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StringComparators: No need to convert to UTF-8 for lexicographic comparison. #11171

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Merged
gianm merged 1 commit into from
Apr 30, 2021
Merged

StringComparators: No need to convert to UTF-8 for lexicographic comparison. #11171

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17 changes: 4 additions & 13 deletions processing/src/main/java/org/apache/druid/query/ordering/StringComparators.java
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Original file line number Diff line number Diff line change
Expand Up @@ -21,9 +21,7 @@

import com.google.common.collect.Ordering;
import com.google.common.primitives.Ints;
import com.google.common.primitives.UnsignedBytes;
import org.apache.druid.common.guava.GuavaUtils;
import org.apache.druid.java.util.common.StringUtils;
import org.apache.maven.artifact.versioning.DefaultArtifactVersion;

import java.math.BigDecimal;
Expand Down Expand Up @@ -51,20 +49,13 @@ public class StringComparators

public static class LexicographicComparator extends StringComparator
{
private static final Ordering<String> ORDERING = Ordering.from(new Comparator<String>()
{
@Override
public int compare(String s, String s2)
{
return UnsignedBytes.lexicographicalComparator().compare(
StringUtils.toUtf8(s), StringUtils.toUtf8(s2));
}
}).nullsFirst();

// Equivalent to comparing UTF-8 encoded strings as byte arrays.
private static final Ordering<String> ORDERING = Ordering.from(String::compareTo).nullsFirst();

@Override
public int compare(String s, String s2)
{
// Avoid conversion to bytes for equal references
// Avoid comparisons for equal references
// Assuming we mostly compare different strings, checking s.equals(s2) will only make the comparison slower.
//noinspection StringEquality
if (s == s2) {
Expand Down