content: /*
   * 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 com.aliyun.odps.lot.operators;
  
  import apsara.odps.lot.LimitProtos;
  import apsara.odps.lot.Lot;
  
  public class Limit extends Operator {
  
    private long count;
  
    public Limit(long count) {
      if (count <= 0) {
        throw new IllegalArgumentException("Parameter 'count' should be greater than 0.");
      }
      this.count = count;
    }
  
    @Override
    public Lot.LogicalOperator toProtoBuf() {
      assert (getParents().size() == 1);
  
      Lot.LogicalOperator.Builder builder = Lot.LogicalOperator.newBuilder();
  
      LimitProtos.Limit.Builder limit = LimitProtos.Limit.newBuilder();
      limit.setId(getId());
      limit.setParentId(getParents().get(0).getId());
      limit.setCount(count);
  
      builder.setLimit(limit.build());
  
      return builder.build();
    }
  }
  