Mercurial > hg
view mercurial/thirdparty/zope/interface/registry.py @ 37176:943d77fc07a3
thirdparty: vendor zope.interface 4.4.3
I've been trying to formalize interfaces for various components
of Mercurial. So far, we've been using the "abc" package. This
package is "good enough" for a lot of tasks. But it quickly
falls over. For example, if you declare an @abc.abstractproperty,
you must implement that attribute with a @property or the class
compile time checking performed by abc will complain. This often
forces you to implement dumb @property wrappers to return a
_ prefixed attribute of the sane name. That's ugly.
I've also wanted to implement automated checking that classes
conform to various interfaces and don't expose other "public"
attributes.
After doing a bit of research and asking around, the general
consensus seems to be that zope.interface is the best package for
doing interface-based programming in Python. It has built-in
support for verifying classes and objects conform to interfaces.
It allows an interface's properties to be defined during __init__.
There's even an "adapter registry" that allow you to register
interfaces and look up which classes implement them. That could
potentially be useful for places where our custom registry.py
modules currently facilitates central registrations, but at a
type level. Imagine extensions providing alternate implementations
of things like the local repository interface to allow opening
repositories with custom requirements.
Anyway, this commit vendors zope.interface 4.4.3. The contents of
the source tarball have been copied into mercurial/thirdparty/zope/
without modifications.
Test modules have been removed because they are not interesting
to us.
The LICENSE.txt file has been copied so it lives next to the
source.
The Python modules don't use relative imports. zope/__init__.py
defines a namespace package. So we'll need to modify the source
code before this package is usable inside Mercurial. This will
be done in subsequent commits.
# no-check-commit for various style failures
Differential Revision: https://phab.mercurial-scm.org/D2928
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Wed, 21 Mar 2018 19:48:50 -0700 |
parents | |
children | 68ee61822182 |
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############################################################################## # # Copyright (c) 2006 Zope Foundation and Contributors. # All Rights Reserved. # # This software is subject to the provisions of the Zope Public License, # Version 2.1 (ZPL). A copy of the ZPL should accompany this distribution. # THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED # WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED # WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS # FOR A PARTICULAR PURPOSE. # ############################################################################## """Basic components support """ from collections import defaultdict try: from zope.event import notify except ImportError: # pragma: no cover def notify(*arg, **kw): pass from zope.interface.interfaces import ISpecification from zope.interface.interfaces import ComponentLookupError from zope.interface.interfaces import IAdapterRegistration from zope.interface.interfaces import IComponents from zope.interface.interfaces import IHandlerRegistration from zope.interface.interfaces import ISubscriptionAdapterRegistration from zope.interface.interfaces import IUtilityRegistration from zope.interface.interfaces import Registered from zope.interface.interfaces import Unregistered from zope.interface.interface import Interface from zope.interface.declarations import implementedBy from zope.interface.declarations import implementer from zope.interface.declarations import implementer_only from zope.interface.declarations import providedBy from zope.interface.adapter import AdapterRegistry from zope.interface._compat import CLASS_TYPES from zope.interface._compat import STRING_TYPES class _UnhashableComponentCounter(object): # defaultdict(int)-like object for unhashable components def __init__(self, otherdict): # [(component, count)] self._data = [item for item in otherdict.items()] def __getitem__(self, key): for component, count in self._data: if component == key: return count return 0 def __setitem__(self, component, count): for i, data in enumerate(self._data): if data[0] == component: self._data[i] = component, count return self._data.append((component, count)) def __delitem__(self, component): for i, data in enumerate(self._data): if data[0] == component: del self._data[i] return raise KeyError(component) # pragma: no cover def _defaultdict_int(): return defaultdict(int) class _UtilityRegistrations(object): def __init__(self, utilities, utility_registrations): # {provided -> {component: count}} self._cache = defaultdict(_defaultdict_int) self._utilities = utilities self._utility_registrations = utility_registrations self.__populate_cache() def __populate_cache(self): for ((p, _), data) in iter(self._utility_registrations.items()): component = data[0] self.__cache_utility(p, component) def __cache_utility(self, provided, component): try: self._cache[provided][component] += 1 except TypeError: # The component is not hashable, and we have a dict. Switch to a strategy # that doesn't use hashing. prov = self._cache[provided] = _UnhashableComponentCounter(self._cache[provided]) prov[component] += 1 def __uncache_utility(self, provided, component): provided = self._cache[provided] # It seems like this line could raise a TypeError if component isn't # hashable and we haven't yet switched to _UnhashableComponentCounter. However, # we can't actually get in that situation. In order to get here, we would # have had to cache the utility already which would have switched # the datastructure if needed. count = provided[component] count -= 1 if count == 0: del provided[component] else: provided[component] = count return count > 0 def _is_utility_subscribed(self, provided, component): try: return self._cache[provided][component] > 0 except TypeError: # Not hashable and we're still using a dict return False def registerUtility(self, provided, name, component, info, factory): subscribed = self._is_utility_subscribed(provided, component) self._utility_registrations[(provided, name)] = component, info, factory self._utilities.register((), provided, name, component) if not subscribed: self._utilities.subscribe((), provided, component) self.__cache_utility(provided, component) def unregisterUtility(self, provided, name, component): del self._utility_registrations[(provided, name)] self._utilities.unregister((), provided, name) subscribed = self.__uncache_utility(provided, component) if not subscribed: self._utilities.unsubscribe((), provided, component) @implementer(IComponents) class Components(object): _v_utility_registrations_cache = None def __init__(self, name='', bases=()): # __init__ is used for test cleanup as well as initialization. # XXX add a separate API for test cleanup. assert isinstance(name, STRING_TYPES) self.__name__ = name self._init_registries() self._init_registrations() self.__bases__ = tuple(bases) self._v_utility_registrations_cache = None def __repr__(self): return "<%s %s>" % (self.__class__.__name__, self.__name__) def __reduce__(self): # Mimic what a persistent.Persistent object does and elide # _v_ attributes so that they don't get saved in ZODB. # This allows us to store things that cannot be pickled in such # attributes. reduction = super(Components, self).__reduce__() # (callable, args, state, listiter, dictiter) # We assume the state is always a dict; the last three items # are technically optional and can be missing or None. filtered_state = {k: v for k, v in reduction[2].items() if not k.startswith('_v_')} reduction = list(reduction) reduction[2] = filtered_state return tuple(reduction) def _init_registries(self): # Subclasses have never been required to call this method # if they override it, merely to fill in these two attributes. self.adapters = AdapterRegistry() self.utilities = AdapterRegistry() def _init_registrations(self): self._utility_registrations = {} self._adapter_registrations = {} self._subscription_registrations = [] self._handler_registrations = [] @property def _utility_registrations_cache(self): # We use a _v_ attribute internally so that data aren't saved in ZODB, # because this object cannot be pickled. cache = self._v_utility_registrations_cache if (cache is None or cache._utilities is not self.utilities or cache._utility_registrations is not self._utility_registrations): cache = self._v_utility_registrations_cache = _UtilityRegistrations( self.utilities, self._utility_registrations) return cache def _getBases(self): # Subclasses might override return self.__dict__.get('__bases__', ()) def _setBases(self, bases): # Subclasses might override self.adapters.__bases__ = tuple([ base.adapters for base in bases]) self.utilities.__bases__ = tuple([ base.utilities for base in bases]) self.__dict__['__bases__'] = tuple(bases) __bases__ = property( lambda self: self._getBases(), lambda self, bases: self._setBases(bases), ) def registerUtility(self, component=None, provided=None, name=u'', info=u'', event=True, factory=None): if factory: if component: raise TypeError("Can't specify factory and component.") component = factory() if provided is None: provided = _getUtilityProvided(component) if name == u'': name = _getName(component) reg = self._utility_registrations.get((provided, name)) if reg is not None: if reg[:2] == (component, info): # already registered return self.unregisterUtility(reg[0], provided, name) self._utility_registrations_cache.registerUtility( provided, name, component, info, factory) if event: notify(Registered( UtilityRegistration(self, provided, name, component, info, factory) )) def unregisterUtility(self, component=None, provided=None, name=u'', factory=None): if factory: if component: raise TypeError("Can't specify factory and component.") component = factory() if provided is None: if component is None: raise TypeError("Must specify one of component, factory and " "provided") provided = _getUtilityProvided(component) old = self._utility_registrations.get((provided, name)) if (old is None) or ((component is not None) and (component != old[0])): return False if component is None: component = old[0] # Note that component is now the old thing registered self._utility_registrations_cache.unregisterUtility( provided, name, component) notify(Unregistered( UtilityRegistration(self, provided, name, component, *old[1:]) )) return True def registeredUtilities(self): for ((provided, name), data ) in iter(self._utility_registrations.items()): yield UtilityRegistration(self, provided, name, *data) def queryUtility(self, provided, name=u'', default=None): return self.utilities.lookup((), provided, name, default) def getUtility(self, provided, name=u''): utility = self.utilities.lookup((), provided, name) if utility is None: raise ComponentLookupError(provided, name) return utility def getUtilitiesFor(self, interface): for name, utility in self.utilities.lookupAll((), interface): yield name, utility def getAllUtilitiesRegisteredFor(self, interface): return self.utilities.subscriptions((), interface) def registerAdapter(self, factory, required=None, provided=None, name=u'', info=u'', event=True): if provided is None: provided = _getAdapterProvided(factory) required = _getAdapterRequired(factory, required) if name == u'': name = _getName(factory) self._adapter_registrations[(required, provided, name) ] = factory, info self.adapters.register(required, provided, name, factory) if event: notify(Registered( AdapterRegistration(self, required, provided, name, factory, info) )) def unregisterAdapter(self, factory=None, required=None, provided=None, name=u'', ): if provided is None: if factory is None: raise TypeError("Must specify one of factory and provided") provided = _getAdapterProvided(factory) if (required is None) and (factory is None): raise TypeError("Must specify one of factory and required") required = _getAdapterRequired(factory, required) old = self._adapter_registrations.get((required, provided, name)) if (old is None) or ((factory is not None) and (factory != old[0])): return False del self._adapter_registrations[(required, provided, name)] self.adapters.unregister(required, provided, name) notify(Unregistered( AdapterRegistration(self, required, provided, name, *old) )) return True def registeredAdapters(self): for ((required, provided, name), (component, info) ) in iter(self._adapter_registrations.items()): yield AdapterRegistration(self, required, provided, name, component, info) def queryAdapter(self, object, interface, name=u'', default=None): return self.adapters.queryAdapter(object, interface, name, default) def getAdapter(self, object, interface, name=u''): adapter = self.adapters.queryAdapter(object, interface, name) if adapter is None: raise ComponentLookupError(object, interface, name) return adapter def queryMultiAdapter(self, objects, interface, name=u'', default=None): return self.adapters.queryMultiAdapter( objects, interface, name, default) def getMultiAdapter(self, objects, interface, name=u''): adapter = self.adapters.queryMultiAdapter(objects, interface, name) if adapter is None: raise ComponentLookupError(objects, interface, name) return adapter def getAdapters(self, objects, provided): for name, factory in self.adapters.lookupAll( list(map(providedBy, objects)), provided): adapter = factory(*objects) if adapter is not None: yield name, adapter def registerSubscriptionAdapter(self, factory, required=None, provided=None, name=u'', info=u'', event=True): if name: raise TypeError("Named subscribers are not yet supported") if provided is None: provided = _getAdapterProvided(factory) required = _getAdapterRequired(factory, required) self._subscription_registrations.append( (required, provided, name, factory, info) ) self.adapters.subscribe(required, provided, factory) if event: notify(Registered( SubscriptionRegistration(self, required, provided, name, factory, info) )) def registeredSubscriptionAdapters(self): for data in self._subscription_registrations: yield SubscriptionRegistration(self, *data) def unregisterSubscriptionAdapter(self, factory=None, required=None, provided=None, name=u'', ): if name: raise TypeError("Named subscribers are not yet supported") if provided is None: if factory is None: raise TypeError("Must specify one of factory and provided") provided = _getAdapterProvided(factory) if (required is None) and (factory is None): raise TypeError("Must specify one of factory and required") required = _getAdapterRequired(factory, required) if factory is None: new = [(r, p, n, f, i) for (r, p, n, f, i) in self._subscription_registrations if not (r == required and p == provided) ] else: new = [(r, p, n, f, i) for (r, p, n, f, i) in self._subscription_registrations if not (r == required and p == provided and f == factory) ] if len(new) == len(self._subscription_registrations): return False self._subscription_registrations[:] = new self.adapters.unsubscribe(required, provided, factory) notify(Unregistered( SubscriptionRegistration(self, required, provided, name, factory, '') )) return True def subscribers(self, objects, provided): return self.adapters.subscribers(objects, provided) def registerHandler(self, factory, required=None, name=u'', info=u'', event=True): if name: raise TypeError("Named handlers are not yet supported") required = _getAdapterRequired(factory, required) self._handler_registrations.append( (required, name, factory, info) ) self.adapters.subscribe(required, None, factory) if event: notify(Registered( HandlerRegistration(self, required, name, factory, info) )) def registeredHandlers(self): for data in self._handler_registrations: yield HandlerRegistration(self, *data) def unregisterHandler(self, factory=None, required=None, name=u''): if name: raise TypeError("Named subscribers are not yet supported") if (required is None) and (factory is None): raise TypeError("Must specify one of factory and required") required = _getAdapterRequired(factory, required) if factory is None: new = [(r, n, f, i) for (r, n, f, i) in self._handler_registrations if r != required ] else: new = [(r, n, f, i) for (r, n, f, i) in self._handler_registrations if not (r == required and f == factory) ] if len(new) == len(self._handler_registrations): return False self._handler_registrations[:] = new self.adapters.unsubscribe(required, None, factory) notify(Unregistered( HandlerRegistration(self, required, name, factory, '') )) return True def handle(self, *objects): self.adapters.subscribers(objects, None) def _getName(component): try: return component.__component_name__ except AttributeError: return u'' def _getUtilityProvided(component): provided = list(providedBy(component)) if len(provided) == 1: return provided[0] raise TypeError( "The utility doesn't provide a single interface " "and no provided interface was specified.") def _getAdapterProvided(factory): provided = list(implementedBy(factory)) if len(provided) == 1: return provided[0] raise TypeError( "The adapter factory doesn't implement a single interface " "and no provided interface was specified.") def _getAdapterRequired(factory, required): if required is None: try: required = factory.__component_adapts__ except AttributeError: raise TypeError( "The adapter factory doesn't have a __component_adapts__ " "attribute and no required specifications were specified" ) elif ISpecification.providedBy(required): raise TypeError("the required argument should be a list of " "interfaces, not a single interface") result = [] for r in required: if r is None: r = Interface elif not ISpecification.providedBy(r): if isinstance(r, CLASS_TYPES): r = implementedBy(r) else: raise TypeError("Required specification must be a " "specification or class." ) result.append(r) return tuple(result) @implementer(IUtilityRegistration) class UtilityRegistration(object): def __init__(self, registry, provided, name, component, doc, factory=None): (self.registry, self.provided, self.name, self.component, self.info, self.factory ) = registry, provided, name, component, doc, factory def __repr__(self): return '%s(%r, %s, %r, %s, %r, %r)' % ( self.__class__.__name__, self.registry, getattr(self.provided, '__name__', None), self.name, getattr(self.component, '__name__', repr(self.component)), self.factory, self.info, ) def __hash__(self): return id(self) def __eq__(self, other): return repr(self) == repr(other) def __ne__(self, other): return repr(self) != repr(other) def __lt__(self, other): return repr(self) < repr(other) def __le__(self, other): return repr(self) <= repr(other) def __gt__(self, other): return repr(self) > repr(other) def __ge__(self, other): return repr(self) >= repr(other) @implementer(IAdapterRegistration) class AdapterRegistration(object): def __init__(self, registry, required, provided, name, component, doc): (self.registry, self.required, self.provided, self.name, self.factory, self.info ) = registry, required, provided, name, component, doc def __repr__(self): return '%s(%r, %s, %s, %r, %s, %r)' % ( self.__class__.__name__, self.registry, '[' + ", ".join([r.__name__ for r in self.required]) + ']', getattr(self.provided, '__name__', None), self.name, getattr(self.factory, '__name__', repr(self.factory)), self.info, ) def __hash__(self): return id(self) def __eq__(self, other): return repr(self) == repr(other) def __ne__(self, other): return repr(self) != repr(other) def __lt__(self, other): return repr(self) < repr(other) def __le__(self, other): return repr(self) <= repr(other) def __gt__(self, other): return repr(self) > repr(other) def __ge__(self, other): return repr(self) >= repr(other) @implementer_only(ISubscriptionAdapterRegistration) class SubscriptionRegistration(AdapterRegistration): pass @implementer_only(IHandlerRegistration) class HandlerRegistration(AdapterRegistration): def __init__(self, registry, required, name, handler, doc): (self.registry, self.required, self.name, self.handler, self.info ) = registry, required, name, handler, doc @property def factory(self): return self.handler provided = None def __repr__(self): return '%s(%r, %s, %r, %s, %r)' % ( self.__class__.__name__, self.registry, '[' + ", ".join([r.__name__ for r in self.required]) + ']', self.name, getattr(self.factory, '__name__', repr(self.factory)), self.info, )