protocol/block.go

   1 package protocol
   2
   3 import (
   4         log "github.com/sirupsen/logrus"
   5
   6         "github.com/bytom/errors"
   7         "github.com/bytom/protocol/bc"
   8         "github.com/bytom/protocol/bc/legacy"
   9         "github.com/bytom/protocol/state"
  10         "github.com/bytom/protocol/validation"
  11 )
  12
  13 var (
  14         // ErrBadBlock is returned when a block is invalid.
  15         ErrBadBlock = errors.New("invalid block")
  16
  17         // ErrBadStateRoot is returned when the computed assets merkle root
  18         // disagrees with the one declared in a block header.
  19         ErrBadStateRoot = errors.New("invalid state merkle root")
  20 )
  21
  22 // BlockExist check is a block in chain or orphan
  23 func (c *Chain) BlockExist(hash *bc.Hash) bool {
  24         return c.orphanManage.BlockExist(hash) || c.store.BlockExist(hash)
  25 }
  26
  27 // GetBlockByHash return a block by given hash
  28 func (c *Chain) GetBlockByHash(hash *bc.Hash) (*legacy.Block, error) {
  29         return c.store.GetBlock(hash)
  30 }
  31
  32 // GetBlockByHeight return a block by given height
  33 func (c *Chain) GetBlockByHeight(height uint64) (*legacy.Block, error) {
  34         c.state.cond.L.Lock()
  35         hash, ok := c.state.mainChain[height]
  36         c.state.cond.L.Unlock()
  37         if !ok {
  38                 return nil, errors.New("can't find block in given hight")
  39         }
  40         return c.GetBlockByHash(hash)
  41 }
  42
  43 // ValidateBlock validates an incoming block in advance of applying it
  44 // to a snapshot (with ApplyValidBlock) and committing it to the
  45 // blockchain (with CommitAppliedBlock).
  46 func (c *Chain) ValidateBlock(block, prev *legacy.Block) error {
  47         blockEnts := legacy.MapBlock(block)
  48         prevEnts := legacy.MapBlock(prev)
  49         if err := validation.ValidateBlock(blockEnts, prevEnts); err != nil {
  50                 return errors.Sub(ErrBadBlock, err)
  51         }
  52         return nil
  53 }
  54
  55 // ConnectBlock append block to end of chain
  56 func (c *Chain) ConnectBlock(block *legacy.Block) error {
  57         c.state.cond.L.Lock()
  58         defer c.state.cond.L.Unlock()
  59         return c.connectBlock(block)
  60 }
  61
  62 func (c *Chain) connectBlock(block *legacy.Block) error {
  63         newSnapshot := state.Copy(c.state.snapshot)
  64         if err := newSnapshot.ApplyBlock(legacy.MapBlock(block)); err != nil {
  65                 return err
  66         }
  67
  68         blockHash := block.Hash()
  69         if err := c.setState(block, newSnapshot, map[uint64]*bc.Hash{block.Height: &blockHash}); err != nil {
  70                 return err
  71         }
  72
  73         for _, tx := range block.Transactions {
  74                 c.txPool.RemoveTransaction(&tx.Tx.ID)
  75         }
  76         return nil
  77 }
  78
  79 func (c *Chain) getReorganizeBlocks(block *legacy.Block) ([]*legacy.Block, []*legacy.Block) {
  80         attachBlocks := []*legacy.Block{}
  81         detachBlocks := []*legacy.Block{}
  82         ancestor := block
  83
  84         for !c.inMainchain(ancestor) {
  85                 attachBlocks = append([]*legacy.Block{ancestor}, attachBlocks...)
  86                 ancestor, _ = c.GetBlockByHash(&ancestor.PreviousBlockHash)
  87         }
  88
  89         for d := c.state.block; d.Hash() != ancestor.Hash(); d, _ = c.GetBlockByHash(&d.PreviousBlockHash) {
  90                 detachBlocks = append(detachBlocks, d)
  91         }
  92
  93         return attachBlocks, detachBlocks
  94 }
  95
  96 func (c *Chain) reorganizeChain(block *legacy.Block) error {
  97         attachBlocks, detachBlocks := c.getReorganizeBlocks(block)
  98         newSnapshot := state.Copy(c.state.snapshot)
  99         chainChanges := map[uint64]*bc.Hash{}
 100
 101         for _, d := range detachBlocks {
 102                 if err := newSnapshot.DetachBlock(legacy.MapBlock(d)); err != nil {
 103                         return err
 104                 }
 105         }
 106
 107         for _, a := range attachBlocks {
 108                 if err := newSnapshot.ApplyBlock(legacy.MapBlock(a)); err != nil {
 109                         return err
 110                 }
 111                 aHash := a.Hash()
 112                 chainChanges[a.Height] = &aHash
 113         }
 114
 115         return c.setState(block, newSnapshot, chainChanges)
 116 }
 117
 118 // SaveBlock will validate and save block into storage
 119 func (c *Chain) SaveBlock(block *legacy.Block) error {
 120         preBlock, _ := c.GetBlockByHash(&block.PreviousBlockHash)
 121         if err := c.ValidateBlock(block, preBlock); err != nil {
 122                 return err
 123         }
 124         if err := c.store.SaveBlock(block); err != nil {
 125                 return err
 126         }
 127         blockHash := block.Hash()
 128         log.WithFields(log.Fields{"height": block.Height, "hash": blockHash.String()}).Info("Block saved on disk")
 129         return nil
 130 }
 131
 132 func (c *Chain) findBestChainTail(block *legacy.Block) (bestBlock *legacy.Block) {
 133         bestBlock = block
 134         blockHash := block.Hash()
 135         preorphans, ok := c.orphanManage.preOrphans[blockHash]
 136         if !ok {
 137                 return
 138         }
 139
 140         for _, preorphan := range preorphans {
 141                 orphanBlock, ok := c.orphanManage.Get(preorphan)
 142                 if !ok {
 143                         continue
 144                 }
 145
 146                 if err := c.SaveBlock(orphanBlock); err != nil {
 147                         log.WithFields(log.Fields{
 148                                 "height": block.Height,
 149                                 "hash":   blockHash.String(),
 150                         }).Errorf("findBestChainTail fail on save block %v", err)
 151                         continue
 152                 }
 153
 154                 if subResult := c.findBestChainTail(orphanBlock); subResult.Height > bestBlock.Height {
 155                         bestBlock = subResult
 156                 }
 157         }
 158
 159         c.orphanManage.Delete(&blockHash)
 160         return
 161 }
 162
 163 // ProcessBlock is the entry for handle block insert
 164 func (c *Chain) ProcessBlock(block *legacy.Block) (bool, error) {
 165         blockHash := block.Hash()
 166         if c.BlockExist(&blockHash) {
 167                 log.WithField("hash", blockHash.String()).Info("Skip process due to block already been handled")
 168                 return false, nil
 169         }
 170         if !c.store.BlockExist(&block.PreviousBlockHash) {
 171                 c.orphanManage.Add(block)
 172                 return true, nil
 173         }
 174         if err := c.SaveBlock(block); err != nil {
 175                 return false, err
 176         }
 177
 178         bestBlock := c.findBestChainTail(block)
 179         c.state.cond.L.Lock()
 180         defer c.state.cond.L.Unlock()
 181         if c.state.block.Hash() == bestBlock.PreviousBlockHash {
 182                 return false, c.connectBlock(bestBlock)
 183         }
 184
 185         if bestBlock.Height > c.state.block.Height && bestBlock.Bits >= c.state.block.Bits {
 186                 return false, c.reorganizeChain(bestBlock)
 187         }
 188
 189         return false, nil
 190 }