1 files changed, 51 insertions, 0 deletions
diff --git a/vendor/github.com/byzantine-lab/dexon-consensus/core/types/position.go b/vendor/github.com/byzantine-lab/dexon-consensus/core/types/position.go
new file mode 100644
index 000000000..81d23c266
--- /dev/null
+++ b/vendor/github.com/byzantine-lab/dexon-consensus/core/types/position.go
@@ -0,0 +1,51 @@
+// Copyright 2018 The dexon-consensus Authors
+// This file is part of the dexon-consensus library.
+//
+// The dexon-consensus library is free software: you can redistribute it
+// and/or modify it under the terms of the GNU Lesser General Public License as
+// published by the Free Software Foundation, either version 3 of the License,
+// or (at your option) any later version.
+//
+// The dexon-consensus library is distributed in the hope that it will be
+// useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
+// General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the dexon-consensus library. If not, see
+// <http://www.gnu.org/licenses/>.
+
+package types
+
+import (
+	"fmt"
+)
+
+// Position describes the position in the block lattice of an entity.
+type Position struct {
+	Round  uint64 `json:"round"`
+	Height uint64 `json:"height"`
+}
+
+func (pos Position) String() string {
+	return fmt.Sprintf("Position{Round:%d Height:%d}", pos.Round, pos.Height)
+}
+
+// Equal checks if two positions are equal.
+func (pos Position) Equal(other Position) bool {
+	return pos.Round == other.Round && pos.Height == other.Height
+}
+
+// Newer checks if one block is newer than another one on the same chain.
+// If two blocks on different chain compared by this function, it would panic.
+func (pos Position) Newer(other Position) bool {
+	return pos.Round > other.Round ||
+		(pos.Round == other.Round && pos.Height > other.Height)
+}
+
+// Older checks if one block is older than another one on the same chain.
+// If two blocks on different chain compared by this function, it would panic.
+func (pos Position) Older(other Position) bool {
+	return pos.Round < other.Round ||
+		(pos.Round == other.Round && pos.Height < other.Height)
+}