You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

209 lines
5.6 KiB

package evidence
import (
"fmt"
dbm "github.com/tendermint/tm-db"
"github.com/tendermint/tendermint/types"
)
/*
Requirements:
- Valid new evidence must be persisted immediately and never forgotten
- Uncommitted evidence must be continuously broadcast
- Uncommitted evidence has a partial order, the evidence's priority
Impl:
- First commit atomically in outqueue, pending, lookup.
- Once broadcast, remove from outqueue. No need to sync
- Once committed, atomically remove from pending and update lookup.
Schema for indexing evidence (note you need both height and hash to find a piece of evidence):
"evidence-lookup"/<evidence-height>/<evidence-hash> -> Info
"evidence-outqueue"/<priority>/<evidence-height>/<evidence-hash> -> Info
"evidence-pending"/<evidence-height>/<evidence-hash> -> Info
*/
type Info struct {
Committed bool
Priority int64
Evidence types.Evidence
}
const (
baseKeyLookup = "evidence-lookup" // all evidence
baseKeyOutqueue = "evidence-outqueue" // not-yet broadcast
baseKeyPending = "evidence-pending" // broadcast but not committed
)
func keyLookup(evidence types.Evidence) []byte {
return keyLookupFromHeightAndHash(evidence.Height(), evidence.Hash())
}
// big endian padded hex
func bE(h int64) string {
return fmt.Sprintf("%0.16X", h)
}
func keyLookupFromHeightAndHash(height int64, hash []byte) []byte {
return _key("%s/%s/%X", baseKeyLookup, bE(height), hash)
}
func keyOutqueue(evidence types.Evidence, priority int64) []byte {
return _key("%s/%s/%s/%X", baseKeyOutqueue, bE(priority), bE(evidence.Height()), evidence.Hash())
}
func keyPending(evidence types.Evidence) []byte {
return _key("%s/%s/%X", baseKeyPending, bE(evidence.Height()), evidence.Hash())
}
func _key(format string, o ...interface{}) []byte {
return []byte(fmt.Sprintf(format, o...))
}
// Store is a store of all the evidence we've seen, including
// evidence that has been committed, evidence that has been verified but not broadcast,
// and evidence that has been broadcast but not yet committed.
type Store struct {
db dbm.DB
}
func NewStore(db dbm.DB) *Store {
return &Store{
db: db,
}
}
// PriorityEvidence returns the evidence from the outqueue, sorted by highest priority.
func (store *Store) PriorityEvidence() (evidence []types.Evidence) {
// reverse the order so highest priority is first
l := store.listEvidence(baseKeyOutqueue, -1)
for i, j := 0, len(l)-1; i < j; i, j = i+1, j-1 {
l[i], l[j] = l[j], l[i]
}
return l
}
// PendingEvidence returns up to maxNum known, uncommitted evidence.
// If maxNum is -1, all evidence is returned.
func (store *Store) PendingEvidence(maxNum int64) (evidence []types.Evidence) {
return store.listEvidence(baseKeyPending, maxNum)
}
// listEvidence lists up to maxNum pieces of evidence for the given prefix key.
// It is wrapped by PriorityEvidence and PendingEvidence for convenience.
// If maxNum is -1, there's no cap on the size of returned evidence.
func (store *Store) listEvidence(prefixKey string, maxNum int64) (evidence []types.Evidence) {
var count int64
iter, err := dbm.IteratePrefix(store.db, []byte(prefixKey))
if err != nil {
panic(err)
}
defer iter.Close()
for ; iter.Valid(); iter.Next() {
val := iter.Value()
if count == maxNum {
return evidence
}
count++
var ei Info
err := cdc.UnmarshalBinaryBare(val, &ei)
if err != nil {
panic(err)
}
evidence = append(evidence, ei.Evidence)
}
return evidence
}
// GetInfo fetches the Info with the given height and hash.
// If not found, ei.Evidence is nil.
func (store *Store) GetInfo(height int64, hash []byte) Info {
key := keyLookupFromHeightAndHash(height, hash)
val, err := store.db.Get(key)
if err != nil {
panic(err)
}
if len(val) == 0 {
return Info{}
}
var ei Info
err = cdc.UnmarshalBinaryBare(val, &ei)
if err != nil {
panic(err)
}
return ei
}
// AddNewEvidence adds the given evidence to the database.
// It returns false if the evidence is already stored.
func (store *Store) AddNewEvidence(evidence types.Evidence, priority int64) bool {
// check if we already have seen it
ei := store.getInfo(evidence)
if ei.Evidence != nil {
return false
}
ei = Info{
Committed: false,
Priority: priority,
Evidence: evidence,
}
eiBytes := cdc.MustMarshalBinaryBare(ei)
// add it to the store
key := keyOutqueue(evidence, priority)
store.db.Set(key, eiBytes)
key = keyPending(evidence)
store.db.Set(key, eiBytes)
key = keyLookup(evidence)
store.db.SetSync(key, eiBytes)
return true
}
// MarkEvidenceAsBroadcasted removes evidence from Outqueue.
func (store *Store) MarkEvidenceAsBroadcasted(evidence types.Evidence) {
ei := store.getInfo(evidence)
if ei.Evidence == nil {
// nothing to do; we did not store the evidence yet (AddNewEvidence):
return
}
// remove from the outqueue
key := keyOutqueue(evidence, ei.Priority)
store.db.Delete(key)
}
// MarkEvidenceAsCommitted removes evidence from pending and outqueue and sets the state to committed.
func (store *Store) MarkEvidenceAsCommitted(evidence types.Evidence) {
// if its committed, its been broadcast
store.MarkEvidenceAsBroadcasted(evidence)
pendingKey := keyPending(evidence)
store.db.Delete(pendingKey)
// committed Info doens't need priority
ei := Info{
Committed: true,
Evidence: evidence,
Priority: 0,
}
lookupKey := keyLookup(evidence)
store.db.SetSync(lookupKey, cdc.MustMarshalBinaryBare(ei))
}
//---------------------------------------------------
// utils
// getInfo is convenience for calling GetInfo if we have the full evidence.
func (store *Store) getInfo(evidence types.Evidence) Info {
return store.GetInfo(evidence.Height(), evidence.Hash())
}