This document describes the current stable version of Kombu (4.0). For development docs, go here.
Source code for vine.five
# -*- coding: utf-8 -*-
"""Python 2/3 compatibility.
Compatibility implementations of features
only available in newer Python versions.
"""
from __future__ import absolute_import, unicode_literals
import errno
import io
import sys
try:
from collections import Counter
except ImportError: # pragma: no cover
from collections import defaultdict
def Counter(): # noqa
"""Create counter."""
return defaultdict(int)
try:
buffer_t = buffer
except NameError: # pragma: no cover
# Py3 does not have buffer, only use this for isa checks.
class buffer_t(object): # noqa
"""Python 3 does not have a buffer type."""
bytes_t = bytes
__all__ = [
'Counter', 'reload', 'UserList', 'UserDict',
'Queue', 'Empty', 'Full', 'LifoQueue', 'builtins', 'array',
'zip_longest', 'map', 'zip', 'string', 'string_t', 'bytes_t',
'bytes_if_py2', 'long_t', 'text_t', 'int_types', 'module_name_t',
'range', 'items', 'keys', 'values', 'nextfun', 'reraise',
'WhateverIO', 'with_metaclass', 'StringIO', 'getfullargspec',
'THREAD_TIMEOUT_MAX', 'format_d', 'monotonic', 'buffer_t',
'python_2_unicode_compatible',
]
# ############# py3k ########################################################
PY3 = sys.version_info[0] >= 3
PY2 = sys.version_info[0] < 3
try:
reload = reload # noqa
except NameError: # pragma: no cover
from imp import reload # noqa
try:
from collections import UserList # noqa
except ImportError: # pragma: no cover
from UserList import UserList # noqa
try:
from collections import UserDict # noqa
except ImportError: # pragma: no cover
from UserDict import UserDict # noqa
# ############# time.monotonic #############################################
if sys.version_info < (3, 3):
import platform
SYSTEM = platform.system()
try:
import ctypes
except ImportError: # pragma: no cover
ctypes = None # noqa
if SYSTEM == 'Darwin' and ctypes is not None:
from ctypes.util import find_library
libSystem = ctypes.CDLL(find_library('libSystem.dylib'))
CoreServices = ctypes.CDLL(find_library('CoreServices'),
use_errno=True)
mach_absolute_time = libSystem.mach_absolute_time
mach_absolute_time.restype = ctypes.c_uint64
absolute_to_nanoseconds = CoreServices.AbsoluteToNanoseconds
absolute_to_nanoseconds.restype = ctypes.c_uint64
absolute_to_nanoseconds.argtypes = [ctypes.c_uint64]
def _monotonic():
return absolute_to_nanoseconds(mach_absolute_time()) * 1e-9
elif SYSTEM == 'Linux' and ctypes is not None:
# from stackoverflow:
# questions/1205722/how-do-i-get-monotonic-time-durations-in-python
import os
CLOCK_MONOTONIC = 1 # see <linux/time.h>
class timespec(ctypes.Structure):
_fields_ = [
('tv_sec', ctypes.c_long),
('tv_nsec', ctypes.c_long),
]
try:
librt = ctypes.CDLL('librt.so.1', use_errno=True)
except Exception:
try:
librt = ctypes.CDLL('librt.so.0', use_errno=True)
except Exception as exc:
error = OSError(
"Could not detect working librt library: {0}".format(
exc))
error.errno = errno.ENOENT
raise error
clock_gettime = librt.clock_gettime
clock_gettime.argtypes = [
ctypes.c_int, ctypes.POINTER(timespec),
]
def _monotonic(): # noqa
t = timespec()
if clock_gettime(CLOCK_MONOTONIC, ctypes.pointer(t)) != 0:
errno_ = ctypes.get_errno()
raise OSError(errno_, os.strerror(errno_))
return t.tv_sec + t.tv_nsec * 1e-9
else:
from time import time as _monotonic
try:
from time import monotonic
except ImportError:
monotonic = _monotonic # noqa
# ############# Py3 <-> Py2 #################################################
if PY3: # pragma: no cover
import builtins
from array import array
from queue import Queue, Empty, Full, LifoQueue
from itertools import zip_longest
map = map
zip = zip
string = str
string_t = str
long_t = int
text_t = str
range = range
int_types = (int,)
module_name_t = str
def bytes_if_py2(s):
"""Convert str to bytes if running under Python 2."""
return s
def items(d):
"""Get dict items iterator."""
return d.items()
def keys(d):
"""Get dict keys iterator."""
return d.keys()
def values(d):
"""Get dict values iterator."""
return d.values()
def nextfun(it):
"""Get iterator next method."""
return it.__next__
exec_ = getattr(builtins, 'exec')
[docs] def reraise(tp, value, tb=None):
"""Reraise exception."""
if value.__traceback__ is not tb:
raise value.with_traceback(tb)
raise value
else:
import __builtin__ as builtins # noqa
from array import array as _array
from Queue import Queue, Empty, Full, LifoQueue # noqa
from itertools import ( # noqa
imap as map,
izip as zip,
izip_longest as zip_longest,
)
string = unicode # noqa
string_t = basestring # noqa
text_t = unicode
long_t = long # noqa
range = xrange
module_name_t = str
int_types = (int, long)
[docs] def array(typecode, *args, **kwargs):
"""Create array."""
if isinstance(typecode, unicode):
typecode = typecode.encode()
return _array(typecode, *args, **kwargs)
[docs] def bytes_if_py2(s):
"""Convert str to bytes if running under Python 2."""
if isinstance(s, unicode):
return s.encode()
return s
def exec_(code, globs=None, locs=None): # pragma: no cover
"""Execute code in a namespace."""
if globs is None:
frame = sys._getframe(1)
globs = frame.f_globals
if locs is None:
locs = frame.f_locals
del frame
elif locs is None:
locs = globs
exec("""exec code in globs, locs""")
exec_("""def reraise(tp, value, tb=None): raise tp, value, tb""")
[docs]def with_metaclass(Type, skip_attrs={'__dict__', '__weakref__'}):
"""Class decorator to set metaclass.
Works with both Python 2 and Python 3 and it does not add
an extra class in the lookup order like ``six.with_metaclass`` does
(that is -- it copies the original class instead of using inheritance).
"""
def _clone_with_metaclass(Class):
attrs = {key: value for key, value in items(vars(Class))
if key not in skip_attrs}
return Type(Class.__name__, Class.__bases__, attrs)
return _clone_with_metaclass
# ############# threading.TIMEOUT_MAX ########################################
try:
from threading import TIMEOUT_MAX as THREAD_TIMEOUT_MAX
except ImportError:
THREAD_TIMEOUT_MAX = 1e10 # noqa
# ############# format(int, ',d') ############################################
if sys.version_info >= (2, 7): # pragma: no cover
def format_d(i):
"""Format number."""
return format(i, ',d')
else: # pragma: no cover
[docs] def format_d(i): # noqa
"""Format number."""
s = '%d' % i
groups = []
while s and s[-1].isdigit():
groups.append(s[-3:])
s = s[:-3]
return s + ','.join(reversed(groups))
StringIO = io.StringIO
_SIO_write = StringIO.write
_SIO_init = StringIO.__init__
[docs]class WhateverIO(StringIO):
"""StringIO that takes bytes or str."""
def __init__(self, v=None, *a, **kw):
_SIO_init(self, v.decode() if isinstance(v, bytes) else v, *a, **kw)
[docs]def python_2_unicode_compatible(cls):
"""Class decorator to ensure class is compatible with Python 2."""
return python_2_non_unicode_str(python_2_non_unicode_repr(cls))
def python_2_non_unicode_repr(cls):
"""Ensure cls.__repr__ returns unicode.
A class decorator that ensures ``__repr__`` returns non-unicode
when running under Python 2.
"""
if PY2:
try:
cls.__dict__['__repr__']
except KeyError:
pass
else:
def __repr__(self, *args, **kwargs):
return self.__unicode_repr__(*args, **kwargs).encode(
'utf-8', 'replace')
cls.__unicode_repr__, cls.__repr__ = cls.__repr__, __repr__
return cls
def python_2_non_unicode_str(cls):
"""Python 2 class string compatibility.
A class decorator that defines ``__unicode__`` and ``__str__`` methods
under Python 2. Under Python 3 it does nothing.
To support Python 2 and 3 with a single code base, define a ``__str__``
method returning text and apply this decorator to the class.
"""
if PY2:
try:
cls.__dict__['__str__']
except KeyError:
pass
else:
def __str__(self, *args, **kwargs):
return self.__unicode__(*args, **kwargs).encode(
'utf-8', 'replace')
cls.__unicode__, cls.__str__ = cls.__str__, __str__
return cls
try: # pragma: no cover
from inspect import formatargspec, getfullargspec
except ImportError: # Py2
from collections import namedtuple
from inspect import formatargspec, getargspec as _getargspec # noqa
FullArgSpec = namedtuple('FullArgSpec', (
'args', 'varargs', 'varkw', 'defaults',
'kwonlyargs', 'kwonlydefaults', 'annotations',
))
[docs] def getfullargspec(fun, _fill=(None, ) * 3): # noqa
"""For compatibility with Python 3."""
s = _getargspec(fun)
return FullArgSpec(*s + _fill)
