dex: implement recovery mechanism (#258)

* dex: implement recovery mechanism

The DEXON recovery protocol allows us to use the Ethereum blockchain as a
fallback consensus chain to coordinate recovery.

* fix

1 files changed, 15 insertions, 2 deletions

diff --git a/vendor/github.com/dexon-foundation/dexon-consensus/core/interfaces.go b/vendor/github.com/dexon-foundation/dexon-consensus/core/interfaces.go
index 45a1fc7d5..ddd6c3bb9 100644
--- a/vendor/github.com/dexon-foundation/dexon-consensus/core/interfaces.go
+++ b/vendor/github.com/dexon-foundation/dexon-consensus/core/interfaces.go
@@ -101,8 +101,12 @@ type Governance interface {
 	// Return the genesis configuration if round == 0.
 	Configuration(round uint64) *types.Config
 
-	// CRS returns the CRS for a given round.
-	// Return the genesis CRS if round == 0.
+	// CRS returns the CRS for a given round. Return the genesis CRS if
+	// round == 0.
+	//
+	// The CRS returned is the proposed or latest reseted one, it would be
+	// changed later if corresponding DKG set failed to generate group public
+	// key.
 	CRS(round uint64) common.Hash
 
 	// Propose a CRS of round.
@@ -162,3 +166,12 @@ type Ticker interface {
 	// Retart the ticker and clear all internal data.
 	Restart()
 }
+
+// Recovery interface for interacting with recovery information.
+type Recovery interface {
+	// ProposeSkipBlock proposes a skip block.
+	ProposeSkipBlock(height uint64) error
+
+	// Votes gets the number of votes of given height.
+	Votes(height uint64) (uint64, error)
+}