Author: orbiter
Date: 2008-03-11 00:28:05 +0100 (Tue, 11 Mar 2008)
New Revision: 4548
Modified:
trunk/source/de/anomic/kelondro/kelondroAbstractRecords.java
trunk/source/de/anomic/yacy/yacySeed.java
Log:
new method for best hash computation
Modified: trunk/source/de/anomic/kelondro/kelondroAbstractRecords.java
===================================================================
--- trunk/source/de/anomic/kelondro/kelondroAbstractRecords.java
2008-03-10 23:23:04 UTC (rev 4547)
+++ trunk/source/de/anomic/kelondro/kelondroAbstractRecords.java
2008-03-10 23:28:05 UTC (rev 4548)
@@ -870,47 +870,7 @@
public final Iterator<EntryIndex> contentRows(long maxInitTime) throws
kelondroException {
return new contentRowIterator(maxInitTime);
}
-
- /*
- public final class contentRowIterator implements Iterator<EntryIndex> {
- // iterator that iterates all kelondroRow.Entry-objects in the file
- // all records that are marked as deleted are omitted
-
- private Iterator<kelondroNode> nodeIterator;
-
- public contentRowIterator(long maxInitTime) {
- nodeIterator = contentNodes(maxInitTime);
- }
- public boolean hasNext() {
- return nodeIterator.hasNext();
- }
-
- public EntryIndex next0() {
- try {
- kelondroNode n = (kelondroNode) nodeIterator.next();
- return row().newEntryIndex(n.getValueRow(), n.handle().index);
- } catch (IOException e) {
- throw new kelondroException(filename, e.getMessage());
- }
- }
-
- public EntryIndex next() {
- try {
- kelondroNode n = (kelondroNode) nodeIterator.next();
- return row().newEntryIndex(n.getValueRow(), n.handle().index);
- } catch (IOException e) {
- throw new kelondroException(filename, e.getMessage());
- }
- }
-
- public void remove() {
- throw new UnsupportedOperationException();
- }
-
- }
- */
-
public final class contentRowIterator implements Iterator<EntryIndex> {
// iterator that iterates all kelondroRow.Entry-objects in the file
// all records that are marked as deleted are omitted
Modified: trunk/source/de/anomic/yacy/yacySeed.java
===================================================================
--- trunk/source/de/anomic/yacy/yacySeed.java 2008-03-10 23:23:04 UTC (rev
4547)
+++ trunk/source/de/anomic/yacy/yacySeed.java 2008-03-10 23:28:05 UTC (rev
4548)
@@ -69,6 +69,7 @@
import java.util.Iterator;
import java.util.Random;
import java.util.Set;
+import java.util.TreeMap;
import de.anomic.kelondro.kelondroBase64Order;
import de.anomic.net.natLib;
@@ -691,9 +692,9 @@
if (from == null) return dhtPosition(to);
final double fromPos = dhtPosition(from);
final double toPos = dhtPosition(to);
- return (fromPos < toPos) ? (toPos - fromPos) : (1.0 - fromPos + toPos);
+ return (fromPos <= toPos) ? (toPos - fromPos) : (1.0 - fromPos +
toPos);
}
-
+ /*
private static String bestNewHash(yacySeedDB seedDB) {
if ((seedDB == null) || (seedDB.sizeConnected() <= 8)) {
// use random hash
@@ -734,7 +735,63 @@
System.out.println("BESTHASH finally is " + bestHash);
return bestHash;
}
+ */
+ private static String bestGap(yacySeedDB seedDB) {
+ if ((seedDB == null) || (seedDB.sizeConnected() <= 2)) {
+ // use random hash
+ return randomHash();
+ }
+ // find gaps
+ TreeMap<Double, String> gaps = hashGaps(seedDB);
+
+ // take one gap; prefer biggest but take also another smaller by chance
+ String interval = null;
+ Random r = new Random();
+ while (gaps.size() > 0) {
+ interval = gaps.remove(gaps.lastKey());
+ if (r.nextBoolean()) break;
+ }
+ if (interval == null) return randomHash();
+
+ // find dht position and size of gap
+ double gapsize = dhtDistance(interval.substring(0, 12),
interval.substring(12));
+ assert gapsize >= 0.0;
+ double gappos = dhtPosition(interval.substring(0, 12)) + (gapsize / 2);
+ if (gappos >= 1.0) gappos = gappos - 1.0; // fix overflow; can only
occur for gap at end
+ return positionToHash(gappos);
+ }
+ private static TreeMap<Double, String> hashGaps(yacySeedDB seedDB) {
+ TreeMap<Double, String>gaps = new TreeMap<Double, String>();
+ if (seedDB == null) return gaps;
+
+ Iterator<yacySeed> i = seedDB.seedsConnected(true, false, null,
(float) 0.0);
+ double d;
+ yacySeed s0 = null, s1, first = null;
+ while (i.hasNext()) {
+ s1 = i.next();
+ if (s0 == null) {
+ s0 = s1;
+ first = s0;
+ continue;
+ }
+ if (s0.hash.equals("fF99P8dMio7M")) {
+ System.out.print(0);
+ }
+ d = dhtDistance(s0.hash, s1.hash);
+ assert d >= 0.0;
+ gaps.put(d, s0.hash + s1.hash);
+ s0 = s1;
+ }
+ // compute also the last gap
+ if ((first != null) && (s0 != null)) {
+ d = dhtDistance(s0.hash, first.hash);
+ assert d >= 0.0;
+ gaps.put(d, s0.hash + first.hash);
+ }
+ return gaps;
+ }
+
private static String positionToHash(double t) {
// transform the position of a peer position into a close peer hash
assert t >= 0.0 : "t = " + t;
@@ -759,7 +816,7 @@
// genera a seed for the local peer
// this is the birthplace of a seed, that then will start to travel to
other peers
- final String hash = bestNewHash(yacyCore.seedDB);
+ final String hash = bestGap(yacyCore.seedDB);
yacyCore.log.logInfo("init: OWN SEED = " + hash);
final yacySeed newSeed = new yacySeed(hash);
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