[#357] Add check of request and resource tags

Signed-off-by: Marina Biryukova <m.biryukova@yadro.com>

api/data/tagging.go

@@ -0,0 +1,30 @@
+package data
+
+import "encoding/xml"
+
+// Tagging contains tag set.
+type Tagging struct {
+	XMLName xml.Name `xml:"http://s3.amazonaws.com/doc/2006-03-01/ Tagging"`
+	TagSet  []Tag    `xml:"TagSet>Tag"`
+}
+
+// Tag is an AWS key-value tag.
+type Tag struct {
+	Key   string
+	Value string
+}
+
+type GetObjectTaggingParams struct {
+	ObjectVersion *ObjectVersion
+
+	// NodeVersion can be nil. If not nil we save one request to tree service.
+	NodeVersion *NodeVersion // optional
+}
+
+type PutObjectTaggingParams struct {
+	ObjectVersion *ObjectVersion
+	TagSet        map[string]string
+
+	// NodeVersion can be nil. If not nil we save one request to tree service.
+	NodeVersion *NodeVersion // optional
+}