/usr/lib/python2.7/dist-packages/pyqtgraph/util/lru_cache.py is in python-pyqtgraph 0.9.10-5.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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import sys
import itertools
_IS_PY3 = sys.version_info[0] == 3
class LRUCache(object):
'''
This LRU cache should be reasonable for short collections (until around 100 items), as it does a
sort on the items if the collection would become too big (so, it is very fast for getting and
setting but when its size would become higher than the max size it does one sort based on the
internal time to decide which items should be removed -- which should be Ok if the resizeTo
isn't too close to the maxSize so that it becomes an operation that doesn't happen all the
time).
'''
def __init__(self, maxSize=100, resizeTo=70):
'''
============== =========================================================
**Arguments:**
maxSize (int) This is the maximum size of the cache. When some
item is added and the cache would become bigger than
this, it's resized to the value passed on resizeTo.
resizeTo (int) When a resize operation happens, this is the size
of the final cache.
============== =========================================================
'''
assert resizeTo < maxSize
self.maxSize = maxSize
self.resizeTo = resizeTo
self._counter = 0
self._dict = {}
if _IS_PY3:
self._nextTime = itertools.count(0).__next__
else:
self._nextTime = itertools.count(0).next
def __getitem__(self, key):
item = self._dict[key]
item[2] = self._nextTime()
return item[1]
def __len__(self):
return len(self._dict)
def __setitem__(self, key, value):
item = self._dict.get(key)
if item is None:
if len(self._dict) + 1 > self.maxSize:
self._resizeTo()
item = [key, value, self._nextTime()]
self._dict[key] = item
else:
item[1] = value
item[2] = self._nextTime()
def __delitem__(self, key):
del self._dict[key]
def get(self, key, default=None):
try:
return self[key]
except KeyError:
return default
def clear(self):
self._dict.clear()
if _IS_PY3:
def values(self):
return [i[1] for i in self._dict.values()]
def keys(self):
return [x[0] for x in self._dict.values()]
def _resizeTo(self):
ordered = sorted(self._dict.values(), key=operator.itemgetter(2))[:self.resizeTo]
for i in ordered:
del self._dict[i[0]]
def iteritems(self, accessTime=False):
'''
:param bool accessTime:
If True sorts the returned items by the internal access time.
'''
if accessTime:
for x in sorted(self._dict.values(), key=operator.itemgetter(2)):
yield x[0], x[1]
else:
for x in self._dict.items():
yield x[0], x[1]
else:
def values(self):
return [i[1] for i in self._dict.itervalues()]
def keys(self):
return [x[0] for x in self._dict.itervalues()]
def _resizeTo(self):
ordered = sorted(self._dict.itervalues(), key=operator.itemgetter(2))[:self.resizeTo]
for i in ordered:
del self._dict[i[0]]
def iteritems(self, accessTime=False):
'''
============= ======================================================
**Arguments**
accessTime (bool) If True sorts the returned items by the
internal access time.
============= ======================================================
'''
if accessTime:
for x in sorted(self._dict.itervalues(), key=operator.itemgetter(2)):
yield x[0], x[1]
else:
for x in self._dict.iteritems():
yield x[0], x[1]
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