class PhraseCache:
"""An LRU cache for ttable lookups"""
def __init__(self, max_size):
self.max_size = max_size
self.pairs_to_scores = OrderedDict()
def get(self, source, target):
key = (source,target)
scores = self.pairs_to_scores.get(key,None)
if scores:
# cache hit - update access time
del self.pairs_to_scores[key]
self.pairs_to_scores[key] = scores
return scores
def add(self,source,target,scores):
key = (source,target)
self.pairs_to_scores[key] = scores
while len(self.pairs_to_scores) > self.max_size:
self.pairs_to_scores.popitem(last=False)
def __init__(self, max_size): self.max_size = max_size self.pairs_to_scores = OrderedDict()