v3 static method

int v3(String key, int seed)

MurmurHash v3

Ported from: https://github.com/garycourt/murmurhash-js

Implementation

static int v3(String key, int seed) {
  int remainder = key.length & 3;
  int bytes = key.length - remainder;
  int h1 = seed;
  int c1 = 0xcc9e2d51;
  int c2 = 0x1b873593;
  int i = 0;
  int k1, h1b;
  while (i < bytes) {
    k1 = ((key.codeUnitAt(i) & 0xff)) |
        ((key.codeUnitAt(++i) & 0xff) << 8) |
        ((key.codeUnitAt(++i) & 0xff) << 16) |
        ((key.codeUnitAt(++i) & 0xff) << 24);
    ++i;
    k1 = ((((k1 & 0xffff) * c1) + ((((k1 >>> 16) * c1) & 0xffff) << 16))) &
        0xffffffff;
    k1 = (k1 << 15) | (k1 >>> 17);
    k1 = ((((k1 & 0xffff) * c2) + ((((k1 >>> 16) * c2) & 0xffff) << 16))) &
        0xffffffff;

    h1 ^= k1;
    h1 = (h1 << 13) | (h1 >>> 19);
    h1b = ((((h1 & 0xffff) * 5) + ((((h1 >>> 16) * 5) & 0xffff) << 16))) &
        0xffffffff;
    h1 = (((h1b & 0xffff) + 0x6b64) +
        ((((h1b >>> 16) + 0xe654) & 0xffff) << 16));
  }
  k1 = 0;

  switch (remainder) {
    case 3:
      k1 ^= (key.codeUnitAt(i + 2) & 0xff) << 16;
      continue case2;
    case2:
    case 2:
      k1 ^= (key.codeUnitAt(i + 1) & 0xff) << 8;
      continue case1;
    case1:
    case 1:
      k1 ^= (key.codeUnitAt(i) & 0xff);

      k1 = (((k1 & 0xffff) * c1) + ((((k1 >>> 16) * c1) & 0xffff) << 16)) &
          0xffffffff;
      k1 = (k1 << 15) | (k1 >>> 17);
      k1 = (((k1 & 0xffff) * c2) + ((((k1 >>> 16) * c2) & 0xffff) << 16)) &
          0xffffffff;
      h1 ^= k1;
  }
  h1 ^= key.length;

  h1 ^= h1 >>> 16;
  h1 = (((h1 & 0xffff) * 0x85ebca6b) +
          ((((h1 >>> 16) * 0x85ebca6b) & 0xffff) << 16)) &
      0xffffffff;
  h1 ^= h1 >>> 13;
  h1 = ((((h1 & 0xffff) * 0xc2b2ae35) +
          ((((h1 >>> 16) * 0xc2b2ae35) & 0xffff) << 16))) &
      0xffffffff;
  h1 ^= h1 >>> 16;

  return h1 >>> 0;
}