Class: Murmur3
- Inherits:
-
Object
- Object
- Murmur3
- Defined in:
- lib/prefab/murmer3.rb
Constant Summary collapse
- MASK32 =
MurmurHash3 was written by Austin Appleby, and is placed in the public domain. The author hereby disclaims copyright to this source code.
0xffffffff
Class Method Summary collapse
- .murmur3_32(str, seed = 0) ⇒ Object
- .murmur3_32__mmix(k1) ⇒ Object
- .murmur3_32_fmix(h) ⇒ Object
- .murmur3_32_rotl(x, r) ⇒ Object
Class Method Details
.murmur3_32(str, seed = 0) ⇒ Object
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# File 'lib/prefab/murmer3.rb', line 28 def self.murmur3_32(str, seed = 0) h1 = seed numbers = str.unpack('V*C*') tailn = str.length % 4 tail = numbers.slice!(numbers.size - tailn, tailn) for k1 in numbers h1 ^= murmur3_32__mmix(k1) h1 = murmur3_32_rotl(h1, 13) h1 = (h1 * 5 + 0xe6546b64) & MASK32 end unless tail.empty? k1 = 0 tail.reverse_each do |c1| k1 = (k1 << 8) | c1 end h1 ^= murmur3_32__mmix(k1) end h1 ^= str.length murmur3_32_fmix(h1) end |
.murmur3_32__mmix(k1) ⇒ Object
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# File 'lib/prefab/murmer3.rb', line 22 def self.murmur3_32__mmix(k1) k1 = (k1 * 0xcc9e2d51) & MASK32 k1 = murmur3_32_rotl(k1, 15) (k1 * 0x1b873593) & MASK32 end |
.murmur3_32_fmix(h) ⇒ Object
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# File 'lib/prefab/murmer3.rb', line 13 def self.murmur3_32_fmix(h) h &= MASK32 h ^= h >> 16 h = (h * 0x85ebca6b) & MASK32 h ^= h >> 13 h = (h * 0xc2b2ae35) & MASK32 h ^ (h >> 16) end |
.murmur3_32_rotl(x, r) ⇒ Object
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# File 'lib/prefab/murmer3.rb', line 9 def self.murmur3_32_rotl(x, r) ((x << r) | (x >> (32 - r))) & MASK32 end |