refactor: use a linked hash map to keep order of file and directory entries, and refactor the json and msgpack marshalling and centralize it further

metadata/directory.go

@@ -1,14 +1,21 @@
 package metadata
 
 import (
+	"encoding/json"
 	"errors"
+	"fmt"
 	"git.lumeweb.com/LumeWeb/libs5-go/serialize"
 	"git.lumeweb.com/LumeWeb/libs5-go/types"
+	"github.com/emirpasic/gods/maps/linkedhashmap"
 	"github.com/vmihailenco/msgpack/v5"
 )
 
-type directoryReferenceMap map[string]DirectoryReference
+type directoryReferenceMap struct {
-type fileReferenceMap map[string]FileReference
+	linkedhashmap.Map
+}
+type fileReferenceMap struct {
+	linkedhashmap.Map
+}
 
 type DirectoryMetadata struct {
 	Details       DirectoryMetadataDetails `json:"details"`
@@ -21,7 +28,7 @@ type DirectoryMetadata struct {
 var _ SerializableMetadata = (*DirectoryMetadata)(nil)
 var _ SerializableMetadata = (*directoryReferenceMap)(nil)
 
-func NewDirectoryMetadata(details DirectoryMetadataDetails, directories map[string]DirectoryReference, files map[string]FileReference, extraMetadata ExtraMetadata) *DirectoryMetadata {
+func NewDirectoryMetadata(details DirectoryMetadataDetails, directories directoryReferenceMap, files fileReferenceMap, extraMetadata ExtraMetadata) *DirectoryMetadata {
 	dirMetadata := &DirectoryMetadata{
 		Details:       details,
 		Directories:   directories,
@@ -95,94 +102,136 @@ func (dm *DirectoryMetadata) DecodeMsgpack(dec *msgpack.Decoder) error {
 	return nil
 }
 func (drm directoryReferenceMap) EncodeMsgpack(enc *msgpack.Encoder) error {
-	// First, encode the length of the map
+	return marshallMapMsgpack(enc, &drm.Map)
-	if err := enc.EncodeMapLen(len(drm)); err != nil {
-		return err
-	}
-
-	// Then, encode each key-value pair
-	for k, v := range drm {
-		if err := enc.EncodeString(k); err != nil {
-			return err
-		}
-		if err := enc.Encode(&v); err != nil { // Assuming DirectoryReference can be encoded by msgpack
-			return err
-		}
-	}
-
-	return nil
 }
 
 func (drm *directoryReferenceMap) DecodeMsgpack(dec *msgpack.Decoder) error {
-	// Read the map length
+	return unmarshalMapMsgpack(dec, &drm.Map, &DirectoryReference{})
-	l, err := dec.DecodeMapLen()
-	if err != nil {
-		return err
-	}
-
-	// Initialize the map if it's nil
-	if *drm == nil {
-		*drm = make(directoryReferenceMap, l)
-	}
-
-	// Decode each key-value pair
-	for i := 0; i < l; i++ {
-		key, err := dec.DecodeString()
-		if err != nil {
-			return err
-		}
-		var value DirectoryReference
-		if err := dec.Decode(&value); err != nil {
-			return err
-		}
-		(*drm)[key] = value
-	}
-
-	return nil
 }
 
 func (frm fileReferenceMap) EncodeMsgpack(enc *msgpack.Encoder) error {
-	// First, encode the length of the map
+	return marshallMapMsgpack(enc, &frm.Map)
-	if err := enc.EncodeMapLen(len(frm)); err != nil {
-		return err
-	}
-
-	// Then, encode each key-value pair
-	for k, v := range frm {
-		if err := enc.EncodeString(k); err != nil {
-			return err
-		}
-		if err := enc.Encode(&v); err != nil { // Assuming DirectoryReference can be encoded by msgpack
-			return err
-		}
-	}
-
-	return nil
 }
 
-func (drm *fileReferenceMap) DecodeMsgpack(dec *msgpack.Decoder) error {
+func (frm *fileReferenceMap) DecodeMsgpack(dec *msgpack.Decoder) error {
-	// Read the map length
+	return unmarshalMapMsgpack(dec, &frm.Map, &FileReference{})
+}
+
+func (frm *fileReferenceMap) UnmarshalJSON(bytes []byte) error {
+	createFileInstance := func() interface{} { return &FileReference{} }
+	return unmarshalMapJson(bytes, &frm.Map, createFileInstance)
+}
+
+type unmarshalNewInstanceFunc func() interface{}
+
+func (drm *directoryReferenceMap) UnmarshalJSON(bytes []byte) error {
+	createDirInstance := func() interface{} { return &DirectoryReference{} }
+	return unmarshalMapJson(bytes, &drm.Map, createDirInstance)
+}
+
+func unmarshalMapMsgpack(dec *msgpack.Decoder, m *linkedhashmap.Map, placeholder interface{}) error {
+	*m = *linkedhashmap.New()
+
 	l, err := dec.DecodeMapLen()
 	if err != nil {
 		return err
 	}
 
-	// Initialize the map if it's nil
-	if *drm == nil {
-		*drm = make(fileReferenceMap, l)
-	}
-
-	// Decode each key-value pair
 	for i := 0; i < l; i++ {
 		key, err := dec.DecodeString()
 		if err != nil {
 			return err
 		}
-		var value FileReference
+
-		if err := dec.Decode(&value); err != nil {
+		fmt.Println("dir: ", key)
-			return err
+
+		switch placeholder.(type) {
+		case *DirectoryReference:
+			var value DirectoryReference
+			if err := dec.Decode(&value); err != nil {
+				return err
+			}
+			m.Put(key, value)
+
+		case *FileReference:
+			var file FileReference
+			if err := dec.Decode(&file); err != nil {
+				return err
+			}
+			m.Put(key, file)
+
+		default:
+			return fmt.Errorf("unsupported type for decoding")
+		}
+	}
+
+	return nil
+}
+
+func marshallMapMsgpack(enc *msgpack.Encoder, m *linkedhashmap.Map) error {
+	// First, encode the length of the map
+	if err := enc.EncodeMapLen(m.Size()); err != nil {
+		return err
+	}
+
+	iter := m.Iterator()
+	for iter.Next() {
+		key := iter.Key().(string)
+		if err := enc.EncodeString(key); err != nil {
+			return err
+		}
+
+		value := iter.Value()
+		switch v := value.(type) {
+		case FileReference:
+			if err := enc.Encode(&v); err != nil {
+				return err
+			}
+		case DirectoryReference:
+			if err := enc.Encode(&v); err != nil {
+				return err
+			}
+		default:
+			return fmt.Errorf("unsupported type for encoding")
+		}
+	}
+
+	return nil
+}
+
+func unmarshalMapJson(bytes []byte, m *linkedhashmap.Map, newInstance unmarshalNewInstanceFunc) error {
+	*m = *linkedhashmap.New()
+	err := m.FromJSON(bytes)
+	if err != nil {
+		return err
+	}
+
+	iter := m.Iterator()
+	for iter.Next() {
+		key := iter.Key()
+		val := iter.Value()
+
+		instance := newInstance()
+
+		data, err := json.Marshal(val)
+		if err != nil {
+			return err
+		}
+
+		err = json.Unmarshal(data, &instance)
+		if err != nil {
+			return err
+		}
+
+		// Type switch to handle different types
+		switch v := instance.(type) {
+		case *DirectoryReference:
+			m.Put(key, *v)
+		case *FileReference:
+			m.Put(key, *v)
+		default:
+			return fmt.Errorf("unhandled type: %T", v)
 		}
-		(*drm)[key] = value
 	}
 
 	return nil