restic/internal/bloblru/cache_test.go
greatroar e5d597fd22 bloblru: Upgrade to hashicorp/golang-lru/v2
The new genericized LRU cache no longer needs to have the IDs separately
allocated:

name   old time/op    new time/op    delta
Add-8     494ns ± 2%     388ns ± 2%  -21.46%  (p=0.000 n=10+9)

name   old alloc/op   new alloc/op   delta
Add-8      176B ± 0%      152B ± 0%  -13.64%  (p=0.000 n=10+10)

name   old allocs/op  new allocs/op  delta
Add-8      5.00 ± 0%      3.00 ± 0%  -40.00%  (p=0.000 n=10+10)
2022-11-27 17:18:13 +01:00

79 lines
1.6 KiB
Go

package bloblru
import (
"math/rand"
"testing"
"github.com/restic/restic/internal/restic"
rtest "github.com/restic/restic/internal/test"
)
func TestCache(t *testing.T) {
var id1, id2, id3 restic.ID
id1[0] = 1
id2[0] = 2
id3[0] = 3
const (
kiB = 1 << 10
cacheSize = 64*kiB + 3*overhead
)
c := New(cacheSize)
addAndCheck := func(id restic.ID, exp []byte) {
c.Add(id, exp)
blob, ok := c.Get(id)
rtest.Assert(t, ok, "blob %v added but not found in cache", id)
rtest.Equals(t, &exp[0], &blob[0])
rtest.Equals(t, exp, blob)
}
// Our blobs have len 1 but larger cap. The cache should check the cap,
// since it more reliably indicates the amount of memory kept alive.
addAndCheck(id1, make([]byte, 1, 32*kiB))
addAndCheck(id2, make([]byte, 1, 30*kiB))
addAndCheck(id3, make([]byte, 1, 10*kiB))
_, ok := c.Get(id2)
rtest.Assert(t, ok, "blob %v not present", id2)
_, ok = c.Get(id1)
rtest.Assert(t, !ok, "blob %v present, but should have been evicted", id1)
c.Add(id1, make([]byte, 1+c.size))
_, ok = c.Get(id1)
rtest.Assert(t, !ok, "blob %v too large but still added to cache")
c.c.Remove(id1)
c.c.Remove(id3)
c.c.Remove(id2)
rtest.Equals(t, cacheSize, c.size)
rtest.Equals(t, cacheSize, c.free)
}
func BenchmarkAdd(b *testing.B) {
const (
MiB = 1 << 20
nblobs = 64
)
c := New(64 * MiB)
buf := make([]byte, 8*MiB)
ids := make([]restic.ID, nblobs)
sizes := make([]int, nblobs)
r := rand.New(rand.NewSource(100))
for i := range ids {
r.Read(ids[i][:])
sizes[i] = r.Intn(8 * MiB)
}
b.ResetTimer()
b.ReportAllocs()
for i := 0; i < b.N; i++ {
c.Add(ids[i%nblobs], buf[:sizes[i%nblobs]])
}
}