core: Add block hash signature functions in core/ctypto.go. (#39)

1 files changed, 23 insertions, 6 deletions

diff --git a/core/types/validator.go b/core/types/validator.go
index 48ce586..86c3acc 100644
--- a/core/types/validator.go
+++ b/core/types/validator.go
@@ -1,15 +1,15 @@
 // Copyright 2018 The dexon-consensus-core Authors
 // This file is part of the dexon-consensus-core library.
 //
-// The dexon-consensus-core library is free software: you can redistribute it and/or
-// modify it under the terms of the GNU Lesser General Public License as
+// The dexon-consensus-core 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-core 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.
+// The dexon-consensus-core 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-core library. If not, see
@@ -18,6 +18,8 @@
 package types
 
 import (
+	"bytes"
+
 	"github.com/dexon-foundation/dexon-consensus-core/common"
 )
 
@@ -25,3 +27,18 @@ import (
 type ValidatorID struct {
 	common.Hash
 }
+
+// ValidatorIDs implements sort.Interface for ValidatorID.
+type ValidatorIDs []ValidatorID
+
+func (v ValidatorIDs) Len() int {
+	return len(v)
+}
+
+func (v ValidatorIDs) Less(i int, j int) bool {
+	return bytes.Compare([]byte(v[i].Hash[:]), []byte(v[j].Hash[:])) == -1
+}
+
+func (v ValidatorIDs) Swap(i int, j int) {
+	v[i], v[j] = v[j], v[i]
+}