com.cloudera.oryx.app.serving.als.AbstractALSResource.java Source code

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Here is the source code for com.cloudera.oryx.app.serving.als.AbstractALSResource.java

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/*
 * Copyright (c) 2014, Cloudera, Inc. All Rights Reserved.
 *
 * Cloudera, Inc. licenses this file to you 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
 *
 * This software 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 com.cloudera.oryx.app.serving.als;

import java.util.Collections;
import java.util.List;
import javax.annotation.PostConstruct;
import javax.ws.rs.core.Response;

import com.google.common.base.Function;
import com.google.common.collect.Lists;
import net.openhft.koloboke.function.ObjDoubleToDoubleFunction;
import net.openhft.koloboke.function.Predicate;

import com.cloudera.oryx.app.als.Rescorer;
import com.cloudera.oryx.app.serving.OryxServingException;
import com.cloudera.oryx.common.collection.Pair;
import com.cloudera.oryx.app.serving.AbstractOryxResource;
import com.cloudera.oryx.app.serving.IDValue;
import com.cloudera.oryx.app.serving.als.model.ALSServingModel;

/**
 * Superclass of all Serving Layer ALS application endpoints.
 */
public abstract class AbstractALSResource extends AbstractOryxResource {

    private ALSServingModel alsServingModel;

    @Override
    @PostConstruct
    public void init() {
        super.init();
        alsServingModel = (ALSServingModel) getServingModelManager().getModel();
    }

    final ALSServingModel getALSServingModel() throws OryxServingException {
        if (alsServingModel == null) {
            throw new OryxServingException(Response.Status.SERVICE_UNAVAILABLE);
        }
        return alsServingModel;
    }

    static <T> List<T> selectedSublist(List<T> values, int howMany, int offset) {
        if (values.size() < offset) {
            return Collections.emptyList();
        }
        return values.subList(offset, Math.min(offset + howMany, values.size()));
    }

    static List<IDValue> toIDValueResponse(List<Pair<String, Double>> pairs, int howMany, int offset) {
        List<Pair<String, Double>> sublist = selectedSublist(pairs, howMany, offset);
        return Lists.transform(sublist, new Function<Pair<String, Double>, IDValue>() {
            @Override
            public IDValue apply(Pair<String, Double> idDot) {
                return new IDValue(idDot.getFirst(), idDot.getSecond());
            }
        });
    }

    static ObjDoubleToDoubleFunction<String> buildRescoreFn(final Rescorer rescorer) {
        return new ObjDoubleToDoubleFunction<String>() {
            @Override
            public double applyAsDouble(String ID, double score) {
                return rescorer.rescore(ID, score);
            }
        };
    }

    static Predicate<String> buildRescorerPredicate(final Rescorer rescorer) {
        return new Predicate<String>() {
            @Override
            public boolean test(String ID) {
                return !rescorer.isFiltered(ID);
            }
        };
    }

}