org.springframework.data.mongodb.core.mapreduce.MapReduceResults.java Source code

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Here is the source code for org.springframework.data.mongodb.core.mapreduce.MapReduceResults.java

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/*
 * Copyright 2011-2019 the original author or authors.
 *
 * 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
 *
 *      https://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.springframework.data.mongodb.core.mapreduce;

import java.util.Iterator;
import java.util.List;

import org.bson.Document;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;

import com.mongodb.MapReduceOutput;

/**
 * Collects the results of performing a MapReduce operations.
 *
 * @author Mark Pollack
 * @author Oliver Gierke
 * @author Christoph Strobl
 * @author Mark Paluch
 * @param <T> The class in which the results are mapped onto, accessible via an iterator.
 */
public class MapReduceResults<T> implements Iterable<T> {

    private final List<T> mappedResults;
    private final @Nullable Document rawResults;
    private final @Nullable String outputCollection;
    private final MapReduceTiming mapReduceTiming;
    private final MapReduceCounts mapReduceCounts;

    /**
     * Creates a new {@link MapReduceResults} from the given mapped results and the raw one.
     *
     * @param mappedResults must not be {@literal null}.
     * @param rawResults must not be {@literal null}.
     * @deprecated since 1.7. Please use {@link #MapReduceResults(List, MapReduceOutput)}
     */
    @Deprecated
    public MapReduceResults(List<T> mappedResults, Document rawResults) {

        Assert.notNull(mappedResults, "List of mapped results must not be null!");
        Assert.notNull(rawResults, "Raw results must not be null!");

        this.mappedResults = mappedResults;
        this.rawResults = rawResults;
        this.mapReduceTiming = parseTiming(rawResults);
        this.mapReduceCounts = parseCounts(rawResults);
        this.outputCollection = parseOutputCollection(rawResults);
    }

    /**
     * Creates a new {@link MapReduceResults} from the given mapped results and the {@link MapReduceOutput}.
     *
     * @param mappedResults must not be {@literal null}.
     * @param mapReduceOutput must not be {@literal null}.
     * @since 1.7
     */
    public MapReduceResults(List<T> mappedResults, MapReduceOutput mapReduceOutput) {

        Assert.notNull(mappedResults, "MappedResults must not be null!");
        Assert.notNull(mapReduceOutput, "MapReduceOutput must not be null!");

        this.mappedResults = mappedResults;
        this.rawResults = null;
        this.mapReduceTiming = parseTiming(mapReduceOutput);
        this.mapReduceCounts = parseCounts(mapReduceOutput);
        this.outputCollection = parseOutputCollection(mapReduceOutput);
    }

    /*
     * (non-Javadoc)
     * @see java.lang.Iterable#iterator()
     */
    public Iterator<T> iterator() {
        return mappedResults.iterator();
    }

    public MapReduceTiming getTiming() {
        return mapReduceTiming;
    }

    public MapReduceCounts getCounts() {
        return mapReduceCounts;
    }

    @Nullable
    public String getOutputCollection() {
        return outputCollection;
    }

    public Document getRawResults() {
        return rawResults;
    }

    private static MapReduceTiming parseTiming(Document rawResults) {

        Document timing = (Document) rawResults.get("timing");

        if (timing == null) {
            return new MapReduceTiming(-1, -1, -1);
        }

        if (timing.get("mapTime") != null && timing.get("emitLoop") != null && timing.get("total") != null) {
            return new MapReduceTiming(getAsLong(timing, "mapTime"), getAsLong(timing, "emitLoop"),
                    getAsLong(timing, "total"));
        }

        return new MapReduceTiming(-1, -1, -1);
    }

    /**
     * Returns the value of the source's field with the given key as {@link Long}.
     *
     * @param source
     * @param key
     * @return
     */
    private static Long getAsLong(Document source, String key) {

        Object raw = source.get(key);

        return raw instanceof Long ? (Long) raw : (Integer) raw;
    }

    /**
     * Parses the raw {@link Document} result into a {@link MapReduceCounts} value object.
     *
     * @param rawResults
     * @return
     */
    private static MapReduceCounts parseCounts(Document rawResults) {

        Document counts = (Document) rawResults.get("counts");

        if (counts == null) {
            return MapReduceCounts.NONE;
        }

        if (counts.get("input") != null && counts.get("emit") != null && counts.get("output") != null) {
            return new MapReduceCounts(getAsLong(counts, "input"), getAsLong(counts, "emit"),
                    getAsLong(counts, "output"));
        }

        return MapReduceCounts.NONE;
    }

    /**
     * Parses the output collection from the raw {@link Document} result.
     *
     * @param rawResults
     * @return
     */
    @Nullable
    private static String parseOutputCollection(Document rawResults) {

        Object resultField = rawResults.get("result");

        if (resultField == null) {
            return null;
        }

        return resultField instanceof Document ? ((Document) resultField).get("collection").toString()
                : resultField.toString();
    }

    private static MapReduceCounts parseCounts(final MapReduceOutput mapReduceOutput) {
        return new MapReduceCounts(mapReduceOutput.getInputCount(), mapReduceOutput.getEmitCount(),
                mapReduceOutput.getOutputCount());
    }

    private static String parseOutputCollection(final MapReduceOutput mapReduceOutput) {
        return mapReduceOutput.getCollectionName();
    }

    private static MapReduceTiming parseTiming(MapReduceOutput mapReduceOutput) {
        return new MapReduceTiming(-1, -1, mapReduceOutput.getDuration());
    }
}