org.apache.druid.query.search.SearchBinaryFn.java Source code

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Here is the source code for org.apache.druid.query.search.SearchBinaryFn.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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
 *
 * 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.apache.druid.query.search;

import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import org.apache.druid.java.util.common.granularity.AllGranularity;
import org.apache.druid.java.util.common.granularity.Granularity;
import org.apache.druid.java.util.common.guava.nary.BinaryFn;
import org.apache.druid.query.Result;
import org.joda.time.DateTime;

import java.util.Arrays;
import java.util.List;

/**
 */
public class SearchBinaryFn
        implements BinaryFn<Result<SearchResultValue>, Result<SearchResultValue>, Result<SearchResultValue>> {
    private final SearchSortSpec searchSortSpec;
    private final Granularity gran;
    private final int limit;

    public SearchBinaryFn(SearchSortSpec searchSortSpec, Granularity granularity, int limit) {
        this.searchSortSpec = searchSortSpec;
        this.gran = granularity;
        this.limit = limit;
    }

    @Override
    public Result<SearchResultValue> apply(Result<SearchResultValue> arg1, Result<SearchResultValue> arg2) {
        if (arg1 == null) {
            return arg2;
        }

        if (arg2 == null) {
            return arg1;
        }

        final int limit = gran instanceof AllGranularity ? this.limit : -1;

        SearchResultValue arg1Vals = arg1.getValue();
        SearchResultValue arg2Vals = arg2.getValue();

        Iterable<SearchHit> merged = Iterables.mergeSorted(Arrays.asList(arg1Vals, arg2Vals),
                searchSortSpec.getComparator());

        int maxSize = arg1Vals.getValue().size() + arg2Vals.getValue().size();
        if (limit > 0) {
            maxSize = Math.min(limit, maxSize);
        }
        List<SearchHit> results = Lists.newArrayListWithExpectedSize(maxSize);

        SearchHit prev = null;
        for (SearchHit searchHit : merged) {
            if (prev == null) {
                prev = searchHit;
                continue;
            }
            if (prev.equals(searchHit)) {
                if (prev.getCount() != null && searchHit.getCount() != null) {
                    prev = new SearchHit(prev.getDimension(), prev.getValue(),
                            prev.getCount() + searchHit.getCount());
                } else {
                    prev = new SearchHit(prev.getDimension(), prev.getValue());
                }
            } else {
                results.add(prev);
                prev = searchHit;
                if (limit > 0 && results.size() >= limit) {
                    break;
                }
            }
        }

        if (prev != null && (limit < 0 || results.size() < limit)) {
            results.add(prev);
        }

        final DateTime timestamp = gran instanceof AllGranularity ? arg1.getTimestamp()
                : gran.bucketStart(arg1.getTimestamp());

        return new Result<SearchResultValue>(timestamp, new SearchResultValue(results));
    }
}