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Improve the speed of RandomPartitioner comparator. patch by Sammy Yu; reviewed by jbellis for CASSANDRA-346 

git-svn-id: https://svn.apache.org/repos/asf/incubator/cassandra/trunk@801493 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Jonathan Ellis 2009-08-06 01:55:29 +00:00
parent 88b0ee7be4
commit e1e6a6c554
1 changed files with 12 additions and 6 deletions
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18
src/java/org/apache/cassandra/dht/RandomPartitioner.java
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@ -20,6 +20,7 @@ package org.apache.cassandra.dht;
import java.math.BigInteger;
import java.util.Comparator;
import java.util.StringTokenizer;
import org.apache.cassandra.config.DatabaseDescriptor;
import org.apache.cassandra.utils.FBUtilities;
@ -34,15 +35,20 @@ public class RandomPartitioner implements IPartitioner
{
public int compare(String o1, String o2)
{
String[] split1 = o1.split(":", 2);
String[] split2 = o2.split(":", 2);
BigInteger i1 = new BigInteger(split1[0]);
BigInteger i2 = new BigInteger(split2[0]);
// StringTokenizer is faster than String.split()
StringTokenizer st1 = new StringTokenizer(o1, ":");
StringTokenizer st2 = new StringTokenizer(o2, ":");
// first, compare on the bigint hash "decoration". usually this will be enough.
BigInteger i1 = new BigInteger(st1.nextToken());
BigInteger i2 = new BigInteger(st2.nextToken());
int v = i1.compareTo(i2);
if (v != 0) {
return v;
}
return split1[1].compareTo(split2[1]);
// if the hashes are equal, compare the strings
return st1.nextToken().compareTo(st2.nextToken());
}
};
private static final Comparator<String> rcomparator = new Comparator<String>()
@ -118,4 +124,4 @@ public class RandomPartitioner implements IPartitioner
{
return new BigIntegerToken(FBUtilities.hash(key));
}
}
}