better stat with when latest block was seen

app/data/pool.go

@@ -73,6 +73,12 @@ func (m *MemPool) DoneTxCount() uint64 {
 	return m.Pending.Processed()
 }
 
+// LastSeenBlock - Last seen block by mempool & when it was seen, to be invoked
+// by stat generator http request handler method
+func (m *MemPool) LastSeenBlock() LastSeenBlock {
+	return m.Pending.GetLastSeenBlock()
+}
+
 // PendingForGTE - Returning list of tx(s), pending for more than
 // x time unit
 func (m *MemPool) PendingForGTE(x time.Duration) []*MemPoolTx {

app/data/response.go

@@ -1,13 +1,17 @@
 package data
 
+import "time"
+
 // Stat - Response to client queries for current mempool state
 // to be sent in this form
 type Stat struct {
-	PendingPoolSize uint64 `json:"pendingPoolSize"`
-	QueuedPoolSize  uint64 `json:"queuedPoolSize"`
-	Uptime          string `json:"uptime"`
-	Processed       uint64 `json:"processed"`
-	NetworkID       uint64 `json:"networkID"`
+	PendingPoolSize uint64        `json:"pendingPoolSize"`
+	QueuedPoolSize  uint64        `json:"queuedPoolSize"`
+	Uptime          string        `json:"uptime"`
+	Processed       uint64        `json:"processed"`
+	LatestBlock     uint64        `json:"latestBlock"`
+	SeenAgo         time.Duration `json:"latestSeenAgo"`
+	NetworkID       uint64        `json:"networkID"`
 }
 
 // Msg - Response message sent to client

app/server/server.go

@@ -71,11 +71,15 @@ func Start(ctx context.Context, res *data.Resource) {
 
 		v1.GET("/stat", func(c echo.Context) error {
 
+			latestBlock := res.Pool.LastSeenBlock()
+
 			return c.JSON(http.StatusOK, &data.Stat{
 				PendingPoolSize: res.Pool.PendingPoolLength(),
 				QueuedPoolSize:  res.Pool.QueuedPoolLength(),
 				Uptime:          time.Now().UTC().Sub(res.StartedAt).String(),
 				Processed:       res.Pool.DoneTxCount(),
+				LatestBlock:     latestBlock.Number,
+				SeenAgo:         time.Now().UTC().Sub(latestBlock.At),
 				NetworkID:       res.NetworkID,
 			})