protocol/state/consensus_result.go

   1 package state
   2
   3 import (
   4         "encoding/hex"
   5         "sort"
   6
   7         "github.com/vapor/common/arithmetic"
   8         "github.com/vapor/config"
   9         "github.com/vapor/consensus"
  10         "github.com/vapor/crypto/ed25519/chainkd"
  11         "github.com/vapor/errors"
  12         "github.com/vapor/math/checked"
  13         "github.com/vapor/protocol/bc"
  14         "github.com/vapor/protocol/bc/types"
  15 )
  16
  17 // fedConsensusPath is used to derive federation root xpubs for signing blocks
  18 var fedConsensusPath = [][]byte{
  19         []byte{0xff, 0xff, 0xff, 0xff},
  20         []byte{0xff, 0x00, 0x00, 0x00},
  21         []byte{0xff, 0xff, 0xff, 0xff},
  22         []byte{0xff, 0x00, 0x00, 0x00},
  23         []byte{0xff, 0x00, 0x00, 0x00},
  24 }
  25
  26 // ConsensusNode represents a consensus node
  27 type ConsensusNode struct {
  28         XPub    chainkd.XPub
  29         VoteNum uint64
  30         Order   uint64
  31 }
  32
  33 type byVote []*ConsensusNode
  34
  35 func (c byVote) Len() int { return len(c) }
  36 func (c byVote) Less(i, j int) bool {
  37         return c[i].VoteNum > c[j].VoteNum || (c[i].VoteNum == c[j].VoteNum && c[i].XPub.String() > c[j].XPub.String())
  38 }
  39 func (c byVote) Swap(i, j int) { c[i], c[j] = c[j], c[i] }
  40
  41 // CoinbaseReward contains receiver and reward
  42 type CoinbaseReward struct {
  43         Amount         uint64
  44         ControlProgram []byte
  45 }
  46
  47 // SortByAmount implements sort.Interface for CoinbaseReward slices
  48 type SortByAmount []CoinbaseReward
  49
  50 func (a SortByAmount) Len() int      { return len(a) }
  51 func (a SortByAmount) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
  52 func (a SortByAmount) Less(i, j int) bool {
  53         return a[i].Amount > a[j].Amount || (a[i].Amount == a[j].Amount && hex.EncodeToString(a[i].ControlProgram) > hex.EncodeToString(a[j].ControlProgram))
  54 }
  55
  56 // CalCoinbaseReward calculate the coinbase reward for block
  57 func CalCoinbaseReward(block *types.Block) (*CoinbaseReward, error) {
  58         result := &CoinbaseReward{}
  59         if len(block.Transactions) > 0 && len(block.Transactions[0].Outputs) > 0 {
  60                 result.ControlProgram = block.Transactions[0].Outputs[0].ControlProgram()
  61         } else {
  62                 return nil, errors.New("not found coinbase receiver")
  63         }
  64
  65         result.Amount = consensus.BlockSubsidy(block.BlockHeader.Height)
  66         for _, tx := range block.Transactions {
  67                 txFee, err := arithmetic.CalculateTxFee(tx)
  68                 if err != nil {
  69                         return nil, errors.Wrap(checked.ErrOverflow, "calculate transaction fee")
  70                 }
  71
  72                 result.Amount += txFee
  73         }
  74         return result, nil
  75 }
  76
  77 // CalcVoteSeq calculate the vote sequence
  78 // seq 0 is the genesis block
  79 // seq 1 is the the block height 1, to block height RoundVoteBlockNums
  80 // seq 2 is the block height RoundVoteBlockNums + 1 to block height 2 * RoundVoteBlockNums
  81 // consensus node of the current round is the final result of previous round
  82 func CalcVoteSeq(blockHeight uint64) uint64 {
  83         if blockHeight == 0 {
  84                 return 0
  85         }
  86         return (blockHeight-1)/consensus.ActiveNetParams.RoundVoteBlockNums + 1
  87 }
  88
  89 // ConsensusResult represents a snapshot of each round of DPOS voting
  90 // Seq indicates the sequence of current votes, which start from zero
  91 // NumOfVote indicates the number of votes each consensus node receives, the key of map represent public key
  92 // CoinbaseReward indicates the coinbase receiver and reward
  93 type ConsensusResult struct {
  94         Seq            uint64
  95         NumOfVote      map[string]uint64
  96         CoinbaseReward map[string]uint64
  97         BlockHash      bc.Hash
  98         BlockHeight    uint64
  99 }
 100
 101 // ApplyBlock calculate the consensus result for new block
 102 func (c *ConsensusResult) ApplyBlock(block *types.Block) error {
 103         if c.BlockHash != block.PreviousBlockHash {
 104                 return errors.New("block parent hash is not equals last block hash of vote result")
 105         }
 106
 107         if err := c.AttachCoinbaseReward(block); err != nil {
 108                 return err
 109         }
 110
 111         for _, tx := range block.Transactions {
 112                 if err := c.ApplyTransaction(tx); err != nil {
 113                         return err
 114                 }
 115         }
 116
 117         c.BlockHash = block.Hash()
 118         c.BlockHeight = block.Height
 119         c.Seq = CalcVoteSeq(block.Height)
 120         return nil
 121 }
 122
 123 // ApplyTransaction calculate the consensus result for transaction
 124 func (c *ConsensusResult) ApplyTransaction(tx *types.Tx) error {
 125         for _, input := range tx.Inputs {
 126                 vetoInput, ok := input.TypedInput.(*types.VetoInput)
 127                 if !ok {
 128                         continue
 129                 }
 130
 131                 pubkey := hex.EncodeToString(vetoInput.Vote)
 132                 c.NumOfVote[pubkey], ok = checked.SubUint64(c.NumOfVote[pubkey], vetoInput.Amount)
 133                 if !ok {
 134                         return checked.ErrOverflow
 135                 }
 136
 137                 if c.NumOfVote[pubkey] == 0 {
 138                         delete(c.NumOfVote, pubkey)
 139                 }
 140         }
 141
 142         for _, output := range tx.Outputs {
 143                 voteOutput, ok := output.TypedOutput.(*types.VoteOutput)
 144                 if !ok {
 145                         continue
 146                 }
 147
 148                 pubkey := hex.EncodeToString(voteOutput.Vote)
 149                 if c.NumOfVote[pubkey], ok = checked.AddUint64(c.NumOfVote[pubkey], voteOutput.Amount); !ok {
 150                         return checked.ErrOverflow
 151                 }
 152         }
 153         return nil
 154 }
 155
 156 // AttachCoinbaseReward attach coinbase reward
 157 func (c *ConsensusResult) AttachCoinbaseReward(block *types.Block) error {
 158         reward, err := CalCoinbaseReward(block)
 159         if err != nil {
 160                 return err
 161         }
 162
 163         if block.Height%consensus.ActiveNetParams.RoundVoteBlockNums == 1 {
 164                 c.CoinbaseReward = map[string]uint64{}
 165         }
 166
 167         var ok bool
 168         program := hex.EncodeToString(reward.ControlProgram)
 169         c.CoinbaseReward[program], ok = checked.AddUint64(c.CoinbaseReward[program], reward.Amount)
 170         if !ok {
 171                 return checked.ErrOverflow
 172         }
 173         return nil
 174 }
 175
 176 // ConsensusNodes returns all consensus nodes
 177 func (c *ConsensusResult) ConsensusNodes() (map[string]*ConsensusNode, error) {
 178         var nodes []*ConsensusNode
 179         for pubkey, voteNum := range c.NumOfVote {
 180                 if voteNum >= consensus.ActiveNetParams.MinConsensusNodeVoteNum {
 181                         var xpub chainkd.XPub
 182                         if err := xpub.UnmarshalText([]byte(pubkey)); err != nil {
 183                                 return nil, err
 184                         }
 185
 186                         nodes = append(nodes, &ConsensusNode{XPub: xpub, VoteNum: voteNum})
 187                 }
 188         }
 189         // In principle, there is no need to sort all voting nodes.
 190         // if there is a performance problem, consider the optimization later.
 191         sort.Sort(byVote(nodes))
 192         result := make(map[string]*ConsensusNode)
 193         for i := 0; i < len(nodes) && int64(i) < consensus.ActiveNetParams.NumOfConsensusNode; i++ {
 194                 nodes[i].Order = uint64(i)
 195                 result[nodes[i].XPub.String()] = nodes[i]
 196         }
 197
 198         if len(result) != 0 {
 199                 return result, nil
 200         }
 201         return federationNodes(), nil
 202 }
 203
 204 // DetachBlock calculate the consensus result for detach block
 205 func (c *ConsensusResult) DetachBlock(block *types.Block) error {
 206         if c.BlockHash != block.Hash() {
 207                 return errors.New("block hash is not equals last block hash of vote result")
 208         }
 209
 210         if err := c.DetachCoinbaseReward(block); err != nil {
 211                 return err
 212         }
 213
 214         for i := len(block.Transactions) - 1; i >= 0; i-- {
 215                 tx := block.Transactions[i]
 216                 for _, input := range tx.Inputs {
 217                         vetoInput, ok := input.TypedInput.(*types.VetoInput)
 218                         if !ok {
 219                                 continue
 220                         }
 221
 222                         pubkey := hex.EncodeToString(vetoInput.Vote)
 223                         if c.NumOfVote[pubkey], ok = checked.AddUint64(c.NumOfVote[pubkey], vetoInput.Amount); !ok {
 224                                 return checked.ErrOverflow
 225                         }
 226                 }
 227
 228                 for _, output := range tx.Outputs {
 229                         voteOutput, ok := output.TypedOutput.(*types.VoteOutput)
 230                         if !ok {
 231                                 continue
 232                         }
 233
 234                         pubkey := hex.EncodeToString(voteOutput.Vote)
 235                         c.NumOfVote[pubkey], ok = checked.SubUint64(c.NumOfVote[pubkey], voteOutput.Amount)
 236                         if !ok {
 237                                 return checked.ErrOverflow
 238                         }
 239
 240                         if c.NumOfVote[pubkey] == 0 {
 241                                 delete(c.NumOfVote, pubkey)
 242                         }
 243                 }
 244         }
 245
 246         c.BlockHash = block.PreviousBlockHash
 247         c.BlockHeight = block.Height - 1
 248         c.Seq = CalcVoteSeq(block.Height - 1)
 249         return nil
 250 }
 251
 252 // DetachCoinbaseReward detach coinbase reward
 253 func (c *ConsensusResult) DetachCoinbaseReward(block *types.Block) error {
 254         if block.Height%consensus.ActiveNetParams.RoundVoteBlockNums == 0 {
 255                 for i, output := range block.Transactions[0].Outputs {
 256                         if i == 0 {
 257                                 continue
 258                         }
 259                         program := output.ControlProgram()
 260                         c.CoinbaseReward[hex.EncodeToString(program)] = output.AssetAmount().Amount
 261                 }
 262         }
 263
 264         reward, err := CalCoinbaseReward(block)
 265         if err != nil {
 266                 return err
 267         }
 268
 269         var ok bool
 270         program := hex.EncodeToString(reward.ControlProgram)
 271         if c.CoinbaseReward[program], ok = checked.SubUint64(c.CoinbaseReward[program], reward.Amount); !ok {
 272                 return checked.ErrOverflow
 273         }
 274
 275         if c.CoinbaseReward[program] == 0 {
 276                 delete(c.CoinbaseReward, program)
 277         }
 278         return nil
 279 }
 280
 281 // Fork copy the ConsensusResult struct
 282 func (c *ConsensusResult) Fork() *ConsensusResult {
 283         f := &ConsensusResult{
 284                 Seq:            c.Seq,
 285                 NumOfVote:      map[string]uint64{},
 286                 CoinbaseReward: map[string]uint64{},
 287                 BlockHash:      c.BlockHash,
 288                 BlockHeight:    c.BlockHeight,
 289         }
 290
 291         for key, value := range c.NumOfVote {
 292                 f.NumOfVote[key] = value
 293         }
 294
 295         for key, value := range c.CoinbaseReward {
 296                 f.CoinbaseReward[key] = value
 297         }
 298         return f
 299 }
 300
 301 // IsFinalize check if the result is end of consensus round
 302 func (c *ConsensusResult) IsFinalize() bool {
 303         return c.BlockHeight%consensus.ActiveNetParams.RoundVoteBlockNums == 0
 304 }
 305
 306 // GetCoinbaseRewards convert into CoinbaseReward array and sort it by amount
 307 func (c *ConsensusResult) GetCoinbaseRewards(blockHeight uint64) ([]CoinbaseReward, error) {
 308         rewards := []CoinbaseReward{}
 309         if blockHeight%consensus.ActiveNetParams.RoundVoteBlockNums != 0 {
 310                 return rewards, nil
 311         }
 312
 313         for p, amount := range c.CoinbaseReward {
 314                 program, err := hex.DecodeString(p)
 315                 if err != nil {
 316                         return nil, err
 317                 }
 318
 319                 rewards = append(rewards, CoinbaseReward{
 320                         Amount:         amount,
 321                         ControlProgram: program,
 322                 })
 323         }
 324         sort.Sort(SortByAmount(rewards))
 325         return rewards, nil
 326 }
 327
 328 func federationNodes() map[string]*ConsensusNode {
 329         consensusResult := map[string]*ConsensusNode{}
 330         for i, xpub := range config.CommonConfig.Federation.Xpubs {
 331                 derivedXPub := xpub.Derive(fedConsensusPath)
 332                 consensusResult[derivedXPub.String()] = &ConsensusNode{XPub: derivedXPub, VoteNum: 0, Order: uint64(i)}
 333         }
 334         return consensusResult
 335 }