| /* |
| * 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.pig.builtin; |
| |
| import java.io.IOException; |
| import java.util.List; |
| |
| import org.apache.pig.EvalFunc; |
| import org.apache.pig.backend.executionengine.ExecException; |
| import org.apache.pig.data.BagFactory; |
| import org.apache.pig.data.DataBag; |
| import org.apache.pig.data.DataType; |
| import org.apache.pig.data.Tuple; |
| import org.apache.pig.data.TupleFactory; |
| import org.apache.pig.impl.logicalLayer.FrontendException; |
| import org.apache.pig.impl.logicalLayer.schema.Schema; |
| import org.apache.pig.impl.logicalLayer.schema.Schema.FieldSchema; |
| |
| import com.google.common.collect.Lists; |
| |
| /** |
| * Produces a DataBag with hierarchy of values (from the most detailed level of |
| * aggregation to most general level of aggregation) of the specified dimensions |
| * For example, (a, b, c) will produce the following bag: |
| * |
| * <pre> |
| * { (a, b, c), (a, b, null), (a, null, null), (null, null, null) } |
| * </pre> |
| */ |
| public class RollupDimensions extends EvalFunc<DataBag> { |
| |
| private static BagFactory bf = BagFactory.getInstance(); |
| private static TupleFactory tf = TupleFactory.getInstance(); |
| private final String allMarker; |
| |
| public RollupDimensions() { |
| this(null); |
| } |
| |
| public RollupDimensions(String allMarker) { |
| super(); |
| this.allMarker = allMarker; |
| } |
| |
| @Override |
| public DataBag exec(Tuple tuple) throws IOException { |
| List<Tuple> result = Lists.newArrayListWithCapacity(tuple.size() + 1); |
| CubeDimensions.convertNullToUnknown(tuple); |
| result.add(tuple); |
| iterativelyRollup(result, tuple); |
| return bf.newDefaultBag(result); |
| } |
| |
| private void iterativelyRollup(List<Tuple> result, Tuple input) throws ExecException { |
| Tuple tempTup = tf.newTuple(input.getAll()); |
| for (int i = input.size() - 1; i >= 0; i--) { |
| tempTup.set(i, allMarker); |
| result.add(tf.newTuple(tempTup.getAll())); |
| } |
| } |
| |
| @Override |
| public Schema outputSchema(Schema input) { |
| // "dimensions" string is the default namespace assigned to the output |
| // schema. this can be overridden by specifying user defined schema |
| // names in foreach operator. if user defined schema names are not |
| // specified then the output schema of foreach operator using this UDF |
| // will have "dimensions::" namespace for all fields in the tuple |
| try { |
| return new Schema(new FieldSchema("dimensions", input, DataType.BAG)); |
| } catch (FrontendException e) { |
| // we are specifying BAG explicitly, so this should not happen. |
| throw new RuntimeException(e); |
| } |
| } |
| } |