| /* |
| * 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.nutch.scoring.opic; |
| |
| import java.lang.invoke.MethodHandles; |
| import java.net.MalformedURLException; |
| import java.net.URL; |
| import java.util.Collection; |
| import java.util.List; |
| import java.util.Map.Entry; |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.io.Text; |
| import org.apache.nutch.crawl.CrawlDatum; |
| import org.apache.nutch.crawl.Inlinks; |
| import org.apache.nutch.indexer.NutchDocument; |
| import org.apache.nutch.metadata.Nutch; |
| import org.apache.nutch.parse.Parse; |
| import org.apache.nutch.parse.ParseData; |
| import org.apache.nutch.protocol.Content; |
| import org.apache.nutch.scoring.ScoringFilter; |
| import org.apache.nutch.scoring.ScoringFilterException; |
| |
| /** |
| * This plugin implements a variant of an Online Page Importance Computation |
| * (OPIC) score, described in this <a href="https://www2003.org/cdrom/papers/refereed/p007/p7-abiteboul.html">paper</a>: |
| * Abiteboul, Serge and Preda, Mihai and Cobena, Gregory (2003), Adaptive |
| * On-Line Page Importance Computation. |
| * |
| * @author Andrzej Bialecki |
| */ |
| public class OPICScoringFilter implements ScoringFilter { |
| |
| private static final Logger LOG = LoggerFactory |
| .getLogger(MethodHandles.lookup().lookupClass()); |
| |
| private Configuration conf; |
| private float scoreInjected; |
| private float scorePower; |
| private float internalScoreFactor; |
| private float externalScoreFactor; |
| private boolean countFiltered; |
| |
| @Override |
| public Configuration getConf() { |
| return conf; |
| } |
| |
| @Override |
| public void setConf(Configuration conf) { |
| this.conf = conf; |
| scorePower = conf.getFloat("indexer.score.power", 0.5f); |
| internalScoreFactor = conf.getFloat("db.score.link.internal", 1.0f); |
| externalScoreFactor = conf.getFloat("db.score.link.external", 1.0f); |
| countFiltered = conf.getBoolean("db.score.count.filtered", false); |
| } |
| |
| @Override |
| public void injectedScore(Text url, CrawlDatum datum) |
| throws ScoringFilterException { |
| } |
| |
| /** |
| * Set to 0.0f (unknown value) - inlink contributions will bring it to a |
| * correct level. Newly discovered pages have at least one inlink. |
| */ |
| @Override |
| public void initialScore(Text url, CrawlDatum datum) |
| throws ScoringFilterException { |
| datum.setScore(0.0f); |
| } |
| |
| /** Use {@link CrawlDatum#getScore()}. */ |
| @Override |
| public float generatorSortValue(Text url, CrawlDatum datum, float initSort) |
| throws ScoringFilterException { |
| return datum.getScore() * initSort; |
| } |
| |
| /** Increase the score by a sum of inlinked scores. */ |
| @Override |
| public void updateDbScore(Text url, CrawlDatum old, CrawlDatum datum, |
| List<CrawlDatum> inlinked) throws ScoringFilterException { |
| float adjust = 0.0f; |
| for (int i = 0; i < inlinked.size(); i++) { |
| CrawlDatum linked = inlinked.get(i); |
| adjust += linked.getScore(); |
| } |
| if (old == null) |
| old = datum; |
| datum.setScore(old.getScore() + adjust); |
| } |
| |
| /** Store a float value of CrawlDatum.getScore() under Fetcher.SCORE_KEY. */ |
| @Override |
| public void passScoreBeforeParsing(Text url, CrawlDatum datum, Content content) { |
| content.getMetadata().set(Nutch.SCORE_KEY, "" + datum.getScore()); |
| } |
| |
| /** Copy the value from Content metadata under Fetcher.SCORE_KEY to parseData. */ |
| @Override |
| public void passScoreAfterParsing(Text url, Content content, Parse parse) { |
| parse.getData().getContentMeta() |
| .set(Nutch.SCORE_KEY, content.getMetadata().get(Nutch.SCORE_KEY)); |
| } |
| |
| /** |
| * Get a float value from Fetcher.SCORE_KEY, divide it by the number of |
| * outlinks and apply. |
| */ |
| @Override |
| public CrawlDatum distributeScoreToOutlinks(Text fromUrl, |
| ParseData parseData, Collection<Entry<Text, CrawlDatum>> targets, |
| CrawlDatum adjust, int allCount) throws ScoringFilterException { |
| float score = scoreInjected; |
| String scoreString = parseData.getContentMeta().get(Nutch.SCORE_KEY); |
| if (scoreString != null) { |
| try { |
| score = Float.parseFloat(scoreString); |
| } catch (Exception e) { |
| LOG.error("Error: ", e); |
| } |
| } |
| int validCount = targets.size(); |
| if (countFiltered) { |
| score /= allCount; |
| } else { |
| if (validCount == 0) { |
| // no outlinks to distribute score, so just return adjust |
| return adjust; |
| } |
| score /= validCount; |
| } |
| // internal and external score factor |
| float internalScore = score * internalScoreFactor; |
| float externalScore = score * externalScoreFactor; |
| for (Entry<Text, CrawlDatum> target : targets) { |
| try { |
| String toHost = new URL(target.getKey().toString()).getHost(); |
| String fromHost = new URL(fromUrl.toString()).getHost(); |
| if (toHost.equalsIgnoreCase(fromHost)) { |
| target.getValue().setScore(internalScore); |
| } else { |
| target.getValue().setScore(externalScore); |
| } |
| } catch (MalformedURLException e) { |
| LOG.error("Error: ", e); |
| target.getValue().setScore(externalScore); |
| } |
| } |
| // XXX (ab) no adjustment? I think this is contrary to the algorithm descr. |
| // XXX in the paper, where page "loses" its score if it's distributed to |
| // XXX linked pages... |
| return adjust; |
| } |
| |
| /** Dampen the boost value by scorePower. */ |
| @Override |
| public float indexerScore(Text url, NutchDocument doc, CrawlDatum dbDatum, |
| CrawlDatum fetchDatum, Parse parse, Inlinks inlinks, float initScore) |
| throws ScoringFilterException { |
| if (dbDatum == null) { |
| return initScore; |
| } |
| return (float) Math.pow(dbDatum.getScore(), scorePower) * initScore; |
| } |
| } |