--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hgdemandimport/demandimportpy2.py Sun May 21 12:10:53 2017 -0700
@@ -0,0 +1,332 @@
+# demandimport.py - global demand-loading of modules for Mercurial
+#
+# Copyright 2006, 2007 Matt Mackall <mpm@selenic.com>
+#
+# This software may be used and distributed according to the terms of the
+# GNU General Public License version 2 or any later version.
+
+'''
+demandimport - automatic demandloading of modules
+
+To enable this module, do:
+
+ import demandimport; demandimport.enable()
+
+Imports of the following forms will be demand-loaded:
+
+ import a, b.c
+ import a.b as c
+ from a import b,c # a will be loaded immediately
+
+These imports will not be delayed:
+
+ from a import *
+ b = __import__(a)
+'''
+
+from __future__ import absolute_import
+
+import contextlib
+import os
+import sys
+
+# __builtin__ in Python 2, builtins in Python 3.
+try:
+ import __builtin__ as builtins
+except ImportError:
+ import builtins
+
+contextmanager = contextlib.contextmanager
+
+_origimport = __import__
+
+nothing = object()
+
+# Python 3 doesn't have relative imports nor level -1.
+level = -1
+if sys.version_info[0] >= 3:
+ level = 0
+_import = _origimport
+
+def _hgextimport(importfunc, name, globals, *args, **kwargs):
+ try:
+ return importfunc(name, globals, *args, **kwargs)
+ except ImportError:
+ if not globals:
+ raise
+ # extensions are loaded with "hgext_" prefix
+ hgextname = 'hgext_%s' % name
+ nameroot = hgextname.split('.', 1)[0]
+ contextroot = globals.get('__name__', '').split('.', 1)[0]
+ if nameroot != contextroot:
+ raise
+ # retry to import with "hgext_" prefix
+ return importfunc(hgextname, globals, *args, **kwargs)
+
+class _demandmod(object):
+ """module demand-loader and proxy
+
+ Specify 1 as 'level' argument at construction, to import module
+ relatively.
+ """
+ def __init__(self, name, globals, locals, level):
+ if '.' in name:
+ head, rest = name.split('.', 1)
+ after = [rest]
+ else:
+ head = name
+ after = []
+ object.__setattr__(self, r"_data",
+ (head, globals, locals, after, level, set()))
+ object.__setattr__(self, r"_module", None)
+ def _extend(self, name):
+ """add to the list of submodules to load"""
+ self._data[3].append(name)
+
+ def _addref(self, name):
+ """Record that the named module ``name`` imports this module.
+
+ References to this proxy class having the name of this module will be
+ replaced at module load time. We assume the symbol inside the importing
+ module is identical to the "head" name of this module. We don't
+ actually know if "as X" syntax is being used to change the symbol name
+ because this information isn't exposed to __import__.
+ """
+ self._data[5].add(name)
+
+ def _load(self):
+ if not self._module:
+ head, globals, locals, after, level, modrefs = self._data
+ mod = _hgextimport(_import, head, globals, locals, None, level)
+ if mod is self:
+ # In this case, _hgextimport() above should imply
+ # _demandimport(). Otherwise, _hgextimport() never
+ # returns _demandmod. This isn't intentional behavior,
+ # in fact. (see also issue5304 for detail)
+ #
+ # If self._module is already bound at this point, self
+ # should be already _load()-ed while _hgextimport().
+ # Otherwise, there is no way to import actual module
+ # as expected, because (re-)invoking _hgextimport()
+ # should cause same result.
+ # This is reason why _load() returns without any more
+ # setup but assumes self to be already bound.
+ mod = self._module
+ assert mod and mod is not self, "%s, %s" % (self, mod)
+ return
+
+ # load submodules
+ def subload(mod, p):
+ h, t = p, None
+ if '.' in p:
+ h, t = p.split('.', 1)
+ if getattr(mod, h, nothing) is nothing:
+ setattr(mod, h, _demandmod(p, mod.__dict__, mod.__dict__,
+ level=1))
+ elif t:
+ subload(getattr(mod, h), t)
+
+ for x in after:
+ subload(mod, x)
+
+ # Replace references to this proxy instance with the actual module.
+ if locals and locals.get(head) == self:
+ locals[head] = mod
+
+ for modname in modrefs:
+ modref = sys.modules.get(modname, None)
+ if modref and getattr(modref, head, None) == self:
+ setattr(modref, head, mod)
+
+ object.__setattr__(self, r"_module", mod)
+
+ def __repr__(self):
+ if self._module:
+ return "<proxied module '%s'>" % self._data[0]
+ return "<unloaded module '%s'>" % self._data[0]
+ def __call__(self, *args, **kwargs):
+ raise TypeError("%s object is not callable" % repr(self))
+ def __getattribute__(self, attr):
+ if attr in ('_data', '_extend', '_load', '_module', '_addref'):
+ return object.__getattribute__(self, attr)
+ self._load()
+ return getattr(self._module, attr)
+ def __setattr__(self, attr, val):
+ self._load()
+ setattr(self._module, attr, val)
+
+_pypy = '__pypy__' in sys.builtin_module_names
+
+def _demandimport(name, globals=None, locals=None, fromlist=None, level=level):
+ if locals is None or name in ignore or fromlist == ('*',):
+ # these cases we can't really delay
+ return _hgextimport(_import, name, globals, locals, fromlist, level)
+ elif not fromlist:
+ # import a [as b]
+ if '.' in name: # a.b
+ base, rest = name.split('.', 1)
+ # email.__init__ loading email.mime
+ if globals and globals.get('__name__', None) == base:
+ return _import(name, globals, locals, fromlist, level)
+ # if a is already demand-loaded, add b to its submodule list
+ if base in locals:
+ if isinstance(locals[base], _demandmod):
+ locals[base]._extend(rest)
+ return locals[base]
+ return _demandmod(name, globals, locals, level)
+ else:
+ # There is a fromlist.
+ # from a import b,c,d
+ # from . import b,c,d
+ # from .a import b,c,d
+
+ # level == -1: relative and absolute attempted (Python 2 only).
+ # level >= 0: absolute only (Python 2 w/ absolute_import and Python 3).
+ # The modern Mercurial convention is to use absolute_import everywhere,
+ # so modern Mercurial code will have level >= 0.
+
+ # The name of the module the import statement is located in.
+ globalname = globals.get('__name__')
+
+ def processfromitem(mod, attr):
+ """Process an imported symbol in the import statement.
+
+ If the symbol doesn't exist in the parent module, and if the
+ parent module is a package, it must be a module. We set missing
+ modules up as _demandmod instances.
+ """
+ symbol = getattr(mod, attr, nothing)
+ nonpkg = getattr(mod, '__path__', nothing) is nothing
+ if symbol is nothing:
+ if nonpkg:
+ # do not try relative import, which would raise ValueError,
+ # and leave unknown attribute as the default __import__()
+ # would do. the missing attribute will be detected later
+ # while processing the import statement.
+ return
+ mn = '%s.%s' % (mod.__name__, attr)
+ if mn in ignore:
+ importfunc = _origimport
+ else:
+ importfunc = _demandmod
+ symbol = importfunc(attr, mod.__dict__, locals, level=1)
+ setattr(mod, attr, symbol)
+
+ # Record the importing module references this symbol so we can
+ # replace the symbol with the actual module instance at load
+ # time.
+ if globalname and isinstance(symbol, _demandmod):
+ symbol._addref(globalname)
+
+ def chainmodules(rootmod, modname):
+ # recurse down the module chain, and return the leaf module
+ mod = rootmod
+ for comp in modname.split('.')[1:]:
+ if getattr(mod, comp, nothing) is nothing:
+ setattr(mod, comp, _demandmod(comp, mod.__dict__,
+ mod.__dict__, level=1))
+ mod = getattr(mod, comp)
+ return mod
+
+ if level >= 0:
+ if name:
+ # "from a import b" or "from .a import b" style
+ rootmod = _hgextimport(_origimport, name, globals, locals,
+ level=level)
+ mod = chainmodules(rootmod, name)
+ elif _pypy:
+ # PyPy's __import__ throws an exception if invoked
+ # with an empty name and no fromlist. Recreate the
+ # desired behaviour by hand.
+ mn = globalname
+ mod = sys.modules[mn]
+ if getattr(mod, '__path__', nothing) is nothing:
+ mn = mn.rsplit('.', 1)[0]
+ mod = sys.modules[mn]
+ if level > 1:
+ mn = mn.rsplit('.', level - 1)[0]
+ mod = sys.modules[mn]
+ else:
+ mod = _hgextimport(_origimport, name, globals, locals,
+ level=level)
+
+ for x in fromlist:
+ processfromitem(mod, x)
+
+ return mod
+
+ # But, we still need to support lazy loading of standard library and 3rd
+ # party modules. So handle level == -1.
+ mod = _hgextimport(_origimport, name, globals, locals)
+ mod = chainmodules(mod, name)
+
+ for x in fromlist:
+ processfromitem(mod, x)
+
+ return mod
+
+ignore = [
+ '__future__',
+ '_hashlib',
+ # ImportError during pkg_resources/__init__.py:fixup_namespace_package
+ '_imp',
+ '_xmlplus',
+ 'fcntl',
+ 'nt', # pathlib2 tests the existence of built-in 'nt' module
+ 'win32com.gen_py',
+ 'win32com.shell', # 'appdirs' tries to import win32com.shell
+ '_winreg', # 2.7 mimetypes needs immediate ImportError
+ 'pythoncom',
+ # imported by tarfile, not available under Windows
+ 'pwd',
+ 'grp',
+ # imported by profile, itself imported by hotshot.stats,
+ # not available under Windows
+ 'resource',
+ # this trips up many extension authors
+ 'gtk',
+ # setuptools' pkg_resources.py expects "from __main__ import x" to
+ # raise ImportError if x not defined
+ '__main__',
+ '_ssl', # conditional imports in the stdlib, issue1964
+ '_sre', # issue4920
+ 'rfc822',
+ 'mimetools',
+ 'sqlalchemy.events', # has import-time side effects (issue5085)
+ # setuptools 8 expects this module to explode early when not on windows
+ 'distutils.msvc9compiler',
+ '__builtin__',
+ 'builtins',
+ 'urwid.command_map', # for pudb
+ ]
+
+if _pypy:
+ ignore.extend([
+ # _ctypes.pointer is shadowed by "from ... import pointer" (PyPy 5)
+ '_ctypes.pointer',
+ ])
+
+def isenabled():
+ return builtins.__import__ == _demandimport
+
+def enable():
+ "enable global demand-loading of modules"
+ if os.environ.get('HGDEMANDIMPORT') != 'disable':
+ builtins.__import__ = _demandimport
+
+def disable():
+ "disable global demand-loading of modules"
+ builtins.__import__ = _origimport
+
+@contextmanager
+def deactivated():
+ "context manager for disabling demandimport in 'with' blocks"
+ demandenabled = isenabled()
+ if demandenabled:
+ disable()
+
+ try:
+ yield
+ finally:
+ if demandenabled:
+ enable()