0x1949 Team - FAZEMRX - MANAGER
Edit File: _compat.py
############################################################################## # # Copyright (c) 2006 Zope Foundation and Contributors. # All Rights Reserved. # # This software is subject to the provisions of the Zope Public License, # Version 2.1 (ZPL). A copy of the ZPL should accompany this distribution. # THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED # WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED # WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS # FOR A PARTICULAR PURPOSE. # ############################################################################## """ Support functions for dealing with differences in platforms, including Python versions and implementations. This file should have no imports from the rest of zope.interface because it is used during early bootstrapping. """ import os import sys import types if sys.version_info[0] < 3: def _normalize_name(name): if isinstance(name, basestring): return unicode(name) raise TypeError("name must be a regular or unicode string") CLASS_TYPES = (type, types.ClassType) STRING_TYPES = (basestring,) _BUILTINS = '__builtin__' PYTHON3 = False PYTHON2 = True else: def _normalize_name(name): if isinstance(name, bytes): name = str(name, 'ascii') if isinstance(name, str): return name raise TypeError("name must be a string or ASCII-only bytes") CLASS_TYPES = (type,) STRING_TYPES = (str,) _BUILTINS = 'builtins' PYTHON3 = True PYTHON2 = False PYPY = hasattr(sys, 'pypy_version_info') PYPY2 = PYTHON2 and PYPY def _skip_under_py3k(test_method): import unittest return unittest.skipIf(sys.version_info[0] >= 3, "Only on Python 2")(test_method) def _skip_under_py2(test_method): import unittest return unittest.skipIf(sys.version_info[0] < 3, "Only on Python 3")(test_method) def _c_optimizations_required(): """ Return a true value if the C optimizations are required. This uses the ``PURE_PYTHON`` variable as documented in `_use_c_impl`. """ pure_env = os.environ.get('PURE_PYTHON') require_c = pure_env == "0" return require_c def _c_optimizations_available(): """ Return the C optimization module, if available, otherwise a false value. If the optimizations are required but not available, this raises the ImportError. This does not say whether they should be used or not. """ catch = () if _c_optimizations_required() else (ImportError,) try: from zope.interface import _zope_interface_coptimizations as c_opt return c_opt except catch: # pragma: no cover (only Jython doesn't build extensions) return False def _c_optimizations_ignored(): """ The opposite of `_c_optimizations_required`. """ pure_env = os.environ.get('PURE_PYTHON') return pure_env is not None and pure_env != "0" def _should_attempt_c_optimizations(): """ Return a true value if we should attempt to use the C optimizations. This takes into account whether we're on PyPy and the value of the ``PURE_PYTHON`` environment variable, as defined in `_use_c_impl`. """ is_pypy = hasattr(sys, 'pypy_version_info') if _c_optimizations_required(): return True if is_pypy: return False return not _c_optimizations_ignored() def _use_c_impl(py_impl, name=None, globs=None): """ Decorator. Given an object implemented in Python, with a name like ``Foo``, import the corresponding C implementation from ``zope.interface._zope_interface_coptimizations`` with the name ``Foo`` and use it instead. If the ``PURE_PYTHON`` environment variable is set to any value other than ``"0"``, or we're on PyPy, ignore the C implementation and return the Python version. If the C implementation cannot be imported, return the Python version. If ``PURE_PYTHON`` is set to 0, *require* the C implementation (let the ImportError propagate); note that PyPy can import the C implementation in this case (and all tests pass). In all cases, the Python version is kept available. in the module globals with the name ``FooPy`` and the name ``FooFallback`` (both conventions have been used; the C implementation of some functions looks for the ``Fallback`` version, as do some of the Sphinx documents). Example:: @_use_c_impl class Foo(object): ... """ name = name or py_impl.__name__ globs = globs or sys._getframe(1).f_globals def find_impl(): if not _should_attempt_c_optimizations(): return py_impl c_opt = _c_optimizations_available() if not c_opt: # pragma: no cover (only Jython doesn't build extensions) return py_impl __traceback_info__ = c_opt return getattr(c_opt, name) c_impl = find_impl() # Always make available by the FooPy name and FooFallback # name (for testing and documentation) globs[name + 'Py'] = py_impl globs[name + 'Fallback'] = py_impl return c_impl