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 org.apache.calcite.interpreter;
  
  import org.apache.calcite.rel.core.Project;
  
  /**
   * Interpreter node that implements a
   * {@link org.apache.calcite.rel.core.Project}.
   */
  public class ProjectNode extends AbstractSingleNode<Project> {
    private final Scalar scalar;
    private final Context context;
    private final int projectCount;
  
    public ProjectNode(Compiler compiler, Project rel) {
      super(compiler, rel);
      this.projectCount = rel.getProjects().size();
      this.scalar =
          compiler.compile(rel.getProjects(), rel.getInput().getRowType());
      this.context = compiler.createContext();
    }
  
    @Override public void run() throws InterruptedException {
      Row row;
      while ((row = source.receive()) != null) {
        context.values = row.getValues();
        Object[] values = new Object[projectCount];
        scalar.execute(context, values);
        sink.send(new Row(values));
      }
    }
  }
  