package evidence import ( "fmt" "sync" clist "github.com/tendermint/tendermint/libs/clist" dbm "github.com/tendermint/tendermint/libs/db" "github.com/tendermint/tendermint/libs/log" sm "github.com/tendermint/tendermint/state" "github.com/tendermint/tendermint/types" ) // EvidencePool maintains a pool of valid evidence // in an EvidenceStore. type EvidencePool struct { logger log.Logger evidenceStore *EvidenceStore evidenceList *clist.CList // concurrent linked-list of evidence // needed to load validators to verify evidence stateDB dbm.DB // latest state mtx sync.Mutex state sm.State } func NewEvidencePool(stateDB dbm.DB, evidenceStore *EvidenceStore) *EvidencePool { evpool := &EvidencePool{ stateDB: stateDB, state: sm.LoadState(stateDB), logger: log.NewNopLogger(), evidenceStore: evidenceStore, evidenceList: clist.New(), } return evpool } func (evpool *EvidencePool) EvidenceFront() *clist.CElement { return evpool.evidenceList.Front() } func (evpool *EvidencePool) EvidenceWaitChan() <-chan struct{} { return evpool.evidenceList.WaitChan() } // SetLogger sets the Logger. func (evpool *EvidencePool) SetLogger(l log.Logger) { evpool.logger = l } // PriorityEvidence returns the priority evidence. func (evpool *EvidencePool) PriorityEvidence() []types.Evidence { return evpool.evidenceStore.PriorityEvidence() } // PendingEvidence returns up to maxNum uncommitted evidence. // If maxNum is -1, all evidence is returned. func (evpool *EvidencePool) PendingEvidence(maxNum int64) []types.Evidence { return evpool.evidenceStore.PendingEvidence(maxNum) } // State returns the current state of the evpool. func (evpool *EvidencePool) State() sm.State { evpool.mtx.Lock() defer evpool.mtx.Unlock() return evpool.state } // Update loads the latest func (evpool *EvidencePool) Update(block *types.Block, state sm.State) { // sanity check if state.LastBlockHeight != block.Height { panic(fmt.Sprintf("Failed EvidencePool.Update sanity check: got state.Height=%d with block.Height=%d", state.LastBlockHeight, block.Height)) } // update the state evpool.mtx.Lock() evpool.state = state evpool.mtx.Unlock() // remove evidence from pending and mark committed evpool.MarkEvidenceAsCommitted(block.Height, block.Evidence.Evidence) } // AddEvidence checks the evidence is valid and adds it to the pool. func (evpool *EvidencePool) AddEvidence(evidence types.Evidence) (err error) { // TODO: check if we already have evidence for this // validator at this height so we dont get spammed if err := sm.VerifyEvidence(evpool.stateDB, evpool.State(), evidence); err != nil { return err } // fetch the validator and return its voting power as its priority // TODO: something better ? valset, _ := sm.LoadValidators(evpool.stateDB, evidence.Height()) _, val := valset.GetByAddress(evidence.Address()) priority := val.VotingPower added := evpool.evidenceStore.AddNewEvidence(evidence, priority) if !added { // evidence already known, just ignore return } evpool.logger.Info("Verified new evidence of byzantine behaviour", "evidence", evidence) // add evidence to clist evpool.evidenceList.PushBack(evidence) return nil } // MarkEvidenceAsCommitted marks all the evidence as committed and removes it from the queue. func (evpool *EvidencePool) MarkEvidenceAsCommitted(height int64, evidence []types.Evidence) { // make a map of committed evidence to remove from the clist blockEvidenceMap := make(map[string]struct{}) for _, ev := range evidence { evpool.evidenceStore.MarkEvidenceAsCommitted(ev) blockEvidenceMap[evMapKey(ev)] = struct{}{} } // remove committed evidence from the clist maxAge := evpool.State().ConsensusParams.Evidence.MaxAge evpool.removeEvidence(height, maxAge, blockEvidenceMap) } func (evpool *EvidencePool) removeEvidence(height, maxAge int64, blockEvidenceMap map[string]struct{}) { for e := evpool.evidenceList.Front(); e != nil; e = e.Next() { ev := e.Value.(types.Evidence) // Remove the evidence if it's already in a block // or if it's now too old. if _, ok := blockEvidenceMap[evMapKey(ev)]; ok || ev.Height() < height-maxAge { // remove from clist evpool.evidenceList.Remove(e) e.DetachPrev() } } } func evMapKey(ev types.Evidence) string { return string(ev.Hash()) }