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This project contains some of the configurable modules used within the Heritrix application to crawl the web. The modules in this project can be used in applications other than Heritrix, however.
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/*
 *  This file is part of the Heritrix web crawler (crawler.archive.org).
 *
 *  Licensed to the Internet Archive (IA) by one or more individual
 *  contributors.
 *
 *  The IA 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.archive.modules.deciderules;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ForkJoinPool;
import java.util.concurrent.FutureTask;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.regex.Pattern;

import org.archive.modules.CrawlURI;
import org.archive.util.InterruptibleCharSequence;

/**
 * Rule applies configured decision to any CrawlURIs whose String URI
 * matches the supplied regexs.
 * 
 * The list of regular expressions can be considered logically AND or OR.
 *
 * @author Kristinn Sigurdsson
 *
 * @see MatchesRegexDecideRule
 */
public class MatchesListRegexDecideRule extends PredicatedDecideRule {
    private static final long serialVersionUID = 3L;
    private static final Logger logger =
            Logger.getLogger(MatchesListRegexDecideRule.class.getName());

    /**
     * The timeout for regular expression matching, in seconds. If set to 0 or negative then no timeout is specified and
     * there is no upper limit to how long the matching may take. See the corresponding test class MatchesListRegexDecideRuleTest
     * for a pathological example.
     */
    {
        setTimeoutPerRegexSeconds(0L);
    }
    public long getTimeoutPerRegexSeconds() { return (Long) kp.get("timeout");}
    public void setTimeoutPerRegexSeconds(long timeoutPerRegexSeconds) { kp.put("timeout", timeoutPerRegexSeconds);}


    /**
     * The list of regular expressions to evalute against the URI.
     */
    {
        setRegexList(new ArrayList());
    }
    @SuppressWarnings("unchecked")
    public List getRegexList() {
        return (List) kp.get("regexList");
    }
    public void setRegexList(List patterns) {
        kp.put("regexList", patterns);
    }

    /**
     * True if the list of regular expression should be considered as logically
     * AND when matching. False if the list of regular expressions should be
     * considered as logically OR when matching.
     */
    {
        setListLogicalOr(true);
    }
    public boolean getListLogicalOr() {
        return (Boolean) kp.get("listLogicalOr");
    }
    public void setListLogicalOr(boolean listLogicalOr) {
        kp.put("listLogicalOr",listLogicalOr);
    }

    /**
     * Usual constructor. 
     */
    public MatchesListRegexDecideRule() {
    }

    /**
     * Evaluate whether given object's string version
     * matches configured regexes
     */
    @Override
    protected boolean evaluate(CrawlURI uri) {
        List regexes = getRegexList();
        if(regexes.size()==0){
            return false;
        }

        String str = uri.toString();
        boolean listLogicOR = getListLogicalOr();

        for (Pattern p: regexes) {
            boolean matches = false;
            if (getTimeoutPerRegexSeconds() <= 0) {
                matches = p.matcher(str).matches();
            } else {
                InterruptibleCharSequence interruptible = new InterruptibleCharSequence(str);
                FutureTask matchesFuture = new FutureTask<>(() -> p.matcher(interruptible).matches());
                ForkJoinPool.commonPool().submit(matchesFuture);
                try {
                    matchesFuture.get(getTimeoutPerRegexSeconds(), TimeUnit.SECONDS);
                } catch (TimeoutException e) {
                    matchesFuture.cancel(true);
                    logger.warning("Timed out after " + getTimeoutPerRegexSeconds() + " seconds waiting for '" + p + "' to match.");
                } catch (InterruptedException e) {
                    matchesFuture.cancel(true);
                    logger.warning("InterruptedException while waiting for '" + p + "' to match.");
                } catch (ExecutionException e) {
                    matchesFuture.cancel(true);
                    logger.warning("ExecutionException while waiting for '" + p + "' to match: " + e.getMessage());
                }
            }

            if (logger.isLoggable(Level.FINER)) {
                logger.finer("Tested '" + str + "' match with regex '" +
                        p.pattern() + " and result was " + matches);
            }

            if(matches){
                if(listLogicOR){
                    // OR based and we just got a match, done!
                    logger.fine("Matched: " + str);
                    return true;
                }
            } else {
                if(listLogicOR == false){
                    // AND based and we just found a non-match, done!
                    return false;
                }
            }
        }

        if (listLogicOR) {
            return false;
        } else {
            return true;
        }
    }

}