isaac64_test.gno

  1package isaac64
  2
  3import (
  4	"math/rand"
  5	"testing"
  6)
  7
  8type OpenISAAC struct {
  9	Randrsl    [256]uint64
 10	Randcnt    uint64
 11	Mm         [256]uint64
 12	Aa, Bb, Cc uint64
 13	Seed       [256]uint64
 14}
 15
 16func TestISAACSeeding(t *testing.T) {
 17	_ = New()
 18}
 19
 20func TestISAACRand(t *testing.T) {
 21	rnd := New(987654321)
 22	rng := rand.New(rnd)
 23
 24	// Expected outputs for the first 5 random floats with the given seed
 25	expected := []float64{
 26		0.2818878834295122,
 27		0.8575461830821571,
 28		0.9878021063787968,
 29		0.6503544780116336,
 30		0.5158329690433359,
 31		0.7959152461588924,
 32		0.5432366486934906,
 33		0.824665978209607,
 34		0.8615372170680458,
 35		0.22954589404739578,
 36	}
 37
 38	for i, exp := range expected {
 39		val := rng.Float64()
 40		if exp != val {
 41			t.Errorf("Rand.Float64() at iteration %d: got %g, expected %g", i, val, exp)
 42		}
 43	}
 44}
 45
 46func TestISAACUint64(t *testing.T) {
 47	rnd := New(1000)
 48
 49	expected := []uint64{
 50		10083220283665581455,
 51		10039389761195725041,
 52		6820016387036140989,
 53		6784213597523088182,
 54		13120722600477653778,
 55		3491117614651563646,
 56		1297676147275528930,
 57		15006384980354042338,
 58		3104467119059991036,
 59		4914319123654344819,
 60	}
 61
 62	for i, exp := range expected {
 63		val := rnd.Uint64()
 64		if exp != val {
 65			t.Errorf("ISAAC.Uint64() at iteration %d: got %d, expected %d", i, val, exp)
 66		}
 67	}
 68}
 69
 70func dupState(i *ISAAC) *OpenISAAC {
 71	state := &OpenISAAC{}
 72	state.Seed = i.seed
 73	state.Randrsl = i.randrsl
 74	state.Mm = i.mm
 75	state.Aa = i.aa
 76	state.Bb = i.bb
 77	state.Cc = i.cc
 78	state.Randcnt = i.randcnt
 79
 80	return state
 81}
 82
 83func TestISAACMarshalUnmarshal(t *testing.T) {
 84	rnd := New(1001)
 85
 86	expected1 := []uint64{
 87		4398183556077595549,
 88		14479654616302101831,
 89		15852653767232940552,
 90		2801765968457115882,
 91		8875575139772470433,
 92	}
 93
 94	expected2 := []uint64{
 95		17583056722733587141,
 96		16906215529544723388,
 97		7599862885469865851,
 98		9623269843822592805,
 99		4311429062865512072,
100	}
101
102	for i, exp := range expected1 {
103		val := rnd.Uint64()
104		if exp != val {
105			t.Errorf("ISAAC.Uint64() at iteration %d: got %d, expected %d", i, val, exp)
106		}
107	}
108
109	marshalled, err := rnd.MarshalBinary()
110
111	// t.Logf("State: [%v]\n", dupState(rnd))
112	// t.Logf("Marshalled State: [%x] -- %v\n", marshalled, err)
113	state_before := dupState(rnd)
114
115	if err != nil {
116		t.Errorf("ISAAC.MarshalBinary() error: %v", err)
117	}
118
119	// Advance state by one number; then check the next 5. The expectation is that they _will_ fail.
120	rnd.Uint64()
121
122	for i, exp := range expected2 {
123		val := rnd.Uint64()
124		if exp == val {
125			t.Errorf("  Iteration %d matched %d; which is from iteration %d; something strange is happening.", (i + 6), val, (i + 5))
126		}
127	}
128
129	// t.Logf("State before unmarshall: [%v]\n", dupState(rnd))
130
131	// Now restore the state of the PRNG
132	err = rnd.UnmarshalBinary(marshalled)
133
134	// t.Logf("State after unmarshall: [%v]\n", dupState(rnd))
135
136	if state_before.Seed != dupState(rnd).Seed {
137		t.Errorf("Seed mismatch")
138	}
139	if state_before.Randrsl != dupState(rnd).Randrsl {
140		t.Errorf("Randrsl mismatch")
141	}
142	if state_before.Mm != dupState(rnd).Mm {
143		t.Errorf("Mm mismatch")
144	}
145	if state_before.Aa != dupState(rnd).Aa {
146		t.Errorf("Aa mismatch")
147	}
148	if state_before.Bb != dupState(rnd).Bb {
149		t.Errorf("Bb mismatch")
150	}
151	if state_before.Cc != dupState(rnd).Cc {
152		t.Errorf("Cc mismatch")
153	}
154	if state_before.Randcnt != dupState(rnd).Randcnt {
155		t.Errorf("Randcnt mismatch")
156	}
157
158	// Now we should be back on track for the last 5 numbers
159	for i, exp := range expected2 {
160		val := rnd.Uint64()
161		if exp != val {
162			t.Errorf("ISAAC.Uint64() at iteration %d: got %d, expected %d", (i + 5), val, exp)
163		}
164	}
165}