com.opengamma.master.historicaltimeseries.impl.DefaultHistoricalTimeSeriesSelector.java Source code

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Here is the source code for com.opengamma.master.historicaltimeseries.impl.DefaultHistoricalTimeSeriesSelector.java

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/**
 * Copyright (C) 2012 - present by OpenGamma Inc. and the OpenGamma group of companies
 * 
 * Please see distribution for license.
 */
package com.opengamma.master.historicaltimeseries.impl;

import java.util.Collection;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.base.Objects;
import com.google.common.collect.Iterables;
import com.opengamma.core.config.ConfigSource;
import com.opengamma.master.historicaltimeseries.HistoricalTimeSeriesSelector;
import com.opengamma.master.historicaltimeseries.ManageableHistoricalTimeSeriesInfo;
import com.opengamma.util.ArgumentChecker;

/**
 * A time-series resolver for a specific data source which uses configuration to interpret the resolution key.
 */
public class DefaultHistoricalTimeSeriesSelector implements HistoricalTimeSeriesSelector {

    /**
     * Logger.
     */
    private static final Logger s_logger = LoggerFactory.getLogger(DefaultHistoricalTimeSeriesSelector.class);

    /**
     * The source of configuration.
     */
    private final ConfigSource _configSource;

    public DefaultHistoricalTimeSeriesSelector(ConfigSource configSource) {
        ArgumentChecker.notNull(configSource, "configSource");
        _configSource = configSource;
    }

    //-------------------------------------------------------------------------
    @Override
    public ManageableHistoricalTimeSeriesInfo select(Collection<ManageableHistoricalTimeSeriesInfo> candidates,
            String selectionKey) {
        selectionKey = Objects.firstNonNull(selectionKey, HistoricalTimeSeriesRatingFieldNames.DEFAULT_CONFIG_NAME);

        //IGN-139 - avoid rating unless we have to
        switch (candidates.size()) {
        case 0:
            return null;
        case 1:
            return Iterables.getOnlyElement(candidates);
        default:
            // Pick best using rules from configuration
            HistoricalTimeSeriesRating rating = _configSource.getLatestByName(HistoricalTimeSeriesRating.class,
                    selectionKey);
            if (rating == null) {
                s_logger.warn("Resolver failed to find configuration: {}", selectionKey);
                return null;
            }
            return bestMatch(candidates, rating);
        }
    }

    //-------------------------------------------------------------------------
    /**
     * Choose the best match using the configured rules.
     * 
     * @param matches  the list of matches, not null
     * @param rating  the rules for scoring the matches, not null
     * @return the best match, null if no match
     */
    private ManageableHistoricalTimeSeriesInfo bestMatch(Collection<ManageableHistoricalTimeSeriesInfo> matches,
            HistoricalTimeSeriesRating rating) {
        s_logger.debug("Find best match using rules: {}", rating);
        int currentScore = Integer.MIN_VALUE;
        ManageableHistoricalTimeSeriesInfo bestMatch = null;
        for (ManageableHistoricalTimeSeriesInfo match : matches) {
            int score = rating.rate(match);
            s_logger.debug("Score: {} for info: {}", score, match);
            if (score > currentScore) {
                currentScore = score;
                bestMatch = match;
            }
        }
        return bestMatch;
    }

}