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Location: kallithea/rhodecode/lib/dbmigrate/migrate/versioning/util/keyedinstance.py - annotation
d162de13caec
1.1 KiB
text/x-python
memory optimizations, call diffs only when needed ie. after checking for binary, and cutoff limit.
reduces memory consumption a lot on binary files ! Additionally checking for binary before the size gives little more performance as well
reduces memory consumption a lot on binary files ! Additionally checking for binary before the size gives little more performance as well
9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 9753e0907827 | #!/usr/bin/env python
# -*- coding: utf-8 -*-
class KeyedInstance(object):
"""A class whose instances have a unique identifier of some sort
No two instances with the same unique ID should exist - if we try to create
a second instance, the first should be returned.
"""
_instances = dict()
def __new__(cls, *p, **k):
instances = cls._instances
clskey = str(cls)
if clskey not in instances:
instances[clskey] = dict()
instances = instances[clskey]
key = cls._key(*p, **k)
if key not in instances:
instances[key] = super(KeyedInstance, cls).__new__(cls)
return instances[key]
@classmethod
def _key(cls, *p, **k):
"""Given a unique identifier, return a dictionary key
This should be overridden by child classes, to specify which parameters
should determine an object's uniqueness
"""
raise NotImplementedError()
@classmethod
def clear(cls):
# Allow cls.clear() as well as uniqueInstance.clear(cls)
if str(cls) in cls._instances:
del cls._instances[str(cls)]
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