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ffd2cf1dba
This module depends on _winreg, which is windows-only. Recent versions of setuptools load distutils.msvc9compiler and expect it to ImportError immediately when on non-Windows platforms, so we need to let them do that. This breaks in an especially mystifying way, because setuptools uses vars() on the imported module. We then throw an exception, which vars doesn't pick up on well. For example: In [3]: class wat(object): ...: @property ...: def __dict__(self): ...: assert False ...: In [4]: vars(wat()) --------------------------------------------------------------------------- TypeError Traceback (most recent call last) <ipython-input-4-2781ada5ffe6> in <module>() ----> 1 vars(wat()) TypeError: vars() argument must have __dict__ attribute Which is similar to the problem we run into.
182 lines
6.1 KiB
Python
182 lines
6.1 KiB
Python
# demandimport.py - global demand-loading of modules for Mercurial
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#
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# Copyright 2006, 2007 Matt Mackall <mpm@selenic.com>
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#
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# This software may be used and distributed according to the terms of the
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# GNU General Public License version 2 or any later version.
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'''
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demandimport - automatic demandloading of modules
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To enable this module, do:
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import demandimport; demandimport.enable()
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Imports of the following forms will be demand-loaded:
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import a, b.c
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import a.b as c
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from a import b,c # a will be loaded immediately
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These imports will not be delayed:
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from a import *
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b = __import__(a)
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'''
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import __builtin__, os, sys
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_origimport = __import__
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nothing = object()
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try:
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# Python 3 doesn't have relative imports nor level -1.
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level = -1
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if sys.version_info[0] >= 3:
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level = 0
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_origimport(__builtin__.__name__, {}, {}, None, level)
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except TypeError: # no level argument
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def _import(name, globals, locals, fromlist, level):
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"call _origimport with no level argument"
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return _origimport(name, globals, locals, fromlist)
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else:
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_import = _origimport
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def _hgextimport(importfunc, name, globals, *args):
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try:
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return importfunc(name, globals, *args)
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except ImportError:
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if not globals:
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raise
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# extensions are loaded with "hgext_" prefix
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hgextname = 'hgext_%s' % name
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nameroot = hgextname.split('.', 1)[0]
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contextroot = globals.get('__name__', '').split('.', 1)[0]
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if nameroot != contextroot:
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raise
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# retry to import with "hgext_" prefix
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return importfunc(hgextname, globals, *args)
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class _demandmod(object):
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"""module demand-loader and proxy"""
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def __init__(self, name, globals, locals, level=level):
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if '.' in name:
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head, rest = name.split('.', 1)
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after = [rest]
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else:
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head = name
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after = []
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object.__setattr__(self, "_data",
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(head, globals, locals, after, level))
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object.__setattr__(self, "_module", None)
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def _extend(self, name):
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"""add to the list of submodules to load"""
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self._data[3].append(name)
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def _load(self):
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if not self._module:
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head, globals, locals, after, level = self._data
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mod = _hgextimport(_import, head, globals, locals, None, level)
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# load submodules
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def subload(mod, p):
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h, t = p, None
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if '.' in p:
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h, t = p.split('.', 1)
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if getattr(mod, h, nothing) is nothing:
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setattr(mod, h, _demandmod(p, mod.__dict__, mod.__dict__))
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elif t:
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subload(getattr(mod, h), t)
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for x in after:
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subload(mod, x)
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# are we in the locals dictionary still?
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if locals and locals.get(head) == self:
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locals[head] = mod
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object.__setattr__(self, "_module", mod)
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def __repr__(self):
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if self._module:
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return "<proxied module '%s'>" % self._data[0]
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return "<unloaded module '%s'>" % self._data[0]
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def __call__(self, *args, **kwargs):
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raise TypeError("%s object is not callable" % repr(self))
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def __getattribute__(self, attr):
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if attr in ('_data', '_extend', '_load', '_module'):
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return object.__getattribute__(self, attr)
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self._load()
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return getattr(self._module, attr)
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def __setattr__(self, attr, val):
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self._load()
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setattr(self._module, attr, val)
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def _demandimport(name, globals=None, locals=None, fromlist=None, level=level):
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if not locals or name in ignore or fromlist == ('*',):
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# these cases we can't really delay
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return _hgextimport(_import, name, globals, locals, fromlist, level)
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elif not fromlist:
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# import a [as b]
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if '.' in name: # a.b
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base, rest = name.split('.', 1)
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# email.__init__ loading email.mime
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if globals and globals.get('__name__', None) == base:
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return _import(name, globals, locals, fromlist, level)
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# if a is already demand-loaded, add b to its submodule list
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if base in locals:
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if isinstance(locals[base], _demandmod):
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locals[base]._extend(rest)
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return locals[base]
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return _demandmod(name, globals, locals, level)
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else:
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if level != -1:
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# from . import b,c,d or from .a import b,c,d
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return _origimport(name, globals, locals, fromlist, level)
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# from a import b,c,d
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mod = _hgextimport(_origimport, name, globals, locals)
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# recurse down the module chain
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for comp in name.split('.')[1:]:
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if getattr(mod, comp, nothing) is nothing:
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setattr(mod, comp, _demandmod(comp, mod.__dict__, mod.__dict__))
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mod = getattr(mod, comp)
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for x in fromlist:
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# set requested submodules for demand load
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if getattr(mod, x, nothing) is nothing:
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setattr(mod, x, _demandmod(x, mod.__dict__, locals))
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return mod
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ignore = [
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'_hashlib',
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'_xmlplus',
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'fcntl',
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'win32com.gen_py',
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'_winreg', # 2.7 mimetypes needs immediate ImportError
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'pythoncom',
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# imported by tarfile, not available under Windows
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'pwd',
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'grp',
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# imported by profile, itself imported by hotshot.stats,
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# not available under Windows
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'resource',
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# this trips up many extension authors
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'gtk',
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# setuptools' pkg_resources.py expects "from __main__ import x" to
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# raise ImportError if x not defined
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'__main__',
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'_ssl', # conditional imports in the stdlib, issue1964
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'rfc822',
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'mimetools',
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# setuptools 8 expects this module to explode early when not on windows
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'distutils.msvc9compiler'
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]
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def isenabled():
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return __builtin__.__import__ == _demandimport
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def enable():
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"enable global demand-loading of modules"
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if os.environ.get('HGDEMANDIMPORT') != 'disable':
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__builtin__.__import__ = _demandimport
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def disable():
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"disable global demand-loading of modules"
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__builtin__.__import__ = _origimport
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