Benchmarks of some Java hash functions. Please note that this benchmark only computes the hash function performance, not its quality. A good slow hash function will always provide better hashtable performance than a bad fast hash function. However, some of the fast functions benchmarked, such as XXHash and Murmur3 are known to be good hash functions (XXHash for instance has a SMHasher score of 10).

The souce code used for this benchmark can be found at github.com/jpountz/jvm-checksum-benchmark.

• Arrays.hashCode is the hash function specified in the java.util.Arrays.hashCode(byte[]) method,
• CRC-32 is the java.util.zip.CRC32.
• Adler-32 is the java.util.zip.Adler32.
• Murmur2 is a Java implementation of the version 2 of MurmurHash.
• Murmur3 is the Java implementation of MurmurHash version 3 found in Guava.
• Hashing.goodFastHash(32) and Hashing.goodFastHash(64) are two hash implementations from Guava.
• the XXHash hash functions are those found in lz4-java.