restic/internal/bloblru/cache_test.go
greatroar 634a9c162d Check cap instead of len in bloblru
restic dump uses bloblru.Cache to keep buffers alive, but also reuses
evicted buffers. That means large buffers may be used to store small
blobs, causing the cache to think it's using less memory than it
actually does.
2021-10-03 09:34:17 +02:00

52 lines
1.2 KiB
Go

package bloblru
import (
"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)
}