Add app source, add vendoring and module support

vendor/github.com/dgryski/go-farm/farmhashmk.go

@@ -0,0 +1,102 @@
+package farm
+
+func hash32Len5to12(s []byte, seed uint32) uint32 {
+	slen := len(s)
+	a := uint32(len(s))
+	b := uint32(len(s) * 5)
+	c := uint32(9)
+	d := b + seed
+	a += fetch32(s, 0)
+	b += fetch32(s, slen-4)
+	c += fetch32(s, ((slen >> 1) & 4))
+	return fmix(seed ^ mur(c, mur(b, mur(a, d))))
+}
+
+// Hash32 hashes a byte slice and returns a uint32 hash value
+func Hash32(s []byte) uint32 {
+
+	slen := len(s)
+
+	if slen <= 24 {
+		if slen <= 12 {
+			if slen <= 4 {
+				return hash32Len0to4(s, 0)
+			}
+			return hash32Len5to12(s, 0)
+		}
+		return hash32Len13to24Seed(s, 0)
+	}
+
+	// len > 24
+	h := uint32(slen)
+	g := c1 * uint32(slen)
+	f := g
+	a0 := rotate32(fetch32(s, slen-4)*c1, 17) * c2
+	a1 := rotate32(fetch32(s, slen-8)*c1, 17) * c2
+	a2 := rotate32(fetch32(s, slen-16)*c1, 17) * c2
+	a3 := rotate32(fetch32(s, slen-12)*c1, 17) * c2
+	a4 := rotate32(fetch32(s, slen-20)*c1, 17) * c2
+	h ^= a0
+	h = rotate32(h, 19)
+	h = h*5 + 0xe6546b64
+	h ^= a2
+	h = rotate32(h, 19)
+	h = h*5 + 0xe6546b64
+	g ^= a1
+	g = rotate32(g, 19)
+	g = g*5 + 0xe6546b64
+	g ^= a3
+	g = rotate32(g, 19)
+	g = g*5 + 0xe6546b64
+	f += a4
+	f = rotate32(f, 19) + 113
+	iters := (slen - 1) / 20
+	for {
+		a := fetch32(s, 0)
+		b := fetch32(s, 4)
+		c := fetch32(s, 8)
+		d := fetch32(s, 12)
+		e := fetch32(s, 16)
+		h += a
+		g += b
+		f += c
+		h = mur(d, h) + e
+		g = mur(c, g) + a
+		f = mur(b+e*c1, f) + d
+		f += g
+		g += f
+		s = s[20:]
+		iters--
+		if iters == 0 {
+			break
+		}
+	}
+	g = rotate32(g, 11) * c1
+	g = rotate32(g, 17) * c1
+	f = rotate32(f, 11) * c1
+	f = rotate32(f, 17) * c1
+	h = rotate32(h+g, 19)
+	h = h*5 + 0xe6546b64
+	h = rotate32(h, 17) * c1
+	h = rotate32(h+f, 19)
+	h = h*5 + 0xe6546b64
+	h = rotate32(h, 17) * c1
+	return h
+}
+
+// Hash32WithSeed hashes a byte slice and a uint32 seed and returns a uint32 hash value
+func Hash32WithSeed(s []byte, seed uint32) uint32 {
+	slen := len(s)
+
+	if slen <= 24 {
+		if slen >= 13 {
+			return hash32Len13to24Seed(s, seed*c1)
+		}
+		if slen >= 5 {
+			return hash32Len5to12(s, seed)
+		}
+		return hash32Len0to4(s, seed)
+	}
+	h := hash32Len13to24Seed(s[:24], seed^uint32(slen))
+	return mur(Hash32(s[24:])+seed, h)
+}