com.azure.cosmos.implementation.query.orderbyquery.OrderbyRowComparer Maven / Gradle / Ivy
// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License.
package com.azure.cosmos.implementation.query.orderbyquery;
import com.azure.cosmos.implementation.query.ItemComparator;
import com.azure.cosmos.implementation.query.QueryItem;
import com.azure.cosmos.implementation.query.SortOrder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Comparator;
import java.util.List;
import static java.lang.Integer.signum;
public final class OrderbyRowComparer implements Comparator>, Serializable {
private static final Logger logger = LoggerFactory.getLogger(OrderbyRowComparer.class);
private static final long serialVersionUID = 7296627879628897315L;
private final List sortOrders;
public OrderbyRowComparer(Collection sortOrders) {
this.sortOrders = new ArrayList<>(sortOrders);
}
@Override
public int compare(OrderByRowResult r1, OrderByRowResult r2) {
try {
// comparing document (row) vs document (row)
List result1 = r1.getOrderByItems();
List result2 = r2.getOrderByItems();
if (result1.size() != result2.size()) {
throw new IllegalStateException("OrderByItems cannot have different sizes.");
}
if (result1.size() != this.sortOrders.size()) {
throw new IllegalStateException("OrderByItems cannot have a different size than sort orders.");
}
for (int i = 0; i < result1.size(); ++i) {
int cmp = ItemComparator.getInstance().compare(result1.get(i).getItem(), result2.get(i).getItem());
if (cmp != 0) {
switch (this.sortOrders.get(i)) {
case Ascending:
return signum(cmp);
case Descending:
return -signum(cmp);
}
}
}
return r1.getSourceRange().getRange().getMin()
.compareTo(r2.getSourceRange().getRange().getMin());
} catch (Exception e) {
// Due to a bug in rxjava-extras <= 0.8.0.15 dependency,
// if OrderbyRowComparer throws an unexpected exception,
// then the observable returned by Transformers.orderedMergeWith(.) will never emit a terminal event.
// rxjava-extras lib provided a quick fix on the bugreport:
// https://github.com/davidmoten/rxjava-extras/issues/30 (0.8.0.16)
// we are also capturing the exception stacktrace here
logger.error("Orderby Row comparison failed {}, {}", r1.toJson(), r2.toJson(), e);
throw e;
}
}
public List getSortOrders() {
return this.sortOrders;
}
}