mirror of
https://github.com/SickGear/SickGear.git
synced 2024-12-05 02:43:37 +00:00
387 lines
12 KiB
Python
387 lines
12 KiB
Python
|
# event/attr.py
|
||
|
# Copyright (C) 2005-2014 the SQLAlchemy authors and contributors <see AUTHORS file>
|
||
|
#
|
||
|
# This module is part of SQLAlchemy and is released under
|
||
|
# the MIT License: http://www.opensource.org/licenses/mit-license.php
|
||
|
|
||
|
"""Attribute implementation for _Dispatch classes.
|
||
|
|
||
|
The various listener targets for a particular event class are represented
|
||
|
as attributes, which refer to collections of listeners to be fired off.
|
||
|
These collections can exist at the class level as well as at the instance
|
||
|
level. An event is fired off using code like this::
|
||
|
|
||
|
some_object.dispatch.first_connect(arg1, arg2)
|
||
|
|
||
|
Above, ``some_object.dispatch`` would be an instance of ``_Dispatch`` and
|
||
|
``first_connect`` is typically an instance of ``_ListenerCollection``
|
||
|
if event listeners are present, or ``_EmptyListener`` if none are present.
|
||
|
|
||
|
The attribute mechanics here spend effort trying to ensure listener functions
|
||
|
are available with a minimum of function call overhead, that unnecessary
|
||
|
objects aren't created (i.e. many empty per-instance listener collections),
|
||
|
as well as that everything is garbage collectable when owning references are
|
||
|
lost. Other features such as "propagation" of listener functions across
|
||
|
many ``_Dispatch`` instances, "joining" of multiple ``_Dispatch`` instances,
|
||
|
as well as support for subclass propagation (e.g. events assigned to
|
||
|
``Pool`` vs. ``QueuePool``) are all implemented here.
|
||
|
|
||
|
"""
|
||
|
|
||
|
from __future__ import absolute_import, with_statement
|
||
|
|
||
|
from .. import util
|
||
|
from ..util import threading
|
||
|
from . import registry
|
||
|
from . import legacy
|
||
|
from itertools import chain
|
||
|
import weakref
|
||
|
|
||
|
|
||
|
class RefCollection(object):
|
||
|
@util.memoized_property
|
||
|
def ref(self):
|
||
|
return weakref.ref(self, registry._collection_gced)
|
||
|
|
||
|
class _DispatchDescriptor(RefCollection):
|
||
|
"""Class-level attributes on :class:`._Dispatch` classes."""
|
||
|
|
||
|
def __init__(self, parent_dispatch_cls, fn):
|
||
|
self.__name__ = fn.__name__
|
||
|
argspec = util.inspect_getargspec(fn)
|
||
|
self.arg_names = argspec.args[1:]
|
||
|
self.has_kw = bool(argspec.keywords)
|
||
|
self.legacy_signatures = list(reversed(
|
||
|
sorted(
|
||
|
getattr(fn, '_legacy_signatures', []),
|
||
|
key=lambda s: s[0]
|
||
|
)
|
||
|
))
|
||
|
self.__doc__ = fn.__doc__ = legacy._augment_fn_docs(
|
||
|
self, parent_dispatch_cls, fn)
|
||
|
|
||
|
self._clslevel = weakref.WeakKeyDictionary()
|
||
|
self._empty_listeners = weakref.WeakKeyDictionary()
|
||
|
|
||
|
def _adjust_fn_spec(self, fn, named):
|
||
|
if named:
|
||
|
fn = self._wrap_fn_for_kw(fn)
|
||
|
if self.legacy_signatures:
|
||
|
try:
|
||
|
argspec = util.get_callable_argspec(fn, no_self=True)
|
||
|
except TypeError:
|
||
|
pass
|
||
|
else:
|
||
|
fn = legacy._wrap_fn_for_legacy(self, fn, argspec)
|
||
|
return fn
|
||
|
|
||
|
def _wrap_fn_for_kw(self, fn):
|
||
|
def wrap_kw(*args, **kw):
|
||
|
argdict = dict(zip(self.arg_names, args))
|
||
|
argdict.update(kw)
|
||
|
return fn(**argdict)
|
||
|
return wrap_kw
|
||
|
|
||
|
|
||
|
def insert(self, event_key, propagate):
|
||
|
target = event_key.dispatch_target
|
||
|
assert isinstance(target, type), \
|
||
|
"Class-level Event targets must be classes."
|
||
|
stack = [target]
|
||
|
while stack:
|
||
|
cls = stack.pop(0)
|
||
|
stack.extend(cls.__subclasses__())
|
||
|
if cls is not target and cls not in self._clslevel:
|
||
|
self.update_subclass(cls)
|
||
|
else:
|
||
|
if cls not in self._clslevel:
|
||
|
self._clslevel[cls] = []
|
||
|
self._clslevel[cls].insert(0, event_key._listen_fn)
|
||
|
registry._stored_in_collection(event_key, self)
|
||
|
|
||
|
def append(self, event_key, propagate):
|
||
|
target = event_key.dispatch_target
|
||
|
assert isinstance(target, type), \
|
||
|
"Class-level Event targets must be classes."
|
||
|
|
||
|
stack = [target]
|
||
|
while stack:
|
||
|
cls = stack.pop(0)
|
||
|
stack.extend(cls.__subclasses__())
|
||
|
if cls is not target and cls not in self._clslevel:
|
||
|
self.update_subclass(cls)
|
||
|
else:
|
||
|
if cls not in self._clslevel:
|
||
|
self._clslevel[cls] = []
|
||
|
self._clslevel[cls].append(event_key._listen_fn)
|
||
|
registry._stored_in_collection(event_key, self)
|
||
|
|
||
|
def update_subclass(self, target):
|
||
|
if target not in self._clslevel:
|
||
|
self._clslevel[target] = []
|
||
|
clslevel = self._clslevel[target]
|
||
|
for cls in target.__mro__[1:]:
|
||
|
if cls in self._clslevel:
|
||
|
clslevel.extend([
|
||
|
fn for fn
|
||
|
in self._clslevel[cls]
|
||
|
if fn not in clslevel
|
||
|
])
|
||
|
|
||
|
def remove(self, event_key):
|
||
|
target = event_key.dispatch_target
|
||
|
stack = [target]
|
||
|
while stack:
|
||
|
cls = stack.pop(0)
|
||
|
stack.extend(cls.__subclasses__())
|
||
|
if cls in self._clslevel:
|
||
|
self._clslevel[cls].remove(event_key._listen_fn)
|
||
|
registry._removed_from_collection(event_key, self)
|
||
|
|
||
|
def clear(self):
|
||
|
"""Clear all class level listeners"""
|
||
|
|
||
|
to_clear = set()
|
||
|
for dispatcher in self._clslevel.values():
|
||
|
to_clear.update(dispatcher)
|
||
|
dispatcher[:] = []
|
||
|
registry._clear(self, to_clear)
|
||
|
|
||
|
def for_modify(self, obj):
|
||
|
"""Return an event collection which can be modified.
|
||
|
|
||
|
For _DispatchDescriptor at the class level of
|
||
|
a dispatcher, this returns self.
|
||
|
|
||
|
"""
|
||
|
return self
|
||
|
|
||
|
def __get__(self, obj, cls):
|
||
|
if obj is None:
|
||
|
return self
|
||
|
elif obj._parent_cls in self._empty_listeners:
|
||
|
ret = self._empty_listeners[obj._parent_cls]
|
||
|
else:
|
||
|
self._empty_listeners[obj._parent_cls] = ret = \
|
||
|
_EmptyListener(self, obj._parent_cls)
|
||
|
# assigning it to __dict__ means
|
||
|
# memoized for fast re-access. but more memory.
|
||
|
obj.__dict__[self.__name__] = ret
|
||
|
return ret
|
||
|
|
||
|
class _HasParentDispatchDescriptor(object):
|
||
|
def _adjust_fn_spec(self, fn, named):
|
||
|
return self.parent._adjust_fn_spec(fn, named)
|
||
|
|
||
|
class _EmptyListener(_HasParentDispatchDescriptor):
|
||
|
"""Serves as a class-level interface to the events
|
||
|
served by a _DispatchDescriptor, when there are no
|
||
|
instance-level events present.
|
||
|
|
||
|
Is replaced by _ListenerCollection when instance-level
|
||
|
events are added.
|
||
|
|
||
|
"""
|
||
|
def __init__(self, parent, target_cls):
|
||
|
if target_cls not in parent._clslevel:
|
||
|
parent.update_subclass(target_cls)
|
||
|
self.parent = parent # _DispatchDescriptor
|
||
|
self.parent_listeners = parent._clslevel[target_cls]
|
||
|
self.name = parent.__name__
|
||
|
self.propagate = frozenset()
|
||
|
self.listeners = ()
|
||
|
|
||
|
|
||
|
def for_modify(self, obj):
|
||
|
"""Return an event collection which can be modified.
|
||
|
|
||
|
For _EmptyListener at the instance level of
|
||
|
a dispatcher, this generates a new
|
||
|
_ListenerCollection, applies it to the instance,
|
||
|
and returns it.
|
||
|
|
||
|
"""
|
||
|
result = _ListenerCollection(self.parent, obj._parent_cls)
|
||
|
if obj.__dict__[self.name] is self:
|
||
|
obj.__dict__[self.name] = result
|
||
|
return result
|
||
|
|
||
|
def _needs_modify(self, *args, **kw):
|
||
|
raise NotImplementedError("need to call for_modify()")
|
||
|
|
||
|
exec_once = insert = append = remove = clear = _needs_modify
|
||
|
|
||
|
def __call__(self, *args, **kw):
|
||
|
"""Execute this event."""
|
||
|
|
||
|
for fn in self.parent_listeners:
|
||
|
fn(*args, **kw)
|
||
|
|
||
|
def __len__(self):
|
||
|
return len(self.parent_listeners)
|
||
|
|
||
|
def __iter__(self):
|
||
|
return iter(self.parent_listeners)
|
||
|
|
||
|
def __bool__(self):
|
||
|
return bool(self.parent_listeners)
|
||
|
|
||
|
__nonzero__ = __bool__
|
||
|
|
||
|
|
||
|
class _CompoundListener(_HasParentDispatchDescriptor):
|
||
|
_exec_once = False
|
||
|
|
||
|
@util.memoized_property
|
||
|
def _exec_once_mutex(self):
|
||
|
return threading.Lock()
|
||
|
|
||
|
def exec_once(self, *args, **kw):
|
||
|
"""Execute this event, but only if it has not been
|
||
|
executed already for this collection."""
|
||
|
|
||
|
if not self._exec_once:
|
||
|
with self._exec_once_mutex:
|
||
|
if not self._exec_once:
|
||
|
try:
|
||
|
self(*args, **kw)
|
||
|
finally:
|
||
|
self._exec_once = True
|
||
|
|
||
|
def __call__(self, *args, **kw):
|
||
|
"""Execute this event."""
|
||
|
|
||
|
for fn in self.parent_listeners:
|
||
|
fn(*args, **kw)
|
||
|
for fn in self.listeners:
|
||
|
fn(*args, **kw)
|
||
|
|
||
|
def __len__(self):
|
||
|
return len(self.parent_listeners) + len(self.listeners)
|
||
|
|
||
|
def __iter__(self):
|
||
|
return chain(self.parent_listeners, self.listeners)
|
||
|
|
||
|
def __bool__(self):
|
||
|
return bool(self.listeners or self.parent_listeners)
|
||
|
|
||
|
__nonzero__ = __bool__
|
||
|
|
||
|
class _ListenerCollection(RefCollection, _CompoundListener):
|
||
|
"""Instance-level attributes on instances of :class:`._Dispatch`.
|
||
|
|
||
|
Represents a collection of listeners.
|
||
|
|
||
|
As of 0.7.9, _ListenerCollection is only first
|
||
|
created via the _EmptyListener.for_modify() method.
|
||
|
|
||
|
"""
|
||
|
|
||
|
def __init__(self, parent, target_cls):
|
||
|
if target_cls not in parent._clslevel:
|
||
|
parent.update_subclass(target_cls)
|
||
|
self.parent_listeners = parent._clslevel[target_cls]
|
||
|
self.parent = parent
|
||
|
self.name = parent.__name__
|
||
|
self.listeners = []
|
||
|
self.propagate = set()
|
||
|
|
||
|
def for_modify(self, obj):
|
||
|
"""Return an event collection which can be modified.
|
||
|
|
||
|
For _ListenerCollection at the instance level of
|
||
|
a dispatcher, this returns self.
|
||
|
|
||
|
"""
|
||
|
return self
|
||
|
|
||
|
def _update(self, other, only_propagate=True):
|
||
|
"""Populate from the listeners in another :class:`_Dispatch`
|
||
|
object."""
|
||
|
|
||
|
existing_listeners = self.listeners
|
||
|
existing_listener_set = set(existing_listeners)
|
||
|
self.propagate.update(other.propagate)
|
||
|
other_listeners = [l for l
|
||
|
in other.listeners
|
||
|
if l not in existing_listener_set
|
||
|
and not only_propagate or l in self.propagate
|
||
|
]
|
||
|
|
||
|
existing_listeners.extend(other_listeners)
|
||
|
|
||
|
to_associate = other.propagate.union(other_listeners)
|
||
|
registry._stored_in_collection_multi(self, other, to_associate)
|
||
|
|
||
|
def insert(self, event_key, propagate):
|
||
|
if event_key._listen_fn not in self.listeners:
|
||
|
event_key.prepend_to_list(self, self.listeners)
|
||
|
if propagate:
|
||
|
self.propagate.add(event_key._listen_fn)
|
||
|
|
||
|
def append(self, event_key, propagate):
|
||
|
if event_key._listen_fn not in self.listeners:
|
||
|
event_key.append_to_list(self, self.listeners)
|
||
|
if propagate:
|
||
|
self.propagate.add(event_key._listen_fn)
|
||
|
|
||
|
def remove(self, event_key):
|
||
|
self.listeners.remove(event_key._listen_fn)
|
||
|
self.propagate.discard(event_key._listen_fn)
|
||
|
registry._removed_from_collection(event_key, self)
|
||
|
|
||
|
def clear(self):
|
||
|
registry._clear(self, self.listeners)
|
||
|
self.propagate.clear()
|
||
|
self.listeners[:] = []
|
||
|
|
||
|
|
||
|
class _JoinedDispatchDescriptor(object):
|
||
|
def __init__(self, name):
|
||
|
self.name = name
|
||
|
|
||
|
def __get__(self, obj, cls):
|
||
|
if obj is None:
|
||
|
return self
|
||
|
else:
|
||
|
obj.__dict__[self.name] = ret = _JoinedListener(
|
||
|
obj.parent, self.name,
|
||
|
getattr(obj.local, self.name)
|
||
|
)
|
||
|
return ret
|
||
|
|
||
|
|
||
|
class _JoinedListener(_CompoundListener):
|
||
|
_exec_once = False
|
||
|
|
||
|
def __init__(self, parent, name, local):
|
||
|
self.parent = parent
|
||
|
self.name = name
|
||
|
self.local = local
|
||
|
self.parent_listeners = self.local
|
||
|
|
||
|
@property
|
||
|
def listeners(self):
|
||
|
return getattr(self.parent, self.name)
|
||
|
|
||
|
def _adjust_fn_spec(self, fn, named):
|
||
|
return self.local._adjust_fn_spec(fn, named)
|
||
|
|
||
|
def for_modify(self, obj):
|
||
|
self.local = self.parent_listeners = self.local.for_modify(obj)
|
||
|
return self
|
||
|
|
||
|
def insert(self, event_key, propagate):
|
||
|
self.local.insert(event_key, propagate)
|
||
|
|
||
|
def append(self, event_key, propagate):
|
||
|
self.local.append(event_key, propagate)
|
||
|
|
||
|
def remove(self, event_key):
|
||
|
self.local.remove(event_key)
|
||
|
|
||
|
def clear(self):
|
||
|
raise NotImplementedError()
|
||
|
|
||
|
|