netsync/block_fetcher.go

   1 package netsync
   2
   3 import (
   4         log "github.com/sirupsen/logrus"
   5         "gopkg.in/karalabe/cookiejar.v2/collections/prque"
   6
   7         "github.com/vapor/chain"
   8         "github.com/vapor/protocol/bc"
   9 )
  10
  11 const (
  12         maxBlockDistance = 64
  13         maxMsgSetSize    = 128
  14         newBlockChSize   = 64
  15 )
  16
  17 // blockFetcher is responsible for accumulating block announcements from various peers
  18 // and scheduling them for retrieval.
  19 type blockFetcher struct {
  20         chain chain.Chain
  21         peers *peerSet
  22
  23         newBlockCh chan *blockMsg
  24         queue      *prque.Prque
  25         msgSet     map[bc.Hash]*blockMsg
  26 }
  27
  28 //NewBlockFetcher creates a block fetcher to retrieve blocks of the new mined.
  29 func newBlockFetcher(chain chain.Chain, peers *peerSet) *blockFetcher {
  30         f := &blockFetcher{
  31                 chain:      chain,
  32                 peers:      peers,
  33                 newBlockCh: make(chan *blockMsg, newBlockChSize),
  34                 queue:      prque.New(),
  35                 msgSet:     make(map[bc.Hash]*blockMsg),
  36         }
  37         go f.blockProcessor()
  38         return f
  39 }
  40
  41 func (f *blockFetcher) blockProcessor() {
  42         for {
  43                 height := f.chain.BestBlockHeight()
  44                 for !f.queue.Empty() {
  45                         msg := f.queue.PopItem().(*blockMsg)
  46                         if msg.block.Height > height+1 {
  47                                 f.queue.Push(msg, -float32(msg.block.Height))
  48                                 break
  49                         }
  50
  51                         f.insert(msg)
  52                         delete(f.msgSet, msg.block.Hash())
  53                 }
  54                 f.add(<-f.newBlockCh)
  55         }
  56 }
  57
  58 func (f *blockFetcher) add(msg *blockMsg) {
  59         bestHeight := f.chain.BestBlockHeight()
  60         if len(f.msgSet) > maxMsgSetSize || bestHeight > msg.block.Height || msg.block.Height-bestHeight > maxBlockDistance {
  61                 return
  62         }
  63
  64         blockHash := msg.block.Hash()
  65         if _, ok := f.msgSet[blockHash]; !ok {
  66                 f.msgSet[blockHash] = msg
  67                 f.queue.Push(msg, -float32(msg.block.Height))
  68                 log.WithFields(log.Fields{
  69                         "module":       logModule,
  70                         "block height": msg.block.Height,
  71                         "block hash":   blockHash.String(),
  72                 }).Debug("blockFetcher receive mine block")
  73         }
  74 }
  75
  76 func (f *blockFetcher) insert(msg *blockMsg) {
  77         if _, err := f.chain.ProcessBlock(msg.block); err != nil {
  78                 peer := f.peers.getPeer(msg.peerID)
  79                 if peer == nil {
  80                         return
  81                 }
  82
  83                 f.peers.addBanScore(msg.peerID, 20, 0, err.Error())
  84                 return
  85         }
  86
  87         if err := f.peers.broadcastMinedBlock(msg.block); err != nil {
  88                 log.WithFields(log.Fields{"module": logModule, "err": err}).Error("blockFetcher fail on broadcast new block")
  89                 return
  90         }
  91 }
  92
  93 func (f *blockFetcher) processNewBlock(msg *blockMsg) {
  94         f.newBlockCh <- msg
  95 }