/*
* Copyright (c) [2016] [ <ether.camp> ]
* This file is part of the ethereumJ library.
*
* The ethereumJ library is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* The ethereumJ library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with the ethereumJ library. If not, see <http://www.gnu.org/licenses/>.
*/
package org.ethereum.datasource;
import java.util.Collection;
/**
* Source which internally caches underlying Source key-value pairs
*
* Created by Anton Nashatyrev on 21.10.2016.
*/
public interface CachedSource<Key, Value> extends Source<Key, Value> {
/**
* @return The underlying Source
*/
Source<Key, Value> getSource();
/**
* @return Modified entry keys if this is a write cache
*/
Collection<Key> getModified();
/**
* @return indicates the cache has modified entries
*/
boolean hasModified();
/**
* Estimates the size of cached entries in bytes.
* This value shouldn't be precise size of Java objects
* @return cache size in bytes
*/
long estimateCacheSize();
/**
* Just a convenient shortcut to the most popular Sources with byte[] key
*/
interface BytesKey<Value> extends CachedSource<byte[], Value> {}
}