Author: jbellis
Date: Thu Aug 6 01:55:29 2009
New Revision: 801493
URL: http://svn.apache.org/viewvc?rev=801493&view=rev
Log:
Improve the speed of RandomPartitioner comparator. patch by Sammy Yu; reviewed by jbellis for CASSANDRA-346
Modified:
incubator/cassandra/trunk/src/java/org/apache/cassandra/dht/RandomPartitioner.java
Modified: incubator/cassandra/trunk/src/java/org/apache/cassandra/dht/RandomPartitioner.java
URL: http://svn.apache.org/viewvc/incubator/cassandra/trunk/src/java/org/apache/cassandra/dht/RandomPartitioner.java?rev=801493&r1=801492&r2=801493&view=diff
==============================================================================
--- incubator/cassandra/trunk/src/java/org/apache/cassandra/dht/RandomPartitioner.java (original)
+++ incubator/cassandra/trunk/src/java/org/apache/cassandra/dht/RandomPartitioner.java Thu Aug 6 01:55:29 2009
@@ -20,6 +20,7 @@
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 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 @@
{
return new BigIntegerToken(FBUtilities.hash(key));
}
-}
\ No newline at end of file
+}