gistfile1.java

/////// MongoScoreScript.java
/////// Looks up score values in the map it is constructed with

package com.dressipi.elastic;

import org.elasticsearch.script.AbstractLongSearchScript;
import com.mongodb.BasicDBObject;

public class MongoScorerScript extends AbstractLongSearchScript {
    BasicDBObject score_map;
    
    public MongoScorerScript(BasicDBObject a_score_map){
      score_map = a_score_map;
    }
    @Override
    public long runAsLong() {
      String g_id = Integer.toString(doc().numeric("id").getIntValue());
      Integer value = (Integer)score_map.get(g_id);
      if(value == null){
        return 0;
      }else{
        return value.intValue();
      }
    }
}

///////// MongoScorerFactory
///////// Factory class for the native script
package com.dressipi.elastic;

import org.elasticsearch.common.Nullable;
import org.elasticsearch.script.ExecutableScript;
import org.elasticsearch.script.NativeScriptFactory;

import java.util.Map;
import com.dressipi.elastic.MongoScorerScript;
import com.dressipi.elastic.ScoreMapCache;
import com.mongodb.BasicDBObject;

public class MongoScorerFactory implements NativeScriptFactory {
    
    ScoreMapCache cache;
    
    @Override public ExecutableScript newScript(@Nullable Map<String, Object> params) {
        Integer profileId = (Integer)params.get("profile_id");
        BasicDBObject map = cache.get(profileId);
        
        return new MongoScorerScript(map);
    }

    public MongoScorerFactory() throws java.net.UnknownHostException{
        cache = new ScoreMapCache();
    }
}


//// ScoreMapCache: looks up our maps of doc-id -> score from mongo
//// Implements a very simple LRU cache of those maps
////
package com.dressipi.elastic;

import com.mongodb.Mongo;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.BasicDBObject;
import com.mongodb.DBObject;
import com.mongodb.DBCursor;

import java.util.LinkedHashMap;
import java.util.Map;

public class ScoreMapCache {

  public static final int CACHE_SIZE = 100;

  DBCollection recommendation_score_maps;

  LinkedHashMap<Integer,BasicDBObject> cache;

  BasicDBObject get(Integer profileId){
    BasicDBObject result;
    
    synchronized(this){
      result = cache.get(profileId);
    
      if(result == null){
        result = fetchMapForProfileId(profileId);
        cache.put(profileId, result);
      }
    }
    return result;
  }
  
  BasicDBObject fetchMapForProfileId(Integer profileId){
    BasicDBObject query = new BasicDBObject();
    query.put("profile_id", profileId);
    DBCursor cur = recommendation_score_maps.find(query);

    if(cur.hasNext()){
      BasicDBObject recommendation_score_map = (BasicDBObject)cur.next();
      return (BasicDBObject)recommendation_score_map.get("map");      
    }else{
      return new BasicDBObject();
    }
  }

  public ScoreMapCache() throws java.net.UnknownHostException{    
    cache = new LinkedHashMap<Integer,BasicDBObject>(20, 0.75f, true){
         @Override protected boolean removeEldestEntry (Map.Entry<Integer,BasicDBObject> eldest) {
            return size() > ScoreMapCache.CACHE_SIZE; 
         }
    };
    Mongo m = new Mongo("127.0.0.1");
    DB db = m.getDB("dressipi-development");
    recommendation_score_maps = db.getCollection("recommendation_score_maps");      
  }
  
}