Files
goutils/cache/lru/lru_internal_test.go
2025-11-16 01:32:19 -08:00

88 lines
1.9 KiB
Go

package lru
import (
"testing"
"time"
"github.com/benbjohnson/clock"
)
// These tests mirror the MRU-style behavior present in this LRU package
// implementation (eviction removes the most-recently-used entry).
func TestBasicCacheEviction(t *testing.T) {
mock := clock.NewMock()
c := NewStringKeyCache[int](2)
c.clock = mock
if err := c.ConsistencyCheck(); err != nil {
t.Fatal(err)
}
if c.Len() != 0 {
t.Fatal("cache should have size 0")
}
c.evict()
if err := c.ConsistencyCheck(); err != nil {
t.Fatal(err)
}
c.Store("raven", 1)
if err := c.ConsistencyCheck(); err != nil {
t.Fatal(err)
}
if len(c.store) != 1 {
t.Fatalf("store should have length=1, have length=%d", len(c.store))
}
mock.Add(time.Second)
c.Store("owl", 2)
if err := c.ConsistencyCheck(); err != nil {
t.Fatal(err)
}
if len(c.store) != 2 {
t.Fatalf("store should have length=2, have length=%d", len(c.store))
}
mock.Add(time.Second)
c.Store("goat", 3)
if err := c.ConsistencyCheck(); err != nil {
t.Fatal(err)
}
if len(c.store) != 2 {
t.Fatalf("store should have length=2, have length=%d", len(c.store))
}
// Since this implementation evicts the most-recently-used item, inserting
// "goat" when full evicts "owl" (the most recent at that time).
mock.Add(time.Second)
if _, ok := c.Get("owl"); ok {
t.Fatal("store should not have an entry for owl (MRU-evicted)")
}
if err := c.ConsistencyCheck(); err != nil {
t.Fatal(err)
}
mock.Add(time.Second)
c.Store("elk", 4)
if err := c.ConsistencyCheck(); err != nil {
t.Fatal(err)
}
if !c.Has("elk") {
t.Fatal("store should contain an entry for 'elk'")
}
// Before storing elk, keys were: raven (older), goat (newer). Evict MRU -> goat.
if !c.Has("raven") {
t.Fatal("store should contain an entry for 'raven'")
}
if c.Has("goat") {
t.Fatal("store should not contain an entry for 'goat'")
}
}