Current File : //home/waritko/yacy/source/net/yacy/cora/sorting/ConcurrentScoreMap.java
/**
* ConcurrentScoreMap
* Copyright 2010 by Michael Peter Christen, mc@yacy.net, Frankfurt am Main, Germany
* First released 13.03.2011 at http://yacy.net
*
* $LastChangedDate: 2011-03-08 02:51:51 +0100 (Di, 08 Mrz 2011) $
* $LastChangedRevision: 7567 $
* $LastChangedBy: low012 $
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program in the file lgpl21.txt
* If not, see <http://www.gnu.org/licenses/>.
*/
package net.yacy.cora.sorting;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;
import java.util.TreeSet;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicInteger;
public class ConcurrentScoreMap<E> extends AbstractScoreMap<E> implements ScoreMap<E> {
/** a mapping from a reference to the cluster key */
protected final ConcurrentHashMap<E, AtomicInteger> map;
/** sum of all scores */
private long gcount;
/** Eventual registered object listening on map updates */
private ScoreMapUpdatesListener updatesListener;
public ConcurrentScoreMap() {
this(null);
}
/**
* @param updatesListener an eventual object listening on score map updates
*/
public ConcurrentScoreMap(final ScoreMapUpdatesListener updatesListener) {
this.map = new ConcurrentHashMap<E, AtomicInteger>();
this.gcount = 0;
this.updatesListener = updatesListener;
}
/**
* Dispatch the update event to the eventually registered listener.
*/
private void dispatchUpdateToListener() {
if(this.updatesListener != null) {
this.updatesListener.updatedScoreMap();
}
}
@Override
public Iterator<E> iterator() {
return this.map.keySet().iterator();
}
@Override
public synchronized void clear() {
this.map.clear();
this.gcount = 0;
dispatchUpdateToListener();
}
@Override
public int shrinkToMaxSize(final int maxsize) {
if (this.map.size() <= maxsize) {
return 0;
}
int deletedNb = 0;
int minScore = getMinScore();
while (this.map.size() > maxsize) {
minScore++;
deletedNb += shrinkToMinScore(minScore);
}
// No need to dispatch to listener, it is already done in shrinkToMinScore()
return deletedNb;
}
@Override
public int shrinkToMinScore(final int minScore) {
final Iterator<Map.Entry<E, AtomicInteger>> i = this.map.entrySet().iterator();
Map.Entry<E, AtomicInteger> entry;
int deletedNb = 0;
while (i.hasNext()) {
entry = i.next();
if (entry.getValue().intValue() < minScore) {
i.remove();
deletedNb++;
}
}
if(deletedNb > 0) {
dispatchUpdateToListener();
}
return deletedNb;
}
public long totalCount() {
return this.gcount;
}
@Override
public int size() {
return this.map.size();
}
@Override
public boolean sizeSmaller(final int size) {
return this.map.size() < size;
}
@Override
public boolean isEmpty() {
return this.map.isEmpty();
}
@Override
public void inc(final E obj) {
if (obj == null) return;
// use atomic operations
this.map.putIfAbsent(obj, new AtomicInteger(0));
this.map.get(obj).incrementAndGet();
// increase overall counter
this.gcount++;
dispatchUpdateToListener();
}
@Override
public void dec(final E obj) {
if (obj == null) return;
// use atomic operations
this.map.putIfAbsent(obj, new AtomicInteger(0));
this.map.get(obj).decrementAndGet();
// increase overall counter
this.gcount--;
dispatchUpdateToListener();
}
@Override
public void set(final E obj, final int newScore) {
if (obj == null) return;
// use atomic operations
final AtomicInteger old = this.map.putIfAbsent(obj, new AtomicInteger(newScore));
// adjust overall counter if value replaced
if (old != null) {
this.gcount -= old.intValue(); // must use old before setting a new value (it's a object reference)
this.map.get(obj).set(newScore);
}
// increase overall counter
this.gcount += newScore;
dispatchUpdateToListener();
}
@Override
public void inc(final E obj, final int incrementScore) {
if (obj == null) return;
// use atomic operations
this.map.putIfAbsent(obj, new AtomicInteger(0));
this.map.get(obj).addAndGet(incrementScore);
// increase overall counter
this.gcount += incrementScore;
dispatchUpdateToListener();
}
@Override
public void dec(final E obj, final int decrementScore) {
inc(obj, -decrementScore);
}
@Override
public int delete(final E obj) {
// deletes entry and returns previous score
if (obj == null) return 0;
final AtomicInteger score = this.map.remove(obj);
if (score == null) return 0;
// decrease overall counter
this.gcount -= score.intValue();
dispatchUpdateToListener();
return score.intValue();
}
@Override
public boolean containsKey(final E obj) {
return this.map.containsKey(obj);
}
@Override
public int get(final E obj) {
if (obj == null) return 0;
final AtomicInteger score = this.map.get(obj);
if (score == null) return 0;
return score.intValue();
}
public int getMinScore() {
if (this.map.isEmpty()) return -1;
int minScore = Integer.MAX_VALUE;
for (final Map.Entry<E, AtomicInteger> entry : this.map.entrySet())
if (entry.getValue().intValue() < minScore) {
minScore = entry.getValue().intValue();
}
return minScore;
}
public int getMaxScore() {
if (this.map.isEmpty())
return -1;
int maxScore = Integer.MIN_VALUE;
for (final Map.Entry<E, AtomicInteger> entry : this.map.entrySet())
if (entry.getValue().intValue() > maxScore) {
maxScore = entry.getValue().intValue();
}
return maxScore;
}
@Override
public String toString() {
return this.map.toString();
}
/**
* Creates and returns a sorted view to the keys. Sortorder is the score value.
* @param up true = asc order, false = reverse order
* @return iterator accessing the keys in order of score values
*/
@Override
public Iterator<E> keys(final boolean up) {
// re-organize entries
final TreeMap<Integer, Set<E>> m = new TreeMap<Integer, Set<E>>();
Set<E> s;
Integer is;
for (final Map.Entry<E, AtomicInteger> entry: this.map.entrySet()) {
is = entry.getValue().intValue();
s = m.get(is);
if (s == null) {
s = new HashSet<E>();
s.add(entry.getKey());
m.put(is, s);
} else {
s.add(entry.getKey());
}
}
// flatten result
final List<E> l = new ArrayList<E>(m.size());
for (final Set<E> f: m.values()) {
for (final E e: f) l.add(e);
}
if (up) return l.iterator();
// optionally reverse list
final List<E> r = new ArrayList<E>(l.size());
for (int i = l.size() - 1; i >= 0; i--) r.add(l.get(i));
return r.iterator();
}
/**
* Creates and returns a sorted view of the keys, sorted by their own natural order.
* @param up true = asc order, false = reverse order
* @return iterator accessing the keys in natural order
*/
public Iterator<E> keysByNaturalOrder(final boolean up) {
TreeSet<E> sortedKeys;
if(up) {
sortedKeys = new TreeSet<>();
} else {
sortedKeys = new TreeSet<>(Collections.reverseOrder());
}
for(E key : this.map.keySet()) {
sortedKeys.add(key);
}
return sortedKeys.iterator();
}
/**
* @param updatesListener an eventual object which wants to listen to successful updates on this score map
*/
public void setUpdatesListener(final ScoreMapUpdatesListener updatesListener) {
this.updatesListener = updatesListener;
}
public static void main(final String[] args) {
final ConcurrentScoreMap<String> a = new ConcurrentScoreMap<String>();
a.set("a", 55);
a.set("b", 3);
a.set("c", 80);
final Iterator<String> i = a.keys(true);
while (i.hasNext()) System.out.println(i.next());
}
}
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