org.elasticsearch.cluster.routing.PlainShardsIterator Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of elasticsearch Show documentation
Show all versions of elasticsearch Show documentation
Elasticsearch subproject :server
/*
* 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.cluster.routing;
import java.util.List;
/**
* A simple {@link ShardsIterator} that iterates a list or sub-list of
* {@link ShardRouting shard routings}.
*/
public class PlainShardsIterator implements ShardsIterator {
private final List shards;
// Calls to nextOrNull might be performed on different threads in the transport actions so we need the volatile
// keyword in order to ensure visibility. Note that it is fine to use `volatile` for a counter in that case given
// that although nextOrNull might be called from different threads, it can never happen concurrently.
private volatile int index;
public PlainShardsIterator(List shards) {
this.shards = shards;
reset();
}
@Override
public void reset() {
index = 0;
}
@Override
public int remaining() {
return shards.size() - index;
}
@Override
public ShardRouting nextOrNull() {
if (index == shards.size()) {
return null;
} else {
return shards.get(index++);
}
}
@Override
public int size() {
return shards.size();
}
@Override
public int sizeActive() {
int count = 0;
for (ShardRouting shard : shards) {
if (shard.active()) {
count++;
}
}
return count;
}
@Override
public int assignedReplicasIncludingRelocating() {
int count = 0;
for (ShardRouting shard : shards) {
if (shard.unassigned()) {
continue;
}
// if the shard is primary and relocating, add one to the counter since we perform it on the replica as well
// (and we already did it on the primary)
if (shard.primary()) {
if (shard.relocating()) {
count++;
}
} else {
count++;
// if we are relocating the replica, we want to perform the index operation on both the relocating
// shard and the target shard. This means that we won't loose index operations between end of recovery
// and reassignment of the shard by the master node
if (shard.relocating()) {
count++;
}
}
}
return count;
}
@Override
public Iterable asUnordered() {
return shards;
}
}