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mirror of https://github.com/octoleo/restic.git synced 2024-12-11 21:57:58 +00:00
restic/internal/restic/zeroprefix_test.go
2022-09-24 21:39:39 +02:00

53 lines
1.1 KiB
Go

package restic_test
import (
"math/rand"
"testing"
"github.com/restic/restic/internal/restic"
"github.com/restic/restic/internal/test"
)
func TestZeroPrefixLen(t *testing.T) {
var buf [2048]byte
// test zero prefixes of various lengths
for i := len(buf) - 1; i >= 0; i-- {
buf[i] = 42
skipped := restic.ZeroPrefixLen(buf[:])
test.Equals(t, i, skipped)
}
// test buffers of various sizes
for i := 0; i < len(buf); i++ {
skipped := restic.ZeroPrefixLen(buf[i:])
test.Equals(t, 0, skipped)
}
}
func BenchmarkZeroPrefixLen(b *testing.B) {
var (
buf [4<<20 + 37]byte
r = rand.New(rand.NewSource(0x618732))
sumSkipped int64
)
b.ReportAllocs()
b.SetBytes(int64(len(buf)))
b.ResetTimer()
for i := 0; i < b.N; i++ {
j := r.Intn(len(buf))
buf[j] = 0xff
skipped := restic.ZeroPrefixLen(buf[:])
sumSkipped += int64(skipped)
buf[j] = 0
}
// The closer this is to .5, the better. If it's far off, give the
// benchmark more time to run with -benchtime.
b.Logf("average number of zeros skipped: %.3f",
float64(sumSkipped)/(float64(b.N*len(buf))))
}