/*
* Copyright 2009-2013 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.Outlink;
import bixo.datum.ParsedDatum;
import bixo.datum.UrlDatum;
import bixo.urls.BaseUrlNormalizer;
import bixo.urls.BaseUrlValidator;
import cascading.flow.FlowProcess;
import cascading.operation.BaseOperation;
import cascading.operation.Function;
import cascading.operation.FunctionCall;
import cascading.operation.OperationCall;
import cascading.tuple.TupleEntryCollector;
@SuppressWarnings({"serial", "rawtypes"})
public class CreateUrlDatumFromOutlinksFunction extends BaseOperation<NullContext> implements Function<NullContext> {
private static final Logger LOGGER = LoggerFactory.getLogger(CreateUrlDatumFromOutlinksFunction.class);
private BaseUrlNormalizer _normalizer;
private BaseUrlValidator _validator;
public CreateUrlDatumFromOutlinksFunction(BaseUrlNormalizer normalizer, BaseUrlValidator urlValidator) {
super(UrlDatum.FIELDS);
_normalizer = normalizer;
_validator = urlValidator;
}
@Override
public void prepare(FlowProcess process, OperationCall<NullContext> operationCall) {
LOGGER.info("Starting creation of outlink URLs");
}
@Override
public void cleanup(FlowProcess process, OperationCall<NullContext> operationCall) {
LOGGER.info("Ending creation of outlink URLs");
}
@Override
public void operate(FlowProcess process, FunctionCall<NullContext> funcCall) {
ParsedDatum datum = new ParsedDatum(funcCall.getArguments());
Outlink outlinks[] = datum.getOutlinks();
// Bump the crawl depth value only on a successful parse
int crawlDepth = (Integer) datum.getPayloadValue(CrawlDbDatum.CRAWL_DEPTH);
datum.setPayloadValue(CrawlDbDatum.CRAWL_DEPTH, crawlDepth + 1);
TupleEntryCollector collector = funcCall.getOutputCollector();
for (Outlink outlink : outlinks) {
String url = outlink.getToUrl();
url = url.replaceAll("[\n\r]", "");
url = _normalizer.normalize(url);
if (_validator.isValid(url)) {
UrlDatum urlDatum = new UrlDatum(url);
urlDatum.setPayload(datum.getPayload());
collector.add(urlDatum.getTuple());
}
}
}
}