/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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
* "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 org.elasticsearch.index.translog;
import java.io.IOException;
import java.util.Arrays;
/**
* A snapshot composed out of multiple snapshots
*/
final class MultiSnapshot implements Translog.Snapshot {
private final Translog.Snapshot[] translogs;
private final int totalOperations;
private int index;
/**
* Creates a new point in time snapshot of the given snapshots. Those snapshots are always iterated in-order.
*/
MultiSnapshot(Translog.Snapshot[] translogs) {
this.translogs = translogs;
totalOperations = Arrays.stream(translogs).mapToInt(Translog.Snapshot::totalOperations).sum();
index = 0;
}
@Override
public int totalOperations() {
return totalOperations;
}
@Override
public Translog.Operation next() throws IOException {
for (; index < translogs.length; index++) {
final Translog.Snapshot current = translogs[index];
Translog.Operation op = current.next();
if (op != null) { // if we are null we move to the next snapshot
return op;
}
}
return null;
}
}