package org.ethereum.datasource;
import com.google.common.util.concurrent.ListenableFuture;
import java.util.concurrent.Future;
/**
* Represents cache Source which is able to do asynchronous flush
*
* Created by Anton Nashatyrev on 02.02.2017.
*/
public interface AsyncFlushable {
/**
* Flip the backing storage so the current state will be flushed
* when call {@link #flushAsync()} and all the newer changes will
* be collected to a new backing store and will be flushed only on
* subsequent flush call
*
* The method is intended to make consistent flush from several
* sources. I.e. at some point all the related Sources are flipped
* synchronously first (this doesn't consume any time normally) and then
* are flushed asynchronously
*
* This call may block until a previous flush is completed (if still in progress)
*
* @throws InterruptedException
*/
void flipStorage() throws InterruptedException;
/**
* Does async flush, i.e. returns immediately while starts doing flush in a separate thread
* This call may still block if the previous flush is not complete yet
*
* @return Future when the actual flush is complete
*/
ListenableFuture<Boolean> flushAsync() throws InterruptedException;
}