AggResetContextImpl.java

/*
 * 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.enumerable.impl;

import org.apache.calcite.adapter.enumerable.AggResetContext;
import org.apache.calcite.adapter.enumerable.NestedBlockBuilderImpl;
import org.apache.calcite.linq4j.tree.BlockBuilder;
import org.apache.calcite.linq4j.tree.Expression;
import org.apache.calcite.rel.core.AggregateCall;

import java.util.List;

/**
 * Implementation of
 * {@link org.apache.calcite.adapter.enumerable.AggResetContext}.
 */
public abstract class AggResetContextImpl extends NestedBlockBuilderImpl
    implements AggResetContext {
  private final List<Expression> accumulator;

  /**
   * Creates aggregate reset context.
   *
   * @param block Code block that will contain the added initialization
   * @param accumulator Accumulator variables that store the intermediate
   *                    aggregate state
   */
  protected AggResetContextImpl(BlockBuilder block, List<Expression> accumulator) {
    super(block);
    this.accumulator = accumulator;
  }

  @Override public List<Expression> accumulator() {
    return accumulator;
  }

  public AggregateCall call() {
    throw new UnsupportedOperationException();
  }
}