exec/java-exec/src/main/java/org/apache/drill/exec/store/mock/FieldGen.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.drill.exec.store.mock;

import org.apache.drill.exec.vector.accessor.ScalarWriter;

/**
 * Interface which all mock column data generators must
 * implement. Each has a {@link #setup} method which is given
 * the column definition for the column. This definition may have
 * additional configuration information for the column (column width,
 * precision, etc.). Each also has a {@link #setValue} method that
 * does the work of setting a specific value vector position to the
 * generated value. The implementation is expected to cast the
 * vector to the type supported by that particular generator.
 * (This is test code; we're not overly concerned with the overhead
 * of such casts.)
 */
public interface FieldGen {
  void setup(ColumnDef colDef, ScalarWriter colLoader);
  void setValue();
}