Use Replace instead of update for replacing item

resource/resource.go

@@ -381,6 +381,23 @@ func (r *Resource) Update(ctx context.Context, item *Item, original *Item) (err
 	return
 }
 
+// Replace implements Storer interface
+func (r *Resource) Replace(ctx context.Context, item *Item, original *Item) (err error) {
+	if LoggerLevel <= LogLevelDebug && Logger != nil {
+		defer func(t time.Time) {
+			Logger(ctx, LogLevelDebug, fmt.Sprintf("%s.Replace(%v, %v)", r.path, item.ID, original.ID), map[string]interface{}{
+				"duration": time.Since(t),
+				"error":    err,
+			})
+		}(time.Now())
+	}
+	if err = r.hooks.onUpdate(ctx, item, original); err == nil {
+		err = r.storage.Replace(ctx, item, original)
+	}
+	r.hooks.onUpdated(ctx, item, original, &err)
+	return
+}
+
 // Delete implements Storer interface
 func (r *Resource) Delete(ctx context.Context, item *Item) (err error) {
 	if LoggerLevel <= LogLevelDebug && Logger != nil {

resource/storage.go

@@ -47,6 +47,20 @@ type Storer interface {
 	// on the passed ctx. If the operation is stopped due to context cancellation, the
 	// function must return the result of the ctx.Err() method.
 	Update(ctx context.Context, item *Item, original *Item) error
+	// Replace replace an item in the backend store by a new version. The ResourceHandler must)
+	// ensure that the original item exists in the database and has the same Etag field.
+	// This check should be performed atomically. If the original item is not
+	// found, a resource.ErrNotFound must be returned. If the etags don't match, a
+	// resource.ErrConflict must be returned.
+	//
+	// The item payload must be stored together with the etag and the updated field.
+	// The item.ID and the payload["id"] is garantied to be identical, so there's not need
+	// to store both.
+	//
+	// If the storage of the data is not immediate, the method must listen for cancellation
+	// on the passed ctx. If the operation is stopped due to context cancellation, the
+	// function must return the result of the ctx.Err() method.
+	Replace(ctx context.Context, item *Item, original *Item) error
 	// Delete deletes the provided item by its ID. The Etag of the item stored in the
 	// backend store must match the Etag of the provided item or a resource.ErrConflict
 	// must be returned. This check should be performed atomically.
@@ -221,6 +235,16 @@ func (s storageWrapper) Update(ctx context.Context, item *Item, original *Item)
 	return s.Storer.Update(ctx, item, original)
 }
 
+func (s storageWrapper) Replace(ctx context.Context, item *Item, original *Item) (err error) {
+	if s.Storer == nil {
+		return ErrNoStorage
+	}
+	if ctx.Err() != nil {
+		return ctx.Err()
+	}
+	return s.Storer.Replace(ctx, item, original)
+}
+
 func (s storageWrapper) Delete(ctx context.Context, item *Item) (err error) {
 	if s.Storer == nil {
 		return ErrNoStorage

rest/method_item_put.go

@@ -87,7 +87,7 @@ func itemPut(ctx context.Context, r *http.Request, route *RouteMatch) (status in
 	// supposed check the original etag before storing when an original object
 	// is provided.
 	if original != nil {
-		if err := rsrc.Update(ctx, item, original); err != nil {
+		if err := rsrc.Replace(ctx, item, original); err != nil {
 			e = NewError(err)
 			return e.Code, nil, e
 		}