| /* |
| * 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.giraph.block_app.library.pagerank; |
| |
| import org.apache.giraph.block_app.framework.block.Block; |
| import org.apache.giraph.block_app.framework.block.RepeatUntilBlock; |
| import org.apache.giraph.block_app.framework.block.SequenceBlock; |
| import org.apache.giraph.conf.GiraphConfiguration; |
| import org.apache.giraph.function.ObjectTransfer; |
| import org.apache.giraph.function.vertex.ConsumerWithVertex; |
| import org.apache.giraph.function.vertex.SupplierFromVertex; |
| import org.apache.hadoop.io.DoubleWritable; |
| import org.apache.hadoop.io.NullWritable; |
| import org.apache.hadoop.io.Writable; |
| import org.apache.hadoop.io.WritableComparable; |
| |
| /** |
| * Utility class that helps to construct page rank block |
| */ |
| public class PageRankBlockUtils { |
| /** Do not instantiate */ |
| private PageRankBlockUtils() { |
| } |
| |
| public static <I extends WritableComparable, V extends Writable> Block |
| weightedPagerank( |
| ConsumerWithVertex<I, V, DoubleWritable, DoubleWritable> valueSetter, |
| SupplierFromVertex<I, V, DoubleWritable, DoubleWritable> valueGetter, |
| GiraphConfiguration conf) { |
| return new SequenceBlock( |
| new PageRankInitializeAndNormalizeEdgesPiece<>(), |
| pagerank(valueSetter, valueGetter, |
| (vertex, edgeValue) -> edgeValue.get(), conf)); |
| } |
| |
| public static <I extends WritableComparable, V extends Writable> Block |
| unweightedPagerank( |
| ConsumerWithVertex<I, V, NullWritable, DoubleWritable> valueSetter, |
| SupplierFromVertex<I, V, NullWritable, DoubleWritable> valueGetter, |
| GiraphConfiguration conf) { |
| return pagerank(valueSetter, valueGetter, |
| (UnweightedEdgeValueGetter<I, V, NullWritable>) |
| vertex -> |
| vertex.getNumEdges() == 0 ? 0 : 1.0 / vertex.getNumEdges(), |
| conf); |
| } |
| |
| public static <I extends WritableComparable, V extends Writable, |
| E extends Writable> Block pagerank( |
| ConsumerWithVertex<I, V, E, DoubleWritable> valueSetter, |
| SupplierFromVertex<I, V, E, DoubleWritable> valueGetter, |
| EdgeValueGetter<I, V, E> edgeValueGetter, |
| GiraphConfiguration conf) { |
| ObjectTransfer<Boolean> haltCondition = new ObjectTransfer<>(); |
| ObjectTransfer<DoubleWritable> valueTransfer = new ObjectTransfer<>(); |
| return new SequenceBlock( |
| new RepeatUntilBlock(PageRankSettings.getIterations(conf) + 1, |
| new PageRankIteration<>(valueSetter, valueGetter, edgeValueGetter, |
| valueTransfer, haltCondition, conf), |
| haltCondition |
| ) |
| ); |
| } |
| } |