fix: also persist metadata files on import to persistent db

collection.go

@@ -111,23 +111,7 @@ func newCollection(name string, metadata map[string]string, embed EmbeddingFunc,
 		safeName := hash2hex(name)
 		c.persistDirectory = filepath.Join(dbDir, safeName)
 		c.compress = compress
-		// Persist name and metadata
-		metadataPath := filepath.Join(c.persistDirectory, metadataFileName)
-		metadataPath += ".gob"
-		if c.compress {
-			metadataPath += ".gz"
-		}
-		pc := struct {
-			Name     string
-			Metadata map[string]string
-		}{
-			Name:     name,
-			Metadata: m,
-		}
-		err := persistToFile(metadataPath, pc, compress, "")
-		if err != nil {
-			return nil, fmt.Errorf("couldn't persist collection metadata: %w", err)
-		}
+		return c, c.persistMetadata()
 	}
 
 	return c, nil
@@ -545,3 +529,26 @@ func (c *Collection) getDocPath(docID string) string {
 	}
 	return docPath
 }
+
+// persistMetadata persists the collection metadata to disk
+func (c *Collection) persistMetadata() error {
+	// Persist name and metadata
+	metadataPath := filepath.Join(c.persistDirectory, metadataFileName)
+	metadataPath += ".gob"
+	if c.compress {
+		metadataPath += ".gz"
+	}
+	pc := struct {
+		Name     string
+		Metadata map[string]string
+	}{
+		Name:     c.Name,
+		Metadata: c.metadata,
+	}
+	err := persistToFile(metadataPath, pc, c.compress, "")
+	if err != nil {
+		return err
+	}
+
+	return nil
+}

db.go

@@ -259,9 +259,13 @@ func (db *DB) ImportFromFile(filePath string, encryptionKey string, collections
 		if db.persistDirectory != "" {
 			c.persistDirectory = filepath.Join(db.persistDirectory, hash2hex(pc.Name))
 			c.compress = db.compress
+			err = c.persistMetadata()
+			if err != nil {
+				return fmt.Errorf("couldn't persist collection metadata: %w", err)
+			}
 			for _, doc := range c.documents {
 				docPath := c.getDocPath(doc.ID)
-				err := persistToFile(docPath, doc, c.compress, "")
+				err = persistToFile(docPath, doc, c.compress, "")
 				if err != nil {
 					return fmt.Errorf("couldn't persist document to %q: %w", docPath, err)
 				}
@@ -326,6 +330,10 @@ func (db *DB) ImportFromReader(reader io.ReadSeeker, encryptionKey string, colle
 		if db.persistDirectory != "" {
 			c.persistDirectory = filepath.Join(db.persistDirectory, hash2hex(pc.Name))
 			c.compress = db.compress
+			err = c.persistMetadata()
+			if err != nil {
+				return fmt.Errorf("couldn't persist collection metadata: %w", err)
+			}
 			for _, doc := range c.documents {
 				docPath := c.getDocPath(doc.ID)
 				err := persistToFile(docPath, doc, c.compress, "")