samza-sql/src/main/java/org/apache/samza/sql/data/Expression.java

/*
* Licensed to the Apache Software Foundation (ASF) under one
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* distributed with this work for additional information
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* 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
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*/

package org.apache.samza.sql.data;

import org.apache.calcite.DataContext;
import org.apache.samza.context.Context;


/**
 * {@link RexToJavaCompiler} creates the Java code for each relational expression at runtime.
 * This is the interface which the runtime generated java code for each Relational expression should implement.
 */
public interface Expression {
  /**
   * This method is used to implement the expressions that takes in columns as input and returns multiple values.
   * @param sqlContext SamzaSqlExecution context
   * @param context Samza context that contains both framework and application specific context.
   * @param root Calcite DataContext
   * @param inputValues All the relational columns for the particular row
   * @param results the results Result values after executing the java code corresponding to the relational expression.
   */
  void execute(SamzaSqlExecutionContext sqlContext, Context context, DataContext root, Object[] inputValues, Object[] results);
}