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 {