com.microsoft.azure.documentdb.internal.routing.RoutingMapProviderHelper Maven / Gradle / Ivy

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package com.microsoft.azure.documentdb.internal.routing;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

import com.microsoft.azure.documentdb.PartitionKeyRange;

/**
 * Provide utility functionality to route request in direct connectivity mode in the Azure Cosmos DB database service.
 */
public final class RoutingMapProviderHelper {
    private static final Range.MaxComparator MAX_COMPARATOR = new Range.MaxComparator();

    private static String max(String left, String right) {
        return left.compareTo(right) < 0 ? right : left;
    }

    private static > boolean IsSortedAndNonOverlapping(List> list) {
        for (int i = 1; i < list.size(); i++) {
            Range previousRange = list.get(i - 1);
            Range currentRange = list.get(i);

            int compareResult = previousRange.getMax().compareTo(currentRange.getMin());
            if (compareResult > 0) {
                return false;
            } else if (compareResult == 0 && previousRange.isMaxInclusive() && currentRange.isMinInclusive()) {
                return false;
            }
        }

        return true;
    }

    public static Collection getOverlappingRanges(RoutingMapProvider routingMapProvider,
            String collectionSelfLink, List> sortedRanges) {
        if (!IsSortedAndNonOverlapping(sortedRanges)) {
            throw new IllegalArgumentException("sortedRanges");
        }

        List targetRanges = new ArrayList();
        int currentProvidedRange = 0;
        while (currentProvidedRange < sortedRanges.size()) {
            if (sortedRanges.get(currentProvidedRange).isEmpty()) {
                currentProvidedRange++;
                continue;
            }

            Range queryRange;
            if (!targetRanges.isEmpty()) {
                String left = max(targetRanges.get(targetRanges.size() - 1).getMaxExclusive(),
                        sortedRanges.get(currentProvidedRange).getMin());

                boolean leftInclusive = left.compareTo(sortedRanges.get(currentProvidedRange).getMin()) == 0
                        ? sortedRanges.get(currentProvidedRange).isMinInclusive() : false;

                queryRange = new Range(left, sortedRanges.get(currentProvidedRange).getMax(), leftInclusive,
                        sortedRanges.get(currentProvidedRange).isMaxInclusive());
            } else {
                queryRange = sortedRanges.get(currentProvidedRange);
            }

            targetRanges.addAll(routingMapProvider.getOverlappingRanges(collectionSelfLink, queryRange, false));

            Range lastKnownTargetRange = targetRanges.get(targetRanges.size() - 1).toRange();
            while (currentProvidedRange < sortedRanges.size()
                    && MAX_COMPARATOR.compare(sortedRanges.get(currentProvidedRange), lastKnownTargetRange) <= 0) {
                currentProvidedRange++;
            }
        }

        return targetRanges;
    }
}