added consensus mechanism

Author: BChainbuddy

block/blockchain.go

@@ -131,6 +131,7 @@ func (bc *Blockchain) Chain() []*Block {
 
 func (bc *Blockchain) Run() {
 	bc.StartSyncNeighbors()
+	bc.ResolveConflicts()
 }
 
 func (bc *Blockchain) SetNeighbors() {
@@ -301,6 +302,15 @@ func (bc *Blockchain) Mining() bool {
 	previousHash := bc.LastBlock().Hash()
 	bc.CreateBlock(nonce, previousHash)
 	log.Println("action=mining, status=success")
+
+	for _, n := range bc.neighbors {
+		endpoint := fmt.Sprintf("http://%s/consensus", n)
+		client := &http.Client{}
+		req, _ := http.NewRequest("PUT", endpoint, nil)
+		resp, _ := client.Do(req)
+		log.Printf("%v", resp)
+	}
+
 	return true
 }
 

blockchain_server/blockchain_server.go

@@ -189,6 +189,24 @@ func (bcs *BlockchainServer) Amount(w http.ResponseWriter, req *http.Request) {
 	}
 }
 
+func (bcs *BlockchainServer) Consensus(w http.ResponseWriter, req *http.Request) {
+	switch req.Method {
+	case http.MethodPut:
+		bc := bcs.GetBlockchain()
+		replaced := bc.ResolveConflicts()
+
+		w.Header().Add("Content-Type", "application/json")
+		if replaced {
+			io.WriteString(w, string(utils.JsonStatus("success")))
+		} else {
+			io.WriteString(w, string(utils.JsonStatus("fail")))
+		}
+	default:
+		log.Printf("ERROR: Invalid HTTP Method")
+		w.WriteHeader(http.StatusBadRequest)
+	}
+}
+
 func (bcs *BlockchainServer) Run() {
 	bcs.GetBlockchain().Run()
 
@@ -197,5 +215,6 @@ func (bcs *BlockchainServer) Run() {
 	http.HandleFunc("/mine", bcs.Mine)
 	http.HandleFunc("/mine/start", bcs.StartMine)
 	http.HandleFunc("/amount", bcs.Amount)
+	http.HandleFunc("/consensus", bcs.Consensus)
 	log.Fatal(http.ListenAndServe("0.0.0.0:"+strconv.Itoa(int(bcs.Port())), nil))
 }