// plasmaDHTChunk.java
// ------------------------------
// part of YaCy
// (C) by Michael Peter Christen; mc@anomic.de
// first published on http://www.anomic.de
// Frankfurt, Germany, 2006
// created: 18.02.2006
//
// 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
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// Contributions and changes to the program code must be marked as such.
package de.anomic.plasma;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import de.anomic.kelondro.kelondroBase64Order;
import de.anomic.kelondro.kelondroException;
import de.anomic.server.serverCodings;
import de.anomic.server.logging.serverLog;
import de.anomic.yacy.yacyCore;
import de.anomic.yacy.yacyDHTAction;
import de.anomic.yacy.yacySeedDB;
public class plasmaDHTChunk {
public static final int chunkStatus_UNDEFINED = -1;
public static final int chunkStatus_FAILED = 0;
public static final int chunkStatus_FILLED = 1;
public static final int chunkStatus_RUNNING = 2;
public static final int chunkStatus_INTERRUPTED = 3;
public static final int chunkStatus_COMPLETE = 4;
public static final int peerRedundancy = 3;
private plasmaWordIndex wordIndex;
private serverLog log;
private plasmaCrawlLURL lurls;
private int status = chunkStatus_UNDEFINED;
private String startPointHash;
private plasmaWordIndexEntryContainer[] indexContainers = null;
private HashMap urlCache; // String (url-hash) / plasmaCrawlLURL.Entry
private int idxCount;
public plasmaWordIndexEntryContainer firstContainer() {
return indexContainers[0];
}
public plasmaWordIndexEntryContainer lastContainer() {
return indexContainers[indexContainers.length - 1];
}
public plasmaWordIndexEntryContainer[] containers() {
return indexContainers;
}
public int containerSize() {
return indexContainers.length;
}
public int indexCount() {
return this.idxCount;
}
private int indexCounter() {
int c = 0;
for (int i = 0; i < indexContainers.length; i++) {
c += indexContainers[i].size();
}
return c;
}
public HashMap urlCacheMap() {
return urlCache;
}
public void setStatus(int newStatus) {
this.status = newStatus;
}
public int getStatus() {
return this.status;
}
public plasmaDHTChunk(serverLog log, plasmaWordIndex wordIndex, plasmaCrawlLURL lurls, int minCount, int maxCount) {
this.log = log;
this.wordIndex = wordIndex;
this.lurls = lurls;
startPointHash = selectTransferStart();
log.logFine("Selected hash " + startPointHash + " as start point for index distribution, distance = " + yacyDHTAction.dhtDistance(yacyCore.seedDB.mySeed.hash, startPointHash));
selectTransferContainers(startPointHash, minCount, maxCount);
// count the indexes, can be smaller as expected
this.idxCount = indexCounter();
if (idxCount < minCount) {
log.logFine("Too few (" + idxCount + ") indexes selected for transfer.");
this.status = chunkStatus_FAILED;
}
}
public plasmaDHTChunk(serverLog log, plasmaWordIndex wordIndex, plasmaCrawlLURL lurls, int minCount, int maxCount, String startHash) {
this.log = log;
this.wordIndex = wordIndex;
this.lurls = lurls;
log.logFine("Demanded hash " + startHash + " as start point for index distribution, distance = " + yacyDHTAction.dhtDistance(yacyCore.seedDB.mySeed.hash, startPointHash));
selectTransferContainers(startHash, minCount, maxCount);
// count the indexes, can be smaller as expected
this.idxCount = indexCounter();
if (idxCount < minCount) {
log.logFine("Too few (" + idxCount + ") indexes selected for transfer.");
this.status = chunkStatus_FAILED;
}
}
private String selectTransferStart() {
String startPointHash;
// first try to select with increasing probality a good start point
double minimumDistance = ((double) peerRedundancy) / ((double) yacyCore.seedDB.sizeConnected());
if (Math.round(Math.random() * 6) != 4)
for (int i = 9; i > 0; i--) {
startPointHash = kelondroBase64Order.enhancedCoder.encode(serverCodings.encodeMD5Raw(Long.toString(i + System.currentTimeMillis()))).substring(2, 2 + yacySeedDB.commonHashLength);
if (yacyDHTAction.dhtDistance(yacyCore.seedDB.mySeed.hash, startPointHash) > (minimumDistance + ((double) i / (double) 10)))
return startPointHash;
}
// if that fails, take simply the best start point (this is usually avoided, since that leads to always the same target peers)
startPointHash = yacyCore.seedDB.mySeed.hash.substring(0, 11) + "z";
return startPointHash;
}
private void selectTransferContainers(String hash, int mincount, int maxcount) {
int refcountRAM = selectTransferContainersResource(hash, plasmaWordIndex.RL_RAMCACHE, maxcount);
if (refcountRAM >= mincount) {
log.logFine("DHT selection from RAM: " + refcountRAM + " entries");
return;
}
int refcountFile = selectTransferContainersResource(hash, plasmaWordIndex.RL_WORDFILES, maxcount);
log.logFine("DHT selection from FILE: " + refcountFile + " entries, RAM provided only " + refcountRAM + " entries");
return;
}
private int selectTransferContainersResource(String hash, int resourceLevel, int maxcount) {
// the hash is a start hash from where the indexes are picked
ArrayList tmpContainers = new ArrayList(maxcount);
String nexthash = "";
try {
Iterator wordHashIterator = wordIndex.wordHashSet(hash, resourceLevel, true, maxcount).iterator();
plasmaWordIndexEntryContainer indexContainer;
Iterator urlIter;
plasmaWordIndexEntry indexEntry;
plasmaCrawlLURL.Entry lurl;
int refcount = 0;
urlCache = new HashMap();
double maximumDistance = ((double) peerRedundancy * 2) / ((double) yacyCore.seedDB.sizeConnected());
while ((maxcount > refcount) && (wordHashIterator.hasNext()) && ((nexthash = (String) wordHashIterator.next()) != null) && (nexthash.trim().length() > 0)
&& ((tmpContainers.size() == 0) || (yacyDHTAction.dhtDistance(nexthash, ((plasmaWordIndexEntryContainer) tmpContainers.get(0)).wordHash()) < maximumDistance))) {
// make an on-the-fly entity and insert values
indexContainer = wordIndex.getContainer(nexthash, true, 10000);
int notBoundCounter = 0;
try {
urlIter = indexContainer.entries();
// iterate over indexes to fetch url entries and store them in the urlCache
while ((urlIter.hasNext()) && (maxcount > refcount)) {
indexEntry = (plasmaWordIndexEntry) urlIter.next();
try {
lurl = lurls.getEntry(indexEntry.getUrlHash(), indexEntry);
if ((lurl == null) || (lurl.url() == null)) {
notBoundCounter++;
urlIter.remove();
wordIndex.removeEntries(nexthash, new String[] { indexEntry.getUrlHash() }, true);
} else {
urlCache.put(indexEntry.getUrlHash(), lurl);
refcount++;
}
} catch (IOException e) {
notBoundCounter++;
urlIter.remove();
wordIndex.removeEntries(nexthash, new String[] { indexEntry.getUrlHash() }, true);
}
}
// remove all remaining; we have enough
while (urlIter.hasNext()) {
indexEntry = (plasmaWordIndexEntry) urlIter.next();
urlIter.remove();
}
// use whats left
log.logFine("Selected partial index (" + indexContainer.size() + " from " + wordIndex.indexSize(nexthash) + " URLs, " + notBoundCounter + " not bound) for word " + indexContainer.wordHash());
tmpContainers.add(indexContainer);
} catch (kelondroException e) {
log.logSevere("plasmaWordIndexDistribution/2: deleted DB for word " + nexthash, e);
wordIndex.deleteIndex(nexthash);
}
}
// create result
indexContainers = (plasmaWordIndexEntryContainer[]) tmpContainers.toArray(new plasmaWordIndexEntryContainer[tmpContainers.size()]);
if ((indexContainers == null) || (indexContainers.length == 0)) {
log.logFine("No index available for index transfer, hash start-point " + startPointHash);
this.status = chunkStatus_FAILED;
return 0;
}
this.status = chunkStatus_FILLED;
return refcount;
} catch (kelondroException e) {
log.logSevere("selectTransferIndexes database corrupted: " + e.getMessage(), e);
indexContainers = new plasmaWordIndexEntryContainer[0];
urlCache = new HashMap();
this.status = chunkStatus_FAILED;
return 0;
} catch (IOException e) {
log.logSevere("selectTransferIndexes database corrupted: " + e.getMessage(), e);
indexContainers = new plasmaWordIndexEntryContainer[0];
urlCache = new HashMap();
this.status = chunkStatus_FAILED;
return 0;
}
}
public int deleteTransferIndexes() {
Iterator urlIter;
plasmaWordIndexEntry indexEntry;
String[] urlHashes;
int count = 0;
synchronized (wordIndex) {
for (int i = 0; i < this.indexContainers.length; i++) {
// delete entries separately
int c = 0;
urlHashes = new String[this.indexContainers[i].size()];
urlIter = this.indexContainers[i].entries();
while (urlIter.hasNext()) {
indexEntry = (plasmaWordIndexEntry) urlIter.next();
urlHashes[c++] = indexEntry.getUrlHash();
}
count += wordIndex.removeEntries(this.indexContainers[i].wordHash(), urlHashes, true);
log.logFine("Deleted partial index (" + c + " URLs) for word " + this.indexContainers[i].wordHash() + "; " + this.wordIndex.indexSize(indexContainers[i].wordHash()) + " entries left");
this.indexContainers[i] = null;
}
}
return count;
}
}