/*
* Copyright (c) 2010 Lockheed Martin Corporation
*
* 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 org.eurekastreams.server.service.actions.strategies.activity.datasources;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import net.sf.json.JSONObject;
import org.eurekastreams.server.persistence.mappers.DomainMapper;
import org.eurekastreams.server.service.actions.strategies.activity.ListCollider;
/**
* Gets activity IDs from memcache based on the query.
*
*/
public class PersistenceDataSource implements DescendingOrderDataSource
{
/**
* A map of search params and key generators.
*/
private HashMap<String, DomainMapper<Object, List<?>>> mappers;
/**
* Transformers.
*/
private HashMap<String, PersistenceDataSourceRequestTransformer> transformers;
/**
* Everyone mapper.
*/
private DomainMapper<Object, List<Long>> everyoneMapper;
/**
* The or collider.
*/
private ListCollider orCollider;
/**
* The max we want this data source to return.
*/
private static final int MAXITEMS = 10000;
/**
* Default constructor.
*
* @param inEveryoneMapper
* the everyoneMapper
* @param inMappers
* the mappers .
* @param inTransformers
* the transformers.
* @param inOrCollider
* collider.
*/
public PersistenceDataSource(final DomainMapper<Object, List<Long>> inEveryoneMapper,
final HashMap<String, DomainMapper<Object, List<?>>> inMappers,
final HashMap<String, PersistenceDataSourceRequestTransformer> inTransformers,
final ListCollider inOrCollider)
{
everyoneMapper = inEveryoneMapper;
mappers = inMappers;
transformers = inTransformers;
orCollider = inOrCollider;
}
/**
* Given the request, give me back all the results relevant from memcache.
*
* @param request
* the JSON request from the user.
* @param userEntityId
* the user entity ID.
* @return the list of activity longs.
*/
public List<Long> fetch(final JSONObject request, final Long userEntityId)
{
boolean unHandled = false;
List<List<Long>> returnedDataSets = new ArrayList<List<Long>>();
JSONObject jsonQuery = request.getJSONObject("query");
if (jsonQuery.size() == 0
|| (jsonQuery.size() == 1 && jsonQuery.containsKey("sortBy") && jsonQuery.getString("sortBy").equals(
"date")))
{
// get everyone list
returnedDataSets.add(everyoneMapper.execute(null));
}
else
{
for (Object objParam : jsonQuery.keySet())
{
DomainMapper<Object, List<?>> mapper = mappers.get(objParam);
if (mapper != null)
{
List<?> data = null;
if (transformers.containsKey(objParam) && transformers.get(objParam) != null)
{
data = mapper.execute(transformers.get(objParam).transform(jsonQuery, userEntityId));
}
else
{
data = mapper.execute(jsonQuery);
}
if (data.size() > 0)
{
// List of lists
if (data.get(0) instanceof List)
{
List<List<Long>> dataList = (List<List<Long>>) data;
for (List<Long> subList : dataList)
{
returnedDataSets.add(subList);
}
}
else
{
returnedDataSets.add((List<Long>) data);
}
}
}
else
{
unHandled = true;
}
}
if (returnedDataSets.size() == 0)
{
// if the query isn't empty, but we don't handle any of it, return null, stating such
return null;
}
}
List<Long> returned = new ArrayList<Long>();
for (List<Long> dataSet : returnedDataSets)
{
Integer maxCount = request.getInt("count");
if (unHandled)
{
maxCount = MAXITEMS;
}
returned = orCollider.collide(dataSet, returned, maxCount);
}
return returned;
}
}