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Part 3 of pedant day: replaced all tabs in Django with spaces. Python the way Guido intended it, baby!

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git-svn-id: http://code.djangoproject.com/svn/django/trunk@3415 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Jacob Kaplan-Moss
2006-07-21 20:48:17 +00:00
parent a926046ba6
commit 1687b025dc
18 changed files with 775 additions and 777 deletions
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810
django/dispatch/dispatcher.py
View File

@@ -6,24 +6,24 @@ system.
Module attributes of note:
Any -- Singleton used to signal either "Any Sender" or
"Any Signal". See documentation of the _Any class.
Anonymous -- Singleton used to signal "Anonymous Sender"
See documentation of the _Anonymous class.
Any -- Singleton used to signal either "Any Sender" or
"Any Signal". See documentation of the _Any class.
Anonymous -- Singleton used to signal "Anonymous Sender"
See documentation of the _Anonymous class.
Internal attributes:
WEAKREF_TYPES -- tuple of types/classes which represent
weak references to receivers, and thus must be de-
referenced on retrieval to retrieve the callable
object
connections -- { senderkey (id) : { signal : [receivers...]}}
senders -- { senderkey (id) : weakref(sender) }
used for cleaning up sender references on sender
deletion
sendersBack -- { receiverkey (id) : [senderkey (id)...] }
used for cleaning up receiver references on receiver
deletion, (considerably speeds up the cleanup process
vs. the original code.)
WEAKREF_TYPES -- tuple of types/classes which represent
weak references to receivers, and thus must be de-
referenced on retrieval to retrieve the callable
object
connections -- { senderkey (id) : { signal : [receivers...]}}
senders -- { senderkey (id) : weakref(sender) }
used for cleaning up sender references on sender
deletion
sendersBack -- { receiverkey (id) : [senderkey (id)...] }
used for cleaning up receiver references on receiver
deletion, (considerably speeds up the cleanup process
vs. the original code.)
"""
from __future__ import generators
import types, weakref
@@ -34,44 +34,44 @@ __cvsid__ = "$Id: dispatcher.py,v 1.9 2005/09/17 04:55:57 mcfletch Exp $"
__version__ = "$Revision: 1.9 $"[11:-2]
try:
True
True
except NameError:
True = 1==1
False = 1==0
True = 1==1
False = 1==0
class _Parameter:
"""Used to represent default parameter values."""
def __repr__(self):
return self.__class__.__name__
"""Used to represent default parameter values."""
def __repr__(self):
return self.__class__.__name__
class _Any(_Parameter):
"""Singleton used to signal either "Any Sender" or "Any Signal"
"""Singleton used to signal either "Any Sender" or "Any Signal"
The Any object can be used with connect, disconnect,
send, or sendExact to signal that the parameter given
Any should react to all senders/signals, not just
a particular sender/signal.
"""
The Any object can be used with connect, disconnect,
send, or sendExact to signal that the parameter given
Any should react to all senders/signals, not just
a particular sender/signal.
"""
Any = _Any()
class _Anonymous(_Parameter):
"""Singleton used to signal "Anonymous Sender"
"""Singleton used to signal "Anonymous Sender"
The Anonymous object is used to signal that the sender
of a message is not specified (as distinct from being
"any sender"). Registering callbacks for Anonymous
will only receive messages sent without senders. Sending
with anonymous will only send messages to those receivers
registered for Any or Anonymous.
The Anonymous object is used to signal that the sender
of a message is not specified (as distinct from being
"any sender"). Registering callbacks for Anonymous
will only receive messages sent without senders. Sending
with anonymous will only send messages to those receivers
registered for Any or Anonymous.
Note:
The default sender for connect is Any, while the
default sender for send is Anonymous. This has
the effect that if you do not specify any senders
in either function then all messages are routed
as though there was a single sender (Anonymous)
being used everywhere.
"""
Note:
The default sender for connect is Any, while the
default sender for send is Anonymous. This has
the effect that if you do not specify any senders
in either function then all messages are routed
as though there was a single sender (Anonymous)
being used everywhere.
"""
Anonymous = _Anonymous()
WEAKREF_TYPES = (weakref.ReferenceType, saferef.BoundMethodWeakref)
@@ -82,416 +82,416 @@ sendersBack = {}
def connect(receiver, signal=Any, sender=Any, weak=True):
"""Connect receiver to sender for signal
"""Connect receiver to sender for signal
receiver -- a callable Python object which is to receive
messages/signals/events. Receivers must be hashable
objects.
receiver -- a callable Python object which is to receive
messages/signals/events. Receivers must be hashable
objects.
if weak is True, then receiver must be weak-referencable
(more precisely saferef.safeRef() must be able to create
a reference to the receiver).
Receivers are fairly flexible in their specification,
as the machinery in the robustApply module takes care
of most of the details regarding figuring out appropriate
subsets of the sent arguments to apply to a given
receiver.
if weak is True, then receiver must be weak-referencable
(more precisely saferef.safeRef() must be able to create
a reference to the receiver).
Receivers are fairly flexible in their specification,
as the machinery in the robustApply module takes care
of most of the details regarding figuring out appropriate
subsets of the sent arguments to apply to a given
receiver.
Note:
if receiver is itself a weak reference (a callable),
it will be de-referenced by the system's machinery,
so *generally* weak references are not suitable as
receivers, though some use might be found for the
facility whereby a higher-level library passes in
pre-weakrefed receiver references.
Note:
if receiver is itself a weak reference (a callable),
it will be de-referenced by the system's machinery,
so *generally* weak references are not suitable as
receivers, though some use might be found for the
facility whereby a higher-level library passes in
pre-weakrefed receiver references.
signal -- the signal to which the receiver should respond
if Any, receiver will receive any signal from the
indicated sender (which might also be Any, but is not
necessarily Any).
Otherwise must be a hashable Python object other than
None (DispatcherError raised on None).
sender -- the sender to which the receiver should respond
if Any, receiver will receive the indicated signals
from any sender.
if Anonymous, receiver will only receive indicated
signals from send/sendExact which do not specify a
sender, or specify Anonymous explicitly as the sender.
signal -- the signal to which the receiver should respond
if Any, receiver will receive any signal from the
indicated sender (which might also be Any, but is not
necessarily Any).
Otherwise must be a hashable Python object other than
None (DispatcherError raised on None).
sender -- the sender to which the receiver should respond
if Any, receiver will receive the indicated signals
from any sender.
if Anonymous, receiver will only receive indicated
signals from send/sendExact which do not specify a
sender, or specify Anonymous explicitly as the sender.
Otherwise can be any python object.
weak -- whether to use weak references to the receiver
By default, the module will attempt to use weak
references to the receiver objects. If this parameter
is false, then strong references will be used.
Otherwise can be any python object.
weak -- whether to use weak references to the receiver
By default, the module will attempt to use weak
references to the receiver objects. If this parameter
is false, then strong references will be used.
returns None, may raise DispatcherTypeError
"""
if signal is None:
raise errors.DispatcherTypeError(
'Signal cannot be None (receiver=%r sender=%r)'%( receiver,sender)
)
if weak:
receiver = saferef.safeRef(receiver, onDelete=_removeReceiver)
senderkey = id(sender)
if connections.has_key(senderkey):
signals = connections[senderkey]
else:
connections[senderkey] = signals = {}
# Keep track of senders for cleanup.
# Is Anonymous something we want to clean up?
if sender not in (None, Anonymous, Any):
def remove(object, senderkey=senderkey):
_removeSender(senderkey=senderkey)
# Skip objects that can not be weakly referenced, which means
# they won't be automatically cleaned up, but that's too bad.
try:
weakSender = weakref.ref(sender, remove)
senders[senderkey] = weakSender
except:
pass
receiverID = id(receiver)
# get current set, remove any current references to
# this receiver in the set, including back-references
if signals.has_key(signal):
receivers = signals[signal]
_removeOldBackRefs(senderkey, signal, receiver, receivers)
else:
receivers = signals[signal] = []
try:
current = sendersBack.get( receiverID )
if current is None:
sendersBack[ receiverID ] = current = []
if senderkey not in current:
current.append(senderkey)
except:
pass
returns None, may raise DispatcherTypeError
"""
if signal is None:
raise errors.DispatcherTypeError(
'Signal cannot be None (receiver=%r sender=%r)'%( receiver,sender)
)
if weak:
receiver = saferef.safeRef(receiver, onDelete=_removeReceiver)
senderkey = id(sender)
if connections.has_key(senderkey):
signals = connections[senderkey]
else:
connections[senderkey] = signals = {}
# Keep track of senders for cleanup.
# Is Anonymous something we want to clean up?
if sender not in (None, Anonymous, Any):
def remove(object, senderkey=senderkey):
_removeSender(senderkey=senderkey)
# Skip objects that can not be weakly referenced, which means
# they won't be automatically cleaned up, but that's too bad.
try:
weakSender = weakref.ref(sender, remove)
senders[senderkey] = weakSender
except:
pass
receiverID = id(receiver)
# get current set, remove any current references to
# this receiver in the set, including back-references
if signals.has_key(signal):
receivers = signals[signal]
_removeOldBackRefs(senderkey, signal, receiver, receivers)
else:
receivers = signals[signal] = []
try:
current = sendersBack.get( receiverID )
if current is None:
sendersBack[ receiverID ] = current = []
if senderkey not in current:
current.append(senderkey)
except:
pass
receivers.append(receiver)
receivers.append(receiver)
def disconnect(receiver, signal=Any, sender=Any, weak=True):
"""Disconnect receiver from sender for signal
"""Disconnect receiver from sender for signal
receiver -- the registered receiver to disconnect
signal -- the registered signal to disconnect
sender -- the registered sender to disconnect
weak -- the weakref state to disconnect
receiver -- the registered receiver to disconnect
signal -- the registered signal to disconnect
sender -- the registered sender to disconnect
weak -- the weakref state to disconnect
disconnect reverses the process of connect,
the semantics for the individual elements are
logically equivalent to a tuple of
(receiver, signal, sender, weak) used as a key
to be deleted from the internal routing tables.
(The actual process is slightly more complex
but the semantics are basically the same).
disconnect reverses the process of connect,
the semantics for the individual elements are
logically equivalent to a tuple of
(receiver, signal, sender, weak) used as a key
to be deleted from the internal routing tables.
(The actual process is slightly more complex
but the semantics are basically the same).
Note:
Using disconnect is not required to cleanup
routing when an object is deleted, the framework
will remove routes for deleted objects
automatically. It's only necessary to disconnect
if you want to stop routing to a live object.
returns None, may raise DispatcherTypeError or
DispatcherKeyError
"""
if signal is None:
raise errors.DispatcherTypeError(
'Signal cannot be None (receiver=%r sender=%r)'%( receiver,sender)
)
if weak: receiver = saferef.safeRef(receiver)
senderkey = id(sender)
try:
signals = connections[senderkey]
receivers = signals[signal]
except KeyError:
raise errors.DispatcherKeyError(
"""No receivers found for signal %r from sender %r""" %(
signal,
sender
)
)
try:
# also removes from receivers
_removeOldBackRefs(senderkey, signal, receiver, receivers)
except ValueError:
raise errors.DispatcherKeyError(
"""No connection to receiver %s for signal %s from sender %s""" %(
receiver,
signal,
sender
)
)
_cleanupConnections(senderkey, signal)
Note:
Using disconnect is not required to cleanup
routing when an object is deleted, the framework
will remove routes for deleted objects
automatically. It's only necessary to disconnect
if you want to stop routing to a live object.
returns None, may raise DispatcherTypeError or
DispatcherKeyError
"""
if signal is None:
raise errors.DispatcherTypeError(
'Signal cannot be None (receiver=%r sender=%r)'%( receiver,sender)
)
if weak: receiver = saferef.safeRef(receiver)
senderkey = id(sender)
try:
signals = connections[senderkey]
receivers = signals[signal]
except KeyError:
raise errors.DispatcherKeyError(
"""No receivers found for signal %r from sender %r""" %(
signal,
sender
)
)
try:
# also removes from receivers
_removeOldBackRefs(senderkey, signal, receiver, receivers)
except ValueError:
raise errors.DispatcherKeyError(
"""No connection to receiver %s for signal %s from sender %s""" %(
receiver,
signal,
sender
)
)
_cleanupConnections(senderkey, signal)
def getReceivers( sender = Any, signal = Any ):
"""Get list of receivers from global tables
"""Get list of receivers from global tables
This utility function allows you to retrieve the
raw list of receivers from the connections table
for the given sender and signal pair.
This utility function allows you to retrieve the
raw list of receivers from the connections table
for the given sender and signal pair.
Note:
there is no guarantee that this is the actual list
stored in the connections table, so the value
should be treated as a simple iterable/truth value
rather than, for instance a list to which you
might append new records.
Note:
there is no guarantee that this is the actual list
stored in the connections table, so the value
should be treated as a simple iterable/truth value
rather than, for instance a list to which you
might append new records.
Normally you would use liveReceivers( getReceivers( ...))
to retrieve the actual receiver objects as an iterable
object.
"""
try:
return connections[id(sender)][signal]
except KeyError:
return []
Normally you would use liveReceivers( getReceivers( ...))
to retrieve the actual receiver objects as an iterable
object.
"""
try:
return connections[id(sender)][signal]
except KeyError:
return []
def liveReceivers(receivers):
"""Filter sequence of receivers to get resolved, live receivers
"""Filter sequence of receivers to get resolved, live receivers
This is a generator which will iterate over
the passed sequence, checking for weak references
and resolving them, then returning all live
receivers.
"""
for receiver in receivers:
if isinstance( receiver, WEAKREF_TYPES):
# Dereference the weak reference.
receiver = receiver()
if receiver is not None:
yield receiver
else:
yield receiver
This is a generator which will iterate over
the passed sequence, checking for weak references
and resolving them, then returning all live
receivers.
"""
for receiver in receivers:
if isinstance( receiver, WEAKREF_TYPES):
# Dereference the weak reference.
receiver = receiver()
if receiver is not None:
yield receiver
else:
yield receiver
def getAllReceivers( sender = Any, signal = Any ):
"""Get list of all receivers from global tables
"""Get list of all receivers from global tables
This gets all receivers which should receive
the given signal from sender, each receiver should
be produced only once by the resulting generator
"""
receivers = {}
for set in (
# Get receivers that receive *this* signal from *this* sender.
getReceivers( sender, signal ),
# Add receivers that receive *any* signal from *this* sender.
getReceivers( sender, Any ),
# Add receivers that receive *this* signal from *any* sender.
getReceivers( Any, signal ),
# Add receivers that receive *any* signal from *any* sender.
getReceivers( Any, Any ),
):
for receiver in set:
if receiver: # filter out dead instance-method weakrefs
try:
if not receivers.has_key( receiver ):
receivers[receiver] = 1
yield receiver
except TypeError:
# dead weakrefs raise TypeError on hash...
pass
This gets all receivers which should receive
the given signal from sender, each receiver should
be produced only once by the resulting generator
"""
receivers = {}
for set in (
# Get receivers that receive *this* signal from *this* sender.
getReceivers( sender, signal ),
# Add receivers that receive *any* signal from *this* sender.
getReceivers( sender, Any ),
# Add receivers that receive *this* signal from *any* sender.
getReceivers( Any, signal ),
# Add receivers that receive *any* signal from *any* sender.
getReceivers( Any, Any ),
):
for receiver in set:
if receiver: # filter out dead instance-method weakrefs
try:
if not receivers.has_key( receiver ):
receivers[receiver] = 1
yield receiver
except TypeError:
# dead weakrefs raise TypeError on hash...
pass
def send(signal=Any, sender=Anonymous, *arguments, **named):
"""Send signal from sender to all connected receivers.
signal -- (hashable) signal value, see connect for details
"""Send signal from sender to all connected receivers.
signal -- (hashable) signal value, see connect for details
sender -- the sender of the signal
if Any, only receivers registered for Any will receive
the message.
sender -- the sender of the signal
if Any, only receivers registered for Any will receive
the message.
if Anonymous, only receivers registered to receive
messages from Anonymous or Any will receive the message
if Anonymous, only receivers registered to receive
messages from Anonymous or Any will receive the message
Otherwise can be any python object (normally one
registered with a connect if you actually want
something to occur).
Otherwise can be any python object (normally one
registered with a connect if you actually want
something to occur).
arguments -- positional arguments which will be passed to
*all* receivers. Note that this may raise TypeErrors
if the receivers do not allow the particular arguments.
Note also that arguments are applied before named
arguments, so they should be used with care.
arguments -- positional arguments which will be passed to
*all* receivers. Note that this may raise TypeErrors
if the receivers do not allow the particular arguments.
Note also that arguments are applied before named
arguments, so they should be used with care.
named -- named arguments which will be filtered according
to the parameters of the receivers to only provide those
acceptable to the receiver.
named -- named arguments which will be filtered according
to the parameters of the receivers to only provide those
acceptable to the receiver.
Return a list of tuple pairs [(receiver, response), ... ]
Return a list of tuple pairs [(receiver, response), ... ]
if any receiver raises an error, the error propagates back
through send, terminating the dispatch loop, so it is quite
possible to not have all receivers called if a raises an
error.
"""
# Call each receiver with whatever arguments it can accept.
# Return a list of tuple pairs [(receiver, response), ... ].
responses = []
for receiver in liveReceivers(getAllReceivers(sender, signal)):
response = robustapply.robustApply(
receiver,
signal=signal,
sender=sender,
*arguments,
**named
)
responses.append((receiver, response))
return responses
if any receiver raises an error, the error propagates back
through send, terminating the dispatch loop, so it is quite
possible to not have all receivers called if a raises an
error.
"""
# Call each receiver with whatever arguments it can accept.
# Return a list of tuple pairs [(receiver, response), ... ].
responses = []
for receiver in liveReceivers(getAllReceivers(sender, signal)):
response = robustapply.robustApply(
receiver,
signal=signal,
sender=sender,
*arguments,
**named
)
responses.append((receiver, response))
return responses
def sendExact( signal=Any, sender=Anonymous, *arguments, **named ):
"""Send signal only to those receivers registered for exact message
"""Send signal only to those receivers registered for exact message
sendExact allows for avoiding Any/Anonymous registered
handlers, sending only to those receivers explicitly
registered for a particular signal on a particular
sender.
"""
responses = []
for receiver in liveReceivers(getReceivers(sender, signal)):
response = robustapply.robustApply(
receiver,
signal=signal,
sender=sender,
*arguments,
**named
)
responses.append((receiver, response))
return responses
sendExact allows for avoiding Any/Anonymous registered
handlers, sending only to those receivers explicitly
registered for a particular signal on a particular
sender.
"""
responses = []
for receiver in liveReceivers(getReceivers(sender, signal)):
response = robustapply.robustApply(
receiver,
signal=signal,
sender=sender,
*arguments,
**named
)
responses.append((receiver, response))
return responses
def _removeReceiver(receiver):
"""Remove receiver from connections."""
if not sendersBack:
# During module cleanup the mapping will be replaced with None
return False
backKey = id(receiver)
for senderkey in sendersBack.get(backKey,()):
try:
signals = connections[senderkey].keys()
except KeyError,err:
pass
else:
for signal in signals:
try:
receivers = connections[senderkey][signal]
except KeyError:
pass
else:
try:
receivers.remove( receiver )
except Exception, err:
pass
_cleanupConnections(senderkey, signal)
try:
del sendersBack[ backKey ]
except KeyError:
pass
"""Remove receiver from connections."""
if not sendersBack:
# During module cleanup the mapping will be replaced with None
return False
backKey = id(receiver)
for senderkey in sendersBack.get(backKey,()):
try:
signals = connections[senderkey].keys()
except KeyError,err:
pass
else:
for signal in signals:
try:
receivers = connections[senderkey][signal]
except KeyError:
pass
else:
try:
receivers.remove( receiver )
except Exception, err:
pass
_cleanupConnections(senderkey, signal)
try:
del sendersBack[ backKey ]
except KeyError:
pass
def _cleanupConnections(senderkey, signal):
"""Delete any empty signals for senderkey. Delete senderkey if empty."""
try:
receivers = connections[senderkey][signal]
except:
pass
else:
if not receivers:
# No more connected receivers. Therefore, remove the signal.
try:
signals = connections[senderkey]
except KeyError:
pass
else:
del signals[signal]
if not signals:
# No more signal connections. Therefore, remove the sender.
_removeSender(senderkey)
"""Delete any empty signals for senderkey. Delete senderkey if empty."""
try:
receivers = connections[senderkey][signal]
except:
pass
else:
if not receivers:
# No more connected receivers. Therefore, remove the signal.
try:
signals = connections[senderkey]
except KeyError:
pass
else:
del signals[signal]
if not signals:
# No more signal connections. Therefore, remove the sender.
_removeSender(senderkey)
def _removeSender(senderkey):
"""Remove senderkey from connections."""
_removeBackrefs(senderkey)
try:
del connections[senderkey]
except KeyError:
pass
# Senderkey will only be in senders dictionary if sender
# could be weakly referenced.
try:
del senders[senderkey]
except:
pass
"""Remove senderkey from connections."""
_removeBackrefs(senderkey)
try:
del connections[senderkey]
except KeyError:
pass
# Senderkey will only be in senders dictionary if sender
# could be weakly referenced.
try:
del senders[senderkey]
except:
pass
def _removeBackrefs( senderkey):
"""Remove all back-references to this senderkey"""
try:
signals = connections[senderkey]
except KeyError:
signals = None
else:
items = signals.items()
def allReceivers( ):
for signal,set in items:
for item in set:
yield item
for receiver in allReceivers():
_killBackref( receiver, senderkey )
"""Remove all back-references to this senderkey"""
try:
signals = connections[senderkey]
except KeyError:
signals = None
else:
items = signals.items()
def allReceivers( ):
for signal,set in items:
for item in set:
yield item
for receiver in allReceivers():
_killBackref( receiver, senderkey )
def _removeOldBackRefs(senderkey, signal, receiver, receivers):
"""Kill old sendersBack references from receiver
"""Kill old sendersBack references from receiver
This guards against multiple registration of the same
receiver for a given signal and sender leaking memory
as old back reference records build up.
This guards against multiple registration of the same
receiver for a given signal and sender leaking memory
as old back reference records build up.
Also removes old receiver instance from receivers
"""
try:
index = receivers.index(receiver)
# need to scan back references here and remove senderkey
except ValueError:
return False
else:
oldReceiver = receivers[index]
del receivers[index]
found = 0
signals = connections.get(signal)
if signals is not None:
for sig,recs in connections.get(signal,{}).iteritems():
if sig != signal:
for rec in recs:
if rec is oldReceiver:
found = 1
break
if not found:
_killBackref( oldReceiver, senderkey )
return True
return False
Also removes old receiver instance from receivers
"""
try:
index = receivers.index(receiver)
# need to scan back references here and remove senderkey
except ValueError:
return False
else:
oldReceiver = receivers[index]
del receivers[index]
found = 0
signals = connections.get(signal)
if signals is not None:
for sig,recs in connections.get(signal,{}).iteritems():
if sig != signal:
for rec in recs:
if rec is oldReceiver:
found = 1
break
if not found:
_killBackref( oldReceiver, senderkey )
return True
return False
def _killBackref( receiver, senderkey ):
"""Do the actual removal of back reference from receiver to senderkey"""
receiverkey = id(receiver)
set = sendersBack.get( receiverkey, () )
while senderkey in set:
try:
set.remove( senderkey )
except:
break
if not set:
try:
del sendersBack[ receiverkey ]
except KeyError:
pass
return True
"""Do the actual removal of back reference from receiver to senderkey"""
receiverkey = id(receiver)
set = sendersBack.get( receiverkey, () )
while senderkey in set:
try:
set.remove( senderkey )
except:
break
if not set:
try:
del sendersBack[ receiverkey ]
except KeyError:
pass
return True

6
django/dispatch/errors.py
View File

@@ -2,9 +2,9 @@
"""
class DispatcherError(Exception):
"""Base class for all Dispatcher errors"""
"""Base class for all Dispatcher errors"""
class DispatcherKeyError(KeyError, DispatcherError):
"""Error raised when unknown (sender,signal) set specified"""
"""Error raised when unknown (sender,signal) set specified"""
class DispatcherTypeError(TypeError, DispatcherError):
"""Error raised when inappropriate signal-type specified (None)"""
"""Error raised when inappropriate signal-type specified (None)"""

62
django/dispatch/license.txt
View File

@@ -1,34 +1,34 @@
PyDispatcher License
Copyright (c) 2001-2003, Patrick K. O'Brien and Contributors
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 binary 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.
The name of Patrick K. O'Brien, or the name of any Contributor,
may not be used to endorse or promote products derived from this
software without specific prior written permission.
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 AND 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.
Copyright (c) 2001-2003, Patrick K. O'Brien and Contributors
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 binary 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.
The name of Patrick K. O'Brien, or the name of any Contributor,
may not be used to endorse or promote products derived from this
software without specific prior written permission.
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 AND 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.

88
django/dispatch/robust.py
View File

@@ -3,55 +3,55 @@ from django.dispatch.dispatcher import Any, Anonymous, liveReceivers, getAllRece
from django.dispatch.robustapply import robustApply
def sendRobust(
signal=Any,
sender=Anonymous,
*arguments, **named
signal=Any,
sender=Anonymous,
*arguments, **named
):
"""Send signal from sender to all connected receivers catching errors
signal -- (hashable) signal value, see connect for details
"""Send signal from sender to all connected receivers catching errors
signal -- (hashable) signal value, see connect for details
sender -- the sender of the signal
if Any, only receivers registered for Any will receive
the message.
sender -- the sender of the signal
if Any, only receivers registered for Any will receive
the message.
if Anonymous, only receivers registered to receive
messages from Anonymous or Any will receive the message
if Anonymous, only receivers registered to receive
messages from Anonymous or Any will receive the message
Otherwise can be any python object (normally one
registered with a connect if you actually want
something to occur).
Otherwise can be any python object (normally one
registered with a connect if you actually want
something to occur).
arguments -- positional arguments which will be passed to
*all* receivers. Note that this may raise TypeErrors
if the receivers do not allow the particular arguments.
Note also that arguments are applied before named
arguments, so they should be used with care.
arguments -- positional arguments which will be passed to
*all* receivers. Note that this may raise TypeErrors
if the receivers do not allow the particular arguments.
Note also that arguments are applied before named
arguments, so they should be used with care.
named -- named arguments which will be filtered according
to the parameters of the receivers to only provide those
acceptable to the receiver.
named -- named arguments which will be filtered according
to the parameters of the receivers to only provide those
acceptable to the receiver.
Return a list of tuple pairs [(receiver, response), ... ]
Return a list of tuple pairs [(receiver, response), ... ]
if any receiver raises an error (specifically any subclass of Exception),
the error instance is returned as the result for that receiver.
"""
# Call each receiver with whatever arguments it can accept.
# Return a list of tuple pairs [(receiver, response), ... ].
responses = []
for receiver in liveReceivers(getAllReceivers(sender, signal)):
try:
response = robustApply(
receiver,
signal=signal,
sender=sender,
*arguments,
**named
)
except Exception, err:
responses.append((receiver, err))
else:
responses.append((receiver, response))
return responses
if any receiver raises an error (specifically any subclass of Exception),
the error instance is returned as the result for that receiver.
"""
# Call each receiver with whatever arguments it can accept.
# Return a list of tuple pairs [(receiver, response), ... ].
responses = []
for receiver in liveReceivers(getAllReceivers(sender, signal)):
try:
response = robustApply(
receiver,
signal=signal,
sender=sender,
*arguments,
**named
)
except Exception, err:
responses.append((receiver, err))
else:
responses.append((receiver, response))
return responses

70
django/dispatch/robustapply.py
View File

@@ -7,43 +7,41 @@ those which are acceptable.
"""
def function( receiver ):
"""Get function-like callable object for given receiver
"""Get function-like callable object for given receiver
returns (function_or_method, codeObject, fromMethod)
returns (function_or_method, codeObject, fromMethod)
If fromMethod is true, then the callable already
has its first argument bound
"""
if hasattr(receiver, '__call__'):
# receiver is a class instance; assume it is callable.
# Reassign receiver to the actual method that will be called.
if hasattr( receiver.__call__, 'im_func') or hasattr( receiver.__call__, 'im_code'):
receiver = receiver.__call__
if hasattr( receiver, 'im_func' ):
# an instance-method...
return receiver, receiver.im_func.func_code, 1
elif not hasattr( receiver, 'func_code'):
raise ValueError('unknown reciever type %s %s'%(receiver, type(receiver)))
return receiver, receiver.func_code, 0
If fromMethod is true, then the callable already
has its first argument bound
"""
if hasattr(receiver, '__call__'):
# receiver is a class instance; assume it is callable.
# Reassign receiver to the actual method that will be called.
if hasattr( receiver.__call__, 'im_func') or hasattr( receiver.__call__, 'im_code'):
receiver = receiver.__call__
if hasattr( receiver, 'im_func' ):
# an instance-method...
return receiver, receiver.im_func.func_code, 1
elif not hasattr( receiver, 'func_code'):
raise ValueError('unknown reciever type %s %s'%(receiver, type(receiver)))
return receiver, receiver.func_code, 0
def robustApply(receiver, *arguments, **named):
"""Call receiver with arguments and an appropriate subset of named
"""
receiver, codeObject, startIndex = function( receiver )
acceptable = codeObject.co_varnames[startIndex+len(arguments):codeObject.co_argcount]
for name in codeObject.co_varnames[startIndex:startIndex+len(arguments)]:
if named.has_key( name ):
raise TypeError(
"""Argument %r specified both positionally and as a keyword for calling %r"""% (
name, receiver,
)
)
if not (codeObject.co_flags & 8):
# fc does not have a **kwds type parameter, therefore
# remove unacceptable arguments.
for arg in named.keys():
if arg not in acceptable:
del named[arg]
return receiver(*arguments, **named)
"""Call receiver with arguments and an appropriate subset of named
"""
receiver, codeObject, startIndex = function( receiver )
acceptable = codeObject.co_varnames[startIndex+len(arguments):codeObject.co_argcount]
for name in codeObject.co_varnames[startIndex:startIndex+len(arguments)]:
if named.has_key( name ):
raise TypeError(
"""Argument %r specified both positionally and as a keyword for calling %r"""% (
name, receiver,
)
)
if not (codeObject.co_flags & 8):
# fc does not have a **kwds type parameter, therefore
# remove unacceptable arguments.
for arg in named.keys():
if arg not in acceptable:
del named[arg]
return receiver(*arguments, **named)

298
django/dispatch/saferef.py
View File

@@ -2,164 +2,164 @@
import weakref, traceback
def safeRef(target, onDelete = None):
"""Return a *safe* weak reference to a callable target
"""Return a *safe* weak reference to a callable target
target -- the object to be weakly referenced, if it's a
bound method reference, will create a BoundMethodWeakref,
otherwise creates a simple weakref.
onDelete -- if provided, will have a hard reference stored
to the callable to be called after the safe reference
goes out of scope with the reference object, (either a
weakref or a BoundMethodWeakref) as argument.
"""
if hasattr(target, 'im_self'):
if target.im_self is not None:
# Turn a bound method into a BoundMethodWeakref instance.
# Keep track of these instances for lookup by disconnect().
assert hasattr(target, 'im_func'), """safeRef target %r has im_self, but no im_func, don't know how to create reference"""%( target,)
reference = BoundMethodWeakref(
target=target,
onDelete=onDelete
)
return reference
if callable(onDelete):
return weakref.ref(target, onDelete)
else:
return weakref.ref( target )
target -- the object to be weakly referenced, if it's a
bound method reference, will create a BoundMethodWeakref,
otherwise creates a simple weakref.
onDelete -- if provided, will have a hard reference stored
to the callable to be called after the safe reference
goes out of scope with the reference object, (either a
weakref or a BoundMethodWeakref) as argument.
"""
if hasattr(target, 'im_self'):
if target.im_self is not None:
# Turn a bound method into a BoundMethodWeakref instance.
# Keep track of these instances for lookup by disconnect().
assert hasattr(target, 'im_func'), """safeRef target %r has im_self, but no im_func, don't know how to create reference"""%( target,)
reference = BoundMethodWeakref(
target=target,
onDelete=onDelete
)
return reference
if callable(onDelete):
return weakref.ref(target, onDelete)
else:
return weakref.ref( target )
class BoundMethodWeakref(object):
"""'Safe' and reusable weak references to instance methods
"""'Safe' and reusable weak references to instance methods
BoundMethodWeakref objects provide a mechanism for
referencing a bound method without requiring that the
method object itself (which is normally a transient
object) is kept alive. Instead, the BoundMethodWeakref
object keeps weak references to both the object and the
function which together define the instance method.
BoundMethodWeakref objects provide a mechanism for
referencing a bound method without requiring that the
method object itself (which is normally a transient
object) is kept alive. Instead, the BoundMethodWeakref
object keeps weak references to both the object and the
function which together define the instance method.
Attributes:
key -- the identity key for the reference, calculated
by the class's calculateKey method applied to the
target instance method
deletionMethods -- sequence of callable objects taking
single argument, a reference to this object which
will be called when *either* the target object or
target function is garbage collected (i.e. when
this object becomes invalid). These are specified
as the onDelete parameters of safeRef calls.
weakSelf -- weak reference to the target object
weakFunc -- weak reference to the target function
Attributes:
key -- the identity key for the reference, calculated
by the class's calculateKey method applied to the
target instance method
deletionMethods -- sequence of callable objects taking
single argument, a reference to this object which
will be called when *either* the target object or
target function is garbage collected (i.e. when
this object becomes invalid). These are specified
as the onDelete parameters of safeRef calls.
weakSelf -- weak reference to the target object
weakFunc -- weak reference to the target function
Class Attributes:
_allInstances -- class attribute pointing to all live
BoundMethodWeakref objects indexed by the class's
calculateKey(target) method applied to the target
objects. This weak value dictionary is used to
short-circuit creation so that multiple references
to the same (object, function) pair produce the
same BoundMethodWeakref instance.
Class Attributes:
_allInstances -- class attribute pointing to all live
BoundMethodWeakref objects indexed by the class's
calculateKey(target) method applied to the target
objects. This weak value dictionary is used to
short-circuit creation so that multiple references
to the same (object, function) pair produce the
same BoundMethodWeakref instance.
"""
_allInstances = weakref.WeakValueDictionary()
def __new__( cls, target, onDelete=None, *arguments,**named ):
"""Create new instance or return current instance
"""
_allInstances = weakref.WeakValueDictionary()
def __new__( cls, target, onDelete=None, *arguments,**named ):
"""Create new instance or return current instance
Basically this method of construction allows us to
short-circuit creation of references to already-
referenced instance methods. The key corresponding
to the target is calculated, and if there is already
an existing reference, that is returned, with its
deletionMethods attribute updated. Otherwise the
new instance is created and registered in the table
of already-referenced methods.
"""
key = cls.calculateKey(target)
current =cls._allInstances.get(key)
if current is not None:
current.deletionMethods.append( onDelete)
return current
else:
base = super( BoundMethodWeakref, cls).__new__( cls )
cls._allInstances[key] = base
base.__init__( target, onDelete, *arguments,**named)
return base
def __init__(self, target, onDelete=None):
"""Return a weak-reference-like instance for a bound method
Basically this method of construction allows us to
short-circuit creation of references to already-
referenced instance methods. The key corresponding
to the target is calculated, and if there is already
an existing reference, that is returned, with its
deletionMethods attribute updated. Otherwise the
new instance is created and registered in the table
of already-referenced methods.
"""
key = cls.calculateKey(target)
current =cls._allInstances.get(key)
if current is not None:
current.deletionMethods.append( onDelete)
return current
else:
base = super( BoundMethodWeakref, cls).__new__( cls )
cls._allInstances[key] = base
base.__init__( target, onDelete, *arguments,**named)
return base
def __init__(self, target, onDelete=None):
"""Return a weak-reference-like instance for a bound method
target -- the instance-method target for the weak
reference, must have im_self and im_func attributes
and be reconstructable via:
target.im_func.__get__( target.im_self )
which is true of built-in instance methods.
onDelete -- optional callback which will be called
when this weak reference ceases to be valid
(i.e. either the object or the function is garbage
collected). Should take a single argument,
which will be passed a pointer to this object.
"""
def remove(weak, self=self):
"""Set self.isDead to true when method or instance is destroyed"""
methods = self.deletionMethods[:]
del self.deletionMethods[:]
try:
del self.__class__._allInstances[ self.key ]
except KeyError:
pass
for function in methods:
try:
if callable( function ):
function( self )
except Exception, e:
try:
traceback.print_exc()
except AttributeError, err:
print '''Exception during saferef %s cleanup function %s: %s'''%(
self, function, e
)
self.deletionMethods = [onDelete]
self.key = self.calculateKey( target )
self.weakSelf = weakref.ref(target.im_self, remove)
self.weakFunc = weakref.ref(target.im_func, remove)
self.selfName = str(target.im_self)
self.funcName = str(target.im_func.__name__)
def calculateKey( cls, target ):
"""Calculate the reference key for this reference
target -- the instance-method target for the weak
reference, must have im_self and im_func attributes
and be reconstructable via:
target.im_func.__get__( target.im_self )
which is true of built-in instance methods.
onDelete -- optional callback which will be called
when this weak reference ceases to be valid
(i.e. either the object or the function is garbage
collected). Should take a single argument,
which will be passed a pointer to this object.
"""
def remove(weak, self=self):
"""Set self.isDead to true when method or instance is destroyed"""
methods = self.deletionMethods[:]
del self.deletionMethods[:]
try:
del self.__class__._allInstances[ self.key ]
except KeyError:
pass
for function in methods:
try:
if callable( function ):
function( self )
except Exception, e:
try:
traceback.print_exc()
except AttributeError, err:
print '''Exception during saferef %s cleanup function %s: %s'''%(
self, function, e
)
self.deletionMethods = [onDelete]
self.key = self.calculateKey( target )
self.weakSelf = weakref.ref(target.im_self, remove)
self.weakFunc = weakref.ref(target.im_func, remove)
self.selfName = str(target.im_self)
self.funcName = str(target.im_func.__name__)
def calculateKey( cls, target ):
"""Calculate the reference key for this reference
Currently this is a two-tuple of the id()'s of the
target object and the target function respectively.
"""
return (id(target.im_self),id(target.im_func))
calculateKey = classmethod( calculateKey )
def __str__(self):
"""Give a friendly representation of the object"""
return """%s( %s.%s )"""%(
self.__class__.__name__,
self.selfName,
self.funcName,
)
__repr__ = __str__
def __nonzero__( self ):
"""Whether we are still a valid reference"""
return self() is not None
def __cmp__( self, other ):
"""Compare with another reference"""
if not isinstance (other,self.__class__):
return cmp( self.__class__, type(other) )
return cmp( self.key, other.key)
def __call__(self):
"""Return a strong reference to the bound method
Currently this is a two-tuple of the id()'s of the
target object and the target function respectively.
"""
return (id(target.im_self),id(target.im_func))
calculateKey = classmethod( calculateKey )
def __str__(self):
"""Give a friendly representation of the object"""
return """%s( %s.%s )"""%(
self.__class__.__name__,
self.selfName,
self.funcName,
)
__repr__ = __str__
def __nonzero__( self ):
"""Whether we are still a valid reference"""
return self() is not None
def __cmp__( self, other ):
"""Compare with another reference"""
if not isinstance (other,self.__class__):
return cmp( self.__class__, type(other) )
return cmp( self.key, other.key)
def __call__(self):
"""Return a strong reference to the bound method
If the target cannot be retrieved, then will
return None, otherwise returns a bound instance
method for our object and function.
If the target cannot be retrieved, then will
return None, otherwise returns a bound instance
method for our object and function.
Note:
You may call this method any number of times,
as it does not invalidate the reference.
"""
target = self.weakSelf()
if target is not None:
function = self.weakFunc()
if function is not None:
return function.__get__(target)
return None
Note:
You may call this method any number of times,
as it does not invalidate the reference.
"""
target = self.weakSelf()
if target is not None:
function = self.weakFunc()
if function is not None:
return function.__get__(target)
return None