def apply()

in util-hashing/src/main/scala/com/twitter/hashing/Hashable.scala [246:311]

• 53 lines of code
• 15 McCabe index (conditional complexity)

    def apply(key: Array[Byte]): Long = {
      var a, b, c = 0xdeadbeef + key.length

      def rot(x: Int, k: Int) = (((x) << (k)) | ((x) >> (32 - (k))))

      def mix(): Unit = {
        a -= c; a ^= rot(c, 4); c += b
        b -= a; b ^= rot(a, 6); a += c
        c -= b; c ^= rot(b, 8); b += a
        a -= c; a ^= rot(c, 16); c += b
        b -= a; b ^= rot(a, 19); a += c
        c -= b; c ^= rot(b, 4); b += a
      }

      def fin(): Unit = {
        c ^= b; c -= rot(b, 14); a ^= c; a -= rot(c, 11)
        b ^= a; b -= rot(a, 25); c ^= b; c -= rot(b, 16)
        a ^= c; a -= rot(c, 4); b ^= a; b -= rot(a, 14)
        c ^= b; c -= rot(b, 24)
      }

      var block = 0
      val numBlocks = (key.length - 1) / 12
      while (block < numBlocks) {
        val offset = block * 12
        a += key(offset)
        a += key(offset + 1) << 8
        a += key(offset + 2) << 16
        a += key(offset + 3) << 24

        b += key(offset + 4)
        b += key(offset + 5) << 8
        b += key(offset + 6) << 16
        b += key(offset + 7) << 24

        c += key(offset + 8)
        c += key(offset + 9) << 8
        c += key(offset + 10) << 16
        c += key(offset + 11) << 24

        mix()
        block += 1
      }

      val remaining = key.length - (numBlocks * 12)
      val offset = numBlocks * 12

      if (remaining > 0) a += key(offset)
      if (remaining > 1) a += key(offset + 1) << 8
      if (remaining > 2) a += key(offset + 2) << 16
      if (remaining > 3) a += key(offset + 3) << 24

      if (remaining > 4) b += key(offset + 4)
      if (remaining > 5) b += key(offset + 5) << 8
      if (remaining > 6) b += key(offset + 6) << 16
      if (remaining > 7) b += key(offset + 7) << 24

      if (remaining > 8) c += key(offset + 8)
      if (remaining > 9) c += key(offset + 9) << 8
      if (remaining > 10) c += key(offset + 10) << 16
      if (remaining > 11) c += key(offset + 11) << 24

      if (key.length > 0) fin()

      (b.toLong << 32) + c.toLong
    }