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.enumerable.impl;
  
  import org.apache.calcite.adapter.enumerable.AggResultContext;
  import org.apache.calcite.adapter.enumerable.PhysType;
  import org.apache.calcite.adapter.enumerable.RexToLixTranslator;
  import org.apache.calcite.linq4j.tree.BlockBuilder;
  import org.apache.calcite.linq4j.tree.Expression;
  import org.apache.calcite.linq4j.tree.ParameterExpression;
  import org.apache.calcite.rel.core.AggregateCall;
  import org.apache.calcite.sql.validate.SqlConformanceEnum;
  
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  import java.util.List;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * Implementation of
   * {@link org.apache.calcite.adapter.enumerable.AggResultContext}.
   */
  public class AggResultContextImpl extends AggResetContextImpl
      implements AggResultContext {
    private final @Nullable AggregateCall call;
    private final @Nullable ParameterExpression key;
    private final @Nullable PhysType keyPhysType;
  
    /**
     * Creates aggregate result context.
     *
     * @param block Code block that will contain the result calculation statements
     * @param call Aggregate call
     * @param accumulator Accumulator variables that store the intermediate
     *                    aggregate state
     * @param key Key
     */
    public AggResultContextImpl(BlockBuilder block, @Nullable AggregateCall call,
        List<Expression> accumulator, @Nullable ParameterExpression key,
        @Nullable PhysType keyPhysType) {
      super(block, accumulator);
      this.call = call; // null for AggAddContextImpl
      this.key = key;
      this.keyPhysType = keyPhysType; // null for AggAddContextImpl
    }
  
    @Override public @Nullable Expression key() {
      return key;
    }
  
    @Override public Expression keyField(int i) {
      return requireNonNull(keyPhysType, "keyPhysType")
          .fieldReference(requireNonNull(key, "key"), i);
    }
  
    @Override public AggregateCall call() {
      return requireNonNull(call, "call");
    }
  
    @Override public RexToLixTranslator resultTranslator() {
      requireNonNull(keyPhysType, "keyPhysType");
      return RexToLixTranslator.forAggregation(keyPhysType.getTypeFactory(),
          currentBlock(), null, SqlConformanceEnum.DEFAULT);
    }
  }
  