Java Utililty Methods Murmur Hash

int murmur(String str, int seed)
murmur

if (str == null)
 throw new IllegalArgumentException("str cannot be null");
final int m = 0xc6a4a793;
final int r = 16;
int hash = seed ^ (str.length() * m);
byte b[] = str.getBytes();
int len = b.length;
int i = 0;
...

int murmur2(final byte[] data)
murmur

int length = data.length;
int seed = 0x9747b28c;
final int m = 0x5bd1e995;
final int r = 24;
int h = seed ^ length;
int length4 = length / 4;
for (int i = 0; i < length4; i++) {
 final int i4 = i * 4;
...

int murmur2(int value, int salt)
The Murmur2 hash function.

final int M = 0x5bd1e995;
final int R = 24;
int hash = salt;
value *= M;
value ^= value >>> R;
value *= M;
hash *= M;
hash ^= value;
...

int murmur3fmix(int value)
The Murmur3 Fmix function.

value ^= value >>> 16;
value *= 0x85ebca6b;
value ^= value >>> 13;
value *= 0xc2b2ae35;
value ^= value >>> 16;
return value;

int murmurHash(byte[] data, int offset, int length)
murmur Hash

int m = 0x5bd1e995;
int r = 24;
int h = length;
int len_4 = length >> 2;
for (int i = 0; i < len_4; i++) {
 int i_4 = offset + (i << 2);
 int k = data[i_4 + 3];
 k = k << 8;
...

int murmurHash(int code)
murmur Hash

code *= 0xcc9e2d51;
code = Integer.rotateLeft(code, 15);
code *= 0x1b873593;
code = Integer.rotateLeft(code, 13);
code *= 0xe6546b64;
code ^= 4;
code ^= code >>> 16;
code *= 0x85ebca6b;
...

long murmurhash2_64(final byte[] data, int length, int seed)
murmur hash 2.0, The murmur hash is a relatively fast hash function from http://murmurhash.googlepages.com/ for platforms with efficient multiplication.

final long m = 0xc6a4a7935bd1e995L;
final int r = 47;
long h = (seed & 0xffffffffl) ^ (length * m);
int length8 = length / 8;
for (int i = 0; i < length8; i++) {
 final int i8 = i * 8;
 long k = ((long) data[i8 + 0] & 0xff) 
 + (((long) data[i8 + 1] & 0xff) << 8) 
...

int murmurHash3(int k)
murmur Hash

k ^= k >>> 16;
k *= 0x85ebca6b;
k ^= k >>> 13;
k *= 0xc2b2ae35;
k ^= k >>> 16;
return k;

int murmurHash3(int x)
Avalanches the bits of an integer by applying the finalisation step of MurmurHash3.

x ^= x >>> 16;
x *= 0x85ebca6b;
x ^= x >>> 13;
x *= 0xc2b2ae35;
x ^= x >>> 16;
return x;

int murmurHash3(int x)
murmur Hash

x ^= x >>> 16;
x *= -2048144789;
x ^= x >>> 13;
x *= -1028477387;
x ^= x >>> 16;
return x;