containerd/archive/compression/compression_test.go

68 lines
1.8 KiB
Go
Raw Normal View History

package compression
import (
"bytes"
"crypto/rand"
"io/ioutil"
"testing"
)
// generateData generates data that composed of 2 random parts
// and single zero-filled part within them.
// Typically, the compression ratio would be about 67%.
func generateData(t *testing.T, size int) []byte {
part0 := size / 3 // random
part2 := size / 3 // random
part1 := size - part0 - part2 // zero-filled
part0Data := make([]byte, part0)
if _, err := rand.Read(part0Data); err != nil {
t.Fatal(err)
}
part1Data := make([]byte, part1)
part2Data := make([]byte, part2)
if _, err := rand.Read(part2Data); err != nil {
t.Fatal(err)
}
return append(part0Data, append(part1Data, part2Data...)...)
}
func testCompressDecompress(t *testing.T, size int, compression Compression) {
orig := generateData(t, size)
var b bytes.Buffer
compressor, err := CompressStream(&b, compression)
if err != nil {
t.Fatal(err)
}
if n, err := compressor.Write(orig); err != nil || n != size {
t.Fatal(err)
}
compressor.Close()
compressed := b.Bytes()
t.Logf("compressed %d bytes to %d bytes (%.2f%%)",
len(orig), len(compressed), 100.0*float32(len(compressed))/float32(len(orig)))
if compared := bytes.Compare(orig, compressed); (compression == Uncompressed && compared != 0) ||
(compression != Uncompressed && compared == 0) {
t.Fatal("strange compressed data")
}
decompressor, err := DecompressStream(bytes.NewReader(compressed))
if err != nil {
t.Fatal(err)
}
decompressed, err := ioutil.ReadAll(decompressor)
if err != nil {
t.Fatal(err)
}
if bytes.Compare(orig, decompressed) != 0 {
t.Fatal("strange decompressed data")
}
}
func TestCompressDecompressGzip(t *testing.T) {
testCompressDecompress(t, 1024*1024, Gzip)
}
func TestCompressDecompressUncompressed(t *testing.T) {
testCompressDecompress(t, 1024*1024, Uncompressed)
}