/*
* Licensed to Crate under one or more contributor license agreements.
* See the NOTICE file distributed with this work for additional
* information regarding copyright ownership. Crate 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.
*
* However, if you have executed another commercial license agreement
* with Crate these terms will supersede the license and you may use the
* software solely pursuant to the terms of the relevant commercial
* agreement.
*/
package io.crate.testing;
import io.crate.data.Row;
import io.crate.data.RowN;
import java.util.Iterator;
import java.util.NoSuchElementException;
public class RowGenerator {
/**
* Generate a range of rows.
* Both increasing (e.g. 0 -> 10) and decreasing ranges (10 -> 0) are supported.
*
* @param from start (inclusive)
* @param to end (exclusive)
*/
public static Iterable<Row> range(final int from, final int to) {
return new Iterable<Row>() {
@Override
public Iterator<Row> iterator() {
return new Iterator<Row>() {
private Object[] columns = new Object[1];
private RowN sharedRow = new RowN(columns);
private int i = from;
private int step = from < to ? 1 : -1;
@Override
public boolean hasNext() {
return step >= 0 ? i < to : i > to;
}
@Override
public Row next() {
if (!hasNext()) {
throw new NoSuchElementException("Iterator exhausted");
}
columns[0] = i;
i += step;
return sharedRow;
}
@Override
public void remove() {
throw new UnsupportedOperationException("Remove not supported");
}
};
}
};
}
/**
* Return a Iterable where each Row has the same instance, but the data changes depending on the given iterable.
*
* @param iterable iterable containing values for the first column of the Rows in the result.
*/
public static <T> Iterable<Row> fromSingleColValues(Iterable<T> iterable) {
return () -> new Iterator<Row>() {
private Object[] cells = new Object[1];
private RowN row = new RowN(cells);
private Iterator<?> iterator = iterable.iterator();
@Override
public boolean hasNext() {
return iterator.hasNext();
}
@Override
public Row next() {
cells[0] = iterator.next();
return row;
}
};
}
}