You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
yacy_search_server/source/de/anomic/yacy/yacyDHTAction.java

375 lines
15 KiB

// yacyDHTAction.java
// -------------------------------------
// (C) by Michael Peter Christen; mc@yacy.net
// first published on http://www.anomic.de
// Frankfurt, Germany, 2005
//
// $LastChangedDate$
// $LastChangedRevision$
// $LastChangedBy$
//
// 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.yacy;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.TreeMap;
import java.util.TreeSet;
import de.anomic.kelondro.kelondroBase64Order;
import de.anomic.kelondro.kelondroCloneableIterator;
import de.anomic.kelondro.kelondroCloneableMapIterator;
import de.anomic.kelondro.kelondroException;
import de.anomic.kelondro.kelondroMScoreCluster;
import de.anomic.kelondro.kelondroRotateIterator;
import de.anomic.server.logging.serverLog;
public class yacyDHTAction {
protected yacySeedDB seedDB;
protected kelondroMScoreCluster<String> seedCrawlReady;
public yacyDHTAction(final yacySeedDB seedDB) {
this.seedDB = seedDB;
this.seedCrawlReady = new kelondroMScoreCluster<String>();
// init crawl-ready table
try {
final Iterator<yacySeed> en = seedDB.seedsConnected(true, false, null, (float) 0.0);
yacySeed ys;
while (en.hasNext()) {
ys = en.next();
if ((ys != null) && (ys.getVersion() >= ((float) 0.3))) seedCrawlReady.setScore(ys.hash, yacyCore.yacyTime());
}
} catch (final IllegalArgumentException e) {
}
}
public void close() {
// the seedDB should be cleared elsewhere
seedCrawlReady = null;
}
public Iterator<yacySeed> getDHTSeeds(final boolean up, final String firstHash, final float minVersion) {
// enumerates seed-type objects: all seeds with starting point in the middle, rotating at the end/beginning
return new seedDHTEnum(up, firstHash, minVersion);
}
class seedDHTEnum implements Iterator<yacySeed> {
Iterator<yacySeed> e1, e2;
boolean up;
int steps;
float minVersion;
public seedDHTEnum(final boolean up, final String firstHash, final float minVersion) {
this.steps = seedDB.sizeConnected();
this.up = up;
this.minVersion = minVersion;
this.e1 = seedDB.seedsConnected(up, false, firstHash, minVersion);
this.e2 = null;
}
public boolean hasNext() {
return (steps > 0) && ((e2 == null) || (e2.hasNext()));
}
public yacySeed next() {
if (steps == 0) return null;
steps--;
if (e1 == null || !e1.hasNext()) {
if (e2 == null) {
e1 = null;
e2 = seedDB.seedsConnected(up, false, null, minVersion);
}
return e2.next();
}
final yacySeed n = e1.next();
if (!(e1.hasNext())) {
e1 = null;
e2 = seedDB.seedsConnected(up, false, null, minVersion);
}
return n;
}
public void remove() {
throw new UnsupportedOperationException();
}
}
public Iterator<yacySeed> getProvidesRemoteCrawlURLs() {
return new providesRemoteCrawlURLsEnum();
}
class providesRemoteCrawlURLsEnum implements Iterator<yacySeed> {
Iterator<yacySeed> se;
yacySeed nextSeed;
public providesRemoteCrawlURLsEnum() {
se = getDHTSeeds(true, null, yacyVersion.YACY_POVIDES_REMOTECRAWL_LISTS);
nextSeed = nextInternal();
}
public boolean hasNext() {
return nextSeed != null;
}
private yacySeed nextInternal() {
yacySeed s;
try {
while (se.hasNext()) {
s = se.next();
if (s == null) return null;
if (s.getLong(yacySeed.RCOUNT, 0) > 0) return s;
}
} catch (final kelondroException e) {
System.out.println("DEBUG providesRemoteCrawlURLsEnum:" + e.getMessage());
yacyCore.log.logSevere("database inconsistency (" + e.getMessage() + "), re-set of db.");
seedDB.resetActiveTable();
return null;
}
return null;
}
public yacySeed next() {
final yacySeed next = nextSeed;
nextSeed = nextInternal();
return next;
}
public void remove() {
throw new UnsupportedOperationException();
}
}
public Iterator<yacySeed> getAcceptRemoteIndexSeeds(final String starthash) {
// returns an enumeration of yacySeed-Objects
// that have the AcceptRemoteIndex-Flag set
// the seeds are enumerated in the right order according DHT
return new acceptRemoteIndexSeedEnum(starthash);
}
class acceptRemoteIndexSeedEnum implements Iterator<yacySeed> {
Iterator<yacySeed> se;
yacySeed nextSeed;
public acceptRemoteIndexSeedEnum(final String starthash) {
se = getDHTSeeds(true, starthash, yacyVersion.YACY_HANDLES_COLLECTION_INDEX);
nextSeed = nextInternal();
}
public boolean hasNext() {
return nextSeed != null;
}
private yacySeed nextInternal() {
yacySeed s;
try {
while (se.hasNext()) {
s = se.next();
if (s == null) return null;
if (s.getFlagAcceptRemoteIndex()) return s;
}
} catch (final kelondroException e) {
System.out.println("DEBUG acceptRemoteIndexSeedEnum:" + e.getMessage());
yacyCore.log.logSevere("database inconsistency (" + e.getMessage() + "), re-set of db.");
seedDB.resetActiveTable();
return null;
}
return null;
}
public yacySeed next() {
final yacySeed next = nextSeed;
nextSeed = nextInternal();
return next;
}
public void remove() {
throw new UnsupportedOperationException();
}
}
public Iterator<yacySeed> getAcceptRemoteCrawlSeeds(final String starthash, final boolean available) {
return new acceptRemoteCrawlSeedEnum(starthash, available);
}
class acceptRemoteCrawlSeedEnum implements Iterator<yacySeed> {
Iterator<yacySeed> se;
yacySeed nextSeed;
boolean available;
public acceptRemoteCrawlSeedEnum(final String starthash, final boolean available) {
this.se = getDHTSeeds(true, starthash, (float) 0.0);
this.available = available;
nextSeed = nextInternal();
}
public boolean hasNext() {
return nextSeed != null;
}
private yacySeed nextInternal() {
yacySeed s;
while (se.hasNext()) {
s = se.next();
if (s == null) return null;
s.available = seedCrawlReady.getScore(s.hash);
if (available) {
if (seedCrawlReady.getScore(s.hash) < yacyCore.yacyTime()) return s;
} else {
if (seedCrawlReady.getScore(s.hash) > yacyCore.yacyTime()) return s;
}
}
return null;
}
public yacySeed next() {
final yacySeed next = nextSeed;
nextSeed = nextInternal();
return next;
}
public void remove() {
throw new UnsupportedOperationException();
}
}
public synchronized yacySeed getGlobalCrawlSeed(final String urlHash) {
Iterator<yacySeed> e = getAcceptRemoteCrawlSeeds(urlHash, true);
yacySeed seed;
if (e.hasNext()) seed = e.next(); else seed = null;
e = null;
return seed;
}
public synchronized yacySeed getPublicClusterCrawlSeed(final String urlHash, final TreeMap<String, String> clusterhashes) {
// clusterhashes is a String(hash)/String(IP) - mapping
final kelondroCloneableIterator<String> i = new kelondroRotateIterator<String>(new kelondroCloneableMapIterator<String>(clusterhashes, urlHash), null, clusterhashes.size());
String hash;
int count = clusterhashes.size(); // counter to ensure termination
while ((i.hasNext()) && (count-- > 0)) {
hash = i.next();
final yacySeed seed = seedDB.getConnected(hash);
if (seed == null) continue;
seed.setAlternativeAddress(clusterhashes.get(hash));
return seed;
}
return null;
}
public void setCrawlTime(final String seedHash, int newYacyTime) {
if (newYacyTime < yacyCore.yacyTime()) newYacyTime = yacyCore.yacyTime();
seedCrawlReady.setScore(seedHash, newYacyTime);
}
public void setCrawlDelay(final String seedHash, final int newDelay) {
seedCrawlReady.setScore(seedHash, yacyCore.yacyTime() + newDelay);
}
public void processPeerArrival(final yacySeed peer, final boolean direct) {
if (peer.getVersion() >= ((float) 0.3)) {
if (!(seedCrawlReady.existsScore(peer.hash))) seedCrawlReady.setScore(peer.hash, yacyCore.yacyTime());
} else {
seedCrawlReady.deleteScore(peer.hash);
}
}
public void processPeerDeparture(final yacySeed peer) {
seedCrawlReady.deleteScore(peer.hash);
}
public static boolean shallBeOwnWord(final yacySeedDB seedDB, final String wordhash) {
if (seedDB == null) return false;
if (seedDB.mySeed().isPotential()) return false;
final double distance = dhtDistance(seedDB.mySeed().hash, wordhash);
final double max = 1.2 / seedDB.sizeConnected();
//System.out.println("Distance for " + wordhash + ": " + distance + "; max is " + max);
return (distance > 0) && (distance <= max);
}
public static double dhtDistance(final String peer, final String word) {
// the dht distance is a positive value between 0 and 1
// if the distance is small, the word more probably belongs to the peer
final double d = hashDistance(peer, word);
if (d > 0) {
return d; // case where the word is 'before' the peer
}
return 1 + d; // wrap-around case
}
private static double hashDistance(final String from, final String to) {
// computes the distance between two hashes.
// the maximum distance between two hashes is 1, the minimum -1
// this can be used like "from - to"
// the result is positive if from > to
assert (from != null);
assert (to != null);
assert (from.length() == 12) : "from.length = " + from.length() + ", from = " + from;
assert (to.length() == 12) : "to.length = " + to.length() + ", to = " + to;
return ((double) (kelondroBase64Order.enhancedCoder.cardinal(from.getBytes()) - kelondroBase64Order.enhancedCoder.cardinal(to.getBytes()))) / ((double) Long.MAX_VALUE);
}
public synchronized ArrayList<yacySeed> getDHTTargets(final yacySeedDB seedDB, final serverLog log, final int primaryPeerCount, final int reservePeerCount, final String firstKey, final String lastKey, final double maxDist) {
// find a list of DHT-peers
assert firstKey != null;
assert lastKey != null;
assert seedDB != null;
assert seedDB.mySeed() != null;
assert seedDB.mySeed().hash != null;
/*
assert
!(kelondroBase64Order.enhancedCoder.cardinal(firstKey.getBytes()) < kelondroBase64Order.enhancedCoder.cardinal(yacyCore.seedDB.mySeed.hash.getBytes()) &&
kelondroBase64Order.enhancedCoder.cardinal(lastKey.getBytes()) > kelondroBase64Order.enhancedCoder.cardinal(yacyCore.seedDB.mySeed.hash.getBytes()));
*/
final ArrayList<yacySeed> seeds = new ArrayList<yacySeed>();
yacySeed seed;
//double ownDistance = Math.min(yacyDHTAction.dhtDistance(yacyCore.seedDB.mySeed.hash, firstKey), yacyDHTAction.dhtDistance(yacyCore.seedDB.mySeed.hash, lastKey));
//double maxDistance = Math.min(ownDistance, maxDist);
double firstdist, lastdist;
Iterator<yacySeed> e = this.getAcceptRemoteIndexSeeds(lastKey);
final TreeSet<String> doublecheck = new TreeSet<String>(kelondroBase64Order.enhancedComparator);
int maxloop = Math.min(100, seedDB.sizeConnected()); // to ensure termination
if (log != null) log.logInfo("Collecting DHT target peers for first_hash = " + firstKey + ", last_hash = " + lastKey);
while ((e.hasNext()) && (seeds.size() < (primaryPeerCount + reservePeerCount)) && (maxloop-- > 0)) {
seed = e.next();
if (seed == null || seed.hash == null) continue;
firstdist = yacyDHTAction.dhtDistance(seed.hash, firstKey);
lastdist = yacyDHTAction.dhtDistance(seed.hash, lastKey);
if (lastdist > maxDist) {
if (log != null && yacyCore.log.isFine()) log.logFine("Discarded too distant DHT target peer " + seed.getName() + ":" + seed.hash + ", distance2first = " + firstdist + ", distance2last = " + lastdist);
} else if (doublecheck.contains(seed.hash)) {
if (log != null && yacyCore.log.isFine()) log.logFine("Discarded double DHT target peer " + seed.getName() + ":" + seed.hash + ", distance2first = " + firstdist + ", distance2last = " + lastdist);
} else {
if (log != null) log.logInfo("Selected " + ((seeds.size() < primaryPeerCount) ? "primary" : "reserve") + " DHT target peer " + seed.getName() + ":" + seed.hash + ", distance2first = " + firstdist + ", distance2last = " + lastdist);
seeds.add(seed);
doublecheck.add(seed.hash);
}
}
e = null; // finish enumeration
return seeds;
}
}