/*
* Copyright 2017-present Open Networking Foundation
*
* Licensed 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.
*/
package io.atomix.storage.journal;
import java.util.Iterator;
/**
* Log reader.
*
* @author Jordan Halterman
*/
public interface JournalReader extends Iterator>, AutoCloseable {
/**
* Raft log reader mode.
*/
enum Mode {
/**
* Reads all entries from the log.
*/
ALL,
/**
* Reads committed entries from the log.
*/
COMMITS,
}
/**
* Returns the first index in the journal.
*
* @return the first index in the journal
*/
long getFirstIndex();
/**
* Returns the current reader index.
*
* @return The current reader index.
*/
long getCurrentIndex();
/**
* Returns the last read entry.
*
* @return The last read entry.
*/
Indexed getCurrentEntry();
/**
* Returns the next reader index.
*
* @return The next reader index.
*/
long getNextIndex();
/**
* Returns whether the reader has a next entry to read.
*
* @return Whether the reader has a next entry to read.
*/
@Override
boolean hasNext();
/**
* Returns the next entry in the reader.
*
* @return The next entry in the reader.
*/
@Override
Indexed next();
/**
* Resets the reader to the start.
*/
void reset();
/**
* Resets the reader to the given index.
*
* @param index The index to which to reset the reader.
*/
void reset(long index);
@Override
void close();
}