text: /*
   * Copyright 2009-2015 Scale Unlimited
   *
   * Licensed 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 bixo.examples.crawl;
  
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import com.scaleunlimited.cascading.NullContext;
  
  import bixo.datum.StatusDatum;
  import bixo.datum.UrlDatum;
  import bixo.datum.UrlStatus;
  import cascading.flow.FlowProcess;
  import cascading.operation.BaseOperation;
  import cascading.operation.Function;
  import cascading.operation.FunctionCall;
  import cascading.operation.OperationCall;
  
  
  @SuppressWarnings({"serial", "rawtypes"})
  public class CreateUrlDatumFromStatusFunction extends BaseOperation<NullContext> implements Function<NullContext> {
      private static final Logger LOGGER = LoggerFactory.getLogger(CreateUrlDatumFromStatusFunction.class);
  
      private int _numCreated;
  
      public CreateUrlDatumFromStatusFunction() {
          super(UrlDatum.FIELDS);
      }
  
      @Override
      public void prepare(FlowProcess process, OperationCall<NullContext> operationCall) {
          LOGGER.info("Starting creation of URLs from status");
          _numCreated = 0;
      }
  
      @Override
      public void cleanup(FlowProcess process, OperationCall<NullContext> operationCall) {
          LOGGER.info("Ending creation of URLs from status");
          LOGGER.info(String.format("Created %d URLs", _numCreated));
      }
  
      @Override
      public void operate(FlowProcess process, FunctionCall<NullContext> funcCall) {
          StatusDatum datum = new StatusDatum(funcCall.getArguments());
          UrlStatus status = datum.getStatus();
          String url = datum.getUrl();
          long statusTime = datum.getStatusTime();
          
          long fetchTime = statusTime; // Not exactly true... since in some cases we
                      // may not have fetched the url. But because we are sharing this logic
                      // between the JDBCCrawlTool and the DemoCrawlTool, we use the value
                      // of the fetchTime while selecting the "latest" url. Newly added urls
                      // have a fetchTime of 0, so in order to preserve say a SKIPPED status
                      // we set the fetch time here.
  
          _numCreated += 1;
  
          UrlDatum urlDatum = new UrlDatum(url);
          urlDatum.setPayloadValue(CrawlDbDatum.LAST_FETCHED_FIELD, fetchTime);
          urlDatum.setPayloadValue(CrawlDbDatum.LAST_UPDATED_FIELD, statusTime);
          urlDatum.setPayloadValue(CrawlDbDatum.LAST_STATUS_FIELD, status.name());
          // Don't change the crawl depth here - we do that only in the case of a
          // successful parse
          urlDatum.setPayloadValue(CrawlDbDatum.CRAWL_DEPTH, datum.getPayloadValue(CrawlDbDatum.CRAWL_DEPTH));
  
          funcCall.getOutputCollector().add(urlDatum.getTuple());
      }
  }
  