1 files changed, 53 insertions, 0 deletions
diff --git a/core/governance.go b/core/governance.go
new file mode 100644
index 0000000..a3bc3af
--- /dev/null
+++ b/core/governance.go
@@ -0,0 +1,53 @@
+// 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
+// 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.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the dexon-consensus-core library. If not, see
+// <http://www.gnu.org/licenses/>.
+
+package core
+
+import (
+	"github.com/cobinhood/decimal"
+
+	"github.com/dexon-foundation/dexon-consensus-core/core/types"
+)
+
+// MembershipActionType specifies the action of a membership event.
+type MembershipActionType int
+
+// Event enums.
+const (
+	MembershipActionAdd    MembershipActionType = 0
+	MembershipActionDelete MembershipActionType = 1
+)
+
+// MembershipEvent specifies the event of membership changes.
+type MembershipEvent struct {
+	Epoch  int
+	Action MembershipActionType
+}
+
+// Governance interface specifies interface to control the governance contract.
+// Note that there are a lot more methods in the governance contract, that this
+// interface only define those that are required to run the consensus algorithm.
+type Governance interface {
+	// Get the current validator set and it's corresponding stake.
+	GetValidatorSet() map[types.ValidatorID]decimal.Decimal
+
+	// Get block proposing interval (in milliseconds).
+	GetBlockProposingInterval() int
+
+	// Get membership events after a certain epoch.
+	GetMembershipEvents(epoch int) []MembershipEvent
+}