First Commit of Voltha-Go-Controller from Radisys
Change-Id: I8e2e908e7ab09a4fe3d86849da18b6d69dcf4ab0
diff --git a/vendor/github.com/dgryski/go-rendezvous/rdv.go b/vendor/github.com/dgryski/go-rendezvous/rdv.go
new file mode 100644
index 0000000..7a6f820
--- /dev/null
+++ b/vendor/github.com/dgryski/go-rendezvous/rdv.go
@@ -0,0 +1,79 @@
+package rendezvous
+
+type Rendezvous struct {
+ nodes map[string]int
+ nstr []string
+ nhash []uint64
+ hash Hasher
+}
+
+type Hasher func(s string) uint64
+
+func New(nodes []string, hash Hasher) *Rendezvous {
+ r := &Rendezvous{
+ nodes: make(map[string]int, len(nodes)),
+ nstr: make([]string, len(nodes)),
+ nhash: make([]uint64, len(nodes)),
+ hash: hash,
+ }
+
+ for i, n := range nodes {
+ r.nodes[n] = i
+ r.nstr[i] = n
+ r.nhash[i] = hash(n)
+ }
+
+ return r
+}
+
+func (r *Rendezvous) Lookup(k string) string {
+ // short-circuit if we're empty
+ if len(r.nodes) == 0 {
+ return ""
+ }
+
+ khash := r.hash(k)
+
+ var midx int
+ var mhash = xorshiftMult64(khash ^ r.nhash[0])
+
+ for i, nhash := range r.nhash[1:] {
+ if h := xorshiftMult64(khash ^ nhash); h > mhash {
+ midx = i + 1
+ mhash = h
+ }
+ }
+
+ return r.nstr[midx]
+}
+
+func (r *Rendezvous) Add(node string) {
+ r.nodes[node] = len(r.nstr)
+ r.nstr = append(r.nstr, node)
+ r.nhash = append(r.nhash, r.hash(node))
+}
+
+func (r *Rendezvous) Remove(node string) {
+ // find index of node to remove
+ nidx := r.nodes[node]
+
+ // remove from the slices
+ l := len(r.nstr)
+ r.nstr[nidx] = r.nstr[l]
+ r.nstr = r.nstr[:l]
+
+ r.nhash[nidx] = r.nhash[l]
+ r.nhash = r.nhash[:l]
+
+ // update the map
+ delete(r.nodes, node)
+ moved := r.nstr[nidx]
+ r.nodes[moved] = nidx
+}
+
+func xorshiftMult64(x uint64) uint64 {
+ x ^= x >> 12 // a
+ x ^= x << 25 // b
+ x ^= x >> 27 // c
+ return x * 2685821657736338717
+}