451 lines
15 KiB
Python
451 lines
15 KiB
Python
|
# Copyright (c) 2009, Giampaolo Rodola'. All rights reserved.
|
||
|
|
# Use of this source code is governed by a BSD-style license that can be
|
||
|
|
# found in the LICENSE file.
|
||
|
|
|
||
|
|
"""Module which provides compatibility with older Python versions.
|
||
|
|
This is more future-compatible rather than the opposite (prefer latest
|
||
|
|
Python 3 way of doing things).
|
||
|
|
"""
|
||
|
|
|
||
|
|
import collections
|
||
|
|
import contextlib
|
||
|
|
import errno
|
||
|
|
import functools
|
||
|
|
import os
|
||
|
|
import sys
|
||
|
|
import types
|
||
|
|
|
||
|
|
|
||
|
|
__all__ = [
|
||
|
|
# constants
|
||
|
|
"PY3",
|
||
|
|
# builtins
|
||
|
|
"long", "range", "super", "unicode", "basestring",
|
||
|
|
# literals
|
||
|
|
"u", "b",
|
||
|
|
# collections module
|
||
|
|
"lru_cache",
|
||
|
|
# shutil module
|
||
|
|
"which", "get_terminal_size",
|
||
|
|
# contextlib module
|
||
|
|
"redirect_stderr",
|
||
|
|
# python 3 exceptions
|
||
|
|
"FileNotFoundError", "PermissionError", "ProcessLookupError",
|
||
|
|
"InterruptedError", "ChildProcessError", "FileExistsError"]
|
||
|
|
|
||
|
|
|
||
|
|
PY3 = sys.version_info[0] == 3
|
||
|
|
_SENTINEL = object()
|
||
|
|
|
||
|
|
if PY3:
|
||
|
|
long = int
|
||
|
|
xrange = range
|
||
|
|
unicode = str
|
||
|
|
basestring = str
|
||
|
|
range = range
|
||
|
|
|
||
|
|
def u(s):
|
||
|
|
return s
|
||
|
|
|
||
|
|
def b(s):
|
||
|
|
return s.encode("latin-1")
|
||
|
|
else:
|
||
|
|
long = long
|
||
|
|
range = xrange
|
||
|
|
unicode = unicode
|
||
|
|
basestring = basestring
|
||
|
|
|
||
|
|
def u(s):
|
||
|
|
return unicode(s, "unicode_escape")
|
||
|
|
|
||
|
|
def b(s):
|
||
|
|
return s
|
||
|
|
|
||
|
|
|
||
|
|
# --- builtins
|
||
|
|
|
||
|
|
|
||
|
|
# Python 3 super().
|
||
|
|
# Taken from "future" package.
|
||
|
|
# Credit: Ryan Kelly
|
||
|
|
if PY3:
|
||
|
|
super = super
|
||
|
|
else:
|
||
|
|
_builtin_super = super
|
||
|
|
|
||
|
|
def super(type_=_SENTINEL, type_or_obj=_SENTINEL, framedepth=1):
|
||
|
|
"""Like Python 3 builtin super(). If called without any arguments
|
||
|
|
it attempts to infer them at runtime.
|
||
|
|
"""
|
||
|
|
if type_ is _SENTINEL:
|
||
|
|
f = sys._getframe(framedepth)
|
||
|
|
try:
|
||
|
|
# Get the function's first positional argument.
|
||
|
|
type_or_obj = f.f_locals[f.f_code.co_varnames[0]]
|
||
|
|
except (IndexError, KeyError):
|
||
|
|
raise RuntimeError('super() used in a function with no args')
|
||
|
|
try:
|
||
|
|
# Get the MRO so we can crawl it.
|
||
|
|
mro = type_or_obj.__mro__
|
||
|
|
except (AttributeError, RuntimeError):
|
||
|
|
try:
|
||
|
|
mro = type_or_obj.__class__.__mro__
|
||
|
|
except AttributeError:
|
||
|
|
raise RuntimeError('super() used in a non-newstyle class')
|
||
|
|
for type_ in mro:
|
||
|
|
# Find the class that owns the currently-executing method.
|
||
|
|
for meth in type_.__dict__.values():
|
||
|
|
# Drill down through any wrappers to the underlying func.
|
||
|
|
# This handles e.g. classmethod() and staticmethod().
|
||
|
|
try:
|
||
|
|
while not isinstance(meth, types.FunctionType):
|
||
|
|
if isinstance(meth, property):
|
||
|
|
# Calling __get__ on the property will invoke
|
||
|
|
# user code which might throw exceptions or
|
||
|
|
# have side effects
|
||
|
|
meth = meth.fget
|
||
|
|
else:
|
||
|
|
try:
|
||
|
|
meth = meth.__func__
|
||
|
|
except AttributeError:
|
||
|
|
meth = meth.__get__(type_or_obj, type_)
|
||
|
|
except (AttributeError, TypeError):
|
||
|
|
continue
|
||
|
|
if meth.func_code is f.f_code:
|
||
|
|
break # found
|
||
|
|
else:
|
||
|
|
# Not found. Move onto the next class in MRO.
|
||
|
|
continue
|
||
|
|
break # found
|
||
|
|
else:
|
||
|
|
raise RuntimeError('super() called outside a method')
|
||
|
|
|
||
|
|
# Dispatch to builtin super().
|
||
|
|
if type_or_obj is not _SENTINEL:
|
||
|
|
return _builtin_super(type_, type_or_obj)
|
||
|
|
return _builtin_super(type_)
|
||
|
|
|
||
|
|
|
||
|
|
# --- exceptions
|
||
|
|
|
||
|
|
|
||
|
|
if PY3:
|
||
|
|
FileNotFoundError = FileNotFoundError # NOQA
|
||
|
|
PermissionError = PermissionError # NOQA
|
||
|
|
ProcessLookupError = ProcessLookupError # NOQA
|
||
|
|
InterruptedError = InterruptedError # NOQA
|
||
|
|
ChildProcessError = ChildProcessError # NOQA
|
||
|
|
FileExistsError = FileExistsError # NOQA
|
||
|
|
else:
|
||
|
|
# https://github.com/PythonCharmers/python-future/blob/exceptions/
|
||
|
|
# src/future/types/exceptions/pep3151.py
|
||
|
|
import platform
|
||
|
|
|
||
|
|
def _instance_checking_exception(base_exception=Exception):
|
||
|
|
def wrapped(instance_checker):
|
||
|
|
class TemporaryClass(base_exception):
|
||
|
|
|
||
|
|
def __init__(self, *args, **kwargs):
|
||
|
|
if len(args) == 1 and isinstance(args[0], TemporaryClass):
|
||
|
|
unwrap_me = args[0]
|
||
|
|
for attr in dir(unwrap_me):
|
||
|
|
if not attr.startswith('__'):
|
||
|
|
setattr(self, attr, getattr(unwrap_me, attr))
|
||
|
|
else:
|
||
|
|
super(TemporaryClass, self).__init__(*args, **kwargs)
|
||
|
|
|
||
|
|
class __metaclass__(type):
|
||
|
|
def __instancecheck__(cls, inst):
|
||
|
|
return instance_checker(inst)
|
||
|
|
|
||
|
|
def __subclasscheck__(cls, classinfo):
|
||
|
|
value = sys.exc_info()[1]
|
||
|
|
return isinstance(value, cls)
|
||
|
|
|
||
|
|
TemporaryClass.__name__ = instance_checker.__name__
|
||
|
|
TemporaryClass.__doc__ = instance_checker.__doc__
|
||
|
|
return TemporaryClass
|
||
|
|
|
||
|
|
return wrapped
|
||
|
|
|
||
|
|
@_instance_checking_exception(EnvironmentError)
|
||
|
|
def FileNotFoundError(inst):
|
||
|
|
return getattr(inst, 'errno', _SENTINEL) == errno.ENOENT
|
||
|
|
|
||
|
|
@_instance_checking_exception(EnvironmentError)
|
||
|
|
def ProcessLookupError(inst):
|
||
|
|
return getattr(inst, 'errno', _SENTINEL) == errno.ESRCH
|
||
|
|
|
||
|
|
@_instance_checking_exception(EnvironmentError)
|
||
|
|
def PermissionError(inst):
|
||
|
|
return getattr(inst, 'errno', _SENTINEL) in (
|
||
|
|
errno.EACCES, errno.EPERM)
|
||
|
|
|
||
|
|
@_instance_checking_exception(EnvironmentError)
|
||
|
|
def InterruptedError(inst):
|
||
|
|
return getattr(inst, 'errno', _SENTINEL) == errno.EINTR
|
||
|
|
|
||
|
|
@_instance_checking_exception(EnvironmentError)
|
||
|
|
def ChildProcessError(inst):
|
||
|
|
return getattr(inst, 'errno', _SENTINEL) == errno.ECHILD
|
||
|
|
|
||
|
|
@_instance_checking_exception(EnvironmentError)
|
||
|
|
def FileExistsError(inst):
|
||
|
|
return getattr(inst, 'errno', _SENTINEL) == errno.EEXIST
|
||
|
|
|
||
|
|
if platform.python_implementation() != "CPython":
|
||
|
|
try:
|
||
|
|
raise OSError(errno.EEXIST, "perm")
|
||
|
|
except FileExistsError:
|
||
|
|
pass
|
||
|
|
except OSError:
|
||
|
|
raise RuntimeError(
|
||
|
|
"broken or incompatible Python implementation, see: "
|
||
|
|
"https://github.com/giampaolo/psutil/issues/1659")
|
||
|
|
|
||
|
|
|
||
|
|
# --- stdlib additions
|
||
|
|
|
||
|
|
|
||
|
|
# py 3.2 functools.lru_cache
|
||
|
|
# Taken from: http://code.activestate.com/recipes/578078
|
||
|
|
# Credit: Raymond Hettinger
|
||
|
|
try:
|
||
|
|
from functools import lru_cache
|
||
|
|
except ImportError:
|
||
|
|
try:
|
||
|
|
from threading import RLock
|
||
|
|
except ImportError:
|
||
|
|
from dummy_threading import RLock
|
||
|
|
|
||
|
|
_CacheInfo = collections.namedtuple(
|
||
|
|
"CacheInfo", ["hits", "misses", "maxsize", "currsize"])
|
||
|
|
|
||
|
|
class _HashedSeq(list):
|
||
|
|
__slots__ = 'hashvalue'
|
||
|
|
|
||
|
|
def __init__(self, tup, hash=hash):
|
||
|
|
self[:] = tup
|
||
|
|
self.hashvalue = hash(tup)
|
||
|
|
|
||
|
|
def __hash__(self):
|
||
|
|
return self.hashvalue
|
||
|
|
|
||
|
|
def _make_key(args, kwds, typed,
|
||
|
|
kwd_mark=(_SENTINEL, ),
|
||
|
|
fasttypes=set((int, str, frozenset, type(None))), # noqa
|
||
|
|
sorted=sorted, tuple=tuple, type=type, len=len):
|
||
|
|
key = args
|
||
|
|
if kwds:
|
||
|
|
sorted_items = sorted(kwds.items())
|
||
|
|
key += kwd_mark
|
||
|
|
for item in sorted_items:
|
||
|
|
key += item
|
||
|
|
if typed:
|
||
|
|
key += tuple(type(v) for v in args)
|
||
|
|
if kwds:
|
||
|
|
key += tuple(type(v) for k, v in sorted_items)
|
||
|
|
elif len(key) == 1 and type(key[0]) in fasttypes:
|
||
|
|
return key[0]
|
||
|
|
return _HashedSeq(key)
|
||
|
|
|
||
|
|
def lru_cache(maxsize=100, typed=False):
|
||
|
|
"""Least-recently-used cache decorator, see:
|
||
|
|
http://docs.python.org/3/library/functools.html#functools.lru_cache
|
||
|
|
"""
|
||
|
|
def decorating_function(user_function):
|
||
|
|
cache = {}
|
||
|
|
stats = [0, 0]
|
||
|
|
HITS, MISSES = 0, 1
|
||
|
|
make_key = _make_key
|
||
|
|
cache_get = cache.get
|
||
|
|
_len = len
|
||
|
|
lock = RLock()
|
||
|
|
root = []
|
||
|
|
root[:] = [root, root, None, None]
|
||
|
|
nonlocal_root = [root]
|
||
|
|
PREV, NEXT, KEY, RESULT = 0, 1, 2, 3
|
||
|
|
if maxsize == 0:
|
||
|
|
def wrapper(*args, **kwds):
|
||
|
|
result = user_function(*args, **kwds)
|
||
|
|
stats[MISSES] += 1
|
||
|
|
return result
|
||
|
|
elif maxsize is None:
|
||
|
|
def wrapper(*args, **kwds):
|
||
|
|
key = make_key(args, kwds, typed)
|
||
|
|
result = cache_get(key, root)
|
||
|
|
if result is not root:
|
||
|
|
stats[HITS] += 1
|
||
|
|
return result
|
||
|
|
result = user_function(*args, **kwds)
|
||
|
|
cache[key] = result
|
||
|
|
stats[MISSES] += 1
|
||
|
|
return result
|
||
|
|
else:
|
||
|
|
def wrapper(*args, **kwds):
|
||
|
|
if kwds or typed:
|
||
|
|
key = make_key(args, kwds, typed)
|
||
|
|
else:
|
||
|
|
key = args
|
||
|
|
lock.acquire()
|
||
|
|
try:
|
||
|
|
link = cache_get(key)
|
||
|
|
if link is not None:
|
||
|
|
root, = nonlocal_root
|
||
|
|
link_prev, link_next, key, result = link
|
||
|
|
link_prev[NEXT] = link_next
|
||
|
|
link_next[PREV] = link_prev
|
||
|
|
last = root[PREV]
|
||
|
|
last[NEXT] = root[PREV] = link
|
||
|
|
link[PREV] = last
|
||
|
|
link[NEXT] = root
|
||
|
|
stats[HITS] += 1
|
||
|
|
return result
|
||
|
|
finally:
|
||
|
|
lock.release()
|
||
|
|
result = user_function(*args, **kwds)
|
||
|
|
lock.acquire()
|
||
|
|
try:
|
||
|
|
root, = nonlocal_root
|
||
|
|
if key in cache:
|
||
|
|
pass
|
||
|
|
elif _len(cache) >= maxsize:
|
||
|
|
oldroot = root
|
||
|
|
oldroot[KEY] = key
|
||
|
|
oldroot[RESULT] = result
|
||
|
|
root = nonlocal_root[0] = oldroot[NEXT]
|
||
|
|
oldkey = root[KEY]
|
||
|
|
root[KEY] = root[RESULT] = None
|
||
|
|
del cache[oldkey]
|
||
|
|
cache[key] = oldroot
|
||
|
|
else:
|
||
|
|
last = root[PREV]
|
||
|
|
link = [last, root, key, result]
|
||
|
|
last[NEXT] = root[PREV] = cache[key] = link
|
||
|
|
stats[MISSES] += 1
|
||
|
|
finally:
|
||
|
|
lock.release()
|
||
|
|
return result
|
||
|
|
|
||
|
|
def cache_info():
|
||
|
|
"""Report cache statistics"""
|
||
|
|
lock.acquire()
|
||
|
|
try:
|
||
|
|
return _CacheInfo(stats[HITS], stats[MISSES], maxsize,
|
||
|
|
len(cache))
|
||
|
|
finally:
|
||
|
|
lock.release()
|
||
|
|
|
||
|
|
def cache_clear():
|
||
|
|
"""Clear the cache and cache statistics"""
|
||
|
|
lock.acquire()
|
||
|
|
try:
|
||
|
|
cache.clear()
|
||
|
|
root = nonlocal_root[0]
|
||
|
|
root[:] = [root, root, None, None]
|
||
|
|
stats[:] = [0, 0]
|
||
|
|
finally:
|
||
|
|
lock.release()
|
||
|
|
|
||
|
|
wrapper.__wrapped__ = user_function
|
||
|
|
wrapper.cache_info = cache_info
|
||
|
|
wrapper.cache_clear = cache_clear
|
||
|
|
return functools.update_wrapper(wrapper, user_function)
|
||
|
|
|
||
|
|
return decorating_function
|
||
|
|
|
||
|
|
|
||
|
|
# python 3.3
|
||
|
|
try:
|
||
|
|
from shutil import which
|
||
|
|
except ImportError:
|
||
|
|
def which(cmd, mode=os.F_OK | os.X_OK, path=None):
|
||
|
|
"""Given a command, mode, and a PATH string, return the path which
|
||
|
|
conforms to the given mode on the PATH, or None if there is no such
|
||
|
|
file.
|
||
|
|
|
||
|
|
`mode` defaults to os.F_OK | os.X_OK. `path` defaults to the result
|
||
|
|
of os.environ.get("PATH"), or can be overridden with a custom search
|
||
|
|
path.
|
||
|
|
"""
|
||
|
|
def _access_check(fn, mode):
|
||
|
|
return (os.path.exists(fn) and os.access(fn, mode) and
|
||
|
|
not os.path.isdir(fn))
|
||
|
|
|
||
|
|
if os.path.dirname(cmd):
|
||
|
|
if _access_check(cmd, mode):
|
||
|
|
return cmd
|
||
|
|
return None
|
||
|
|
|
||
|
|
if path is None:
|
||
|
|
path = os.environ.get("PATH", os.defpath)
|
||
|
|
if not path:
|
||
|
|
return None
|
||
|
|
path = path.split(os.pathsep)
|
||
|
|
|
||
|
|
if sys.platform == "win32":
|
||
|
|
if os.curdir not in path:
|
||
|
|
path.insert(0, os.curdir)
|
||
|
|
|
||
|
|
pathext = os.environ.get("PATHEXT", "").split(os.pathsep)
|
||
|
|
if any(cmd.lower().endswith(ext.lower()) for ext in pathext):
|
||
|
|
files = [cmd]
|
||
|
|
else:
|
||
|
|
files = [cmd + ext for ext in pathext]
|
||
|
|
else:
|
||
|
|
files = [cmd]
|
||
|
|
|
||
|
|
seen = set()
|
||
|
|
for dir in path:
|
||
|
|
normdir = os.path.normcase(dir)
|
||
|
|
if normdir not in seen:
|
||
|
|
seen.add(normdir)
|
||
|
|
for thefile in files:
|
||
|
|
name = os.path.join(dir, thefile)
|
||
|
|
if _access_check(name, mode):
|
||
|
|
return name
|
||
|
|
return None
|
||
|
|
|
||
|
|
|
||
|
|
# python 3.3
|
||
|
|
try:
|
||
|
|
from shutil import get_terminal_size
|
||
|
|
except ImportError:
|
||
|
|
def get_terminal_size(fallback=(80, 24)):
|
||
|
|
try:
|
||
|
|
import fcntl
|
||
|
|
import struct
|
||
|
|
import termios
|
||
|
|
except ImportError:
|
||
|
|
return fallback
|
||
|
|
else:
|
||
|
|
try:
|
||
|
|
# This should work on Linux.
|
||
|
|
res = struct.unpack(
|
||
|
|
'hh', fcntl.ioctl(1, termios.TIOCGWINSZ, '1234'))
|
||
|
|
return (res[1], res[0])
|
||
|
|
except Exception:
|
||
|
|
return fallback
|
||
|
|
|
||
|
|
|
||
|
|
# python 3.3
|
||
|
|
try:
|
||
|
|
from subprocess import TimeoutExpired as SubprocessTimeoutExpired
|
||
|
|
except ImportError:
|
||
|
|
class SubprocessTimeoutExpired(Exception):
|
||
|
|
pass
|
||
|
|
|
||
|
|
|
||
|
|
# python 3.5
|
||
|
|
try:
|
||
|
|
from contextlib import redirect_stderr
|
||
|
|
except ImportError:
|
||
|
|
@contextlib.contextmanager
|
||
|
|
def redirect_stderr(new_target):
|
||
|
|
original = sys.stderr
|
||
|
|
try:
|
||
|
|
sys.stderr = new_target
|
||
|
|
yield new_target
|
||
|
|
finally:
|
||
|
|
sys.stderr = original
|