/*

* java-tron is free software: you can redistribute it and/or modify

* it under the terms of the GNU General Public License as published by

* the Free Software Foundation, either version 3 of the License, or

* (at your option) any later version.

*

* java-tron 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 General Public License for more details.

*

* You should have received a copy of the GNU General Public License

* along with this program. If not, see <http://www.gnu.org/licenses/>.

*/

package org.tron.datasource;

import java.util.Collection;

/**

* Source which internally caches underlying Source key-value pairs

*/

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> {

}

}