add vendor

vendor/github.com/segmentio/fasthash/fnv1a/hash32.go

@@ -0,0 +1,53 @@
+package fnv1a
+
+const (
+	// FNV-1a
+	offset32 = uint32(2166136261)
+	prime32  = uint32(16777619)
+
+	// Init32 is what 32 bits hash values should be initialized with.
+	Init32 = offset32
+)
+
+// HashString32 returns the hash of s.
+func HashString32(s string) uint32 {
+	return AddString32(Init32, s)
+}
+
+// HashUint32 returns the hash of u.
+func HashUint32(u uint32) uint32 {
+	return AddUint32(Init32, u)
+}
+
+// AddString32 adds the hash of s to the precomputed hash value h.
+func AddString32(h uint32, s string) uint32 {
+	i := 0
+	n := (len(s) / 8) * 8
+
+	for i != n {
+		h = (h ^ uint32(s[i])) * prime32
+		h = (h ^ uint32(s[i+1])) * prime32
+		h = (h ^ uint32(s[i+2])) * prime32
+		h = (h ^ uint32(s[i+3])) * prime32
+		h = (h ^ uint32(s[i+4])) * prime32
+		h = (h ^ uint32(s[i+5])) * prime32
+		h = (h ^ uint32(s[i+6])) * prime32
+		h = (h ^ uint32(s[i+7])) * prime32
+		i += 8
+	}
+
+	for _, c := range s[i:] {
+		h = (h ^ uint32(c)) * prime32
+	}
+
+	return h
+}
+
+// AddUint32 adds the hash value of the 8 bytes of u to h.
+func AddUint32(h, u uint32) uint32 {
+	h = (h ^ ((u >> 24) & 0xFF)) * prime32
+	h = (h ^ ((u >> 16) & 0xFF)) * prime32
+	h = (h ^ ((u >> 8) & 0xFF)) * prime32
+	h = (h ^ ((u >> 0) & 0xFF)) * prime32
+	return h
+}