Initial cloud-services repo - gateway service + pkg modules

pkg/utils/mt19937/mt19937.go

@@ -0,0 +1,92 @@
+package mt19937
+
+type MT19937 struct {
+	state []uint64
+	index int
+}
+
+func New() *MT19937 {
+	mt := &MT19937{
+		state: make([]uint64, n),
+		index: n,
+	}
+	mt.Seed(5489)
+	return mt
+}
+
+func (mt *MT19937) Seed(seed uint64) {
+	x := mt.state
+	x[0] = seed
+	for i := 1; i < n; i++ {
+		x[i] = f*(x[i-1]^(x[i-1]>>(w-2))) + uint64(i)
+	}
+}
+
+func (mt *MT19937) Random() uint64 {
+	x := mt.state
+	if mt.index == n {
+		mt.twist()
+	}
+	var z uint64 = x[mt.index]
+
+	mt.index++
+
+	z ^= ((z >> u) & d)
+	z ^= ((z << s) & b)
+	z ^= ((z << t) & c)
+	z ^= (z >> l)
+	return z
+}
+
+const (
+	// The variables used in the algorithm are as follows:
+	// w: length (in bits)
+	// n: recursion length
+	// m: period parameter, used as the offset of the third stage
+	// r: low-order mask / low-order bits to be extracted
+	// a: the parameters of the rotation matrix
+	// b,c: TGFSR mask
+	// s, t: the displacement of TGFSR
+	// u,d,l: mask and displacement required for additional mason rotation
+	// f: Initialize the required parameters of the Mason rotating chain
+
+	w = 64
+	n = 312
+	m = 156
+	r = 31
+
+	a = 0xb5026f5aa96619e9
+
+	u = 29
+	d = 0x5555555555555555
+
+	s = 17
+	b = 0x71d67fffeda60000
+
+	t = 37
+	c = 0xfff7eee000000000
+
+	l = 43
+
+	f = 6364136223846793005
+)
+
+func (mt *MT19937) twist() {
+	x := mt.state
+	const lower_mask uint64 = 1<<r - 1
+	const upper_mask uint64 = ^lower_mask
+
+	for j := 0; j < n-m; j++ {
+		var y uint64 = (x[j] & upper_mask) | (x[j+1] & lower_mask)
+		x[j] = x[j+m] ^ (y >> 1) ^ ((x[j+1] & 1) * a)
+	}
+
+	for j := n - m; j < n-1; j++ {
+		var y uint64 = (x[j] & upper_mask) | (x[j+1] & lower_mask)
+		x[j] = x[j-(n-m)] ^ (y >> 1) ^ ((x[j+1] & 1) * a)
+	}
+
+	var y uint64 = (x[n-1] & upper_mask) | (x[0] & lower_mask)
+	x[n-1] = x[m-1] ^ (y >> 1) ^ ((x[0] & 1) * a)
+	mt.index = 0
+}