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.java.JavaTypeFactory;
  import org.apache.calcite.linq4j.QueryProvider;
  import org.apache.calcite.schema.SchemaPlus;
  
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  import static java.lang.Integer.parseInt;
  
  /**
   * A special DataContext which handles correlation variable for batch nested loop joins.
   */
  public class JdbcCorrelationDataContext implements DataContext {
    public static final int OFFSET = Integer.MAX_VALUE - 10000;
  
    private final DataContext delegate;
    private final Object[] parameters;
  
    public JdbcCorrelationDataContext(DataContext delegate, Object[] parameters) {
      this.delegate = delegate;
      this.parameters = parameters;
    }
  
    @Override public @Nullable SchemaPlus getRootSchema() {
      return delegate.getRootSchema();
    }
  
    @Override public JavaTypeFactory getTypeFactory() {
      return delegate.getTypeFactory();
    }
  
    @Override public QueryProvider getQueryProvider() {
      return delegate.getQueryProvider();
    }
  
    @Override public @Nullable Object get(String name) {
      if (name.startsWith("?")) {
        int index = parseInt(name.substring(1));
        if (index >= OFFSET && index < OFFSET + parameters.length) {
          return parameters[index - OFFSET];
        }
      }
      return delegate.get(name);
    }
  }
  