added a JumpConsistentHash implementation

lukekalbfleisch · Sep 3, 2014 · 918ad6c · 918ad6c
1 parent 5f1a0d3
commit 918ad6c
Showing 1 changed file with 15 additions and 0 deletions.
diff --git a/hash/jumpconsistenthash.go b/hash/jumpconsistenthash.go
@@ -0,0 +1,15 @@
+package hash
+
+const prime = 2862933555777941757
+
+// JumpConsistentHash a fast, minimal memory, consistent hash algorithm based on the
+// [paper](http://arxiv.org/pdf/1406.2294v1.pdf) by John Lamping and Eric Veach.
+func JumpConsistentHash(key uint64, buckets int) (b int) {
+	j := 0
+	for j < buckets {
+		b = j
+		key = key*prime + 1
+		j = int(float64(b+1) * (float64(1<<31) / float64(key>>33+1)))
+	}
+	return b
+}