The core protocol of WoopChain
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
woop/consensus/consensus_leader.go

308 lines
8.3 KiB

package consensus
import (
"log"
"sync"
"bytes"
"encoding/binary"
"errors"
"fmt"
"harmony-benchmark/blockchain"
"harmony-benchmark/p2p"
"crypto/sha256"
"strings"
)
var mutex = &sync.Mutex{}
// WaitForNewBlock waits for a new block.
func (consensus *Consensus) WaitForNewBlock(blockChannel chan blockchain.Block) {
for { // keep waiting for new blocks
newBlock := <-blockChannel
// TODO: think about potential race condition
if consensus.state == READY {
consensus.startConsensus(&newBlock)
}
}
}
// ProcessMessageLeader is the leader's consensus message dispatcher
func (consensus *Consensus) ProcessMessageLeader(message []byte) {
msgType, err := GetConsensusMessageType(message)
if err != nil {
log.Print(err)
}
payload, err := GetConsensusMessagePayload(message)
if err != nil {
log.Print(err)
}
log.Printf("[Leader-%d] Received and processing message: %s\n", consensus.ShardId, msgType)
switch msgType {
case ANNOUNCE:
log.Printf("Unexpected message type: %s", msgType)
case COMMIT:
consensus.processCommitMessage(payload)
case CHALLENGE:
log.Printf("Unexpected message type: %s", msgType)
case RESPONSE:
consensus.processResponseMessage(payload)
case START_CONSENSUS:
consensus.processStartConsensusMessage(payload)
default:
log.Printf("Unexpected message type: %s", msgType)
}
}
// Handler for message which triggers consensus process
func (consensus *Consensus) processStartConsensusMessage(payload []byte) {
tx := blockchain.NewCoinbaseTX("x", "y")
consensus.startConsensus(blockchain.NewGenesisBlock(tx))
}
func (consensus *Consensus) startConsensus(newBlock *blockchain.Block) {
// prepare message and broadcast to validators
// Construct new block
//newBlock := constructNewBlock()
copy(newBlock.Hash[:32], consensus.blockHash[:])
msgToSend, err := consensus.constructAnnounceMessage()
if err != nil {
return
}
// Set state to ANNOUNCE_DONE
consensus.state = ANNOUNCE_DONE
p2p.BroadcastMessage(consensus.validators, msgToSend)
}
// Construct the announce message to send to validators
func (consensus Consensus) constructAnnounceMessage() ([]byte, error) {
buffer := bytes.NewBuffer([]byte{})
// 4 byte consensus id
fourBytes := make([]byte, 4)
binary.BigEndian.PutUint32(fourBytes, consensus.consensusId)
buffer.Write(fourBytes)
// 32 byte block hash
if len(consensus.blockHash) != 32 {
return buffer.Bytes(), errors.New(fmt.Sprintf("Block Hash size is %d bytes", len(consensus.blockHash)))
}
buffer.Write(consensus.blockHash[:])
// 2 byte leader id
twoBytes := make([]byte, 2)
binary.BigEndian.PutUint16(twoBytes, consensus.nodeId)
buffer.Write(twoBytes)
// n byte of block header
blockHeader := getBlockHeader()
buffer.Write(blockHeader)
// 4 byte of payload size
sizeOfPayload := uint32(len(blockHeader))
binary.BigEndian.PutUint32(fourBytes, sizeOfPayload)
buffer.Write(fourBytes)
// 64 byte of signature on previous data
signature := signMessage(buffer.Bytes())
buffer.Write(signature)
return consensus.ConstructConsensusMessage(ANNOUNCE, buffer.Bytes()), nil
}
// Get the hash of a block's byte stream
func getBlockHash(block []byte) [32]byte {
return sha256.Sum256(block)
}
// TODO: fill in this function
func getBlockHeader() []byte {
return make([]byte, 200)
}
func signMessage(message []byte) []byte {
// TODO: implement real ECC signature
mockSignature := sha256.Sum256(message)
return append(mockSignature[:], mockSignature[:]...)
}
func (consensus *Consensus) processCommitMessage(payload []byte) {
//#### Read payload data
offset := 0
// 4 byte consensus id
consensusId := binary.BigEndian.Uint32(payload[offset : offset+4])
offset += 4
// 32 byte block hash
blockHash := payload[offset : offset+32]
offset += 32
// 2 byte validator id
validatorId := string(payload[offset : offset+2])
offset += 2
// 33 byte commit
commit := payload[offset : offset+33]
offset += 33
// 64 byte of signature on previous data
signature := payload[offset : offset+64]
offset += 64
//#### END: Read payload data
// TODO: make use of the data. This is just to avoid the unused variable warning
_ = consensusId
_ = blockHash
_ = commit
_ = signature
// proceed only when the message is not received before and this consensus phase is not done.
mutex.Lock()
_, ok := consensus.commits[validatorId]
shouldProcess := !ok && consensus.state == ANNOUNCE_DONE
if shouldProcess {
consensus.commits[validatorId] = validatorId
log.Printf("Number of commits received: %d", len(consensus.commits))
}
mutex.Unlock()
if !shouldProcess {
return
}
mutex.Lock()
if len(consensus.commits) >= (2*len(consensus.validators))/3+1 {
log.Printf("Enough commits received with %d signatures", len(consensus.commits))
if consensus.state == ANNOUNCE_DONE {
// Set state to CHALLENGE_DONE
consensus.state = CHALLENGE_DONE
}
// Broadcast challenge
msgToSend := consensus.constructChallengeMessage()
p2p.BroadcastMessage(consensus.validators, msgToSend)
}
mutex.Unlock()
}
// Construct the challenge message to send to validators
func (consensus Consensus) constructChallengeMessage() []byte {
buffer := bytes.NewBuffer([]byte{})
// 4 byte consensus id
fourBytes := make([]byte, 4)
binary.BigEndian.PutUint32(fourBytes, consensus.consensusId)
buffer.Write(fourBytes)
// 32 byte block hash
buffer.Write(consensus.blockHash[:])
// 2 byte leader id
twoBytes := make([]byte, 2)
binary.BigEndian.PutUint16(twoBytes, consensus.nodeId)
buffer.Write(twoBytes)
// 33 byte aggregated commit
buffer.Write(getAggregatedCommit(consensus.commits))
// 33 byte aggregated key
buffer.Write(getAggregatedKey(consensus.commits))
// 32 byte challenge
buffer.Write(getChallenge())
// 64 byte of signature on previous data
signature := signMessage(buffer.Bytes())
buffer.Write(signature)
return consensus.ConstructConsensusMessage(CHALLENGE, buffer.Bytes())
}
func getAggregatedCommit(commits map[string]string) []byte {
// TODO: implement actual commit aggregation
var commitArray []string
for _, val := range commits {
commitArray = append(commitArray, val)
}
var commit [32]byte
commit = sha256.Sum256([]byte(strings.Join(commitArray, "")))
return append(commit[:], byte(0))
}
func getAggregatedKey(commits map[string]string) []byte {
// TODO: implement actual key aggregation
var commitArray []string
for key := range commits {
commitArray = append(commitArray, key)
}
var commit [32]byte
commit = sha256.Sum256([]byte(strings.Join(commitArray, "")))
return append(commit[:], byte(0))
}
func getChallenge() []byte {
// TODO: implement actual challenge data
return make([]byte, 32)
}
func (consensus *Consensus) processResponseMessage(payload []byte) {
//#### Read payload data
offset := 0
// 4 byte consensus id
consensusId := binary.BigEndian.Uint32(payload[offset : offset+4])
offset += 4
// 32 byte block hash
blockHash := payload[offset : offset+32]
offset += 32
// 2 byte validator id
validatorId := string(payload[offset : offset+2])
offset += 2
// 32 byte response
response := payload[offset : offset+32]
offset += 32
// 64 byte of signature on previous data
signature := payload[offset : offset+64]
offset += 64
//#### END: Read payload data
// TODO: make use of the data. This is just to avoid the unused variable warning
_ = consensusId
_ = blockHash
_ = response
_ = signature
// proceed only when the message is not received before and this consensus phase is not done.
mutex.Lock()
_, ok := consensus.responses[validatorId]
shouldProcess := !ok && consensus.state == CHALLENGE_DONE
if shouldProcess {
consensus.responses[validatorId] = validatorId
log.Printf("Number of responses received: %d", len(consensus.responses))
}
mutex.Unlock()
if !shouldProcess {
return
}
mutex.Lock()
if len(consensus.responses) >= (2*len(consensus.validators))/3+1 {
log.Printf("Consensus reached with %d signatures.", len(consensus.responses))
if consensus.state == CHALLENGE_DONE {
// Set state to FINISHED
consensus.state = FINISHED
// TODO: do followups on the consensus
log.Printf("[Shard %d] HOORAY!!! CONSENSUS REACHED AMONG %d NODES WITH CONSENSUS ID %d!!!\n", consensus.ShardId, len(consensus.validators), consensus.consensusId)
consensus.ResetState()
consensus.consensusId++
consensus.ReadySignal <- 1
}
// TODO: composes new block and broadcast the new block to validators
}
mutex.Unlock()
}