// plasmaEURL.java
// -----------------------
// part of YaCy
// (C) by Michael Peter Christen; mc@anomic.de
// first published on http://www.anomic.de
// Frankfurt, Germany, 2004
// last major change: 09.08.2004
//
// 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
//
// Using this software in any meaning (reading, learning, copying, compiling,
// running) means that you agree that the Author(s) is (are) not responsible
// for cost, loss of data or any harm that may be caused directly or indirectly
// by usage of this softare or this documentation. The usage of this software
// is on your own risk. The installation and usage (starting/running) of this
// software may allow other people or application to access your computer and
// any attached devices and is highly dependent on the configuration of the
// software which must be done by the user of the software; the author(s) is
// (are) also not responsible for proper configuration and usage of the
// software, even if provoked by documentation provided together with
// the software.
//
// Any changes to this file according to the GPL as documented in the file
// gpl.txt aside this file in the shipment you received can be done to the
// lines that follows this copyright notice here, but changes must not be
// done inside the copyright notive above. A re-distribution must contain
// the intact and unchanged copyright notice.
// Contributions and changes to the program code must be marked as such.
// EURL - noticed (known but not loaded) URL's
package de.anomic.plasma;
import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.util.Date;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.Iterator;
import de.anomic.kelondro.kelondroBase64Order;
import de.anomic.kelondro.kelondroTree;
import de.anomic.tools.bitfield;
public class plasmaCrawlEURL extends plasmaURL {
private LinkedList rejectedStack = new LinkedList(); // strings: url
public plasmaCrawlEURL(File cachePath, int bufferkb) {
super();
int[] ce = {
urlHashLength, // the url's hash
urlHashLength, // the url's referrer hash
urlHashLength, // the crawling initiator
urlHashLength, // the crawling executor
urlStringLength, // the url as string
urlNameLength, // the name of the url, from anchor tag <a>name</a>
urlDateLength, // the time when the url was first time appeared
urlDateLength, // the time when the url was last time tried to load
urlRetryLength, // number of load retries
urlErrorLength, // string describing load failure
urlFlagLength // extra space
};
if (cachePath.exists()) try {
// open existing cache
urlHashCache = new kelondroTree(cachePath, bufferkb * 0x400);
} catch (IOException e) {
cachePath.delete();
urlHashCache = new kelondroTree(cachePath, bufferkb * 0x400, ce, true);
} else {
// create new cache
cachePath.getParentFile().mkdirs();
urlHashCache = new kelondroTree(cachePath, bufferkb * 0x400, ce, true);
}
}
public synchronized Entry newEntry(URL url, String referrer, String initiator, String executor,
String name, String failreason, bitfield flags, boolean retry) {
if ((referrer == null) || (referrer.length() < urlHashLength)) referrer = dummyHash;
if ((initiator == null) || (initiator.length() < urlHashLength)) initiator = dummyHash;
if ((executor == null) || (executor.length() < urlHashLength)) executor = dummyHash;
if (failreason == null) failreason = "unknown";
// create a stack entry
HashMap map = new HashMap();
map.put("url", url);
map.put("referrer", referrer);
map.put("initiator", initiator);
map.put("executor", executor);
map.put("name", name);
map.put("failreason", failreason);
map.put("flags", flags);
rejectedStack.add(map);
Entry e = new Entry(url, referrer, initiator, executor, name, failreason, flags);
// put in table
if (retry) e.store();
return e;
}
public synchronized Entry getEntry(String hash) throws IOException {
return new Entry(hash);
}
public void clearStack() {
rejectedStack.clear();
}
public int stackSize() {
return rejectedStack.size();
}
public Entry getStack(int pos) {
HashMap m = (HashMap) rejectedStack.get(pos);
return new Entry((URL) m.get("url"), (String) m.get("referrer"), (String) m.get("initiator"), (String) m.get("executor"),
(String) m.get("name"), (String) m.get("failreason"), (bitfield) m.get("flags"));
}
public class Entry {
private String hash; // the url's hash
private String referrer; // the url's referrer hash
private String initiator; // the crawling initiator
private String executor; // the crawling initiator
private URL url; // the url as string
private String name; // the name of the url, from anchor tag <a>name</a>
private Date initdate; // the time when the url was first time appeared
private Date trydate; // the time when the url was last time tried to load
private int trycount; // number of tryings
private String failreason; // string describing reason for load fail
private bitfield flags; // extra space
public Entry(URL url, String referrer, String initiator, String executor, String name, String failreason, bitfield flags) {
// create new entry and store it into database
this.hash = urlHash(url);
this.referrer = (referrer == null) ? dummyHash : referrer;
this.initiator = initiator;
this.executor = executor;
this.url = url;
this.name = name;
this.initdate = new Date();
this.trydate = new Date();
this.trycount = 0;
this.failreason = failreason;
this.flags = flags;
}
public Entry(String hash) throws IOException {
// generates an plasmaEURLEntry using the url hash
// to speed up the access, the url-hashes are buffered
// in the hash cache.
// we have two options to find the url:
// - look into the hash cache
// - look into the filed properties
// if the url cannot be found, this returns null
this.hash = hash;
byte[][] entry = urlHashCache.get(hash.getBytes());
if (entry != null) {
this.referrer = new String(entry[1], "UTF-8");
this.initiator = new String(entry[2], "UTF-8");
this.executor = new String(entry[3], "UTF-8");
this.url = new URL(new String(entry[4], "UTF-8").trim());
this.name = new String(entry[5], "UTF-8").trim();
this.initdate = new Date(86400000 * kelondroBase64Order.enhancedCoder.decodeLong(new String(entry[6], "UTF-8")));
this.trydate = new Date(86400000 * kelondroBase64Order.enhancedCoder.decodeLong(new String(entry[7], "UTF-8")));
this.trycount = (int) kelondroBase64Order.enhancedCoder.decodeLong(new String(entry[8], "UTF-8"));
this.failreason = new String(entry[9], "UTF-8");
this.flags = new bitfield(entry[10]);
return;
}
}
private void store() {
// stores the values from the object variables into the database
String initdatestr = kelondroBase64Order.enhancedCoder.encodeLong(initdate.getTime() / 86400000, urlDateLength);
String trydatestr = kelondroBase64Order.enhancedCoder.encodeLong(trydate.getTime() / 86400000, urlDateLength);
// store the hash in the hash cache
try {
// even if the entry exists, we simply overwrite it
byte[][] entry = new byte[][] {
this.hash.getBytes(),
this.referrer.getBytes(),
this.initiator.getBytes(),
this.executor.getBytes(),
this.url.toString().getBytes(),
this.name.getBytes(),
initdatestr.getBytes(),
trydatestr.getBytes(),
kelondroBase64Order.enhancedCoder.encodeLong(this.trycount, urlRetryLength).getBytes(),
this.failreason.getBytes(),
this.flags.getBytes()
};
urlHashCache.put(entry);
} catch (IOException e) {
System.out.println("INTERNAL ERROR AT plasmaEURL:url2hash:" + e.toString());
}
}
public String hash() {
// return a url-hash, based on the md5 algorithm
// the result is a String of 12 bytes within a 72-bit space
// (each byte has an 6-bit range)
// that should be enough for all web pages on the world
return this.hash;
}
public String referrer() {
return this.referrer;
}
public URL url() {
return url;
}
public Date initdate() {
return trydate;
}
public Date trydate() {
return trydate;
}
public String initiator() {
// return the creator's hash
return initiator;
}
public String executor() {
// return the creator's hash
return executor;
}
public String name() {
// return the creator's hash
return name;
}
public String failreason() {
return failreason;
}
}
public class kenum implements Enumeration {
// enumerates entry elements
Iterator i;
public kenum(boolean up, boolean rotating) throws IOException {
i = urlHashCache.rows(up, rotating);
}
public boolean hasMoreElements() {
return i.hasNext();
}
public Object nextElement() {
try {
return new Entry(new String(((byte[][]) i.next())[0]));
} catch (IOException e) {
return null;
}
}
}
public Enumeration elements(boolean up, boolean rotating) throws IOException {
// enumerates entry elements
return new kenum(up, rotating);
}
}