//plasmaCrawlRobotsTxt.java
//-------------------------------------
//part of YACY
//(C) by Michael Peter Christen; mc@yacy.net
//first published on http://www.anomic.de
//Frankfurt, Germany, 2004
//
//This file is contributed by Martin Thelian
// [MC] moved some methods from robotsParser file that had been created by Alexander Schier to this class
//last major change: $LastChangedDate$ by $LastChangedBy$
//Revision: $LastChangedRevision$
//
//This program is free software; you can redistribute it and/or modify
//it under the terms of the GNU General Public License as published by
//the Free Software Foundation; either version 2 of the License, or
//(at your option) any later version.
//
//This program is distributed in the hope that it will be useful,
//but WITHOUT ANY WARRANTY; without even the implied warranty of
//MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
//GNU General Public License for more details.
//
//You should have received a copy of the GNU General Public License
//along with this program; if not, write to the Free Software
//Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
package de.anomic.crawler;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import de.anomic.http.HttpClient;
import de.anomic.http.JakartaCommonsHttpClient;
import de.anomic.http.JakartaCommonsHttpResponse;
import de.anomic.http.httpRequestHeader;
import de.anomic.kelondro.kelondroBLOB;
import de.anomic.kelondro.kelondroBLOBHeap;
import de.anomic.kelondro.kelondroBLOBTree;
import de.anomic.kelondro.kelondroException;
import de.anomic.kelondro.kelondroMap;
import de.anomic.kelondro.kelondroNaturalOrder;
import de.anomic.server.serverByteBuffer;
import de.anomic.server.serverFileUtils;
import de.anomic.server.logging.serverLog;
import de.anomic.yacy.yacyURL;
public class RobotsTxt {
public static final String ROBOTS_DB_PATH_SEPARATOR = ";";
private static final serverLog log = new serverLog("ROBOTS");
kelondroMap robotsTable;
private final File robotsTableFile;
private final ConcurrentHashMap<String, Long> syncObjects;
//private static final HashSet<String> loadedRobots = new HashSet<String>(); // only for debugging
public RobotsTxt(final File robotsTableFile) {
this.robotsTableFile = robotsTableFile;
robotsTableFile.getParentFile().mkdirs();
kelondroBLOB blob = null;
if (robotsTableFile.getName().endsWith(".heap")) {
try {
blob = new kelondroBLOBHeap(robotsTableFile, 64, kelondroNaturalOrder.naturalOrder);
} catch (final IOException e) {
e.printStackTrace();
}
} else {
blob = new kelondroBLOBTree(robotsTableFile, true, true, 256, 512, '_', kelondroNaturalOrder.naturalOrder, false, false, true);
}
robotsTable = new kelondroMap(blob, 100);
syncObjects = new ConcurrentHashMap<String, Long>();
}
private void resetDatabase() {
// deletes the robots.txt database and creates a new one
if (robotsTable != null) robotsTable.close();
if (!(robotsTableFile.delete())) throw new RuntimeException("cannot delete robots.txt database");
robotsTableFile.getParentFile().mkdirs();
robotsTable = new kelondroMap(new kelondroBLOBTree(robotsTableFile, true, true, 256, 512, '_', kelondroNaturalOrder.naturalOrder, false, false, true), 100);
}
public void clear() throws IOException {
this.robotsTable.clear();
}
public void close() {
this.robotsTable.close();
}
public int size() {
return this.robotsTable.size();
}
private Entry getEntry(final String urlHostPort, final boolean fetchOnlineIfNotAvailableOrNotFresh) {
// this method will always return a non-null value
Entry robotsTxt4Host = null;
try {
final Map<String, String> record = this.robotsTable.get(urlHostPort);
if (record != null) robotsTxt4Host = new Entry(urlHostPort, record);
} catch (final kelondroException e) {
resetDatabase();
} catch (final IOException e) {
resetDatabase();
}
if (fetchOnlineIfNotAvailableOrNotFresh && (
robotsTxt4Host == null ||
robotsTxt4Host.getLoadedDate() == null ||
System.currentTimeMillis() - robotsTxt4Host.getLoadedDate().getTime() > 7*24*60*60*1000
)) {
// make or get a synchronization object
Long syncObj = this.syncObjects.get(urlHostPort);
if (syncObj == null) {
syncObj = new Long(System.currentTimeMillis());
this.syncObjects.put(urlHostPort, syncObj);
}
// we can now synchronize for each host separately
synchronized (syncObj) {
// if we have not found any data or the data is older than 7 days, we need to load it from the remote server
// check the robots table again for all threads that come here because they waited for another one
// to complete a download
try {
final Map<String, String> record = this.robotsTable.get(urlHostPort);
if (record != null) robotsTxt4Host = new Entry(urlHostPort, record);
} catch (final kelondroException e) {
resetDatabase();
} catch (final IOException e) {
resetDatabase();
}
if (robotsTxt4Host != null &&
robotsTxt4Host.getLoadedDate() != null &&
System.currentTimeMillis() - robotsTxt4Host.getLoadedDate().getTime() <= 7*24*60*60*1000) {
return robotsTxt4Host;
}
// generating the proper url to download the robots txt
yacyURL robotsURL = null;
try {
robotsURL = new yacyURL("http://" + urlHostPort + "/robots.txt", null);
} catch (final MalformedURLException e) {
log.logSevere("Unable to generate robots.txt URL for host:port '" + urlHostPort + "'.");
robotsURL = null;
}
Object[] result = null;
if (robotsURL != null) {
if (log.isFine()) log.logFine("Trying to download the robots.txt file from URL '" + robotsURL + "'.");
try {
result = downloadRobotsTxt(robotsURL, 5, robotsTxt4Host);
} catch (final Exception e) {
result = null;
}
}
/*
assert !loadedRobots.contains(robotsURL.toNormalform(false, false)) :
"robots-url=" + robotsURL.toString() +
", robots=" + ((result == null || result[DOWNLOAD_ROBOTS_TXT] == null) ? "NULL" : new String((byte[]) result[DOWNLOAD_ROBOTS_TXT])) +
", robotsTxt4Host=" + ((robotsTxt4Host == null) ? "NULL" : robotsTxt4Host.getLoadedDate().toString());
loadedRobots.add(robotsURL.toNormalform(false, false));
*/
if (result == null) {
// no robots.txt available, make an entry to prevent that the robots loading is done twice
if (robotsTxt4Host == null) {
// generate artificial entry
robotsTxt4Host = new Entry(
urlHostPort,
new ArrayList<String>(),
new ArrayList<String>(),
new Date(),
new Date(),
null,
null,
Integer.valueOf(0));
} else {
robotsTxt4Host.setLoadedDate(new Date());
}
// store the data into the robots DB
addEntry(robotsTxt4Host);
} else {
final robotsParser parserResult = new robotsParser((byte[]) result[DOWNLOAD_ROBOTS_TXT]);
ArrayList<String> denyPath = parserResult.denyList();
if (((Boolean) result[DOWNLOAD_ACCESS_RESTRICTED]).booleanValue()) {
denyPath = new ArrayList<String>();
denyPath.add("/");
}
// store the data into the robots DB
robotsTxt4Host = addEntry(
urlHostPort,
parserResult.allowList(),
denyPath,
new Date(),
(Date) result[DOWNLOAD_MODDATE],
(String) result[DOWNLOAD_ETAG],
parserResult.sitemap(),
parserResult.crawlDelayMillis());
}
}
}
return robotsTxt4Host;
}
public long crawlDelayMillis(final yacyURL theURL) {
final String urlHostPort = getHostPort(theURL);
final RobotsTxt.Entry robotsEntry = getEntry(urlHostPort, true);
return robotsEntry.getCrawlDelayMillis();
}
private Entry addEntry(
final String hostName,
final ArrayList<String> allowPathList,
final ArrayList<String> denyPathList,
final Date loadedDate,
final Date modDate,
final String eTag,
final String sitemap,
final long crawlDelayMillis
) {
final Entry entry = new Entry(
hostName, allowPathList, denyPathList, loadedDate, modDate,
eTag, sitemap, crawlDelayMillis);
addEntry(entry);
return entry;
}
private String addEntry(final Entry entry) {
// writes a new page and returns key
try {
this.robotsTable.put(entry.hostName, entry.mem);
return entry.hostName;
} catch (final IOException e) {
return null;
}
}
public static class Entry {
public static final String ALLOW_PATH_LIST = "allow";
public static final String DISALLOW_PATH_LIST = "disallow";
public static final String LOADED_DATE = "date";
public static final String MOD_DATE = "modDate";
public static final String ETAG = "etag";
public static final String SITEMAP = "sitemap";
public static final String CRAWL_DELAY = "crawlDelay";
public static final String CRAWL_DELAY_MILLIS = "crawlDelayMillis";
// this is a simple record structure that holds all properties of a single crawl start
Map<String, String> mem;
private LinkedList<String> allowPathList, denyPathList;
String hostName;
public Entry(final String hostName, final Map<String, String> mem) {
this.hostName = hostName.toLowerCase();
this.mem = mem;
if (this.mem.containsKey(DISALLOW_PATH_LIST)) {
this.denyPathList = new LinkedList<String>();
final String csPl = this.mem.get(DISALLOW_PATH_LIST);
if (csPl.length() > 0){
final String[] pathArray = csPl.split(ROBOTS_DB_PATH_SEPARATOR);
if ((pathArray != null)&&(pathArray.length > 0)) {
this.denyPathList.addAll(Arrays.asList(pathArray));
}
}
} else {
this.denyPathList = new LinkedList<String>();
}
if (this.mem.containsKey(ALLOW_PATH_LIST)) {
this.allowPathList = new LinkedList<String>();
final String csPl = this.mem.get(ALLOW_PATH_LIST);
if (csPl.length() > 0){
final String[] pathArray = csPl.split(ROBOTS_DB_PATH_SEPARATOR);
if ((pathArray != null)&&(pathArray.length > 0)) {
this.allowPathList.addAll(Arrays.asList(pathArray));
}
}
} else {
this.allowPathList = new LinkedList<String>();
}
}
public Entry(
final String hostName,
final ArrayList<String> allowPathList,
final ArrayList<String> disallowPathList,
final Date loadedDate,
final Date modDate,
final String eTag,
final String sitemap,
final long crawlDelayMillis
) {
if ((hostName == null) || (hostName.length() == 0)) throw new IllegalArgumentException("The hostname is missing");
this.hostName = hostName.trim().toLowerCase();
this.allowPathList = new LinkedList<String>();
this.denyPathList = new LinkedList<String>();
this.mem = new HashMap<String, String>(5);
if (loadedDate != null) this.mem.put(LOADED_DATE,Long.toString(loadedDate.getTime()));
if (modDate != null) this.mem.put(MOD_DATE,Long.toString(modDate.getTime()));
if (eTag != null) this.mem.put(ETAG,eTag);
if (sitemap != null) this.mem.put(SITEMAP,sitemap);
if (crawlDelayMillis > 0) this.mem.put(CRAWL_DELAY_MILLIS, Long.toString(crawlDelayMillis));
if ((allowPathList != null)&&(allowPathList.size()>0)) {
this.allowPathList.addAll(allowPathList);
final StringBuffer pathListStr = new StringBuffer();
for (int i=0; i<allowPathList.size();i++) {
pathListStr.append(allowPathList.get(i))
.append(ROBOTS_DB_PATH_SEPARATOR);
}
this.mem.put(ALLOW_PATH_LIST,pathListStr.substring(0,pathListStr.length()-1));
}
if ((disallowPathList != null)&&(disallowPathList.size()>0)) {
this.denyPathList.addAll(disallowPathList);
final StringBuffer pathListStr = new StringBuffer();
for (int i=0; i<disallowPathList.size();i++) {
pathListStr.append(disallowPathList.get(i))
.append(ROBOTS_DB_PATH_SEPARATOR);
}
this.mem.put(DISALLOW_PATH_LIST,pathListStr.substring(0,pathListStr.length()-1));
}
}
public String toString() {
final StringBuffer str = new StringBuffer();
str.append((this.hostName==null)?"null":this.hostName)
.append(": ");
if (this.mem != null) {
str.append(this.mem.toString());
}
return str.toString();
}
public String getSitemap() {
return this.mem.containsKey(SITEMAP)? (String)this.mem.get(SITEMAP): null;
}
public Date getLoadedDate() {
if (this.mem.containsKey(LOADED_DATE)) {
return new Date(Long.valueOf(this.mem.get(LOADED_DATE)).longValue());
}
return null;
}
public void setLoadedDate(final Date newLoadedDate) {
if (newLoadedDate != null) {
this.mem.put(LOADED_DATE,Long.toString(newLoadedDate.getTime()));
}
}
public Date getModDate() {
if (this.mem.containsKey(MOD_DATE)) {
return new Date(Long.valueOf(this.mem.get(MOD_DATE)).longValue());
}
return null;
}
public String getETag() {
if (this.mem.containsKey(ETAG)) {
return this.mem.get(ETAG);
}
return null;
}
public long getCrawlDelayMillis() {
if (this.mem.containsKey(CRAWL_DELAY_MILLIS)) try {
return Long.parseLong(this.mem.get(CRAWL_DELAY_MILLIS));
} catch (final NumberFormatException e) {
return 0;
}
if (this.mem.containsKey(CRAWL_DELAY)) try {
return 1000 * Integer.parseInt(this.mem.get(CRAWL_DELAY));
} catch (final NumberFormatException e) {
return 0;
}
return 0;
}
public boolean isDisallowed(String path) {
if ((this.mem == null) || (this.denyPathList.size() == 0)) return false;
// if the path is null or empty we set it to /
if ((path == null) || (path.length() == 0)) path = "/";
// escaping all occurences of ; because this char is used as special char in the Robots DB
else path = path.replaceAll(ROBOTS_DB_PATH_SEPARATOR,"%3B");
final Iterator<String> pathIter = this.denyPathList.iterator();
while (pathIter.hasNext()) {
final String nextPath = pathIter.next();
// disallow rule
if (path.startsWith(nextPath)) {
return true;
}
}
return false;
}
}
// methods that had been in robotsParser.java:
public static final int DOWNLOAD_ACCESS_RESTRICTED = 0;
public static final int DOWNLOAD_ROBOTS_TXT = 1;
public static final int DOWNLOAD_ETAG = 2;
public static final int DOWNLOAD_MODDATE = 3;
private static final String getHostPort(final yacyURL theURL) {
String urlHostPort = null;
final int port = getPort(theURL);
urlHostPort = theURL.getHost() + ":" + port;
urlHostPort = urlHostPort.toLowerCase().intern();
return urlHostPort;
}
private static final int getPort(final yacyURL theURL) {
int port = theURL.getPort();
if (port == -1) {
if (theURL.getProtocol().equalsIgnoreCase("http")) {
port = 80;
} else if (theURL.getProtocol().equalsIgnoreCase("https")) {
port = 443;
}
}
return port;
}
public yacyURL getSitemapURL(final yacyURL theURL) {
if (theURL == null) throw new IllegalArgumentException();
yacyURL sitemapURL = null;
// generating the hostname:poart string needed to do a DB lookup
final String urlHostPort = getHostPort(theURL);
final RobotsTxt.Entry robotsTxt4Host = this.getEntry(urlHostPort, true);
try {
final String sitemapUrlStr = robotsTxt4Host.getSitemap();
if (sitemapUrlStr != null) sitemapURL = new yacyURL(sitemapUrlStr, null);
} catch (final MalformedURLException e) {/* ignore this */}
return sitemapURL;
}
public Long getCrawlDelayMillis(final yacyURL theURL) {
if (theURL == null) throw new IllegalArgumentException();
Long crawlDelay = null;
// generating the hostname:poart string needed to do a DB lookup
final String urlHostPort = getHostPort(theURL);
final RobotsTxt.Entry robotsTxt4Host = getEntry(urlHostPort, true);
try {
crawlDelay = robotsTxt4Host.getCrawlDelayMillis();
} catch (final NumberFormatException e) {/* ignore this */}
return crawlDelay;
}
public boolean isDisallowed(final yacyURL nexturl) {
if (nexturl == null) throw new IllegalArgumentException();
// generating the hostname:port string needed to do a DB lookup
final String urlHostPort = getHostPort(nexturl);
RobotsTxt.Entry robotsTxt4Host = null;
robotsTxt4Host = getEntry(urlHostPort, true);
return robotsTxt4Host.isDisallowed(nexturl.getFile());
}
private static Object[] downloadRobotsTxt(final yacyURL robotsURL, int redirectionCount, final RobotsTxt.Entry entry) throws Exception {
if (redirectionCount < 0) return new Object[]{Boolean.FALSE,null,null};
redirectionCount--;
boolean accessCompletelyRestricted = false;
byte[] robotsTxt = null;
long downloadStart, downloadEnd;
String eTag=null, oldEtag = null;
Date lastMod=null;
downloadStart = System.currentTimeMillis();
// if we previously have downloaded this robots.txt then we can set the if-modified-since header
httpRequestHeader reqHeaders = new httpRequestHeader();
// add yacybot user agent
reqHeaders.put(httpRequestHeader.USER_AGENT, HTTPLoader.crawlerUserAgent);
// adding referer
reqHeaders.put(httpRequestHeader.REFERER, (yacyURL.newURL(robotsURL,"/")).toNormalform(true, true));
if (entry != null) {
oldEtag = entry.getETag();
reqHeaders = new httpRequestHeader();
final Date modDate = entry.getModDate();
if (modDate != null) reqHeaders.put(httpRequestHeader.IF_MODIFIED_SINCE,HttpClient.dateString(entry.getModDate()));
}
// setup http-client
//TODO: adding Traffic statistic for robots download?
final JakartaCommonsHttpClient client = new JakartaCommonsHttpClient(10000, reqHeaders);
JakartaCommonsHttpResponse res = null;
try {
// sending the get request
res = client.GET(robotsURL.toString());
// check for interruption
if (Thread.currentThread().isInterrupted()) throw new InterruptedException("Shutdown in progress.");
// check the response status
if (res.getStatusLine().startsWith("2")) {
if (!res.getResponseHeader().mime().startsWith("text/plain")) {
robotsTxt = null;
if (log.isFinest()) log.logFinest("Robots.txt from URL '" + robotsURL + "' has wrong mimetype '" + res.getResponseHeader().mime() + "'.");
} else {
// getting some metadata
eTag = res.getResponseHeader().containsKey(httpRequestHeader.ETAG)?(res.getResponseHeader().get(httpRequestHeader.ETAG)).trim():null;
lastMod = res.getResponseHeader().lastModified();
// if the robots.txt file was not changed we break here
if ((eTag != null) && (oldEtag != null) && (eTag.equals(oldEtag))) {
if (log.isFinest()) log.logFinest("Robots.txt from URL '" + robotsURL + "' was not modified. Abort downloading of new version.");
return null;
}
// downloading the content
final serverByteBuffer sbb = new serverByteBuffer();
try {
serverFileUtils.copyToStream(new BufferedInputStream(res.getDataAsStream()), new BufferedOutputStream(sbb));
} finally {
res.closeStream();
}
robotsTxt = sbb.getBytes();
downloadEnd = System.currentTimeMillis();
if (log.isFinest()) log.logFinest("Robots.txt successfully loaded from URL '" + robotsURL + "' in " + (downloadEnd-downloadStart) + " ms.");
}
} else if (res.getStatusCode() == 304) {
return null;
} else if (res.getStatusLine().startsWith("3")) {
// getting redirection URL
String redirectionUrlString = res.getResponseHeader().get(httpRequestHeader.LOCATION);
if (redirectionUrlString==null) {
if (log.isFinest()) log.logFinest("robots.txt could not be downloaded from URL '" + robotsURL + "' because of missing redirecton header. [" + res.getStatusLine() + "].");
robotsTxt = null;
} else {
redirectionUrlString = redirectionUrlString.trim();
// generating the new URL object
final yacyURL redirectionUrl = yacyURL.newURL(robotsURL, redirectionUrlString);
// following the redirection
if (log.isFinest()) log.logFinest("Redirection detected for robots.txt with URL '" + robotsURL + "'." +
"\nRedirecting request to: " + redirectionUrl);
return downloadRobotsTxt(redirectionUrl,redirectionCount,entry);
}
} else if (res.getStatusCode() == 401 || res.getStatusCode() == 403) {
accessCompletelyRestricted = true;
if (log.isFinest()) log.logFinest("Access to Robots.txt not allowed on URL '" + robotsURL + "'.");
} else {
if (log.isFinest()) log.logFinest("robots.txt could not be downloaded from URL '" + robotsURL + "'. [" + res.getStatusLine() + "].");
robotsTxt = null;
}
} catch (final Exception e) {
throw e;
} finally {
if(res != null) {
// release connection
res.closeStream();
}
}
return new Object[]{Boolean.valueOf(accessCompletelyRestricted),robotsTxt,eTag,lastMod};
}
}