| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF 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.apache.drill.common.logical.data; |
| |
| import java.util.Iterator; |
| |
| import org.apache.drill.common.logical.data.visitors.LogicalVisitor; |
| |
| import com.fasterxml.jackson.annotation.JsonCreator; |
| import com.fasterxml.jackson.annotation.JsonProperty; |
| import com.fasterxml.jackson.annotation.JsonTypeName; |
| import com.fasterxml.jackson.databind.ObjectMapper; |
| import com.fasterxml.jackson.databind.node.ObjectNode; |
| import org.apache.drill.shaded.guava.com.google.common.collect.Iterators; |
| |
| @JsonTypeName("limit") |
| public class Limit extends SingleInputOperator { |
| |
| private final Integer first; |
| private final Integer last; |
| |
| @JsonCreator |
| public Limit(@JsonProperty("first") Integer first, @JsonProperty("last") Integer last) { |
| super(); |
| this.first = first; |
| this.last = last; |
| } |
| |
| public Integer getFirst() { |
| return first; |
| } |
| |
| public Integer getLast() { |
| return last; |
| } |
| |
| @Override |
| public <T, X, E extends Throwable> T accept(LogicalVisitor<T, X, E> logicalVisitor, X value) throws E { |
| return logicalVisitor.visitLimit(this, value); |
| } |
| |
| @Override |
| public NodeBuilder<Limit> nodeBuilder() { |
| return new LimitNodeBuilder(); //To change body of implemented methods use File | Settings | File Templates. |
| } |
| |
| @Override |
| public Iterator<LogicalOperator> iterator() { |
| return Iterators.singletonIterator(getInput()); |
| } |
| |
| public static class LimitNodeBuilder implements NodeBuilder<Limit> { |
| |
| @Override |
| public ObjectNode convert(ObjectMapper mapper, Limit operator, Integer inputId) { |
| ObjectNode limitNode = mapper.createObjectNode(); |
| limitNode.put("op", "limit"); |
| limitNode.put("input", inputId); |
| limitNode.put("first", operator.first); |
| limitNode.put("last", operator.last); |
| return limitNode; |
| } |
| } |
| } |