/***********************************************************************************************************************
* Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu)
*
* 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 eu.stratosphere.compiler.util;
import java.util.Arrays;
import eu.stratosphere.api.common.operators.Order;
import eu.stratosphere.api.common.operators.Ordering;
import eu.stratosphere.api.common.operators.util.FieldList;
import eu.stratosphere.api.common.operators.util.FieldSet;
import eu.stratosphere.compiler.CompilerException;
/**
*
*/
public class Utils
{
public static final FieldList createOrderedFromSet(FieldSet set) {
if (set instanceof FieldList) {
return (FieldList) set;
} else {
final int[] cols = set.toArray();
Arrays.sort(cols);
return new FieldList(cols);
}
}
public static final Ordering createOrdering(FieldList fields, boolean[] directions) {
final Ordering o = new Ordering();
for (int i = 0; i < fields.size(); i++) {
o.appendOrdering(fields.get(i), null, directions == null || directions[i] ? Order.ASCENDING : Order.DESCENDING);
}
return o;
}
public static final Ordering createOrdering(FieldList fields) {
final Ordering o = new Ordering();
for (int i = 0; i < fields.size(); i++) {
o.appendOrdering(fields.get(i), null, Order.ANY);
}
return o;
}
public static boolean[] getDirections(Ordering o, int numFields) {
final boolean[] dirs = o.getFieldSortDirections();
if (dirs.length == numFields) {
return dirs;
} else if (dirs.length > numFields) {
final boolean[] subSet = new boolean[numFields];
System.arraycopy(dirs, 0, subSet, 0, numFields);
return subSet;
} else {
throw new CompilerException();
}
}
// --------------------------------------------------------------------------------------------
/**
* No instantiation.
*/
private Utils() {}
}