| 1 | // SPDX-License-Identifier: AGPL-3.0-or-later |
| 2 | |
| 3 | package lru |
| 4 | |
| 5 | import ( |
| 6 | "context" |
| 7 | "errors" |
| 8 | "strconv" |
| 9 | "sync" |
| 10 | "sync/atomic" |
| 11 | "testing" |
| 12 | "time" |
| 13 | ) |
| 14 | |
| 15 | func TestCache_GetSetEviction(t *testing.T) { |
| 16 | t.Parallel() |
| 17 | c := New[string, int](2) |
| 18 | c.Set("a", 1) |
| 19 | c.Set("b", 2) |
| 20 | if v, ok := c.Get("a"); !ok || v != 1 { |
| 21 | t.Fatalf("Get(a) = %d,%v; want 1,true", v, ok) |
| 22 | } |
| 23 | // Touching "a" makes "b" the LRU. |
| 24 | c.Set("c", 3) |
| 25 | if _, ok := c.Get("b"); ok { |
| 26 | t.Errorf("b should have been evicted") |
| 27 | } |
| 28 | if v, ok := c.Get("c"); !ok || v != 3 { |
| 29 | t.Errorf("c = %d,%v; want 3,true", v, ok) |
| 30 | } |
| 31 | if s := c.Stats(); s.Evictions != 1 { |
| 32 | t.Errorf("Evictions = %d; want 1", s.Evictions) |
| 33 | } |
| 34 | } |
| 35 | |
| 36 | func TestCache_TTLExpiry(t *testing.T) { |
| 37 | t.Parallel() |
| 38 | c := NewWithTTL[string, int](4, 50*time.Millisecond) |
| 39 | now := time.Now() |
| 40 | c.now = func() time.Time { return now } |
| 41 | c.Set("k", 42) |
| 42 | if v, ok := c.Get("k"); !ok || v != 42 { |
| 43 | t.Fatalf("fresh hit: got %d,%v; want 42,true", v, ok) |
| 44 | } |
| 45 | now = now.Add(60 * time.Millisecond) |
| 46 | if _, ok := c.Get("k"); ok { |
| 47 | t.Errorf("expired entry should be a miss") |
| 48 | } |
| 49 | } |
| 50 | |
| 51 | func TestCache_DeleteAndStats(t *testing.T) { |
| 52 | t.Parallel() |
| 53 | c := New[string, int](2) |
| 54 | c.Set("a", 1) |
| 55 | c.Get("a") |
| 56 | c.Get("missing") |
| 57 | c.Delete("a") |
| 58 | if c.Len() != 0 { |
| 59 | t.Errorf("Len after Delete = %d; want 0", c.Len()) |
| 60 | } |
| 61 | s := c.Stats() |
| 62 | if s.Hits != 1 || s.Misses != 1 { |
| 63 | t.Errorf("stats = %+v; want hits=1 misses=1", s) |
| 64 | } |
| 65 | } |
| 66 | |
| 67 | func TestSizedCache_BytesBounded(t *testing.T) { |
| 68 | t.Parallel() |
| 69 | c := NewSized[string](100) |
| 70 | c.Set("a", make([]byte, 60)) |
| 71 | c.Set("b", make([]byte, 60)) // forces eviction of "a" |
| 72 | if _, ok := c.Get("a"); ok { |
| 73 | t.Errorf("a should have been evicted to fit b") |
| 74 | } |
| 75 | if c.Bytes() != 60 { |
| 76 | t.Errorf("Bytes = %d; want 60", c.Bytes()) |
| 77 | } |
| 78 | } |
| 79 | |
| 80 | func TestSizedCache_ReplaceShrinks(t *testing.T) { |
| 81 | t.Parallel() |
| 82 | c := NewSized[string](100) |
| 83 | c.Set("a", make([]byte, 80)) |
| 84 | c.Set("a", make([]byte, 10)) // smaller replacement |
| 85 | if c.Bytes() != 10 { |
| 86 | t.Errorf("Bytes after shrink = %d; want 10", c.Bytes()) |
| 87 | } |
| 88 | } |
| 89 | |
| 90 | func TestGroup_SingleFlightCollapsesConcurrentMisses(t *testing.T) { |
| 91 | t.Parallel() |
| 92 | c := New[string, int](16) |
| 93 | g := NewGroup(c, func(s string) string { return s }) |
| 94 | |
| 95 | var calls atomic.Int64 |
| 96 | fetch := func(ctx context.Context) (int, error) { |
| 97 | calls.Add(1) |
| 98 | time.Sleep(20 * time.Millisecond) |
| 99 | return 99, nil |
| 100 | } |
| 101 | |
| 102 | const N = 50 |
| 103 | var wg sync.WaitGroup |
| 104 | wg.Add(N) |
| 105 | for i := 0; i < N; i++ { |
| 106 | go func() { |
| 107 | defer wg.Done() |
| 108 | v, err := g.Do(context.Background(), "k", fetch) |
| 109 | if err != nil || v != 99 { |
| 110 | t.Errorf("Do = %d,%v; want 99,nil", v, err) |
| 111 | } |
| 112 | }() |
| 113 | } |
| 114 | wg.Wait() |
| 115 | |
| 116 | if calls.Load() != 1 { |
| 117 | t.Errorf("upstream called %d times; want 1 (singleflight collapse failed)", calls.Load()) |
| 118 | } |
| 119 | } |
| 120 | |
| 121 | func TestGroup_ErrorNotCached(t *testing.T) { |
| 122 | t.Parallel() |
| 123 | c := New[string, int](4) |
| 124 | g := NewGroup(c, func(s string) string { return s }) |
| 125 | |
| 126 | var attempt atomic.Int64 |
| 127 | fetch := func(ctx context.Context) (int, error) { |
| 128 | n := attempt.Add(1) |
| 129 | if n == 1 { |
| 130 | return 0, errors.New("transient") |
| 131 | } |
| 132 | return 7, nil |
| 133 | } |
| 134 | if _, err := g.Do(context.Background(), "k", fetch); err == nil { |
| 135 | t.Fatalf("expected error on first call") |
| 136 | } |
| 137 | v, err := g.Do(context.Background(), "k", fetch) |
| 138 | if err != nil { |
| 139 | t.Fatalf("second call err: %v", err) |
| 140 | } |
| 141 | if v != 7 { |
| 142 | t.Errorf("v = %d; want 7", v) |
| 143 | } |
| 144 | } |
| 145 | |
| 146 | func BenchmarkCacheSetGet(b *testing.B) { |
| 147 | c := New[int, int](1024) |
| 148 | for i := 0; i < 1024; i++ { |
| 149 | c.Set(i, i) |
| 150 | } |
| 151 | b.ResetTimer() |
| 152 | for i := 0; i < b.N; i++ { |
| 153 | _, _ = c.Get(i & 1023) |
| 154 | } |
| 155 | } |
| 156 | |
| 157 | // Reference for keyer construction in the test above. |
| 158 | var _ = strconv.Itoa |
| 159 |