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                 for _, input := range tx.Inputs {
 113                         vetoInput, ok := input.TypedInput.(*types.VetoInput)
 114                         if !ok {
 115                                 continue
 116                         }
 117
 118                         pubkey := hex.EncodeToString(vetoInput.Vote)
 119                         c.NumOfVote[pubkey], ok = checked.SubUint64(c.NumOfVote[pubkey], vetoInput.Amount)
 120                         if !ok {
 121                                 return checked.ErrOverflow
 122                         }
 123
 124                         if c.NumOfVote[pubkey] == 0 {
 125                                 delete(c.NumOfVote, pubkey)
 126                         }
 127                 }
 128
 129                 for _, output := range tx.Outputs {
 130                         voteOutput, ok := output.TypedOutput.(*types.VoteOutput)
 131                         if !ok {
 132                                 continue
 133                         }
 134
 135                         pubkey := hex.EncodeToString(voteOutput.Vote)
 136                         if c.NumOfVote[pubkey], ok = checked.AddUint64(c.NumOfVote[pubkey], voteOutput.Amount); !ok {
 137                                 return checked.ErrOverflow
 138                         }
 139                 }
 140         }
 141
 142         c.BlockHash = block.Hash()
 143         c.BlockHeight = block.Height
 144         c.Seq = CalcVoteSeq(block.Height)
 145         return nil
 146 }
 147
 148 // AttachCoinbaseReward attach coinbase reward
 149 func (c *ConsensusResult) AttachCoinbaseReward(block *types.Block) error {
 150         reward, err := CalCoinbaseReward(block)
 151         if err != nil {
 152                 return err
 153         }
 154
 155         if block.Height%consensus.ActiveNetParams.RoundVoteBlockNums == 1 {
 156                 c.CoinbaseReward = map[string]uint64{}
 157         }
 158
 159         var ok bool
 160         program := hex.EncodeToString(reward.ControlProgram)
 161         c.CoinbaseReward[program], ok = checked.AddUint64(c.CoinbaseReward[program], reward.Amount)
 162         if !ok {
 163                 return checked.ErrOverflow
 164         }
 165         return nil
 166 }
 167
 168 // ConsensusNodes returns all consensus nodes
 169 func (c *ConsensusResult) ConsensusNodes() (map[string]*ConsensusNode, error) {
 170         var nodes []*ConsensusNode
 171         for pubkey, voteNum := range c.NumOfVote {
 172                 if voteNum >= consensus.ActiveNetParams.MinConsensusNodeVoteNum {
 173                         var xpub chainkd.XPub
 174                         if err := xpub.UnmarshalText([]byte(pubkey)); err != nil {
 175                                 return nil, err
 176                         }
 177
 178                         nodes = append(nodes, &ConsensusNode{XPub: xpub, VoteNum: voteNum})
 179                 }
 180         }
 181         // In principle, there is no need to sort all voting nodes.
 182         // if there is a performance problem, consider the optimization later.
 183         sort.Sort(byVote(nodes))
 184         result := make(map[string]*ConsensusNode)
 185         for i := 0; i < len(nodes) && int64(i) < consensus.ActiveNetParams.NumOfConsensusNode; i++ {
 186                 nodes[i].Order = uint64(i)
 187                 result[nodes[i].XPub.String()] = nodes[i]
 188         }
 189
 190         if len(result) != 0 {
 191                 return result, nil
 192         }
 193         return federationNodes(), nil
 194 }
 195
 196 // DetachBlock calculate the consensus result for detach block
 197 func (c *ConsensusResult) DetachBlock(block *types.Block) error {
 198         if c.BlockHash != block.Hash() {
 199                 return errors.New("block hash is not equals last block hash of vote result")
 200         }
 201
 202         if err := c.DetachCoinbaseReward(block); err != nil {
 203                 return err
 204         }
 205
 206         for i := len(block.Transactions) - 1; i >= 0; i-- {
 207                 tx := block.Transactions[i]
 208                 for _, input := range tx.Inputs {
 209                         vetoInput, ok := input.TypedInput.(*types.VetoInput)
 210                         if !ok {
 211                                 continue
 212                         }
 213
 214                         pubkey := hex.EncodeToString(vetoInput.Vote)
 215                         if c.NumOfVote[pubkey], ok = checked.AddUint64(c.NumOfVote[pubkey], vetoInput.Amount); !ok {
 216                                 return checked.ErrOverflow
 217                         }
 218                 }
 219
 220                 for _, output := range tx.Outputs {
 221                         voteOutput, ok := output.TypedOutput.(*types.VoteOutput)
 222                         if !ok {
 223                                 continue
 224                         }
 225
 226                         pubkey := hex.EncodeToString(voteOutput.Vote)
 227                         c.NumOfVote[pubkey], ok = checked.SubUint64(c.NumOfVote[pubkey], voteOutput.Amount)
 228                         if !ok {
 229                                 return checked.ErrOverflow
 230                         }
 231
 232                         if c.NumOfVote[pubkey] == 0 {
 233                                 delete(c.NumOfVote, pubkey)
 234                         }
 235                 }
 236         }
 237
 238         c.BlockHash = block.PreviousBlockHash
 239         c.BlockHeight = block.Height - 1
 240         c.Seq = CalcVoteSeq(block.Height - 1)
 241         return nil
 242 }
 243
 244 // DetachCoinbaseReward detach coinbase reward
 245 func (c *ConsensusResult) DetachCoinbaseReward(block *types.Block) error {
 246         if block.Height%consensus.ActiveNetParams.RoundVoteBlockNums == 0 {
 247                 for i, output := range block.Transactions[0].Outputs {
 248                         if i == 0 {
 249                                 continue
 250                         }
 251                         program := output.ControlProgram()
 252                         c.CoinbaseReward[hex.EncodeToString(program)] = output.AssetAmount().Amount
 253                 }
 254         }
 255
 256         reward, err := CalCoinbaseReward(block)
 257         if err != nil {
 258                 return err
 259         }
 260
 261         var ok bool
 262         program := hex.EncodeToString(reward.ControlProgram)
 263         if c.CoinbaseReward[program], ok = checked.SubUint64(c.CoinbaseReward[program], reward.Amount); !ok {
 264                 return checked.ErrOverflow
 265         }
 266
 267         if c.CoinbaseReward[program] == 0 {
 268                 delete(c.CoinbaseReward, program)
 269         }
 270         return nil
 271 }
 272
 273 // Fork copy the ConsensusResult struct
 274 func (c *ConsensusResult) Fork() *ConsensusResult {
 275         f := &ConsensusResult{
 276                 Seq:            c.Seq,
 277                 NumOfVote:      map[string]uint64{},
 278                 CoinbaseReward: map[string]uint64{},
 279                 BlockHash:      c.BlockHash,
 280                 BlockHeight:    c.BlockHeight,
 281         }
 282
 283         for key, value := range c.NumOfVote {
 284                 f.NumOfVote[key] = value
 285         }
 286
 287         for key, value := range c.CoinbaseReward {
 288                 f.CoinbaseReward[key] = value
 289         }
 290         return f
 291 }
 292
 293 // IsFinalize check if the result is end of consensus round
 294 func (c *ConsensusResult) IsFinalize() bool {
 295         return c.BlockHeight%consensus.ActiveNetParams.RoundVoteBlockNums == 0
 296 }
 297
 298 // GetCoinbaseRewards convert into CoinbaseReward array and sort it by amount
 299 func (c *ConsensusResult) GetCoinbaseRewards(blockHeight uint64) ([]CoinbaseReward, error) {
 300         rewards := []CoinbaseReward{}
 301         if blockHeight%consensus.ActiveNetParams.RoundVoteBlockNums != 0 {
 302                 return rewards, nil
 303         }
 304
 305         for p, amount := range c.CoinbaseReward {
 306                 program, err := hex.DecodeString(p)
 307                 if err != nil {
 308                         return nil, err
 309                 }
 310
 311                 rewards = append(rewards, CoinbaseReward{
 312                         Amount:         amount,
 313                         ControlProgram: program,
 314                 })
 315         }
 316         sort.Sort(SortByAmount(rewards))
 317         return rewards, nil
 318 }
 319
 320 func federationNodes() map[string]*ConsensusNode {
 321         consensusResult := map[string]*ConsensusNode{}
 322         for i, xpub := range config.CommonConfig.Federation.Xpubs {
 323                 derivedXPub := xpub.Derive(fedConsensusPath)
 324                 consensusResult[derivedXPub.String()] = &ConsensusNode{XPub: derivedXPub, VoteNum: 0, Order: uint64(i)}
 325         }
 326         return consensusResult
 327 }