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compat.py
318 lines | 9.9 KiB | text/x-python | PythonLexer
"""
Various utilities to work with Python < 2.7.
Those utilities may be deleted once ``vcs`` stops support for older Python
versions.
"""
import sys
import array
if sys.version_info >= (2, 7):
unittest = __import__('unittest')
else:
unittest = __import__('unittest2')
if sys.version_info >= (2, 6):
_bytes = bytes
else:
# in py2.6 bytes is a synonim for str
_bytes = str
if sys.version_info >= (2, 6):
_bytearray = bytearray
else:
# no idea if this is correct but all integration tests are passing
# i think we never use bytearray anyway
_bytearray = array
if sys.version_info >= (2, 6):
from collections import deque
else:
#need to implement our own deque with maxlen
class deque(object):
def __init__(self, iterable=(), maxlen= -1):
if not hasattr(self, 'data'):
self.left = self.right = 0
self.data = {}
self.maxlen = maxlen or -1
self.extend(iterable)
def append(self, x):
self.data[self.right] = x
self.right += 1
if self.maxlen != -1 and len(self) > self.maxlen:
self.popleft()
def appendleft(self, x):
self.left -= 1
self.data[self.left] = x
if self.maxlen != -1 and len(self) > self.maxlen:
self.pop()
def pop(self):
if self.left == self.right:
raise IndexError('cannot pop from empty deque')
self.right -= 1
elem = self.data[self.right]
del self.data[self.right]
return elem
def popleft(self):
if self.left == self.right:
raise IndexError('cannot pop from empty deque')
elem = self.data[self.left]
del self.data[self.left]
self.left += 1
return elem
def clear(self):
self.data.clear()
self.left = self.right = 0
def extend(self, iterable):
for elem in iterable:
self.append(elem)
def extendleft(self, iterable):
for elem in iterable:
self.appendleft(elem)
def rotate(self, n=1):
if self:
n %= len(self)
for i in xrange(n):
self.appendleft(self.pop())
def __getitem__(self, i):
if i < 0:
i += len(self)
try:
return self.data[i + self.left]
except KeyError:
raise IndexError
def __setitem__(self, i, value):
if i < 0:
i += len(self)
try:
self.data[i + self.left] = value
except KeyError:
raise IndexError
def __delitem__(self, i):
size = len(self)
if not (-size <= i < size):
raise IndexError
data = self.data
if i < 0:
i += size
for j in xrange(self.left + i, self.right - 1):
data[j] = data[j + 1]
self.pop()
def __len__(self):
return self.right - self.left
def __cmp__(self, other):
if type(self) != type(other):
return cmp(type(self), type(other))
return cmp(list(self), list(other))
def __repr__(self, _track=[]):
if id(self) in _track:
return '...'
_track.append(id(self))
r = 'deque(%r, maxlen=%s)' % (list(self), self.maxlen)
_track.remove(id(self))
return r
def __getstate__(self):
return (tuple(self),)
def __setstate__(self, s):
self.__init__(s[0])
def __hash__(self):
raise TypeError
def __copy__(self):
return self.__class__(self)
def __deepcopy__(self, memo={}):
from copy import deepcopy
result = self.__class__()
memo[id(self)] = result
result.__init__(deepcopy(tuple(self), memo))
return result
#==============================================================================
# threading.Event
#==============================================================================
if sys.version_info >= (2, 6):
from threading import Event, Thread
else:
from threading import _Verbose, Lock, Thread, _time, \
_allocate_lock, RLock, _sleep
def Condition(*args, **kwargs):
return _Condition(*args, **kwargs)
class _Condition(_Verbose):
def __init__(self, lock=None, verbose=None):
_Verbose.__init__(self, verbose)
if lock is None:
lock = RLock()
self.__lock = lock
# Export the lock's acquire() and release() methods
self.acquire = lock.acquire
self.release = lock.release
# If the lock defines _release_save() and/or _acquire_restore(),
# these override the default implementations (which just call
# release() and acquire() on the lock). Ditto for _is_owned().
try:
self._release_save = lock._release_save
except AttributeError:
pass
try:
self._acquire_restore = lock._acquire_restore
except AttributeError:
pass
try:
self._is_owned = lock._is_owned
except AttributeError:
pass
self.__waiters = []
def __enter__(self):
return self.__lock.__enter__()
def __exit__(self, *args):
return self.__lock.__exit__(*args)
def __repr__(self):
return "<Condition(%s, %d)>" % (self.__lock, len(self.__waiters))
def _release_save(self):
self.__lock.release() # No state to save
def _acquire_restore(self, x):
self.__lock.acquire() # Ignore saved state
def _is_owned(self):
# Return True if lock is owned by current_thread.
# This method is called only if __lock doesn't have _is_owned().
if self.__lock.acquire(0):
self.__lock.release()
return False
else:
return True
def wait(self, timeout=None):
if not self._is_owned():
raise RuntimeError("cannot wait on un-acquired lock")
waiter = _allocate_lock()
waiter.acquire()
self.__waiters.append(waiter)
saved_state = self._release_save()
try: # restore state no matter what (e.g., KeyboardInterrupt)
if timeout is None:
waiter.acquire()
if __debug__:
self._note("%s.wait(): got it", self)
else:
# Balancing act: We can't afford a pure busy loop, so we
# have to sleep; but if we sleep the whole timeout time,
# we'll be unresponsive. The scheme here sleeps very
# little at first, longer as time goes on, but never longer
# than 20 times per second (or the timeout time remaining).
endtime = _time() + timeout
delay = 0.0005 # 500 us -> initial delay of 1 ms
while True:
gotit = waiter.acquire(0)
if gotit:
break
remaining = endtime - _time()
if remaining <= 0:
break
delay = min(delay * 2, remaining, .05)
_sleep(delay)
if not gotit:
if __debug__:
self._note("%s.wait(%s): timed out", self, timeout)
try:
self.__waiters.remove(waiter)
except ValueError:
pass
else:
if __debug__:
self._note("%s.wait(%s): got it", self, timeout)
finally:
self._acquire_restore(saved_state)
def notify(self, n=1):
if not self._is_owned():
raise RuntimeError("cannot notify on un-acquired lock")
__waiters = self.__waiters
waiters = __waiters[:n]
if not waiters:
if __debug__:
self._note("%s.notify(): no waiters", self)
return
self._note("%s.notify(): notifying %d waiter%s", self, n,
n != 1 and "s" or "")
for waiter in waiters:
waiter.release()
try:
__waiters.remove(waiter)
except ValueError:
pass
def notifyAll(self):
self.notify(len(self.__waiters))
notify_all = notifyAll
def Event(*args, **kwargs):
return _Event(*args, **kwargs)
class _Event(_Verbose):
# After Tim Peters' event class (without is_posted())
def __init__(self, verbose=None):
_Verbose.__init__(self, verbose)
self.__cond = Condition(Lock())
self.__flag = False
def isSet(self):
return self.__flag
is_set = isSet
def set(self):
self.__cond.acquire()
try:
self.__flag = True
self.__cond.notify_all()
finally:
self.__cond.release()
def clear(self):
self.__cond.acquire()
try:
self.__flag = False
finally:
self.__cond.release()
def wait(self, timeout=None):
self.__cond.acquire()
try:
if not self.__flag:
self.__cond.wait(timeout)
finally:
self.__cond.release()