pkg/image: factor out from prog

Move image compression-related function to a separate package.
In preperation for subsequent changes that make decompression
more complex. Prog package is already large and complex.
Also makes running compression tests/benchmarks much faster.

1 files changed, 44 insertions, 0 deletions

diff --git a/pkg/image/compression_test.go b/pkg/image/compression_test.go
new file mode 100644
index 000000000..cf18ed340
--- /dev/null
+++ b/pkg/image/compression_test.go
@@ -0,0 +1,44 @@
+// Copyright 2022 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+package image
+
+import (
+	"bytes"
+	"fmt"
+	"math/rand"
+	"testing"
+
+	"github.com/google/syzkaller/pkg/testutil"
+)
+
+func TestCompress(t *testing.T) {
+	r := rand.New(testutil.RandSource(t))
+	err := testRoundTrip(r, Compress, Decompress)
+	if err != nil {
+		t.Fatalf("compress/decompress %v", err)
+	}
+}
+
+func TestEncode(t *testing.T) {
+	r := rand.New(testutil.RandSource(t))
+	err := testRoundTrip(r, EncodeB64, DecodeB64)
+	if err != nil {
+		t.Fatalf("encode/decode Base64 %v", err)
+	}
+}
+
+func testRoundTrip(r *rand.Rand, transform func([]byte) []byte, inverse func([]byte) ([]byte, error)) error {
+	for i := 0; i < testutil.IterCount(); i++ {
+		randBytes := testutil.RandMountImage(r)
+		resultBytes := transform(randBytes)
+		resultBytes, err := inverse(resultBytes)
+		if err != nil {
+			return err
+		}
+		if !bytes.Equal(randBytes, resultBytes) {
+			return fmt.Errorf("roundtrip changes data (original length %d)", len(randBytes))
+		}
+	}
+	return nil
+}