Java tutorial
/** * 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 cn.edu.bjtu.cit.recommender; import java.io.Serializable; import java.util.ArrayList; import java.util.Collections; import java.util.Comparator; import java.util.Iterator; import java.util.List; import java.util.PriorityQueue; import java.util.Queue; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.crunch.CombineFn; import org.apache.crunch.DoFn; import org.apache.crunch.Emitter; import org.apache.crunch.MapFn; import org.apache.crunch.PCollection; import org.apache.crunch.PGroupedTable; import org.apache.crunch.PTable; import org.apache.crunch.Pair; import org.apache.crunch.Pipeline; import org.apache.crunch.PipelineResult; import org.apache.crunch.impl.mr.MRPipeline; import org.apache.crunch.impl.mr.plan.ClusterOracle; import org.apache.crunch.profile.Profiler; import org.apache.crunch.types.writable.RecommendedItems; import org.apache.crunch.types.writable.VectorAndPrefs; import org.apache.crunch.types.writable.VectorOrPref; import org.apache.crunch.types.writable.Writables; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.conf.Configured; import org.apache.hadoop.util.GenericOptionsParser; import org.apache.hadoop.util.Tool; import org.apache.hadoop.util.ToolRunner; import org.apache.log4j.PropertyConfigurator; import org.apache.mahout.cf.taste.impl.recommender.GenericRecommendedItem; import org.apache.mahout.cf.taste.recommender.RecommendedItem; import org.apache.mahout.math.RandomAccessSparseVector; import org.apache.mahout.math.Vector; import cn.edu.bjtu.cit.cli.OptionParser; import cn.edu.bjtu.cit.recommender.profile.ProfileConverter; import com.google.common.collect.Lists; import com.google.common.primitives.Floats; @SuppressWarnings("serial") public class Recommender extends Configured implements Tool, Serializable { public static final String PROFILING = "p"; public static final String CLUSTER_SIZE = "cs"; public static final String ESTIMATION = "est"; public static final String OPT_REDUCE = "opt.reduce"; public static final String OPT_MSCR = "opt.mscr"; public static final String ACTIVE_THRESHOLD = "at"; public static final String TOP = "top"; private final Log log = LogFactory.getLog(Recommender.class); private static final Comparator<RecommendedItem> BY_PREFERENCE_VALUE = new Comparator<RecommendedItem>() { @Override public int compare(RecommendedItem one, RecommendedItem two) { return Floats.compare(one.getValue(), two.getValue()); } }; private Profiler profiler; private Estimator est; private String estFile; private String profileFilePath; private int clusterSize = 1; private int top = 10; private int threshold = 20; public Recommender() { est = new Estimator(); } @SuppressWarnings("unchecked") public int run(String[] args) throws Exception { if (args.length < 2) { System.err.println(); System.err.println("Usage: " + this.getClass().getName() + " [generic options] input output [profiling] [estimation] [clustersize]"); System.err.println(); printUsage(); GenericOptionsParser.printGenericCommandUsage(System.err); return 1; } OptionParser parser = new OptionParser(args); Pipeline pipeline = new MRPipeline(Recommender.class, getConf()); if (parser.hasOption(CLUSTER_SIZE)) { pipeline.getConfiguration().setInt(ClusterOracle.CLUSTER_SIZE, Integer.parseInt(parser.getOption(CLUSTER_SIZE).getValue())); } if (parser.hasOption(PROFILING)) { pipeline.getConfiguration().setBoolean(Profiler.IS_PROFILE, true); this.profileFilePath = parser.getOption(PROFILING).getValue(); } if (parser.hasOption(ESTIMATION)) { estFile = parser.getOption(ESTIMATION).getValue(); est = new Estimator(estFile, clusterSize); } if (parser.hasOption(OPT_REDUCE)) { pipeline.getConfiguration().setBoolean(OPT_REDUCE, true); } if (parser.hasOption(OPT_MSCR)) { pipeline.getConfiguration().setBoolean(OPT_MSCR, true); } if (parser.hasOption(ACTIVE_THRESHOLD)) { threshold = Integer.parseInt(parser.getOption("at").getValue()); } if (parser.hasOption(TOP)) { top = Integer.parseInt(parser.getOption("top").getValue()); } profiler = new Profiler(pipeline); /* * input node */ PCollection<String> lines = pipeline.readTextFile(args[0]); if (profiler.isProfiling() && lines.getSize() > 10 * 1024 * 1024) { lines = lines.sample(0.1); } /* * S0 + GBK */ PGroupedTable<Long, Long> userWithPrefs = lines.parallelDo(new MapFn<String, Pair<Long, Long>>() { @Override public Pair<Long, Long> map(String input) { String[] split = input.split(Estimator.DELM); long userID = Long.parseLong(split[0]); long itemID = Long.parseLong(split[1]); return Pair.of(userID, itemID); } @Override public float scaleFactor() { return est.getScaleFactor("S0").sizeFactor; } @Override public float scaleFactorByRecord() { return est.getScaleFactor("S0").recsFactor; } }, Writables.tableOf(Writables.longs(), Writables.longs())).groupByKey(est.getClusterSize()); /* * S1 */ PTable<Long, Vector> userVector = userWithPrefs .parallelDo(new MapFn<Pair<Long, Iterable<Long>>, Pair<Long, Vector>>() { @Override public Pair<Long, Vector> map(Pair<Long, Iterable<Long>> input) { Vector userVector = new RandomAccessSparseVector(Integer.MAX_VALUE, 100); for (long itemPref : input.second()) { userVector.set((int) itemPref, 1.0f); } return Pair.of(input.first(), userVector); } @Override public float scaleFactor() { return est.getScaleFactor("S1").sizeFactor; } @Override public float scaleFactorByRecord() { return est.getScaleFactor("S1").recsFactor; } }, Writables.tableOf(Writables.longs(), Writables.vectors())); userVector = profiler.profile("S0-S1", pipeline, userVector, ProfileConverter.long_vector(), Writables.tableOf(Writables.longs(), Writables.vectors())); /* * S2 */ PTable<Long, Vector> filteredUserVector = userVector .parallelDo(new DoFn<Pair<Long, Vector>, Pair<Long, Vector>>() { @Override public void process(Pair<Long, Vector> input, Emitter<Pair<Long, Vector>> emitter) { if (input.second().getNumNondefaultElements() > threshold) { emitter.emit(input); } } @Override public float scaleFactor() { return est.getScaleFactor("S2").sizeFactor; } @Override public float scaleFactorByRecord() { return est.getScaleFactor("S2").recsFactor; } }, Writables.tableOf(Writables.longs(), Writables.vectors())); filteredUserVector = profiler.profile("S2", pipeline, filteredUserVector, ProfileConverter.long_vector(), Writables.tableOf(Writables.longs(), Writables.vectors())); /* * S3 + GBK */ PGroupedTable<Integer, Integer> coOccurencePairs = filteredUserVector .parallelDo(new DoFn<Pair<Long, Vector>, Pair<Integer, Integer>>() { @Override public void process(Pair<Long, Vector> input, Emitter<Pair<Integer, Integer>> emitter) { Iterator<Vector.Element> it = input.second().iterateNonZero(); while (it.hasNext()) { int index1 = it.next().index(); Iterator<Vector.Element> it2 = input.second().iterateNonZero(); while (it2.hasNext()) { int index2 = it2.next().index(); emitter.emit(Pair.of(index1, index2)); } } } @Override public float scaleFactor() { float size = est.getScaleFactor("S3").sizeFactor; return size; } @Override public float scaleFactorByRecord() { float recs = est.getScaleFactor("S3").recsFactor; return recs; } }, Writables.tableOf(Writables.ints(), Writables.ints())).groupByKey(est.getClusterSize()); /* * S4 */ PTable<Integer, Vector> coOccurenceVector = coOccurencePairs .parallelDo(new MapFn<Pair<Integer, Iterable<Integer>>, Pair<Integer, Vector>>() { @Override public Pair<Integer, Vector> map(Pair<Integer, Iterable<Integer>> input) { Vector cooccurrenceRow = new RandomAccessSparseVector(Integer.MAX_VALUE, 100); for (int itemIndex2 : input.second()) { cooccurrenceRow.set(itemIndex2, cooccurrenceRow.get(itemIndex2) + 1.0); } return Pair.of(input.first(), cooccurrenceRow); } @Override public float scaleFactor() { return est.getScaleFactor("S4").sizeFactor; } @Override public float scaleFactorByRecord() { return est.getScaleFactor("S4").recsFactor; } }, Writables.tableOf(Writables.ints(), Writables.vectors())); coOccurenceVector = profiler.profile("S3-S4", pipeline, coOccurenceVector, ProfileConverter.int_vector(), Writables.tableOf(Writables.ints(), Writables.vectors())); /* * S5 Wrapping co-occurrence columns */ PTable<Integer, VectorOrPref> wrappedCooccurrence = coOccurenceVector .parallelDo(new MapFn<Pair<Integer, Vector>, Pair<Integer, VectorOrPref>>() { @Override public Pair<Integer, VectorOrPref> map(Pair<Integer, Vector> input) { return Pair.of(input.first(), new VectorOrPref(input.second())); } @Override public float scaleFactor() { return est.getScaleFactor("S5").sizeFactor; } @Override public float scaleFactorByRecord() { return est.getScaleFactor("S5").recsFactor; } }, Writables.tableOf(Writables.ints(), VectorOrPref.vectorOrPrefs())); wrappedCooccurrence = profiler.profile("S5", pipeline, wrappedCooccurrence, ProfileConverter.int_vopv(), Writables.tableOf(Writables.ints(), VectorOrPref.vectorOrPrefs())); /* * S6 Splitting user vectors */ PTable<Integer, VectorOrPref> userVectorSplit = filteredUserVector .parallelDo(new DoFn<Pair<Long, Vector>, Pair<Integer, VectorOrPref>>() { @Override public void process(Pair<Long, Vector> input, Emitter<Pair<Integer, VectorOrPref>> emitter) { long userID = input.first(); Vector userVector = input.second(); Iterator<Vector.Element> it = userVector.iterateNonZero(); while (it.hasNext()) { Vector.Element e = it.next(); int itemIndex = e.index(); float preferenceValue = (float) e.get(); emitter.emit(Pair.of(itemIndex, new VectorOrPref(userID, preferenceValue))); } } @Override public float scaleFactor() { return est.getScaleFactor("S6").sizeFactor; } @Override public float scaleFactorByRecord() { return est.getScaleFactor("S6").recsFactor; } }, Writables.tableOf(Writables.ints(), VectorOrPref.vectorOrPrefs())); userVectorSplit = profiler.profile("S6", pipeline, userVectorSplit, ProfileConverter.int_vopp(), Writables.tableOf(Writables.ints(), VectorOrPref.vectorOrPrefs())); /* * S7 Combine VectorOrPrefs */ PTable<Integer, VectorAndPrefs> combinedVectorOrPref = wrappedCooccurrence.union(userVectorSplit) .groupByKey(est.getClusterSize()) .parallelDo(new DoFn<Pair<Integer, Iterable<VectorOrPref>>, Pair<Integer, VectorAndPrefs>>() { @Override public void process(Pair<Integer, Iterable<VectorOrPref>> input, Emitter<Pair<Integer, VectorAndPrefs>> emitter) { Vector vector = null; List<Long> userIDs = Lists.newArrayList(); List<Float> values = Lists.newArrayList(); for (VectorOrPref vop : input.second()) { if (vector == null) { vector = vop.getVector(); } long userID = vop.getUserID(); if (userID != Long.MIN_VALUE) { userIDs.add(vop.getUserID()); } float value = vop.getValue(); if (!Float.isNaN(value)) { values.add(vop.getValue()); } } emitter.emit(Pair.of(input.first(), new VectorAndPrefs(vector, userIDs, values))); } @Override public float scaleFactor() { return est.getScaleFactor("S7").sizeFactor; } @Override public float scaleFactorByRecord() { return est.getScaleFactor("S7").recsFactor; } }, Writables.tableOf(Writables.ints(), VectorAndPrefs.vectorAndPrefs())); combinedVectorOrPref = profiler.profile("S5+S6-S7", pipeline, combinedVectorOrPref, ProfileConverter.int_vap(), Writables.tableOf(Writables.ints(), VectorAndPrefs.vectorAndPrefs())); /* * S8 Computing partial recommendation vectors */ PTable<Long, Vector> partialMultiply = combinedVectorOrPref .parallelDo(new DoFn<Pair<Integer, VectorAndPrefs>, Pair<Long, Vector>>() { @Override public void process(Pair<Integer, VectorAndPrefs> input, Emitter<Pair<Long, Vector>> emitter) { Vector cooccurrenceColumn = input.second().getVector(); List<Long> userIDs = input.second().getUserIDs(); List<Float> prefValues = input.second().getValues(); for (int i = 0; i < userIDs.size(); i++) { long userID = userIDs.get(i); if (userID != Long.MIN_VALUE) { float prefValue = prefValues.get(i); Vector partialProduct = cooccurrenceColumn.times(prefValue); emitter.emit(Pair.of(userID, partialProduct)); } } } @Override public float scaleFactor() { return est.getScaleFactor("S8").sizeFactor; } @Override public float scaleFactorByRecord() { return est.getScaleFactor("S8").recsFactor; } }, Writables.tableOf(Writables.longs(), Writables.vectors())).groupByKey(est.getClusterSize()) .combineValues(new CombineFn<Long, Vector>() { @Override public void process(Pair<Long, Iterable<Vector>> input, Emitter<Pair<Long, Vector>> emitter) { Vector partial = null; for (Vector vector : input.second()) { partial = partial == null ? vector : partial.plus(vector); } emitter.emit(Pair.of(input.first(), partial)); } @Override public float scaleFactor() { return est.getScaleFactor("combine").sizeFactor; } @Override public float scaleFactorByRecord() { return est.getScaleFactor("combine").recsFactor; } }); partialMultiply = profiler.profile("S8-combine", pipeline, partialMultiply, ProfileConverter.long_vector(), Writables.tableOf(Writables.longs(), Writables.vectors())); /* * S9 Producing recommendations from vectors */ PTable<Long, RecommendedItems> recommendedItems = partialMultiply .parallelDo(new DoFn<Pair<Long, Vector>, Pair<Long, RecommendedItems>>() { @Override public void process(Pair<Long, Vector> input, Emitter<Pair<Long, RecommendedItems>> emitter) { Queue<RecommendedItem> topItems = new PriorityQueue<RecommendedItem>(11, Collections.reverseOrder(BY_PREFERENCE_VALUE)); Iterator<Vector.Element> recommendationVectorIterator = input.second().iterateNonZero(); while (recommendationVectorIterator.hasNext()) { Vector.Element element = recommendationVectorIterator.next(); int index = element.index(); float value = (float) element.get(); if (topItems.size() < top) { topItems.add(new GenericRecommendedItem(index, value)); } else if (value > topItems.peek().getValue()) { topItems.add(new GenericRecommendedItem(index, value)); topItems.poll(); } } List<RecommendedItem> recommendations = new ArrayList<RecommendedItem>(topItems.size()); recommendations.addAll(topItems); Collections.sort(recommendations, BY_PREFERENCE_VALUE); emitter.emit(Pair.of(input.first(), new RecommendedItems(recommendations))); } @Override public float scaleFactor() { return est.getScaleFactor("S9").sizeFactor; } @Override public float scaleFactorByRecord() { return est.getScaleFactor("S9").recsFactor; } }, Writables.tableOf(Writables.longs(), RecommendedItems.recommendedItems())); recommendedItems = profiler.profile("S9", pipeline, recommendedItems, ProfileConverter.long_ri(), Writables.tableOf(Writables.longs(), RecommendedItems.recommendedItems())); /* * Profiling */ if (profiler.isProfiling()) { profiler.writeResultToFile(profileFilePath); profiler.cleanup(pipeline.getConfiguration()); return 0; } /* * asText */ pipeline.writeTextFile(recommendedItems, args[1]); PipelineResult result = pipeline.done(); return result.succeeded() ? 0 : 1; } public void printUsage() { System.out.println("profiling: profiling=[profile filename] to enable profiling, otherwise disable"); System.out.println("estimation: estimation=[the profile file generated by profiling]"); System.out.println("clustersize: clustersize=[the number of node in your cluster]"); } public static void main(String[] args) throws Exception { PropertyConfigurator.configure("log4j.properties"); int result = ToolRunner.run(new Configuration(), new Recommender(), args); System.exit(result); } }