Predictor.java

/**
 * ****************************************************************************
 * Copyright (c) 2010-2016 by Min Cai (min.cai.china@gmail.com).
 * <p>
 * This file is part of the Archimulator multicore architectural simulator.
 * <p>
 * Archimulator is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * <p>
 * Archimulator is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * <p>
 * You should have received a copy of the GNU General Public License
 * along with Archimulator. If not, see <http://www.gnu.org/licenses/>.
 * ****************************************************************************
 */
package archimulator.uncore.cache.prediction;

import archimulator.common.report.Reportable;

/**
 * Predictor.
 *
 * @param <PredictableT> the predictable type
 * @author Min Cai
 */
public interface Predictor<PredictableT extends Comparable<PredictableT>> extends Reportable {
    /**
     * Predict the value for the specified address.
     *
     * @param address the address
     * @return the predicted value for the specified address
     */
    PredictableT predict(int address);

    /**
     * Update the observed value for the specified address.
     *
     * @param address       the address
     * @param observedValue the observed value
     */
    void update(int address, PredictableT observedValue);

    /**
     * Get the default value.
     *
     * @return the default value
     */
    PredictableT getDefaultValue();

    /**
     * Get the number of misses.
     *
     * @return the number of misses
     */
    long getNumHits();

    /**
     * Get the number of misses.
     *
     * @return the number of misses
     */
    long getNumMisses();

    /**
     * Get the number of accesses that are failed to predict.
     *
     * @return the number of accesses that are failed to predict
     */
    long getNumFailedToPredict();

    /**
     * Get the number of accesses.
     *
     * @return the number of accesses
     */
    default long getNumAccesses() {
        return this.getNumHits() + this.getNumMisses();
    }

    /**
     * Get the hit ratio.
     *
     * @return the hit ratio
     */
    default double getHitRatio() {
        return this.getNumAccesses() > 0 ? (double) this.getNumHits() / this.getNumAccesses() : 0.0;
    }

    /**
     * Get the coverage of the predictor.
     *
     * @return the coverage of the predictor
     */
    default double getCoverage() {
        return (this.getNumAccesses() + this.getNumFailedToPredict()) > 0 ? (double) this.getNumAccesses() / (this.getNumAccesses() + this.getNumFailedToPredict()) : 0.0;
    }

    /**
     * Get the accuracy of the predictor.
     *
     * @return the accuracy of the predictor
     */
    default double getAccuracy() {
        return this.getHitRatio();
    }
}