fs use binary (um)marshaler

pkg/repo/fs/fs.go

@@ -1,6 +1,7 @@
 package fs
 
 import (
+	"encoding"
 	"errors"
 	"fmt"
 	"math/big"
@@ -74,7 +75,11 @@ func (f *fs) Lock() (func() error, error) {
 	return unlock, nil
 }
 
-func (f *fs) Write(path string, data []byte) error {
+func (f *fs) Write(path string, v encoding.BinaryMarshaler) error {
+	if v == nil {
+		return errors.New("cant't marshal from nil object")
+	}
+
 	if f.lock == nil {
 		return errors.New("lock must be acquired before write")
 	}
@@ -84,6 +89,11 @@ func (f *fs) Write(path string, data []byte) error {
 		return errors.New("can't write to the lock file")
 	}
 
+	data, err := v.MarshalBinary()
+	if err != nil {
+		return fmt.Errorf("marshal data: %s", err)
+	}
+
 	targetDir := filepath.Dir(targetFilePath)
 	if targetDir != f.root {
 		ok, err := dirExists(targetDir)
@@ -146,17 +156,26 @@ func (f *fs) Write(path string, data []byte) error {
 	return nil
 }
 
-func (f *fs) Read(path string) ([]byte, error) {
+func (f *fs) Read(path string, v encoding.BinaryUnmarshaler) error {
+	if v == nil {
+		return errors.New("can't unmarshal to a nil object")
+	}
+
 	if f.lock != nil {
-		return nil, errors.New("lock must be released before read")
+		return errors.New("lock must be released before read")
 	}
 
 	targetFilePath := filepath.Join(f.root, path)
 	if targetFilePath == f.lockFilePath() {
-		return nil, errors.New("can't read from the lock file")
+		return errors.New("can't read from the lock file")
 	}
 
-	return os.ReadFile(targetFilePath)
+	data, err := os.ReadFile(targetFilePath)
+	if err != nil {
+		return fmt.Errorf("reading data file: %s", err)
+	}
+
+	return v.UnmarshalBinary(data)
 }
 
 func (f *fs) lockFilePath() string {

pkg/repo/fs/fs_test.go

@@ -58,7 +58,8 @@ func TestWrite(t *testing.T) {
 		{path: "/" + dirName, err: "wrong type"},
 	} {
 		t.Run(tc.path, func(t *testing.T) {
-			err = fs.Write(tc.path, []byte{0, 1, 2, 3})
+			sd := &sampleData{[]byte{0, 1, 2, 3}}
+			err = fs.Write(tc.path, sd)
 			if tc.err == "" {
 				if err != nil {
 					assert.Fail(t, "not expecting an error", "write to file %s: %s", tc.path, err)
@@ -122,7 +123,8 @@ func TestRead(t *testing.T) {
 					}
 				}()
 			}
-			_, err = fs.Read(tc.path)
+			sd := new(sampleData)
+			err = fs.Read(tc.path, sd)
 			if tc.err == "" {
 				if err != nil {
 					assert.Fail(t, "read: not expecting an error, got: "+err.Error())
@@ -147,7 +149,8 @@ func TestWriteErrorWithoutLock(t *testing.T) {
 	defer cleanup()
 	fs, err := NewFileStorage(root)
 	assert.NoError(t, err, "create file storage")
-	err = fs.Write("some/path", []byte{0, 1, 2, 3})
+	sd := &sampleData{[]byte{0, 1, 2, 3}}
+	err = fs.Write("some/path", sd)
 	assert.Error(t, err, "should return error when no lock acquired")
 	assert.True(t, strings.Contains(err.Error(), "lock must be acquired"), "should return missing lock error")
 }

pkg/repo/fs/helper_test.go

@@ -2,6 +2,7 @@ package fs
 
 import (
 	"os"
+	"slices"
 	"testing"
 )
 
@@ -21,3 +22,16 @@ func createWorkDir(t *testing.T) (string, func()) {
 		}
 	}
 }
+
+type sampleData struct {
+	data []byte
+}
+
+func (sd *sampleData) UnmarshalBinary(data []byte) error {
+	sd.data = slices.Clone(data)
+	return nil
+}
+
+func (sd sampleData) MarshalBinary() (data []byte, err error) {
+	return sd.data, nil
+}