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yacy_search_server/source/de/anomic/plasma/plasmaWordIndexEntryContain...

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// plasmaIndexEntryContainer.java
// ------------------------------
// part of YaCy
// (C) by Michael Peter Christen; mc@anomic.de
// first published on http://www.anomic.de
// Frankfurt, Germany, 2005
// last major change: 07.05.2005
//
// 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.
/*
an indexContainer is a bag of indexEntries for a single word
such an container represents a RWI snippet:
it collects a new RWI until it is so big that it should be flushed to either
- an indexAssortment: collection of indexContainers of same size or
- the backend storage
the creationTime is necessary to organize caching of containers
*/
package de.anomic.plasma;
import java.util.Iterator;
import java.util.Set;
import java.util.TreeMap;
import de.anomic.kelondro.kelondroBase64Order;
import de.anomic.kelondro.kelondroNaturalOrder;
import de.anomic.kelondro.kelondroOrder;
public final class plasmaWordIndexEntryContainer {
private String wordHash;
private final TreeMap container; // urlHash/plasmaWordIndexEntry - Mapping
private long updateTime;
private kelondroOrder ordering;
public plasmaWordIndexEntryContainer(String wordHash) {
this(wordHash, new kelondroNaturalOrder(true));
}
public plasmaWordIndexEntryContainer(String wordHash, kelondroOrder ordering) {
this.wordHash = wordHash;
this.updateTime = 0;
this.ordering = ordering;
container = new TreeMap(ordering); // a urlhash/plasmaWordIndexEntry - relation
}
public void setWordHash(String newWordHash) {
// this is used to replicate a container for different word indexes during global search
this.wordHash = newWordHash;
}
public void clear() {
container.clear();
}
public int size() {
return container.size();
}
public long updated() {
return updateTime;
}
public String wordHash() {
return wordHash;
}
public int add(plasmaWordIndexEntry entry) {
return add(entry, System.currentTimeMillis());
}
public int add(plasmaWordIndexEntry entry, long updateTime) {
this.updateTime = java.lang.Math.max(this.updateTime, updateTime);
return (addi(entry)) ? 1 : 0;
}
public int add(plasmaWordIndexEntry[] entries, long updateTime) {
int c = 0;
for (int i = 0; i < entries.length; i++) if (addi(entries[i])) c++;
this.updateTime = java.lang.Math.max(this.updateTime, updateTime);
return c;
}
public int add(plasmaWordIndexEntryContainer c) {
// returns the number of new elements
if (c == null) return 0;
Iterator i = c.entries();
int x = 0;
while (i.hasNext()) {
if (addi((plasmaWordIndexEntry) i.next())) x++;
}
this.updateTime = java.lang.Math.max(this.updateTime, c.updateTime);
return x;
}
private boolean addi(plasmaWordIndexEntry entry) {
// returns true if the new entry was added, false if it already existet
return (container.put(entry.getUrlHash(), entry) == null);
}
public boolean contains(String urlHash) {
return container.containsKey(urlHash);
}
public plasmaWordIndexEntry get(String urlHash) {
return (plasmaWordIndexEntry) container.get(urlHash);
}
public plasmaWordIndexEntry[] getEntryArray() {
return (plasmaWordIndexEntry[]) container.values().toArray();
}
public plasmaWordIndexEntry remove(String urlHash) {
return (plasmaWordIndexEntry) container.remove(urlHash);
}
public int removeEntries(String wordHash, String[] urlHashes, boolean deleteComplete) {
if (!wordHash.equals(this.wordHash)) return 0;
int count = 0;
for (int i = 0; i < urlHashes.length; i++) count += (remove(urlHashes[i]) == null) ? 0 : 1;
return count;
}
public Iterator entries() {
// returns an iterator of plasmaWordIndexEntry objects
return container.values().iterator();
}
public String toString() {
return "C[" + wordHash + "] has " + container.size() + " entries";
}
public int hashCode() {
return (int) kelondroBase64Order.enhancedCoder.decodeLong(this.wordHash.substring(0, 4));
}
public static plasmaWordIndexEntryContainer joinContainer(Set containers, long time, int maxDistance) {
long stamp = System.currentTimeMillis();
// order entities by their size
TreeMap map = new TreeMap();
plasmaWordIndexEntryContainer singleContainer;
Iterator i = containers.iterator();
int count = 0;
while (i.hasNext()) {
// get next entity:
singleContainer = (plasmaWordIndexEntryContainer) i.next();
// check result
if ((singleContainer == null) || (singleContainer.size() == 0)) return new plasmaWordIndexEntryContainer(null); // as this is a cunjunction of searches, we have no result if any word is not known
// store result in order of result size
map.put(new Long(singleContainer.size() * 1000 + count), singleContainer);
count++;
}
// check if there is any result
if (map.size() == 0) return new plasmaWordIndexEntryContainer(null); // no result, nothing found
// the map now holds the search results in order of number of hits per word
// we now must pairwise build up a conjunction of these sets
Long k = (Long) map.firstKey(); // the smallest, which means, the one with the least entries
plasmaWordIndexEntryContainer searchA, searchB, searchResult = (plasmaWordIndexEntryContainer) map.remove(k);
while ((map.size() > 0) && (searchResult.size() > 0)) {
// take the first element of map which is a result and combine it with result
k = (Long) map.firstKey(); // the next smallest...
time -= (System.currentTimeMillis() - stamp); stamp = System.currentTimeMillis();
searchA = searchResult;
searchB = (plasmaWordIndexEntryContainer) map.remove(k);
searchResult = plasmaWordIndexEntryContainer.joinConstructive(searchA, searchB, 2 * time / (map.size() + 1), maxDistance);
// free resources
searchA = null;
searchB = null;
}
// in 'searchResult' is now the combined search result
if (searchResult.size() == 0) return new plasmaWordIndexEntryContainer(null);
return searchResult;
}
// join methods
private static int log2(int x) {
int l = 0;
while (x > 0) {x = x >> 1; l++;}
return l;
}
public static plasmaWordIndexEntryContainer joinConstructive(plasmaWordIndexEntryContainer i1, plasmaWordIndexEntryContainer i2, long time, int maxDistance) {
if ((i1 == null) || (i2 == null)) return null;
if ((i1.size() == 0) || (i2.size() == 0)) return new plasmaWordIndexEntryContainer(null);
// decide which method to use
int high = ((i1.size() > i2.size()) ? i1.size() : i2.size());
int low = ((i1.size() > i2.size()) ? i2.size() : i1.size());
int stepsEnum = 10 * (high + low - 1);
int stepsTest = 12 * log2(high) * low;
// start most efficient method
if (stepsEnum > stepsTest) {
if (i1.size() < i2.size())
return joinConstructiveByTest(i1, i2, time, maxDistance);
else
return joinConstructiveByTest(i2, i1, time, maxDistance);
} else {
return joinConstructiveByEnumeration(i1, i2, time, maxDistance);
}
}
private static plasmaWordIndexEntryContainer joinConstructiveByTest(plasmaWordIndexEntryContainer small, plasmaWordIndexEntryContainer large, long time, int maxDistance) {
System.out.println("DEBUG: JOIN METHOD BY TEST");
plasmaWordIndexEntryContainer conj = new plasmaWordIndexEntryContainer(null); // start with empty search result
Iterator se = small.entries();
plasmaWordIndexEntry ie0, ie1;
long stamp = System.currentTimeMillis();
while ((se.hasNext()) && ((System.currentTimeMillis() - stamp) < time)) {
ie0 = (plasmaWordIndexEntry) se.next();
ie1 = large.get(ie0.getUrlHash());
if (ie1 != null) {
// this is a hit. Calculate word distance:
ie0.combineDistance(ie1);
if (ie0.worddistance() <= maxDistance) conj.add(ie0);
}
}
return conj;
}
private static plasmaWordIndexEntryContainer joinConstructiveByEnumeration(plasmaWordIndexEntryContainer i1, plasmaWordIndexEntryContainer i2, long time, int maxDistance) {
System.out.println("DEBUG: JOIN METHOD BY ENUMERATION");
plasmaWordIndexEntryContainer conj = new plasmaWordIndexEntryContainer(null); // start with empty search result
if (!(i1.ordering.signature().equals(i2.ordering.signature()))) return conj; // ordering must be equal
Iterator e1 = i1.entries();
Iterator e2 = i2.entries();
int c;
if ((e1.hasNext()) && (e2.hasNext())) {
plasmaWordIndexEntry ie1;
plasmaWordIndexEntry ie2;
ie1 = (plasmaWordIndexEntry) e1.next();
ie2 = (plasmaWordIndexEntry) e2.next();
long stamp = System.currentTimeMillis();
while ((System.currentTimeMillis() - stamp) < time) {
c = i1.ordering.compare(ie1.getUrlHash(), ie2.getUrlHash());
//System.out.println("** '" + ie1.getUrlHash() + "'.compareTo('" + ie2.getUrlHash() + "')="+c);
if (c < 0) {
if (e1.hasNext()) ie1 = (plasmaWordIndexEntry) e1.next(); else break;
} else if (c > 0) {
if (e2.hasNext()) ie2 = (plasmaWordIndexEntry) e2.next(); else break;
} else {
// we have found the same urls in different searches!
ie1.combineDistance(ie2);
if (ie1.worddistance() <= maxDistance) conj.add(ie1);
if (e1.hasNext()) ie1 = (plasmaWordIndexEntry) e1.next(); else break;
if (e2.hasNext()) ie2 = (plasmaWordIndexEntry) e2.next(); else break;
}
}
}
return conj;
}
}