fix a lot of basic mistakes. See https://docs.google.com/document/d/1eIuVFnRra8Ggnj5zSTcGLn9iXGwHEdOHGC6-gHvvuGc

blockchain/blockchain.go

@@ -21,7 +21,7 @@ func (bc *Blockchain) FindBlock(blockHash []byte) *Block {
 		return nil
 	}
 	for _, block := range bc.Blocks {
-		if bytes.Compare(block.Hash[:], blockHash[:]) == 0 {
+		if bytes.Equal(block.Hash[:], blockHash[:]) {
 			return block
 		}
 	}

blockchain/utxopool.go

@@ -472,10 +472,7 @@ func (utxoPool *UTXOPool) LockedUtxoExists(address [20]byte, txID string, index
 		return false
 	}
 	_, ok = utxoPool.LockedUtxoMap[address][txID][index]
-	if !ok {
-		return false
-	}
-	return true
+	return ok
 }
 
 // DeleteOneLockedUtxo deletes one balance item of UTXOPool and clean up if possible.

client/btctxgen/main.go

@@ -104,7 +104,7 @@ func generateSimulatedTransactions(shardID int, dataNodes []*node.Node) ([]*bloc
 	cnt := 0
 
 LOOP:
-	for true {
+	for {
 		btcTx := iter.NextTx()
 		if btcTx == nil {
 			log.Error("Failed to parse tx", "height", iter.GetBlockIndex())
@@ -255,7 +255,7 @@ func main() {
 		leaders = append(leaders, leader)
 	}
 
-	for true {
+	for {
 		allCrossTxs := []*blockchain.Transaction{}
 		// Generate simulated transactions
 		for shardID, leader := range shardIDLeaderMap {

client/config/config.go

@@ -83,11 +83,11 @@ func (config *Config) GetClientPort() string {
 // ReadConfigFile parses the config file and return a 2d array containing the file data
 func (config *Config) ReadConfigFile(filename string) error {
 	file, err := os.Open(filename)
-	defer file.Close()
 	if err != nil {
 		log.Fatal("Failed to read config file ", filename)
 		return err
 	}
+	defer file.Close()
 	fscanner := bufio.NewScanner(file)
 
 	result := []Entry{}

client/txgen/main.go

@@ -148,7 +148,7 @@ func generateCrossShardTx(txInfo *TxInfo) {
 	nodeShardID := txInfo.dataNodes[txInfo.shardID].Consensus.ShardID
 	crossShardID := nodeShardID
 	// a random shard to spend money to
-	for true {
+	for {
 		crossShardID = uint32(rand.Intn(len(txInfo.dataNodes)))
 		if crossShardID != nodeShardID {
 			break
@@ -335,7 +335,7 @@ func main() {
 	client.InitLookUpIntPriKeyMap()
 	subsetCounter := 0
 
-	for true {
+	for {
 		t := time.Now()
 		if totalTime > 0 && t.Sub(start).Seconds() >= totalTime {
 			log.Debug("Generator timer ended.", "duration", (int(t.Sub(start))), "startTime", start, "totalTime", totalTime)

client/wallet/main.go

@@ -275,7 +275,7 @@ func ExecuteTransaction(tx blockchain.Transaction, walletNode *node.Node) error
 
 	doneSignal := make(chan int)
 	go func() {
-		for true {
+		for {
 			if len(walletNode.Client.PendingCrossTxs) == 0 {
 				doneSignal <- 0
 				break
@@ -300,7 +300,7 @@ func FetchUtxos(addresses [][20]byte, walletNode *node.Node) (map[uint32]blockch
 
 	doneSignal := make(chan int)
 	go func() {
-		for true {
+		for {
 			if len(walletNode.Client.ShardUtxoMap) == len(*walletNode.Client.Leaders) {
 				doneSignal <- 0
 				break

consensus/consensus.go

@@ -87,8 +87,8 @@ type Consensus struct {
 // should be stored in this temporary structure. In case the round N-1 finishes, it can catch
 // up to the latest state of round N by using this structure.
 type BlockConsensusStatus struct {
-	blockHeader []byte         // the block header of the block which the consensus is running on
-	state       State // the latest state of the consensus
+	blockHeader []byte // the block header of the block which the consensus is running on
+	state       State  // the latest state of the consensus
 }
 
 // NewConsensus creates a new Consensus object

consensus/consensus_validator.go

@@ -111,7 +111,7 @@ func (consensus *Consensus) processAnnounceMessage(payload []byte) {
 	}
 
 	// check block hash
-	if bytes.Compare(blockHash[:], blockHeaderObj.CalculateBlockHash()[:]) != 0 || bytes.Compare(blockHeaderObj.Hash[:], blockHeaderObj.CalculateBlockHash()[:]) != 0 {
+	if !bytes.Equal(blockHash[:], blockHeaderObj.CalculateBlockHash()[:]) || !bytes.Equal(blockHeaderObj.Hash[:], blockHeaderObj.CalculateBlockHash()[:]) {
 		consensus.Log.Warn("Block hash doesn't match", "consensus", consensus)
 		return
 	}
@@ -193,7 +193,7 @@ func (consensus *Consensus) processChallengeMessage(payload []byte, targetState
 	defer consensus.mutex.Unlock()
 
 	// check block hash
-	if bytes.Compare(blockHash[:], consensus.blockHash[:]) != 0 {
+	if !bytes.Equal(blockHash[:], consensus.blockHash[:]) {
 		consensus.Log.Warn("Block hash doesn't match", "consensus", consensus)
 		return
 	}
@@ -353,7 +353,7 @@ func (consensus *Consensus) processCollectiveSigMessage(payload []byte) {
 	}
 
 	// check block hash
-	if bytes.Compare(blockHash[:], consensus.blockHash[:]) != 0 {
+	if !bytes.Equal(blockHash[:], consensus.blockHash[:]) {
 		consensus.Log.Warn("Block hash doesn't match", "consensus", consensus)
 		return
 	}

node/node.go

@@ -127,7 +127,6 @@ func (node *Node) countNumTransactionsInBlockchain() int {
 func (node *Node) ConnectIdentityChain() {
 	IDCPeer := node.IDCPeer
 	p2p.SendMessage(IDCPeer, identity.ConstructIdentityMessage(identity.Announce, node.SerializeWaitNode()))
-	return
 }
 
 //NewWaitNode is a way to initiate a waiting no

p2p/peer.go

@@ -48,7 +48,7 @@ func BroadcastMessage(peers []Peer, msg []byte) {
 		peerCopy := peer
 		go send(peerCopy.Ip, peerCopy.Port, content)
 	}
-	log.Info("Broadcasting Done", "time spent(s)", time.Now().Sub(start).Seconds())
+	log.Info("Broadcasting Done", "time spent(s)", time.Since(start).Seconds())
 }
 
 func SelectMyPeers(peers []Peer, min int, max int) []Peer {

pow/api.go

@@ -77,10 +77,7 @@ func (req *Request) UnmarshalText(buf []byte) error {
 	}
 	req.Difficulty = uint32(diff)
 	req.Nonce, err = base64.RawStdEncoding.DecodeString(bits[2])
-	if err != nil {
-		return err
-	}
-	return nil
+	return err
 }
 
 // Convenience function to check whether a proof of work is fulfilled

proto/consensus/consensus.go

@@ -68,8 +68,8 @@ Response:
 ----  message end  -----
 */
 
-// ConsensusMessageTypeBytes is the number of bytes consensus message type occupies
-const ConsensusMessageTypeBytes = 1
+// MessageTypeBytes is the number of bytes consensus message type occupies
+const MessageTypeBytes = 1
 
 // ConsensusMessageType is the specific types of message under Consensus category
 type ConsensusMessageType byte
@@ -130,7 +130,7 @@ func GetConsensusMessagePayload(message []byte) ([]byte, error) {
 	if len(message) < 2 {
 		return []byte{}, errors.New("Failed to get consensus message payload: no data available.")
 	}
-	return message[ConsensusMessageTypeBytes:], nil
+	return message[MessageTypeBytes:], nil
 }
 
 // Concatenate msgType as one byte with payload, and return the whole byte array

syncing/syncing.go

@@ -15,12 +15,9 @@ import (
 type SyncPeerConfig struct {
 	peer        p2p.Peer
 	conn        net.Conn
-	block       *blockchain.Block
 	w           *bufio.Writer
-	receivedMsg []byte
 	err         error
 	trusted     bool
-	indexes     []uint16
 	blockHashes [][32]byte
 }
 

utils/distribution_config.go

@@ -74,11 +74,11 @@ func (config *DistributionConfig) GetClientPort() string {
 // Parse the config file and return a 2d array containing the file data
 func (config *DistributionConfig) ReadConfigFile(filename string) error {
 	file, err := os.Open(filename)
-	defer file.Close()
 	if err != nil {
 		log.Fatal("Failed to read config file ", filename)
 		return err
 	}
+	defer file.Close()
 	fscanner := bufio.NewScanner(file)
 
 	result := []ConfigEntry{}