Add API to get latest committed blockInfo, also send it via 'block' message type to stats server (#113)

consensus/XDPoS/api.go

@@ -91,6 +91,11 @@ func (api *API) GetSignersAtHash(hash common.Hash) ([]common.Address, error) {
 	return api.XDPoS.GetAuthorisedSignersFromSnapshot(api.chain, header)
 }
 
+// Get the latest v2 committed block information. Note: This only applies to v2 engine. it doesn't make sense for v1
+func (api *API) GetLatestCommittedBlockHeader() *types.BlockInfo {
+	return api.XDPoS.EngineV2.GetLatestCommittedBlockInfo()
+}
+
 func (api *API) NetworkInformation() NetworkInformation {
 	info := NetworkInformation{}
 	info.NetworkId = api.chain.Config().ChainId

consensus/XDPoS/engines/engine_v2/engine.go

@@ -1019,3 +1019,7 @@ func (x *XDPoS_v2) periodicJob() {
 		}
 	}()
 }
+
+func (x *XDPoS_v2) GetLatestCommittedBlockInfo() *types.BlockInfo {
+	return x.highestCommitBlock
+}

ethstats/ethstats.go

@@ -511,6 +511,13 @@ type blockStats struct {
 	Uncles     uncleStats     `json:"uncles"`
 }
 
+// blockStats is the information to report about individual blocks.
+type latestCommittedBlockStats struct {
+	Number *big.Int    `json:"number"`
+	Hash   common.Hash `json:"hash"`
+	Round  uint64      `json:"round"`
+}
+
 // txStats is the information to report about individual transactions.
 type txStats struct {
 	Hash common.Hash `json:"hash"`
@@ -539,6 +546,17 @@ func (s *Service) reportBlock(conn *websocket.Conn, block *types.Block) error {
 		"id":    s.node,
 		"block": details,
 	}
+
+	// Get the latest committed block information
+	if (s.engine.(*XDPoS.XDPoS).EngineV2 != nil) && (s.engine.(*XDPoS.XDPoS).EngineV2.GetLatestCommittedBlockInfo() != nil) {
+		latestCommittedBlockInfo := s.engine.(*XDPoS.XDPoS).EngineV2.GetLatestCommittedBlockInfo()
+		stats["latestCommittedBlockInfo"] = &latestCommittedBlockStats{
+			Number: latestCommittedBlockInfo.Number,
+			Round:  uint64(latestCommittedBlockInfo.Round),
+			Hash:   latestCommittedBlockInfo.Hash,
+		}
+	}
+
 	report := map[string][]interface{}{
 		"emit": {"block", stats},
 	}

internal/web3ext/web3ext.go

@@ -138,6 +138,10 @@ web3._extend({
 			call: 'XDPoS_getSignersAtHash',
 			params: 1
 		}),
+		new web3._extend.Method({
+			name: 'getLatestCommittedBlockInfo',
+			call: 'XDPoS_getLatestCommittedBlockHeader'
+		}),
 	],
 	properties: [
 		new web3._extend.Property({