[#26] object: Replace Transform header with Split

This commit replaces Transform message with SplitHeader in oneof definition
of Value field of Header message. The latter, unlike the first, carries
complete information about the generation of the object by splitting the
payload. As a result, the message is deleted as no longer used.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>

object/types.proto

@@ -24,8 +24,8 @@ message ExtendedHeader {
         refs.Address Redirect                  = 2;
         // Attribute is a set of K-V object attributes
         Attribute Attribute                    = 3;
-        // Transform defines transform operation (e.g. payload split)
+        // Split carries the position of the object in the split hierarchy.
-        Transform Transform                    = 4;
+        SplitHeader SplitHeader = 4;
         // Tombstone header that set up in deleted objects
         Tombstone Tombstone                    = 5;
         // Token header contains token of the session within which the object was created
@@ -86,20 +86,6 @@ message Link {
     bytes ID = 2;
 }
 
-message Transform {
-    enum Type {
-        Unknown = 0;
-        // Split sets when object created after payload split
-        Split   = 1;
-        // Sign sets when object created after re-signing (doesn't used)
-        Sign    = 2;
-        // Mould sets when object created after filling missing headers in the object
-        Mould   = 3;
-    }
-    // Type of object transformation
-    Type type  = 1;
-}
-
 // SplitHeader groups information about spawning the object through a payload splitting.
 message SplitHeader {
     // Parent carries identifier of the origin object.

proto-docs/object.md

@@ -39,7 +39,6 @@
     - [SplitHeader](#object.SplitHeader)
     - [SystemHeader](#object.SystemHeader)
     - [Tombstone](#object.Tombstone)
-    - [Transform](#object.Transform)
     
 
 - [Scalar Value Types](#scalar-value-types)
@@ -385,7 +384,7 @@ Attribute groups the parameters of the object attributes.
 | Link | [Link](#object.Link) |  | Link to other objects |
 | Redirect | [refs.Address](#refs.Address) |  | Redirect not used yet |
 | Attribute | [Attribute](#object.Attribute) |  | Attribute is a set of K-V object attributes |
-| Transform | [Transform](#object.Transform) |  | Transform defines transform operation (e.g. payload split) |
+| SplitHeader | [SplitHeader](#object.SplitHeader) |  | Split carries the position of the object in the split hierarchy. |
 | Tombstone | [Tombstone](#object.Tombstone) |  | Tombstone header that set up in deleted objects |
 | Token | [service.Token](#service.Token) |  | Token header contains token of the session within which the object was created |
 | HomoHash | [bytes](#bytes) |  | HomoHash is a homomorphic hash of original object payload |
@@ -490,17 +489,6 @@ SplitHeader groups information about spawning the object through a payload split
 
 
 
-
-<a name="object.Transform"></a>
-
-### Message Transform
-
-
-
-| Field | Type | Label | Description |
-| ----- | ---- | ----- | ----------- |
-| type | [Transform.Type](#object.Transform.Type) |  | Type of object transformation |
-
  <!-- end messages -->
 
 
@@ -519,20 +507,6 @@ SplitHeader groups information about spawning the object through a payload split
 | StorageGroup | 5 | Object that included into this storage group |
 
 
-
-<a name="object.Transform.Type"></a>
-
-### Transform.Type
-
-
-| Name | Number | Description |
-| ---- | ------ | ----------- |
-| Unknown | 0 |  |
-| Split | 1 | Split sets when object created after payload split |
-| Sign | 2 | Sign sets when object created after re-signing (doesn't used) |
-| Mould | 3 | Mould sets when object created after filling missing headers in the object |
-
-
  <!-- end enums -->