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models: Take advantage of fact that our hash won't change

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This might just be pointless micro-optimization as I have _not_ measured. But
it seemed silly to recursively hash everything in a model each time a hash is
required. As we know the data can not change.
This commit is contained in:
Thomas Adamcik 2015-04-11 01:10:00 +02:00
parent 79d1862510
commit 777a663896
1 changed files with 8 additions and 5 deletions
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13
mopidy/models.py
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@ -148,7 +148,7 @@ class ImmutableObjectMeta(type):
attrs['_fields'] = fields
attrs['_instances'] = weakref.WeakValueDictionary()
attrs['__slots__'] = fields.values()
attrs['__slots__'] = ['_hash'] + fields.values()
anncestors = [b for base in bases for b in inspect.getmro(base)]
for anncestor in anncestors:
@ -218,10 +218,12 @@ class ImmutableObject(object):
}
def __hash__(self):
hash_sum = 0
for key, value in self._items():
hash_sum += hash(key) + hash(value)
return hash_sum
if not hasattr(self, '_hash'):
hash_sum = 0
for key, value in self._items():
hash_sum += hash(key) + hash(value)
super(ImmutableObject, self).__setattr__('_hash', hash_sum)
return self._hash
def __eq__(self, other):
if not isinstance(other, self.__class__):
@ -267,6 +269,7 @@ class ImmutableObject(object):
raise TypeError(
'copy() got an unexpected keyword argument "%s"' % key)
super(ImmutableObject, other).__setattr__(key, value)
super(ImmutableObject, other).__delattr__('_hash')
return self._instances.setdefault(weakref.ref(other), other)
def serialize(self):