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 * 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
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package org.apache.nutch.crawl;

import java.text.SimpleDateFormat;
import java.util.Collection;
import java.util.HashSet;
import java.util.Map;

import org.apache.avro.util.Utf8;
import org.apache.gora.filter.FilterOp;
import org.apache.gora.filter.MapFieldValueFilter;
import org.apache.gora.filter.SingleFieldValueFilter;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.apache.nutch.crawl.UrlWithScore.UrlOnlyPartitioner;
import org.apache.nutch.crawl.UrlWithScore.UrlScoreComparator;
import org.apache.nutch.crawl.UrlWithScore.UrlScoreComparator.UrlOnlyComparator;
import org.apache.nutch.metadata.Nutch;
import org.apache.nutch.scoring.ScoringFilters;
import org.apache.nutch.storage.Mark;
import org.apache.nutch.storage.StorageUtils;
import org.apache.nutch.storage.WebPage;
import org.apache.nutch.util.NutchConfiguration;
import org.apache.nutch.util.NutchJob;
import org.apache.nutch.util.NutchTool;
import org.apache.nutch.util.TimingUtil;
import org.apache.nutch.util.ToolUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class DbUpdaterJob extends NutchTool implements Tool {

  public static final Logger LOG = LoggerFactory.getLogger(DbUpdaterJob.class);

  private static final Collection<WebPage.Field> FIELDS = new HashSet<WebPage.Field>();

  static {
    FIELDS.add(WebPage.Field.OUTLINKS);
    FIELDS.add(WebPage.Field.INLINKS);
    FIELDS.add(WebPage.Field.STATUS);
    FIELDS.add(WebPage.Field.PREV_SIGNATURE);
    FIELDS.add(WebPage.Field.SIGNATURE);
    FIELDS.add(WebPage.Field.MARKERS);
    FIELDS.add(WebPage.Field.METADATA);
    FIELDS.add(WebPage.Field.RETRIES_SINCE_FETCH);
    FIELDS.add(WebPage.Field.FETCH_TIME);
    FIELDS.add(WebPage.Field.MODIFIED_TIME);
    FIELDS.add(WebPage.Field.FETCH_INTERVAL);
    FIELDS.add(WebPage.Field.PREV_FETCH_TIME);
    FIELDS.add(WebPage.Field.PREV_MODIFIED_TIME);
    FIELDS.add(WebPage.Field.HEADERS);
  }

  public static final Utf8 DISTANCE = new Utf8("dist");

  public DbUpdaterJob() {

  }

  public DbUpdaterJob(Configuration conf) {
    setConf(conf);
  }

  public Map<String, Object> run(Map<String, Object> args) throws Exception {
    String crawlId = (String) args.get(Nutch.ARG_CRAWL);
    String batchId = (String) args.get(Nutch.ARG_BATCH);
    numJobs = 1;
    currentJobNum = 0;

    if (batchId == null) {
      batchId = Nutch.ALL_BATCH_ID_STR;
    }
    getConf().set(Nutch.BATCH_NAME_KEY, batchId);
    // job.setBoolean(ALL, updateAll);
    ScoringFilters scoringFilters = new ScoringFilters(getConf());
    HashSet<WebPage.Field> fields = new HashSet<WebPage.Field>(FIELDS);
    fields.addAll(scoringFilters.getFields());

    currentJob = new NutchJob(getConf(), "update-table");
    if (crawlId != null) {
      currentJob.getConfiguration().set(Nutch.CRAWL_ID_KEY, crawlId);
    }

    // Partition by {url}, sort by {url,score} and group by {url}.
    // This ensures that the inlinks are sorted by score when they enter
    // the reducer.

    currentJob.setPartitionerClass(UrlOnlyPartitioner.class);
    currentJob.setSortComparatorClass(UrlScoreComparator.class);
    currentJob.setGroupingComparatorClass(UrlOnlyComparator.class);

    MapFieldValueFilter<String, WebPage> batchIdFilter = getBatchIdFilter(batchId);
    StorageUtils.initMapperJob(currentJob, fields, UrlWithScore.class,
        NutchWritable.class, DbUpdateMapper.class, batchIdFilter);
    StorageUtils.initReducerJob(currentJob, DbUpdateReducer.class);
    currentJob.waitForCompletion(true);
    ToolUtil.recordJobStatus(null, currentJob, results);
    return results;
  }

  private MapFieldValueFilter<String, WebPage> getBatchIdFilter(String batchId) {
    if (batchId.equals(Nutch.ALL_CRAWL_ID.toString())) {
      return null;
    }
    MapFieldValueFilter<String, WebPage> filter = new MapFieldValueFilter<String, WebPage>();
    filter.setFieldName(WebPage.Field.MARKERS.toString());
    filter.setFilterOp(FilterOp.EQUALS);
    filter.setFilterIfMissing(true);
    filter.setMapKey(Mark.GENERATE_MARK.getName());
    filter.getOperands().add(new Utf8(batchId));
    return filter;
  }

  private int updateTable(String crawlId, String batchId) throws Exception {

    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    long start = System.currentTimeMillis();
    LOG.info("DbUpdaterJob: starting at " + sdf.format(start));

    if (batchId.equals(Nutch.ALL_BATCH_ID_STR)) {
      LOG.info("DbUpdaterJob: updatinging all");
    } else {
      LOG.info("DbUpdaterJob: batchId: " + batchId);
    }
    run(ToolUtil.toArgMap(Nutch.ARG_CRAWL, crawlId, Nutch.ARG_BATCH, batchId));

    long finish = System.currentTimeMillis();
    LOG.info("DbUpdaterJob: finished at " + sdf.format(finish)
        + ", time elapsed: " + TimingUtil.elapsedTime(start, finish));
    return 0;
  }

  public int run(String[] args) throws Exception {
    String crawlId = null;
    String batchId;

    String usage = "Usage: DbUpdaterJob (<batchId> | -all) [-crawlId <id>] "
        + "    <batchId>     - crawl identifier returned by Generator, or -all for all \n \t \t    generated batchId-s\n"
        + "    -crawlId <id> - the id to prefix the schemas to operate on, \n \t \t    (default: storage.crawl.id)\n";

    if (args.length == 0) {
      System.err.println(usage);
      return -1;
    }

    batchId = args[0];
    if (!batchId.equals("-all") && batchId.startsWith("-")) {
      System.err.println(usage);
      return -1;
    }

    for (int i = 1; i < args.length; i++) {
      if ("-crawlId".equals(args[i])) {
        getConf().set(Nutch.CRAWL_ID_KEY, args[++i]);
      } else {
        throw new IllegalArgumentException("arg " + args[i] + " not recognized");
      }
    }
    return updateTable(crawlId, batchId);
  }

  public static void main(String[] args) throws Exception {
    int res = ToolRunner.run(NutchConfiguration.create(), new DbUpdaterJob(),
        args);
    System.exit(res);
  }

}
