cpp/src/gandiva/cache.h

// 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
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#ifndef GANDIVA_MODULE_CACHE_H
#define GANDIVA_MODULE_CACHE_H

#include <mutex>

#include "gandiva/lru_cache.h"

namespace gandiva {

template <class KeyType, typename ValueType>
class Cache {
 public:
  explicit Cache(size_t capacity = CACHE_SIZE) : cache_(capacity) {}
  ValueType GetModule(KeyType cache_key) {
    boost::optional<ValueType> result;
    mtx_.lock();
    result = cache_.get(cache_key);
    mtx_.unlock();
    return result != boost::none ? *result : nullptr;
  }

  void PutModule(KeyType cache_key, ValueType module) {
    mtx_.lock();
    cache_.insert(cache_key, module);
    mtx_.unlock();
  }

 private:
  LruCache<KeyType, ValueType> cache_;
  static const int CACHE_SIZE = 250;
  std::mutex mtx_;
};
}  // namespace gandiva
#endif  // GANDIVA_MODULE_CACHE_H