/*
* 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.query.support;
import org.elasticsearch.index.mapper.ObjectMapper;
import java.util.Deque;
import java.util.LinkedList;
/**
* During query parsing this keeps track of the current nested level.
*/
public final class NestedScope {
private final Deque<ObjectMapper> levelStack = new LinkedList<>();
/**
* @return For the current nested level returns the object mapper that belongs to that
*/
public ObjectMapper getObjectMapper() {
return levelStack.peek();
}
/**
* Sets the new current nested level and pushes old current nested level down the stack returns that level.
*/
public ObjectMapper nextLevel(ObjectMapper level) {
ObjectMapper previous = levelStack.peek();
levelStack.push(level);
return previous;
}
/**
* Sets the previous nested level as current nested level and removes and returns the current nested level.
*/
public ObjectMapper previousLevel() {
return levelStack.pop();
}
}