CasperSecurity
# -*- test-case-name: twisted.test.test_rebuild -*-
# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.
"""
*Real* reloading support for Python.
"""
import linecache
# System Imports
import sys
import time
import types
from imp import reload
from types import ModuleType
from typing import Dict
# 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.__self__ is None:
return getattr(anObject.im_class, anObject.__name__)
else:
return getattr(anObject.__self__, anObject.__name__)
else:
log.msg("warning returning anObject!")
return anObject
_modDictIDMap: Dict[int, ModuleType] = {}
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.__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__]
if newClass.__module__ == "builtins":
# builtin members can't be reloaded sanely
return newClass
try:
# This makes old-style stuff work
newClass.__bases__ = tuple(newBases)
return newClass
except TypeError:
ctor = type(newClass)
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.
"""
self.__class__ = latestClass(self.__class__)
def __injectedgetattr__(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(f"(rebuilding stale {reflect.qual(self.__class__)} instance ({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(f"Rebuilding {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(f" (scanning {str(module.__name__)}): ")
for k, v in d.items():
if issubclass(type(v), types.FunctionType):
if v.__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.__contains__
newclasses = newclasses.keys()
classes = classes.keys()
functions = functions.keys()
if doLog:
log.msg("")
log.msg(f" (reload {str(module.__name__)})")
# Boom.
reload(module)
# Make sure that my traceback printing will at least be recent...
linecache.clearcache()
if doLog:
log.msg(f" (cleaning {str(module.__name__)}): ")
for clazz in classes:
if getattr(module, clazz.__name__) is clazz:
log.msg(f"WARNING: class {reflect.qual(clazz)} not replaced by reload!")
else:
if doLog:
log.logfile.write("x")
log.logfile.flush()
clazz.__bases__ = ()
clazz.__dict__.clear()
clazz.__getattr__ = __injectedgetattr__
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 {} not replaced by reload!".format(
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(f" (fixing {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
if hasattr(mod, "__bundle__"):
# PyObjC has a few buggy objects which segfault if you hash() them.
# It doesn't make sense to try rebuilding extension modules like
# this anyway, so don't try.
continue
changed = 0
for k, v in mod.__dict__.items():
try:
hash(v)
except Exception:
continue
if fromOldModule(v):
if doLog:
log.logfile.write("f")
log.logfile.flush()
nv = latestFunction(v)
changed = 1
setattr(mod, k, nv)
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(f" Rebuilt {str(module.__name__)}.")
return module