| # Licensed to the Apache Software Foundation (ASF) under one or more |
| # contributor license agreements. See the NOTICE file distributed with |
| # this work for additional information regarding copyright ownership. |
| # The ASF licenses this file to You under the Apache License, Version 2.0 |
| # (the "License"); you may not use this file except in compliance with |
| # the License. You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| |
| |
| from __future__ import division |
| |
| from petastorm.cache import CacheBase |
| |
| |
| class LocalMemoryCache(CacheBase): |
| def __init__(self, size_limit_bytes): |
| """LocalMemoryCache is an adapter to a diskcache implementation. |
| |
| LocalMemoryCache can be used by a pycarbon Reader class to temporarily keep parts of the dataset in local memory. |
| |
| :param size_limit_bytes: Maximal size of the memory to be used by cache. The size of the cache may actually |
| grow somewhat above the size_limit_bytes, so the limit is not very strict. |
| """ |
| |
| self._cache = dict() |
| |
| def get(self, key, fill_cache_func): |
| value = self._cache.get(key) |
| if value is None: |
| value = fill_cache_func() |
| self._cache[key] = value |
| |
| return value |
| |
| def cleanup(self): |
| self._cache.clear() |
| |
| def size(self): |
| return len(self._cache) |