/*
* Copyright (c) 2011 LinkedIn, Inc
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package cleo.search.typeahead;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import krati.util.Chronos;
import org.apache.log4j.Logger;
import cleo.search.Element;
import cleo.search.IndexRoller;
import cleo.search.store.ArrayStoreElement;
import cleo.search.store.ConnectionsStore;
/**
* GenericTypeaheadRoller - GenericTypeahead rolling indexer.
*
* @author jwu
* @since 03/02, 2011
*/
public class GenericTypeaheadIndexRoller<E extends Element> implements IndexRoller<E> {
private final static Logger logger = Logger.getLogger(GenericTypeahead.class);
private final GenericTypeahead<E> ta;
public GenericTypeaheadIndexRoller(GenericTypeahead<E> ta) {
this.ta = ta;
}
@Override
public synchronized boolean roll(Collection<E> elements) {
if(elements == null || elements.size() == 0) {
return false;
}
Chronos c = new Chronos();
HashMap<String, List<E>> map = new HashMap<String, List<E>>();
try {
long maxScn = collect(map, elements);
store(map, maxScn);
logger.info(ta.getName() + " applied rolling update in " + c.tick() + " ms");
return true;
} catch (Exception e) {
logger.error(ta.getName() + " failed to update indexes", e);
} finally {
map.clear();
map = null;
}
return false;
}
protected long collect(HashMap<String, List<E>> map, Collection<E> collection) {
int maxKeyLength = ta.getMaxKeyLength();
long maxScn = 0;
for(E element : collection) {
if(element != null) {
for(String term : element.getTerms()) {
if(term == null) continue;
int len = Math.min(term.length(), maxKeyLength);
for(int k = 1; k <= len; k++) {
String source = term.substring(0, k);
List<E> list = map.get(source);
if(list == null) {
list = new ArrayList<E>(500);
map.put(source, list);
}
list.add(element);
}
}
maxScn = Math.max(element.getTimestamp(), maxScn);
}
}
return maxScn;
}
protected void store(HashMap<String, List<E>> map, long maxScn) throws Exception {
HashSet<E> uniqSet = new HashSet<E>();
ElementScoreCmpDsc scoreCmpDsc = new ElementScoreCmpDsc();
ArrayStoreElement<E> elementStore = ta.getElementStore();
ConnectionsStore<String> connectionsStore = ta.getConnectionsStore();
List<E> list = new ArrayList<E>(100000);
for(String key : map.keySet()) {
List<E> rollingList = map.get(key);
if(rollingList == null || rollingList.size() == 0) {
continue;
}
list.clear();
uniqSet.clear();
// Add elements from original connections
int[] connections = connectionsStore.getConnections(key);
if(connections != null) {
for(int i = 0, cnt = connections.length; i < cnt; i++) {
E element = elementStore.getElement(connections[i]);
if(element != null) {
list.add(element);
uniqSet.add(element);
}
}
}
// Add elements from rolling update
for(E element : rollingList) {
if(element != null && !uniqSet.contains(element)) {
list.add(element);
uniqSet.add(element);
}
}
// Sort elements using score in descending order
Collections.sort(list, scoreCmpDsc);
connections = new int[list.size()];
for(int i = 0, cnt = connections.length; i < cnt; i++) {
connections[i] = list.get(i).getElementId();
}
// Update source connections
connectionsStore.putConnections(key, connections, maxScn);
}
}
public static final class ElementScoreCmpDsc implements Comparator<Element> {
@Override
public int compare(Element e0, Element e1) {
float score0 = e0.getScore();
float score1 = e1.getScore();
// Descending order
return score0 < score1 ? 1 : (score0 == score1 ? (e0.getElementId() - e1.getElementId()) : -1);
}
}
}