/*
* 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.persistence.mappers;
import java.util.Calendar;
import org.apache.commons.logging.Log;
import org.eurekastreams.commons.logging.LogFactory;
import org.eurekastreams.server.action.request.stream.StreamPopularHashTagsRequest;
import org.eurekastreams.server.persistence.mappers.stream.StreamPopularHashTagsReportDTO;
/**
* Wrapping mapper to get the popular hashtags from another mapper, then return null if it's expired.
*/
public class StreamPopularHashTagsMapper implements
DomainMapper<StreamPopularHashTagsRequest, StreamPopularHashTagsReportDTO>
{
/**
* Logger.
*/
private Log log = LogFactory.make();
/**
* Number of minutes to keep the popular hashtags in cache.
*/
private final Integer popularHashTagsExpirationInMinutes;
/**
* Mapper to get the popular hashtags for a stream.
*/
private final DomainMapper<StreamPopularHashTagsRequest, StreamPopularHashTagsReportDTO> popularHashTagsMapper;
/**
* Constructor.
*
* @param inPopularHashTagsMapper
* the mapper to get the popular hashtags for a stream
* @param inPopularHashTagsExpirationInMinutes
* the number of minutes to allow popular hashtags in cache
*/
public StreamPopularHashTagsMapper(
final DomainMapper<StreamPopularHashTagsRequest, StreamPopularHashTagsReportDTO> inPopularHashTagsMapper,
final Integer inPopularHashTagsExpirationInMinutes)
{
popularHashTagsMapper = inPopularHashTagsMapper;
popularHashTagsExpirationInMinutes = inPopularHashTagsExpirationInMinutes;
}
/**
* Get the popular hashtags from the decorated mapper, returning null if it's not found or if found and too old.
*
* @param inRequest
* request containing the stream type and unique key
* @return null if not found or found and generated too long ago
*/
@Override
public StreamPopularHashTagsReportDTO execute(final StreamPopularHashTagsRequest inRequest)
{
StreamPopularHashTagsReportDTO hashTagReport = popularHashTagsMapper.execute(inRequest);
if (hashTagReport != null)
{
// found the report - see if it's too old
Calendar earliestValidReportDate = Calendar.getInstance();
earliestValidReportDate.add(Calendar.MINUTE, 0 - popularHashTagsExpirationInMinutes);
if (hashTagReport.getReportGenerationDate().before(earliestValidReportDate.getTime()))
{
// this report is expired - regenerate
if (log.isInfoEnabled())
{
log.info("Popular HashTag report for stream " + inRequest.getStreamEntityScopeType() + " #"
+ inRequest.getStreamEntityUniqueKey() + " is expired - regenerating.");
}
return null;
}
}
return hashTagReport;
}
}