acl: refactor the package

This commit:

  * replaces the wrappers of the messages to eacl sub-package;

  * renames Target to Group in eacl package;

  * defines Group constants;

  * replaces EACLTable message marshaler (unmarshaler) with custom MarshalTable
    (UnmarshalTable) of the Table.

acl/extended/enum.go

@@ -0,0 +1,126 @@
+package eacl
+
+const (
+	// MatchUnknown is a MatchType value used to mark value as undefined.
+	// Most of the tools consider MatchUnknown as incalculable.
+	// Using MatchUnknown in HeaderFilter is unsafe.
+	MatchUnknown MatchType = iota
+
+	// StringEqual is a MatchType of string equality.
+	StringEqual
+
+	// StringNotEqual is a MatchType of string inequality.
+	StringNotEqual
+)
+
+const (
+	// ActionUnknown is Action used to mark value as undefined.
+	// Most of the tools consider ActionUnknown as incalculable.
+	// Using ActionUnknown in Record is unsafe.
+	ActionUnknown Action = iota
+
+	// ActionAllow is Action used to mark an applicability of ACL rule.
+	ActionAllow
+
+	// ActionDeny is Action used to mark an inapplicability of ACL rule.
+	ActionDeny
+)
+
+const (
+	// GroupUnknown is a Group value used to mark value as undefined.
+	// Most of the tools consider GroupUnknown as incalculable.
+	// Using GroupUnknown in Target is unsafe.
+	GroupUnknown Group = iota
+
+	// GroupUser is a Group value for User access group.
+	GroupUser
+
+	// GroupSystem is a Group value for System access group.
+	GroupSystem
+
+	// GroupOthers is a Group value for Others access group.
+	GroupOthers
+)
+
+const (
+	// HdrTypeUnknown is a HeaderType value used to mark value as undefined.
+	// Most of the tools consider HdrTypeUnknown as incalculable.
+	// Using HdrTypeUnknown in HeaderFilter is unsafe.
+	HdrTypeUnknown HeaderType = iota
+
+	// HdrTypeRequest is a HeaderType for request header.
+	HdrTypeRequest
+
+	// HdrTypeObjSys is a HeaderType for system headers of object.
+	HdrTypeObjSys
+
+	// HdrTypeObjUsr is a HeaderType for user headers of object.
+	HdrTypeObjUsr
+)
+
+const (
+	// OpTypeUnknown is a OperationType value used to mark value as undefined.
+	// Most of the tools consider OpTypeUnknown as incalculable.
+	// Using OpTypeUnknown in Record is unsafe.
+	OpTypeUnknown OperationType = iota
+
+	// OpTypeGet is an OperationType for object.Get RPC
+	OpTypeGet
+
+	// OpTypePut is an OperationType for object.Put RPC
+	OpTypePut
+
+	// OpTypeHead is an OperationType for object.Head RPC
+	OpTypeHead
+
+	// OpTypeSearch is an OperationType for object.Search RPC
+	OpTypeSearch
+
+	// OpTypeDelete is an OperationType for object.Delete RPC
+	OpTypeDelete
+
+	// OpTypeRange is an OperationType for object.GetRange RPC
+	OpTypeRange
+
+	// OpTypeRangeHash is an OperationType for object.GetRangeHash RPC
+	OpTypeRangeHash
+)
+
+const (
+	// HdrObjSysNameID is a name of ID field in system header of object.
+	HdrObjSysNameID = "ID"
+
+	// HdrObjSysNameCID is a name of CID field in system header of object.
+	HdrObjSysNameCID = "CID"
+
+	// HdrObjSysNameOwnerID is a name of OwnerID field in system header of object.
+	HdrObjSysNameOwnerID = "OWNER_ID"
+
+	// HdrObjSysNameVersion is a name of Version field in system header of object.
+	HdrObjSysNameVersion = "VERSION"
+
+	// HdrObjSysNamePayloadLength is a name of PayloadLength field in system header of object.
+	HdrObjSysNamePayloadLength = "PAYLOAD_LENGTH"
+
+	// HdrObjSysNameCreatedUnix is a name of CreatedAt.UnitTime field in system header of object.
+	HdrObjSysNameCreatedUnix = "CREATED_UNIX"
+
+	// HdrObjSysNameCreatedEpoch is a name of CreatedAt.Epoch field in system header of object.
+	HdrObjSysNameCreatedEpoch = "CREATED_EPOCH"
+
+	// HdrObjSysLinkPrev is a name of previous link header in extended headers of object.
+	HdrObjSysLinkPrev = "LINK_PREV"
+
+	// HdrObjSysLinkNext is a name of next link header in extended headers of object.
+	HdrObjSysLinkNext = "LINK_NEXT"
+
+	// HdrObjSysLinkChild is a name of child link header in extended headers of object.
+	HdrObjSysLinkChild = "LINK_CHILD"
+
+	// HdrObjSysLinkPar is a name of parent link header in extended headers of object.
+	HdrObjSysLinkPar = "LINK_PAR"
+
+	// HdrObjSysLinkSG is a name of storage group link header in extended headers of object.
+	HdrObjSysLinkSG = "LINK_SG"
+)
+