--- /dev/null
+package lru
+
+import (
+ "math/rand"
+ "testing"
+ "time"
+)
+
+func init() {
+ rand.Seed(time.Now().Unix())
+}
+
+func BenchmarkARC_Rand(b *testing.B) {
+ l, err := NewARC(8192)
+ if err != nil {
+ b.Fatalf("err: %v", err)
+ }
+
+ trace := make([]int64, b.N*2)
+ for i := 0; i < b.N*2; i++ {
+ trace[i] = rand.Int63() % 32768
+ }
+
+ b.ResetTimer()
+
+ var hit, miss int
+ for i := 0; i < 2*b.N; i++ {
+ if i%2 == 0 {
+ l.Add(trace[i], trace[i])
+ } else {
+ _, ok := l.Get(trace[i])
+ if ok {
+ hit++
+ } else {
+ miss++
+ }
+ }
+ }
+ b.Logf("hit: %d miss: %d ratio: %f", hit, miss, float64(hit)/float64(miss))
+}
+
+func BenchmarkARC_Freq(b *testing.B) {
+ l, err := NewARC(8192)
+ if err != nil {
+ b.Fatalf("err: %v", err)
+ }
+
+ trace := make([]int64, b.N*2)
+ for i := 0; i < b.N*2; i++ {
+ if i%2 == 0 {
+ trace[i] = rand.Int63() % 16384
+ } else {
+ trace[i] = rand.Int63() % 32768
+ }
+ }
+
+ b.ResetTimer()
+
+ for i := 0; i < b.N; i++ {
+ l.Add(trace[i], trace[i])
+ }
+ var hit, miss int
+ for i := 0; i < b.N; i++ {
+ _, ok := l.Get(trace[i])
+ if ok {
+ hit++
+ } else {
+ miss++
+ }
+ }
+ b.Logf("hit: %d miss: %d ratio: %f", hit, miss, float64(hit)/float64(miss))
+}
+
+func TestARC_RandomOps(t *testing.T) {
+ size := 128
+ l, err := NewARC(128)
+ if err != nil {
+ t.Fatalf("err: %v", err)
+ }
+
+ n := 200000
+ for i := 0; i < n; i++ {
+ key := rand.Int63() % 512
+ r := rand.Int63()
+ switch r % 3 {
+ case 0:
+ l.Add(key, key)
+ case 1:
+ l.Get(key)
+ case 2:
+ l.Remove(key)
+ }
+
+ if l.t1.Len()+l.t2.Len() > size {
+ t.Fatalf("bad: t1: %d t2: %d b1: %d b2: %d p: %d",
+ l.t1.Len(), l.t2.Len(), l.b1.Len(), l.b2.Len(), l.p)
+ }
+ if l.b1.Len()+l.b2.Len() > size {
+ t.Fatalf("bad: t1: %d t2: %d b1: %d b2: %d p: %d",
+ l.t1.Len(), l.t2.Len(), l.b1.Len(), l.b2.Len(), l.p)
+ }
+ }
+}
+
+func TestARC_Get_RecentToFrequent(t *testing.T) {
+ l, err := NewARC(128)
+ if err != nil {
+ t.Fatalf("err: %v", err)
+ }
+
+ // Touch all the entries, should be in t1
+ for i := 0; i < 128; i++ {
+ l.Add(i, i)
+ }
+ if n := l.t1.Len(); n != 128 {
+ t.Fatalf("bad: %d", n)
+ }
+ if n := l.t2.Len(); n != 0 {
+ t.Fatalf("bad: %d", n)
+ }
+
+ // Get should upgrade to t2
+ for i := 0; i < 128; i++ {
+ _, ok := l.Get(i)
+ if !ok {
+ t.Fatalf("missing: %d", i)
+ }
+ }
+ if n := l.t1.Len(); n != 0 {
+ t.Fatalf("bad: %d", n)
+ }
+ if n := l.t2.Len(); n != 128 {
+ t.Fatalf("bad: %d", n)
+ }
+
+ // Get be from t2
+ for i := 0; i < 128; i++ {
+ _, ok := l.Get(i)
+ if !ok {
+ t.Fatalf("missing: %d", i)
+ }
+ }
+ if n := l.t1.Len(); n != 0 {
+ t.Fatalf("bad: %d", n)
+ }
+ if n := l.t2.Len(); n != 128 {
+ t.Fatalf("bad: %d", n)
+ }
+}
+
+func TestARC_Add_RecentToFrequent(t *testing.T) {
+ l, err := NewARC(128)
+ if err != nil {
+ t.Fatalf("err: %v", err)
+ }
+
+ // Add initially to t1
+ l.Add(1, 1)
+ if n := l.t1.Len(); n != 1 {
+ t.Fatalf("bad: %d", n)
+ }
+ if n := l.t2.Len(); n != 0 {
+ t.Fatalf("bad: %d", n)
+ }
+
+ // Add should upgrade to t2
+ l.Add(1, 1)
+ if n := l.t1.Len(); n != 0 {
+ t.Fatalf("bad: %d", n)
+ }
+ if n := l.t2.Len(); n != 1 {
+ t.Fatalf("bad: %d", n)
+ }
+
+ // Add should remain in t2
+ l.Add(1, 1)
+ if n := l.t1.Len(); n != 0 {
+ t.Fatalf("bad: %d", n)
+ }
+ if n := l.t2.Len(); n != 1 {
+ t.Fatalf("bad: %d", n)
+ }
+}
+
+func TestARC_Adaptive(t *testing.T) {
+ l, err := NewARC(4)
+ if err != nil {
+ t.Fatalf("err: %v", err)
+ }
+
+ // Fill t1
+ for i := 0; i < 4; i++ {
+ l.Add(i, i)
+ }
+ if n := l.t1.Len(); n != 4 {
+ t.Fatalf("bad: %d", n)
+ }
+
+ // Move to t2
+ l.Get(0)
+ l.Get(1)
+ if n := l.t2.Len(); n != 2 {
+ t.Fatalf("bad: %d", n)
+ }
+
+ // Evict from t1
+ l.Add(4, 4)
+ if n := l.b1.Len(); n != 1 {
+ t.Fatalf("bad: %d", n)
+ }
+
+ // Current state
+ // t1 : (MRU) [4, 3] (LRU)
+ // t2 : (MRU) [1, 0] (LRU)
+ // b1 : (MRU) [2] (LRU)
+ // b2 : (MRU) [] (LRU)
+
+ // Add 2, should cause hit on b1
+ l.Add(2, 2)
+ if n := l.b1.Len(); n != 1 {
+ t.Fatalf("bad: %d", n)
+ }
+ if l.p != 1 {
+ t.Fatalf("bad: %d", l.p)
+ }
+ if n := l.t2.Len(); n != 3 {
+ t.Fatalf("bad: %d", n)
+ }
+
+ // Current state
+ // t1 : (MRU) [4] (LRU)
+ // t2 : (MRU) [2, 1, 0] (LRU)
+ // b1 : (MRU) [3] (LRU)
+ // b2 : (MRU) [] (LRU)
+
+ // Add 4, should migrate to t2
+ l.Add(4, 4)
+ if n := l.t1.Len(); n != 0 {
+ t.Fatalf("bad: %d", n)
+ }
+ if n := l.t2.Len(); n != 4 {
+ t.Fatalf("bad: %d", n)
+ }
+
+ // Current state
+ // t1 : (MRU) [] (LRU)
+ // t2 : (MRU) [4, 2, 1, 0] (LRU)
+ // b1 : (MRU) [3] (LRU)
+ // b2 : (MRU) [] (LRU)
+
+ // Add 4, should evict to b2
+ l.Add(5, 5)
+ if n := l.t1.Len(); n != 1 {
+ t.Fatalf("bad: %d", n)
+ }
+ if n := l.t2.Len(); n != 3 {
+ t.Fatalf("bad: %d", n)
+ }
+ if n := l.b2.Len(); n != 1 {
+ t.Fatalf("bad: %d", n)
+ }
+
+ // Current state
+ // t1 : (MRU) [5] (LRU)
+ // t2 : (MRU) [4, 2, 1] (LRU)
+ // b1 : (MRU) [3] (LRU)
+ // b2 : (MRU) [0] (LRU)
+
+ // Add 0, should decrease p
+ l.Add(0, 0)
+ if n := l.t1.Len(); n != 0 {
+ t.Fatalf("bad: %d", n)
+ }
+ if n := l.t2.Len(); n != 4 {
+ t.Fatalf("bad: %d", n)
+ }
+ if n := l.b1.Len(); n != 2 {
+ t.Fatalf("bad: %d", n)
+ }
+ if n := l.b2.Len(); n != 0 {
+ t.Fatalf("bad: %d", n)
+ }
+ if l.p != 0 {
+ t.Fatalf("bad: %d", l.p)
+ }
+
+ // Current state
+ // t1 : (MRU) [] (LRU)
+ // t2 : (MRU) [0, 4, 2, 1] (LRU)
+ // b1 : (MRU) [5, 3] (LRU)
+ // b2 : (MRU) [0] (LRU)
+}
+
+func TestARC(t *testing.T) {
+ l, err := NewARC(128)
+ if err != nil {
+ t.Fatalf("err: %v", err)
+ }
+
+ for i := 0; i < 256; i++ {
+ l.Add(i, i)
+ }
+ if l.Len() != 128 {
+ t.Fatalf("bad len: %v", l.Len())
+ }
+
+ for i, k := range l.Keys() {
+ if v, ok := l.Get(k); !ok || v != k || v != i+128 {
+ t.Fatalf("bad key: %v", k)
+ }
+ }
+ for i := 0; i < 128; i++ {
+ _, ok := l.Get(i)
+ if ok {
+ t.Fatalf("should be evicted")
+ }
+ }
+ for i := 128; i < 256; i++ {
+ _, ok := l.Get(i)
+ if !ok {
+ t.Fatalf("should not be evicted")
+ }
+ }
+ for i := 128; i < 192; i++ {
+ l.Remove(i)
+ _, ok := l.Get(i)
+ if ok {
+ t.Fatalf("should be deleted")
+ }
+ }
+
+ l.Purge()
+ if l.Len() != 0 {
+ t.Fatalf("bad len: %v", l.Len())
+ }
+ if _, ok := l.Get(200); ok {
+ t.Fatalf("should contain nothing")
+ }
+}
+
+// Test that Contains doesn't update recent-ness
+func TestARC_Contains(t *testing.T) {
+ l, err := NewARC(2)
+ if err != nil {
+ t.Fatalf("err: %v", err)
+ }
+
+ l.Add(1, 1)
+ l.Add(2, 2)
+ if !l.Contains(1) {
+ t.Errorf("1 should be contained")
+ }
+
+ l.Add(3, 3)
+ if l.Contains(1) {
+ t.Errorf("Contains should not have updated recent-ness of 1")
+ }
+}
+
+// Test that Peek doesn't update recent-ness
+func TestARC_Peek(t *testing.T) {
+ l, err := NewARC(2)
+ if err != nil {
+ t.Fatalf("err: %v", err)
+ }
+
+ l.Add(1, 1)
+ l.Add(2, 2)
+ if v, ok := l.Peek(1); !ok || v != 1 {
+ t.Errorf("1 should be set to 1: %v, %v", v, ok)
+ }
+
+ l.Add(3, 3)
+ if l.Contains(1) {
+ t.Errorf("should not have updated recent-ness of 1")
+ }
+}
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