Commit 5a9bcc35 authored by Luke Campagnola's avatar Luke Campagnola
Browse files

Added missing reload.py

parent a330d849
# -*- coding: utf-8 -*-
"""
Magic Reload Library
Luke Campagnola 2010
Python reload function that actually works (the way you expect it to)
- No re-importing necessary
- Modules can be reloaded in any order
- Replaces functions and methods with their updated code
- Changes instances to use updated classes
- Automatically decides which modules to update by comparing file modification times
Does NOT:
- re-initialize exting instances, even if __init__ changes
- update references to any module-level objects
ie, this does not reload correctly:
from module import someObject
print someObject
..but you can use this instead: (this works even for the builtin reload)
import module
print module.someObject
"""
import inspect, os, sys, __builtin__, gc, traceback
from debug import printExc
def reloadAll(prefix=None, debug=False):
"""Automatically reload everything whose __file__ begins with prefix.
- Skips reload if the file has not been updated (if .pyc is newer than .py)
- if prefix is None, checks all loaded modules
"""
for modName, mod in sys.modules.items(): ## don't use iteritems; size may change during reload
if not inspect.ismodule(mod):
continue
if modName == '__main__':
continue
## Ignore if the file name does not start with prefix
if not hasattr(mod, '__file__') or os.path.splitext(mod.__file__)[1] not in ['.py', '.pyc']:
continue
if prefix is not None and mod.__file__[:len(prefix)] != prefix:
continue
## ignore if the .pyc is newer than the .py (or if there is no pyc or py)
py = os.path.splitext(mod.__file__)[0] + '.py'
pyc = py + 'c'
if os.path.isfile(pyc) and os.path.isfile(py) and os.stat(pyc).st_mtime >= os.stat(py).st_mtime:
#if debug:
#print "Ignoring module %s; unchanged" % str(mod)
continue
try:
reload(mod, debug=debug)
except:
printExc("Error while reloading module %s, skipping\n" % mod)
def reload(module, debug=False, lists=False, dicts=False):
"""Replacement for the builtin reload function:
- Reloads the module as usual
- Updates all old functions and class methods to use the new code
- Updates all instances of each modified class to use the new class
- Can update lists and dicts, but this is disabled by default
- Requires that class and function names have not changed
"""
if debug:
print "Reloading", module
## make a copy of the old module dictionary, reload, then grab the new module dictionary for comparison
oldDict = module.__dict__.copy()
__builtin__.reload(module)
newDict = module.__dict__
## Allow modules access to the old dictionary after they reload
if hasattr(module, '__reload__'):
module.__reload__(oldDict)
## compare old and new elements from each dict; update where appropriate
for k in oldDict:
old = oldDict[k]
new = newDict.get(k, None)
if old is new or new is None:
continue
if inspect.isclass(old):
if debug:
print " Updating class %s.%s (0x%x -> 0x%x)" % (module.__name__, k, id(old), id(new))
updateClass(old, new, debug)
elif inspect.isfunction(old):
depth = updateFunction(old, new, debug)
if debug:
extra = ""
if depth > 0:
extra = " (and %d previous versions)" % depth
print " Updating function %s.%s%s" % (module.__name__, k, extra)
elif lists and isinstance(old, list):
l = old.len()
old.extend(new)
for i in range(l):
old.pop(0)
elif dicts and isinstance(old, dict):
old.update(new)
for k in old:
if k not in new:
del old[k]
## For functions:
## 1) update the code and defaults to new versions.
## 2) keep a reference to the previous version so ALL versions get updated for every reload
def updateFunction(old, new, debug, depth=0, visited=None):
#if debug and depth > 0:
#print " -> also updating previous version", old, " -> ", new
old.__code__ = new.__code__
old.__defaults__ = new.__defaults__
if visited is None:
visited = []
if old in visited:
return
visited.append(old)
## finally, update any previous versions still hanging around..
if hasattr(old, '__previous_reload_version__'):
maxDepth = updateFunction(old.__previous_reload_version__, new, debug, depth=depth+1, visited=visited)
else:
maxDepth = depth
## We need to keep a pointer to the previous version so we remember to update BOTH
## when the next reload comes around.
if depth == 0:
new.__previous_reload_version__ = old
return maxDepth
## For classes:
## 1) find all instances of the old class and set instance.__class__ to the new class
## 2) update all old class methods to use code from the new class methods
def updateClass(old, new, debug):
## Track town all instances and subclasses of old
refs = gc.get_referrers(old)
for ref in refs:
try:
if isinstance(ref, old) and ref.__class__ is old:
ref.__class__ = new
if debug:
print " Changed class for", safeStr(ref)
elif inspect.isclass(ref) and issubclass(ref, old) and old in ref.__bases__:
ind = ref.__bases__.index(old)
## Does not work:
#ref.__bases__ = ref.__bases__[:ind] + (new,) + ref.__bases__[ind+1:]
## reason: Even though we change the code on methods, they remain bound
## to their old classes (changing im_class is not allowed). Instead,
## we have to update the __bases__ such that this class will be allowed
## as an argument to older methods.
## This seems to work. Is there any reason not to?
## Note that every time we reload, the class hierarchy becomes more complex.
## (and I presume this may slow things down?)
ref.__bases__ = ref.__bases__[:ind] + (new,old) + ref.__bases__[ind+1:]
if debug:
print " Changed superclass for", safeStr(ref)
#else:
#if debug:
#print " Ignoring reference", type(ref)
except:
print "Error updating reference (%s) for class change (%s -> %s)" % (safeStr(ref), safeStr(old), safeStr(new))
raise
## update all class methods to use new code.
## Generally this is not needed since instances already know about the new class,
## but it fixes a few specific cases (pyqt signals, for one)
for attr in dir(old):
oa = getattr(old, attr)
if inspect.ismethod(oa):
try:
na = getattr(new, attr)
except AttributeError:
if debug:
print " Skipping method update for %s; new class does not have this attribute" % attr
continue
if hasattr(oa, 'im_func') and hasattr(na, 'im_func') and oa.im_func is not na.im_func:
depth = updateFunction(oa.im_func, na.im_func, debug)
#oa.im_class = new ## bind old method to new class ## not allowed
if debug:
extra = ""
if depth > 0:
extra = " (and %d previous versions)" % depth
print " Updating method %s%s" % (attr, extra)
## And copy in new functions that didn't exist previously
for attr in dir(new):
if not hasattr(old, attr):
if debug:
print " Adding missing attribute", attr
setattr(old, attr, getattr(new, attr))
## finally, update any previous versions still hanging around..
if hasattr(old, '__previous_reload_version__'):
updateClass(old.__previous_reload_version__, new, debug)
## It is possible to build classes for which str(obj) just causes an exception.
## Avoid thusly:
def safeStr(obj):
try:
s = str(obj)
except:
try:
s = repr(obj)
except:
s = "<instance of %s at 0x%x>" % (safeStr(type(obj)), id(obj))
return s
## Tests:
# write modules to disk, import, then re-write and run again
if __name__ == '__main__':
doQtTest = True
try:
from PyQt4 import QtCore
if not hasattr(QtCore, 'Signal'):
QtCore.Signal = QtCore.pyqtSignal
#app = QtGui.QApplication([])
class Btn(QtCore.QObject):
sig = QtCore.Signal()
def emit(self):
self.sig.emit()
btn = Btn()
except:
raise
print "Error; skipping Qt tests"
doQtTest = False
import os
if not os.path.isdir('test1'):
os.mkdir('test1')
open('test1/__init__.py', 'w')
modFile1 = "test1/test1.py"
modCode1 = """
import sys
class A(object):
def __init__(self, msg):
object.__init__(self)
self.msg = msg
def fn(self, pfx = ""):
print pfx+"A class:", self.__class__, id(self.__class__)
print pfx+" %%s: %d" %% self.msg
class B(A):
def fn(self, pfx=""):
print pfx+"B class:", self.__class__, id(self.__class__)
print pfx+" %%s: %d" %% self.msg
print pfx+" calling superclass.. (%%s)" %% id(A)
A.fn(self, " ")
"""
modFile2 = "test2.py"
modCode2 = """
from test1.test1 import A
from test1.test1 import B
a1 = A("ax1")
b1 = B("bx1")
class C(A):
def __init__(self, msg):
#print "| C init:"
#print "| C.__bases__ = ", map(id, C.__bases__)
#print "| A:", id(A)
#print "| A.__init__ = ", id(A.__init__.im_func), id(A.__init__.im_func.__code__), id(A.__init__.im_class)
A.__init__(self, msg + "(init from C)")
def fn():
print "fn: %s"
"""
open(modFile1, 'w').write(modCode1%(1,1))
open(modFile2, 'w').write(modCode2%"message 1")
import test1.test1 as test1
import test2
print "Test 1 originals:"
A1 = test1.A
B1 = test1.B
a1 = test1.A("a1")
b1 = test1.B("b1")
a1.fn()
b1.fn()
#print "function IDs a1 bound method: %d a1 func: %d a1 class: %d b1 func: %d b1 class: %d" % (id(a1.fn), id(a1.fn.im_func), id(a1.fn.im_class), id(b1.fn.im_func), id(b1.fn.im_class))
from test2 import fn, C
if doQtTest:
print "Button test before:"
btn.sig.connect(fn)
btn.sig.connect(a1.fn)
btn.emit()
#btn.sig.emit()
print ""
#print "a1.fn referrers:", sys.getrefcount(a1.fn.im_func), gc.get_referrers(a1.fn.im_func)
print "Test2 before reload:"
fn()
oldfn = fn
test2.a1.fn()
test2.b1.fn()
c1 = test2.C('c1')
c1.fn()
os.remove(modFile1+'c')
open(modFile1, 'w').write(modCode1%(2,2))
print "\n----RELOAD test1-----\n"
reloadAll(os.path.abspath(__file__)[:10], debug=True)
print "Subclass test:"
c2 = test2.C('c2')
c2.fn()
os.remove(modFile2+'c')
open(modFile2, 'w').write(modCode2%"message 2")
print "\n----RELOAD test2-----\n"
reloadAll(os.path.abspath(__file__)[:10], debug=True)
if doQtTest:
print "Button test after:"
btn.emit()
#btn.sig.emit()
#print "a1.fn referrers:", sys.getrefcount(a1.fn.im_func), gc.get_referrers(a1.fn.im_func)
print "Test2 after reload:"
fn()
test2.a1.fn()
test2.b1.fn()
print "\n==> Test 1 Old instances:"
a1.fn()
b1.fn()
c1.fn()
#print "function IDs a1 bound method: %d a1 func: %d a1 class: %d b1 func: %d b1 class: %d" % (id(a1.fn), id(a1.fn.im_func), id(a1.fn.im_class), id(b1.fn.im_func), id(b1.fn.im_class))
print "\n==> Test 1 New instances:"
a2 = test1.A("a2")
b2 = test1.B("b2")
a2.fn()
b2.fn()
c2 = test2.C('c2')
c2.fn()
#print "function IDs a1 bound method: %d a1 func: %d a1 class: %d b1 func: %d b1 class: %d" % (id(a1.fn), id(a1.fn.im_func), id(a1.fn.im_class), id(b1.fn.im_func), id(b1.fn.im_class))
os.remove(modFile1+'c')
os.remove(modFile2+'c')
open(modFile1, 'w').write(modCode1%(3,3))
open(modFile2, 'w').write(modCode2%"message 3")
print "\n----RELOAD-----\n"
reloadAll(os.path.abspath(__file__)[:10], debug=True)
if doQtTest:
print "Button test after:"
btn.emit()
#btn.sig.emit()
#print "a1.fn referrers:", sys.getrefcount(a1.fn.im_func), gc.get_referrers(a1.fn.im_func)
print "Test2 after reload:"
fn()
test2.a1.fn()
test2.b1.fn()
print "\n==> Test 1 Old instances:"
a1.fn()
b1.fn()
print "function IDs a1 bound method: %d a1 func: %d a1 class: %d b1 func: %d b1 class: %d" % (id(a1.fn), id(a1.fn.im_func), id(a1.fn.im_class), id(b1.fn.im_func), id(b1.fn.im_class))
print "\n==> Test 1 New instances:"
a2 = test1.A("a2")
b2 = test1.B("b2")
a2.fn()
b2.fn()
print "function IDs a1 bound method: %d a1 func: %d a1 class: %d b1 func: %d b1 class: %d" % (id(a1.fn), id(a1.fn.im_func), id(a1.fn.im_class), id(b1.fn.im_func), id(b1.fn.im_class))
os.remove(modFile1)
os.remove(modFile2)
os.remove(modFile1+'c')
os.remove(modFile2+'c')
os.system('rm -r test1')
#
# Failure graveyard ahead:
#
"""Reload Importer:
Hooks into import system to
1) keep a record of module dependencies as they are imported
2) make sure modules are always reloaded in correct order
3) update old classes and functions to use reloaded code"""
#import imp, sys
## python's import hook mechanism doesn't work since we need to be
## informed every time there is an import statement, not just for new imports
#class ReloadImporter:
#def __init__(self):
#self.depth = 0
#def find_module(self, name, path):
#print " "*self.depth + "find: ", name, path
##if name == 'PyQt4' and path is None:
##print "PyQt4 -> PySide"
##self.modData = imp.find_module('PySide')
##return self
##return None ## return none to allow the import to proceed normally; return self to intercept with load_module
#self.modData = imp.find_module(name, path)
#self.depth += 1
##sys.path_importer_cache = {}
#return self
#def load_module(self, name):
#mod = imp.load_module(name, *self.modData)
#self.depth -= 1
#print " "*self.depth + "load: ", name
#return mod
#def pathHook(path):
#print "path hook:", path
#raise ImportError
#sys.path_hooks.append(pathHook)
#sys.meta_path.append(ReloadImporter())
### replace __import__ with a wrapper that tracks module dependencies
#modDeps = {}
#reloadModule = None
#origImport = __builtins__.__import__
#def _import(name, globals=None, locals=None, fromlist=None, level=-1, stack=[]):
### Note that stack behaves as a static variable.
##print " "*len(importStack) + "import %s" % args[0]
#stack.append(set())
#mod = origImport(name, globals, locals, fromlist, level)
#deps = stack.pop()
#if len(stack) > 0:
#stack[-1].add(mod)
#elif reloadModule is not None: ## If this is the top level import AND we're inside a module reload
#modDeps[reloadModule].add(mod)
#if mod in modDeps:
#modDeps[mod] |= deps
#else:
#modDeps[mod] = deps
#return mod
#__builtins__.__import__ = _import
### replace
#origReload = __builtins__.reload
#def _reload(mod):
#reloadModule = mod
#ret = origReload(mod)
#reloadModule = None
#return ret
#__builtins__.reload = _reload
#def reload(mod, visited=None):
#if visited is None:
#visited = set()
#if mod in visited:
#return
#visited.add(mod)
#for dep in modDeps.get(mod, []):
#reload(dep, visited)
#__builtins__.reload(mod)
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