Source code for pyopus.optimizer.cache

.. inheritance-diagram:: pyopus.optimizer.cache
    :parts: 1
**Point caching (PyOPUS subsystem name: CACHE)**

from hashlib import sha1
import numpy as np

__all__ = [ 'Cache', 'HashableWrapper' ]

[docs]class HashableWrapper(object): """ Constructs a hashable wrapper arounf a numpy array. If *copy* is ``True`` a copy of the array is stored and returned. """ def __init__(self, arr, copy=True): self.copy=copy self.arr=np.array(arr) if copy else arr self.hashValue=int(sha1(arr.view(np.uint8)).hexdigest(), 16) def __eq__(self, other): """ Compares two objects. """ return (self.arr == other.arr).all() def __ne__(self, other): """ Compares two objects. """ return (self.arr != other.arr).any() def __hash__(self): """ Returns a precomputed hash value. """ return self.hashValue
[docs] def array(self): """ Returns the original array. Returns a copy if *copy* is ``True``. """ if self.copy: return np.array(self.arr) else: return self.arr
[docs]class Cache(object): """ Cache for storing points. The point is the key. Every point has an object associated with it. """ def __init__(self): self.reset()
[docs] def reset(self): """ Clears cache and resets hit count. """ self.hits=0{}
[docs] def getHits(self): """ Returns cache hit count. """ return self.hits
[docs] def lookup(self, point): """ Looks up a *point* and returns the associated object. Returns ``None`` if the *point* is not in the cache. Increases hit count if the *point* is found in the cache. """ hw=HashableWrapper(point) if hw in self.hits+=1 return[hw] else: return None
[docs] def insert(self, point, value): """ Inserts an object *value* for point *point*. Returns ``True`` if a point in the cache is replaced. """ hw=HashableWrapper(point) if hw in replaced=True else: replaced=False[hw]=value return replaced
[docs] def remove(self, point): """ Removes a *point* from the cache. Returns ``True`` if a point is found and removed. """ hw=HashableWrapper(point) if hw in del[hw] return True return False