Viewing file:  rebuild.py (7.86 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
# -*- test-case-name: twisted.test.test_rebuild -*-
# Copyright (c) 2001-2009 Twisted Matrix Laboratories.
# See LICENSE for details.
"""
*Real* reloading support for Python.
"""
# System Imports
import sys
import types
import time
import linecache
# Sibling Imports
from twisted.python import log, reflect
lastRebuild = time.time()
class Sensitive:
"""
A utility mixin that's sensitive to rebuilds.
This is a mixin for classes (usually those which represent collections of
callbacks) to make sure that their code is up-to-date before running.
"""
lastRebuild = lastRebuild
def needRebuildUpdate(self):
yn = (self.lastRebuild < lastRebuild)
return yn
def rebuildUpToDate(self):
self.lastRebuild = time.time()
def latestVersionOf(self, anObject):
"""
Get the latest version of an object.
This can handle just about anything callable; instances, functions,
methods, and classes.
"""
t = type(anObject)
if t == types.FunctionType:
return latestFunction(anObject)
elif t == types.MethodType:
if anObject.im_self is None:
return getattr(anObject.im_class, anObject.__name__)
else:
return getattr(anObject.im_self, anObject.__name__)
elif t == types.InstanceType:
# Kick it, if it's out of date.
getattr(anObject, 'nothing', None)
return anObject
elif t == types.ClassType:
return latestClass(anObject)
else:
log.msg('warning returning anObject!')
return anObject
_modDictIDMap = {}
def latestFunction(oldFunc):
"""
Get the latest version of a function.
"""
# This may be CPython specific, since I believe jython instantiates a new
# module upon reload.
dictID = id(oldFunc.func_globals)
module = _modDictIDMap.get(dictID)
if module is None:
return oldFunc
return getattr(module, oldFunc.__name__)
def latestClass(oldClass):
"""
Get the latest version of a class.
"""
module = reflect.namedModule(oldClass.__module__)
newClass = getattr(module, oldClass.__name__)
newBases = [latestClass(base) for base in newClass.__bases__]
try:
# This makes old-style stuff work
newClass.__bases__ = tuple(newBases)
return newClass
except TypeError:
if newClass.__module__ == "__builtin__":
# __builtin__ members can't be reloaded sanely
return newClass
ctor = getattr(newClass, '__metaclass__', type)
return ctor(newClass.__name__, tuple(newBases), dict(newClass.__dict__))
class RebuildError(Exception):
"""
Exception raised when trying to rebuild a class whereas it's not possible.
"""
def updateInstance(self):
"""
Updates an instance to be current.
"""
try:
self.__class__ = latestClass(self.__class__)
except TypeError:
if hasattr(self.__class__, '__slots__'):
raise RebuildError("Can't rebuild class with __slots__ on Python < 2.6")
else:
raise
def __getattr__(self, name):
"""
A getattr method to cause a class to be refreshed.
"""
if name == '__del__':
raise AttributeError("Without this, Python segfaults.")
updateInstance(self)
log.msg("(rebuilding stale %s instance (%s))" % (reflect.qual(self.__class__), name))
result = getattr(self, name)
return result
def rebuild(module, doLog=1):
"""
Reload a module and do as much as possible to replace its references.
"""
global lastRebuild
lastRebuild = time.time()
if hasattr(module, 'ALLOW_TWISTED_REBUILD'):
# Is this module allowed to be rebuilt?
if not module.ALLOW_TWISTED_REBUILD:
raise RuntimeError("I am not allowed to be rebuilt.")
if doLog:
log.msg('Rebuilding %s...' % str(module.__name__))
## Safely handle adapter re-registration
from twisted.python import components
components.ALLOW_DUPLICATES = True
d = module.__dict__
_modDictIDMap[id(d)] = module
newclasses = {}
classes = {}
functions = {}
values = {}
if doLog:
log.msg(' (scanning %s): ' % str(module.__name__))
for k, v in d.items():
if type(v) == types.ClassType:
# Failure condition -- instances of classes with buggy
# __hash__/__cmp__ methods referenced at the module level...
if v.__module__ == module.__name__:
classes[v] = 1
if doLog:
log.logfile.write("c")
log.logfile.flush()
elif type(v) == types.FunctionType:
if v.func_globals is module.__dict__:
functions[v] = 1
if doLog:
log.logfile.write("f")
log.logfile.flush()
elif isinstance(v, type):
if v.__module__ == module.__name__:
newclasses[v] = 1
if doLog:
log.logfile.write("o")
log.logfile.flush()
values.update(classes)
values.update(functions)
fromOldModule = values.has_key
newclasses = newclasses.keys()
classes = classes.keys()
functions = functions.keys()
if doLog:
log.msg('')
log.msg(' (reload %s)' % str(module.__name__))
# Boom.
reload(module)
# Make sure that my traceback printing will at least be recent...
linecache.clearcache()
if doLog:
log.msg(' (cleaning %s): ' % str(module.__name__))
for clazz in classes:
if getattr(module, clazz.__name__) is clazz:
log.msg("WARNING: class %s not replaced by reload!" % reflect.qual(clazz))
else:
if doLog:
log.logfile.write("x")
log.logfile.flush()
clazz.__bases__ = ()
clazz.__dict__.clear()
clazz.__getattr__ = __getattr__
clazz.__module__ = module.__name__
if newclasses:
import gc
for nclass in newclasses:
ga = getattr(module, nclass.__name__)
if ga is nclass:
log.msg("WARNING: new-class %s not replaced by reload!" % reflect.qual(nclass))
else:
for r in gc.get_referrers(nclass):
if getattr(r, '__class__', None) is nclass:
r.__class__ = ga
if doLog:
log.msg('')
log.msg(' (fixing %s): ' % str(module.__name__))
modcount = 0
for mk, mod in sys.modules.items():
modcount = modcount + 1
if mod == module or mod is None:
continue
if not hasattr(mod, '__file__'):
# It's a builtin module; nothing to replace here.
continue
changed = 0
for k, v in mod.__dict__.items():
try:
hash(v)
except Exception:
continue
if fromOldModule(v):
if type(v) == types.ClassType:
if doLog:
log.logfile.write("c")
log.logfile.flush()
nv = latestClass(v)
else:
if doLog:
log.logfile.write("f")
log.logfile.flush()
nv = latestFunction(v)
changed = 1
setattr(mod, k, nv)
else:
# Replace bases of non-module classes just to be sure.
if type(v) == types.ClassType:
for base in v.__bases__:
if fromOldModule(base):
latestClass(v)
if doLog and not changed and ((modcount % 10) ==0) :
log.logfile.write(".")
log.logfile.flush()
components.ALLOW_DUPLICATES = False
if doLog:
log.msg('')
log.msg(' Rebuilt %s.' % str(module.__name__))
return module
|