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yacy_search_server/source/de/anomic/plasma/plasmaWebStructure.java

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// plasmaWebStructure.java
// -----------------------------
// (C) 2007 by Michael Peter Christen; mc@anomic.de, Frankfurt a. M., Germany
// first published 15.05.2007 on http://yacy.net
//
// This is a part of YaCy, a peer-to-peer based web search engine
//
// $LastChangedDate: 2006-04-02 22:40:07 +0200 (So, 02 Apr 2006) $
// $LastChangedRevision: 1986 $
// $LastChangedBy: orbiter $
//
// LICENSE
//
// 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.plasma;
import java.io.File;
import java.io.IOException;
import java.util.ConcurrentModificationException;
import java.util.Date;
import java.util.Iterator;
import java.util.Map;
import java.util.HashMap;
import java.util.TreeMap;
import java.util.SortedMap;
import java.util.TreeSet;
import de.anomic.kelondro.kelondroBase64Order;
import de.anomic.net.URL;
import de.anomic.server.serverDate;
import de.anomic.server.serverFileUtils;
import de.anomic.server.logging.serverLog;
public class plasmaWebStructure {
public static int maxCRLDump = 500000;
public static int maxCRGDump = 200000;
public static int maxref = 200; // maximum number of references, to avoid overflow when a large link farm occurs (i.e. wikipedia)
public static int maxhosts = 4000; // maximum number of hosts in web structure map
private StringBuffer crg; // global citation references
private serverLog log;
private File rankingPath, structureFile;
private String crlFile, crgFile;
private TreeMap structure; // String2String with <b64hash(6)>','<host> to <date-yyyymmdd(8)>{<target-b64hash(6)><target-count-hex(4)>}*
public plasmaWebStructure(serverLog log, File rankingPath, String crlFile, String crgFile, File structureFile) {
this.log = log;
this.rankingPath = rankingPath;
this.crlFile = crlFile;
this.crgFile = crgFile;
this.crg = new StringBuffer(maxCRGDump);
this.structure = new TreeMap();
this.structureFile = structureFile;
// load web structure
Map loadedStructure = serverFileUtils.loadHashMap(this.structureFile);
if (loadedStructure != null) this.structure.putAll(loadedStructure);
// delete outdated entries in case the structure is too big
if (this.structure.size() > maxhosts) {
// fill a set with last-modified - dates of the structure
TreeSet delset = new TreeSet();
Map.Entry entry;
Iterator i = this.structure.entrySet().iterator();
String key, value;
while (i.hasNext()) {
entry = (Map.Entry) i.next();
key = (String) entry.getKey();
value = (String) entry.getValue();
delset.add(value.substring(0, 8) + key);
}
int delcount = this.structure.size() - (maxhosts * 9 / 10);
i = delset.iterator();
while ((delcount > 0) && (i.hasNext())) {
this.structure.remove(((String) i.next()).substring(8));
delcount--;
}
}
}
public Integer[] /*(outlinksSame, outlinksOther)*/ generateCitationReference(URL url, String baseurlhash, Date docDate, plasmaParserDocument document, plasmaCondenser condenser) {
assert plasmaURL.urlHash(url).equals(baseurlhash);
// generate citation reference
Map hl = document.getHyperlinks();
Iterator it = hl.entrySet().iterator();
String nexturlhash;
StringBuffer cpg = new StringBuffer(12 * (hl.size() + 1) + 1);
StringBuffer cpl = new StringBuffer(12 * (hl.size() + 1) + 1);
String lhp = baseurlhash.substring(6); // local hash part
int GCount = 0;
int LCount = 0;
while (it.hasNext()) {
nexturlhash = plasmaURL.urlHash((String) ((Map.Entry) it.next()).getKey());
if (nexturlhash != null) {
if (nexturlhash.substring(6).equals(lhp)) {
// this is a inbound link
cpl.append(nexturlhash.substring(0, 6)); // store only local part
LCount++;
} else {
// this is a outbound link
cpg.append(nexturlhash); // store complete hash
GCount++;
}
}
}
// append this reference to buffer
// generate header info
String head = baseurlhash + "=" +
plasmaWordIndex.microDateHoursStr(docDate.getTime()) + // latest update timestamp of the URL
plasmaWordIndex.microDateHoursStr(System.currentTimeMillis()) + // last visit timestamp of the URL
kelondroBase64Order.enhancedCoder.encodeLongSmart(LCount, 2) + // count of links to local resources
kelondroBase64Order.enhancedCoder.encodeLongSmart(GCount, 2) + // count of links to global resources
kelondroBase64Order.enhancedCoder.encodeLongSmart(document.getImages().size(), 2) + // count of Images in document
kelondroBase64Order.enhancedCoder.encodeLongSmart(0, 2) + // count of links to other documents
kelondroBase64Order.enhancedCoder.encodeLongSmart(document.getTextLength(), 3) + // length of plain text in bytes
kelondroBase64Order.enhancedCoder.encodeLongSmart(condenser.RESULT_NUMB_WORDS, 3) + // count of all appearing words
kelondroBase64Order.enhancedCoder.encodeLongSmart(condenser.words().size(), 3) + // count of all unique words
kelondroBase64Order.enhancedCoder.encodeLongSmart(0, 1); // Flags (update, popularity, attention, vote)
//crl.append(head); crl.append ('|'); crl.append(cpl); crl.append((char) 13); crl.append((char) 10);
crg.append(head); crg.append('|'); crg.append(cpg); crg.append((char) 13); crg.append((char) 10);
learn(url, cpg);
// if buffer is full, flush it.
/*
if (crl.length() > maxCRLDump) {
flushCitationReference(crl, "crl");
crl = new StringBuffer(maxCRLDump);
}
**/
if (crg.length() > maxCRGDump) {
flushCitationReference("crg");
crg = new StringBuffer(maxCRGDump);
}
return new Integer[] {new Integer(LCount), new Integer(GCount)};
}
public void flushCitationReference(String type) {
if (crg.length() < 12) return;
String filename = type.toUpperCase() + "-A-" + new serverDate().toShortString(true) + "." + crg.substring(0, 12) + ".cr.gz";
File path = new File(rankingPath, (type.equals("crl")) ? crlFile : crgFile);
path.mkdirs();
File file = new File(path, filename);
// generate header
StringBuffer header = new StringBuffer(200);
header.append("# Name=YaCy " + ((type.equals("crl")) ? "Local" : "Global") + " Citation Reference Ticket"); header.append((char) 13); header.append((char) 10);
header.append("# Created=" + System.currentTimeMillis()); header.append((char) 13); header.append((char) 10);
header.append("# Structure=<Referee-12>,'=',<UDate-3>,<VDate-3>,<LCount-2>,<GCount-2>,<ICount-2>,<DCount-2>,<TLength-3>,<WACount-3>,<WUCount-3>,<Flags-1>,'|',*<Anchor-" + ((type.equals("crl")) ? "6" : "12") + ">"); header.append((char) 13); header.append((char) 10);
header.append("# ---"); header.append((char) 13); header.append((char) 10);
crg.insert(0, header.toString());
try {
serverFileUtils.writeAndGZip(crg.toString().getBytes(), file);
log.logFine("wrote citation reference dump " + file.toString());
} catch (IOException e) {
e.printStackTrace();
}
}
private static int refstr2count(String refs) {
if ((refs == null) || (refs.length() <= 8)) return 0;
assert (refs.length() - 8) % 10 == 0;
return (refs.length() - 8) / 10;
}
private static Map refstr2map(String refs) {
if ((refs == null) || (refs.length() <= 8)) return new HashMap();
Map map = new HashMap();
String c;
int refsc = refstr2count(refs);
for (int i = 0; i < refsc; i++) {
c = refs.substring(8 + i * 10, 8 + (i + 1) * 10);
map.put(c.substring(0, 6), new Integer(Integer.parseInt(c.substring(6), 16)));
}
return map;
}
private static String map2refstr(Map map) {
StringBuffer s = new StringBuffer(map.size() * 10);
s.append(serverDate.shortDayFormatter.format(new Date()));
Iterator i = map.entrySet().iterator();
Map.Entry entry;
String h;
while (i.hasNext()) {
entry = (Map.Entry) i.next();
s.append((String) entry.getKey());
h = Integer.toHexString(((Integer) entry.getValue()).intValue());
if (h.length() == 0) {
s.append("0000");
} else if (h.length() == 1) {
s.append("000").append(h);
} else if (h.length() == 2) {
s.append("00").append(h);
} else if (h.length() == 3) {
s.append('0').append(h);
} else if (h.length() == 4) {
s.append(h);
} else {
s.append("FFFF");
}
}
return s.toString();
}
public Map references(String domhash) {
// returns a map with a domhash(String):refcount(Integer) relation
assert domhash.length() == 6;
SortedMap tailMap = structure.tailMap(domhash);
if ((tailMap == null) || (tailMap.size() == 0)) return new HashMap();
String key = (String) tailMap.firstKey();
if (key.startsWith(domhash)) {
return refstr2map((String) tailMap.get(key));
} else {
return new HashMap();
}
}
public int referencesCount(String domhash) {
// returns the number of domains that are referenced by this domhash
assert domhash.length() == 6 : "domhash = " + domhash;
try {
SortedMap tailMap = structure.tailMap(domhash);
if ((tailMap == null) || (tailMap.size() == 0)) return 0;
String key = (String) tailMap.firstKey();
if (key.startsWith(domhash)) {
return refstr2count((String) tailMap.get(key));
} else {
return 0;
}
} catch (ConcurrentModificationException e) {
return 0;
}
}
public String resolveDomHash2DomString(String domhash) {
// returns the domain as string, null if unknown
assert domhash.length() == 6;
try {
SortedMap tailMap = structure.tailMap(domhash);
if ((tailMap == null) || (tailMap.size() == 0)) return null;
String key = (String) tailMap.firstKey();
if (key.startsWith(domhash)) {
return key.substring(7);
} else {
return null;
}
} catch (ConcurrentModificationException e) {
// we dont want to implement a synchronization here,
// because this is 'only' used for a graphics application
// just return null
return null;
}
}
private void learn(URL url, StringBuffer reference /*string of b64(12digits)-hashes*/) {
String domhash = plasmaURL.urlHash(url).substring(6);
// parse the new reference string and join it with the stored references
Map refs = references(domhash);
assert reference.length() % 12 == 0;
String dom;
int c;
for (int i = 0; i < reference.length() / 12; i++) {
dom = reference.substring(i * 12 + 6, (i + 1) * 12);
c = 0;
if (refs.containsKey(dom)) {
c = ((Integer) refs.get(dom)).intValue();
}
refs.put(dom, new Integer(++c));
}
// check if the maxref is exceeded
if (refs.size() > maxref) {
int shrink = refs.size() - (maxref * 9 / 10);
delloop: while (shrink > 0) {
// shrink the references: the entry with the smallest number of references is removed
int minrefcount = Integer.MAX_VALUE;
String minrefkey = null;
Iterator i = refs.entrySet().iterator();
Map.Entry entry;
findloop: while (i.hasNext()) {
entry = (Map.Entry) i.next();
if (((Integer) entry.getValue()).intValue() < minrefcount) {
minrefcount = ((Integer) entry.getValue()).intValue();
minrefkey = (String) entry.getKey();
}
if (minrefcount == 1) break findloop;
}
// remove the smallest
if (minrefkey == null) break delloop;
refs.remove(minrefkey);
shrink--;
}
}
// store the map back to the structure
structure.put(domhash + "," + url.getHost(), map2refstr(refs));
}
public void saveWebStructure() {
try {
serverFileUtils.saveMap(this.structureFile, this.structure, "Web Structure Syntax: <b64hash(6)>','<host> to <date-yyyymmdd(8)>{<target-b64hash(6)><target-count-hex(4)>}*");
} catch (IOException e) {
e.printStackTrace();
}
}
public String hostWithMaxReferences() {
// find domain with most references
Iterator i = structure.entrySet().iterator();
int refsize, maxref = 0;
String maxhost = null;
Map.Entry entry;
while (i.hasNext()) {
entry = (Map.Entry) i.next();
refsize = ((String) entry.getValue()).length();
if (refsize > maxref) {
maxref = refsize;
maxhost = ((String) entry.getKey()).substring(7);
}
}
return maxhost;
}
public Iterator structureEntryIterator() {
// iterates objects of type structureEntry
return new structureIterator();
}
public class structureIterator implements Iterator {
private Iterator i;
private structureEntry nextentry;
public structureIterator() {
i = structure.entrySet().iterator();
next0();
}
public boolean hasNext() {
return nextentry != null;
}
private void next0() {
Map.Entry entry = null;
String dom = null, ref;
while (i.hasNext()) {
entry = (Map.Entry) i.next();
dom = (String) entry.getKey();
if (dom.length() >= 8) break;
if (!i.hasNext()) {
nextentry = null;
return;
}
}
if ((entry == null) || (dom == null)) {
nextentry = null;
return;
}
ref = (String) entry.getValue();
nextentry = new structureEntry(dom.substring(0, 6), dom.substring(7), ref.substring(0, 8), refstr2map(ref));
}
public Object next() {
structureEntry r = nextentry;
next0();
return r;
}
public void remove() {
throw new UnsupportedOperationException("not implemented");
}
}
public class structureEntry {
public String domhash, domain, date;
public Map references;
public structureEntry(String domhash, String domain, String date, Map references) {
this.domhash = domhash;
this.domain = domain;
this.date = date;
this.references = references;
}
}
public void close() {
log.logInfo("Saving Web Structure File");
saveWebStructure();
}
}
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