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.adapter.jdbc;
  
  import org.apache.calcite.DataContext;
  import org.apache.calcite.adapter.enumerable.EnumerableRelImplementor;
  import org.apache.calcite.linq4j.tree.BlockBuilder;
  import org.apache.calcite.linq4j.tree.Expression;
  import org.apache.calcite.linq4j.tree.Expressions;
  import org.apache.calcite.linq4j.tree.Types;
  import org.apache.calcite.rel.core.CorrelationId;
  
  import com.google.common.collect.ImmutableList;
  
  import java.lang.reflect.Constructor;
  import java.lang.reflect.Type;
  
  /**
   * An implementation class of JdbcCorrelationDataContext.
   */
  public class JdbcCorrelationDataContextBuilderImpl implements JdbcCorrelationDataContextBuilder {
    private static final Constructor NEW =
        Types.lookupConstructor(JdbcCorrelationDataContext.class, DataContext.class, Object[].class);
    private final ImmutableList.Builder<Expression> parameters = new ImmutableList.Builder<>();
    private int offset = JdbcCorrelationDataContext.OFFSET;
    private final EnumerableRelImplementor implementor;
    private final BlockBuilder builder;
    private final Expression dataContext;
  
    public JdbcCorrelationDataContextBuilderImpl(EnumerableRelImplementor implementor,
        BlockBuilder builder, Expression dataContext) {
      this.implementor = implementor;
      this.builder = builder;
      this.dataContext = dataContext;
    }
  
    @Override public int add(CorrelationId id, int ordinal, Type type) {
      parameters.add(implementor.getCorrelVariableGetter(id.getName()).field(builder, ordinal, type));
      return offset++;
    }
  
    public Expression build() {
      return  Expressions.new_(NEW, dataContext,
        Expressions.newArrayInit(Object.class, 1, parameters.build()));
    }
  }
  