content: /*
   * Copyright (C) 2020 ActiveJ LLC.
   *
   * Licensed 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 io.activej.cube.aggregation.measure;
  
  import io.activej.codegen.expression.Expression;
  import io.activej.codegen.expression.Variable;
  import io.activej.cube.aggregation.fieldtype.FieldType;
  
  @SuppressWarnings("rawtypes")
  public abstract class Measure {
  	protected final FieldType fieldType;
  
  	protected Measure(FieldType fieldType) {
  		this.fieldType = fieldType;
  	}
  
  	public final FieldType getFieldType() {
  		return fieldType;
  	}
  
  	public abstract Expression valueOfAccumulator(Expression accumulator);
  
  	public abstract Expression zeroAccumulator(Variable accumulator);
  
  	public abstract Expression initAccumulatorWithAccumulator(Variable accumulator, Expression firstAccumulator);
  
  	public abstract Expression initAccumulatorWithValue(Variable accumulator, Variable firstValue);
  
  	public abstract Expression reduce(Variable accumulator, Variable nextAccumulator);
  
  	public abstract Expression accumulate(Variable accumulator, Variable nextValue);
  }
  