__module__
- if inspect.isfunction(func):
- argspec = getfullargspec(func)
- self.annotations = getattr(func, '__annotations__', {})
- for a in ('args', 'varargs', 'varkw', 'defaults', 'kwonlyargs',
- 'kwonlydefaults'):
- setattr(self, a, getattr(argspec, a))
- for i, arg in enumerate(self.args):
- setattr(self, 'arg%d' % i, arg)
- allargs = list(self.args)
- allshortargs = list(self.args)
- if self.varargs:
- allargs.append('*' + self.varargs)
- allshortargs.append('*' + self.varargs)
- elif self.kwonlyargs:
- allargs.append('*') # single star syntax
- for a in self.kwonlyargs:
- allargs.append('%s=None' % a)
- allshortargs.append('%s=%s' % (a, a))
- if self.varkw:
- allargs.append('**' + self.varkw)
- allshortargs.append('**' + self.varkw)
- self.signature = ', '.join(allargs)
- self.shortsignature = ', '.join(allshortargs)
- self.dict = func.__dict__.copy()
- # func=None happens when decorating a caller
- if name:
- self.name = name
- if signature is not None:
- self.signature = signature
- if defaults:
- self.defaults = defaults
- if doc:
- self.doc = doc
- if module:
- self.module = module
- if funcdict:
- self.dict = funcdict
- # check existence required attributes
- assert hasattr(self, 'name')
- if not hasattr(self, 'signature'):
- raise TypeError('You are decorating a non function: %s' % func)
- def update(self, func, **kw):
- "Update the signature of func with the data in self"
- func.__name__ = self.name
- func.__doc__ = getattr(self, 'doc', None)
- func.__dict__ = getattr(self, 'dict', {})
- func.__defaults__ = self.defaults
- func.__kwdefaults__ = self.kwonlydefaults or None
- func.__annotations__ = getattr(self, 'annotations', None)
- try:
- frame = sys._getframe(3)
- except AttributeError: # for IronPython and similar implementations
- callermodule = '?'
- else:
- callermodule = frame.f_globals.get('__name__', '?')
- func.__module__ = getattr(self, 'module', callermodule)
- func.__dict__.update(kw)
- def make(self, src_templ, evaldict=None, addsource=False, **attrs):
- "Make a new function from a given template and update the signature"
- src = src_templ % vars(self) # expand name and signature
- evaldict = evaldict or {}
- mo = DEF.search(src)
- if mo is None:
- raise SyntaxError('not a valid function template\n%s' % src)
- name = mo.group(1) # extract the function name
- names = set([name] + [arg.strip(' *') for arg in
- self.shortsignature.split(',')])
- for n in names:
- if n in ('_func_', '_call_'):
- raise NameError('%s is overridden in\n%s' % (n, src))
- if not src.endswith('\n'): # add a newline for old Pythons
- src += '\n'
- # Ensure each generated function has a unique filename for profilers
- # (such as cProfile) that depend on the tuple of (<filename>,
- # <definition line>, <function name>) being unique.
- filename = '<decorator-gen-%d>' % next(self._compile_count)
- try:
- code = compile(src, filename, 'single')
- exec(code, evaldict)
- except Exception:
- print('Error in generated code:', file=sys.stderr)
- print(src, file=sys.stderr)
- raise
- func = evaldict[name]
- if addsource:
- attrs['__source__'] = src
- self.update(func, **attrs)
- return func
- @classmethod
- def create(cls, obj, body, evaldict, defaults=None,
- doc=None, module=None, addsource=True, **attrs):
- """
- Create a function from the strings name, signature and body.
- evaldict is the evaluation dictionary. If addsource is true an
- attribute __source__ is added to the result. The attributes attrs
- are added, if any.
- """
- if isinstance(obj, str): # "name(signature)"
- name, rest = obj.strip().split('(', 1)
- signature = rest[:-1] # strip a right parens
- func = None
- else: # a function
- name = None
- signature = None
- func = obj
- self = cls(func, name, signature, defaults, doc, module)
- ibody = '\n'.join(' ' + line for line in body.splitlines())
- caller = evaldict.get('_call_') # when called from `decorate`
- if caller and iscoroutinefunction(caller):
- body = ('async def %(name)s(%(signature)s):\n' + ibody).replace(
- 'return', 'return await')
- else:
- body = 'def %(name)s(%(signature)s):\n' + ibody
- return self.make(body, evaldict, addsource, **attrs)
- def decorate(func, caller, extras=()):
- """
- decorate(func, caller) decorates a function using a caller.
- If the caller is a generator function, the resulting function
- will be a generator function.
- """
- evaldict = dict(_call_=caller, _func_=func)
- es = ''
- for i, extra in enumerate(extras):
- ex = '_e%d_' % i
- evaldict[ex] = extra
- es += ex + ', '
- if '3.5' <= sys.version < '3.6':
- # with Python 3.5 isgeneratorfunction returns True for all coroutines
- # however we know that it is NOT possible to have a generator
- # coroutine in python 3.5: PEP525 was not there yet
- generatorcaller = isgeneratorfunction(
- caller) and not iscoroutinefunction(caller)
- else:
- generatorcaller = isgeneratorfunction(caller)
- if generatorcaller:
- fun = FunctionMaker.create(
- func, "for res in _call_(_func_, %s%%(shortsignature)s):\n"
- " yield res" % es, evaldict, __wrapped__=func)
- else:
- fun = FunctionMaker.create(
- func, "return _call_(_func_, %s%%(shortsignature)s)" % es,
- evaldict, __wrapped__=func)
- if hasattr(func, '__qualname__'):
- fun.__qualname__ = func.__qualname__
- return fun
- def decorator(caller, _func=None):
- """decorator(caller) converts a caller function into a decorator"""
- if _func is not None: # return a decorated function
- # this is obsolete behavior; you should use decorate instead
- return decorate(_func, caller)
- # else return a decorator function
- defaultargs, defaults = '', ()
- if inspect.isclass(caller):
- name = caller.__name__.lower()
- doc = 'decorator(%s) converts functions/generators into ' \
- 'factories of %s objects' % (caller.__name__, caller.__name__)
- elif inspect.isfunction(caller):
- if caller.__name__ == '<lambda>':
- name = '_lambda_'
- else:
- name = caller.__name__
- doc = caller.__doc__
- nargs = caller.__code__.co_argcount
- ndefs = len(caller.__defaults__ or ())
- defaultargs = ', '.join(caller.__code__.co_varnames[nargs-ndefs:nargs])
- if defaultargs:
- defaultargs += ','
- defaults = caller.__defaults__
- else: # assume caller is an object with a __call__ method
- name = caller.__class__.__name__.lower()
- doc = caller.__call__.__doc__
- evaldict = dict(_call=caller, _decorate_=decorate)
- dec = FunctionMaker.create(
- '%s(func, %s)' % (name, defaultargs),
- 'if func is None: return lambda func: _decorate_(func, _call, (%s))\n'
- 'return _decorate_(func, _call, (%s))' % (defaultargs, defaultargs),
- evaldict, doc=doc, module=caller.__module__, __wrapped__=caller)
- if defaults:
- dec.__defaults__ = (None,) + defaults
- return dec
- # ####################### contextmanager ####################### #
- try: # Python >= 3.2
- from contextlib import _GeneratorContextManager
- except ImportError: # Python >= 2.5
- from contextlib import GeneratorContextManager as _GeneratorContextManager
- class ContextManager(_GeneratorContextManager):
- def __call__(self, func):
- """Context manager decorator"""
- return FunctionMaker.create(
- func, "with _self_: return _func_(%(shortsignature)s)",
- dict(_self_=self, _func_=func), __wrapped__=func)
- init = getfullargspec(_GeneratorContextManager.__init__)
- n_args = len(init.args)
- if n_args == 2 and not init.varargs: # (self, genobj) Python 2.7
- def __init__(self, g, *a, **k):
- return _GeneratorContextManager.__init__(self, g(*a, **k))
- ContextManager.__init__ = __init__
- elif n_args == 2 and init.varargs: # (self, gen, *a, **k) Python 3.4
- pass
- elif n_args == 4: # (self, gen, args, kwds) Python 3.5
- def __init__(self, g, *a, **k):
- return _GeneratorContextManager.__init__(self, g, a, k)
- ContextManager.__init__ = __init__
- _contextmanager = decorator(ContextManager)
- def contextmanager(func):
- # Enable Pylint config: contextmanager-decorators=decorator.contextmanager
- return _contextmanager(func)
- # ############################ dispatch_on ############################ #
- def append(a, vancestors):
- """
- Append ``a`` to the list of the virtual ancestors, unless it is already
- included.
- """
- add = True
- for j, va in enumerate(vancestors):
- if issubclass(va, a):
- add = False
- break
- if issubclass(a, va):
- vancestors[j] = a
- add = False
- if add:
- vancestors.append(a)
- # inspired from simplegeneric by P.J. Eby and functools.singledispatch
- def dispatch_on(*dispatch_args):
- """
- Factory of decorators turning a function into a generic function
- dispatching on the given arguments.
- """
- assert dispatch_args, 'No dispatch args passed'
- dispatch_str = '(%s,)' % ', '.join(dispatch_args)
- def check(arguments, wrong=operator.ne, msg=''):
- """Make sure one passes the expected number of arguments"""
- if wrong(len(arguments), len(dispatch_args)):
- raise TypeError('Expected %d arguments, got %d%s' %
- (len(dispatch_args), len(arguments), msg))
- def gen_func_dec(func):
- """Decorator turning a function into a generic function"""
- # first check the dispatch arguments
- argset = set(getfullargspec(func).args)
- if not set(dispatch_args) <= argset:
- raise NameError('Unknown dispatch arguments %s' % dispatch_str)
- typemap = {}
- def vancestors(*types):
- """
- Get a list of sets of virtual ancestors for the given types
- """
- check(types)
- ras = [[] for _ in range(len(dispatch_args))]
- for types_ in typemap:
- for t, type_, ra in zip(types, types_, ras):
- if issubclass(t, type_) and type_ not in t.mro():
- append(type_, ra)
- return [set(ra) for ra in ras]
- def ancestors(*types):
- """
- Get a list of virtual MROs, one for each type
- """
- check(types)
- lists = []
- for t, vas in zip(types, vancestors(*types)):
- n_vas = len(vas)
- if n_vas > 1:
- raise RuntimeError(
- 'Ambiguous dispatch for %s: %s' % (t, vas))
- elif n_vas == 1:
- va, = vas
- mro = type('t', (t, va), {}).mro()[1:]
- else:
- mro = t.mro()
- lists.append(mro[:-1]) # discard t and object
- return lists
- def register(*types):
- """
- Decorator to register an implementation for the given types
- """
- check(types)
- def dec(f):
- check(getfullargspec(f).args, operator.lt, ' in ' + f.__name__)
- typemap[types] = f
- return f
- return dec
- def dispatch_info(*types):
- """
- An utility to introspect the dispatch algorithm
- """
- check(types)
- lst = []
- for anc in itertools.product(*ancestors(*types)):
- lst.append(tuple(a.__name__ for a in anc))
- return lst
- def _dispatch(dispatch_args, *args, **kw):
- types = tuple(type(arg) for arg in dispatch_args)
- try: # fast path
- f = typemap[types]
- except KeyError:
- pass
- else:
- return f(*args, **kw)
- combinations = itertools.product(*ancestors(*types))
- next(combinations) # the first one has been already tried
- for types_ in combinations:
- f = typemap.get(types_)
- if f is not None:
- return f(*args, **kw)
- # else call the default implementation
- return func(*args, **kw)
- return FunctionMaker.create(
- func, 'return _f_(%s, %%(shortsignature)s)' % dispatch_str,
- dict(_f_=_dispatch), register=register, default=func,
- typemap=typemap, vancestors=vancestors, ancestors=ancestors,
- dispatch_info=dispatch_info, __wrapped__=func)
- gen_func_dec.__name__ = 'dispatch_on' + dispatch_str
- return gen_func_dec
|