package kvstore import ( "bytes" "encoding/hex" "fmt" "strconv" "strings" "github.com/tendermint/abci/example/code" "github.com/tendermint/abci/types" cmn "github.com/tendermint/tmlibs/common" dbm "github.com/tendermint/tmlibs/db" "github.com/tendermint/tmlibs/log" ) const ( ValidatorSetChangePrefix string = "val:" ) //----------------------------------------- var _ types.Application = (*PersistentKVStoreApplication)(nil) type PersistentKVStoreApplication struct { app *KVStoreApplication // validator set ValUpdates []types.Validator logger log.Logger } func NewPersistentKVStoreApplication(dbDir string) *PersistentKVStoreApplication { name := "kvstore" db, err := dbm.NewGoLevelDB(name, dbDir) if err != nil { panic(err) } state := loadState(db) return &PersistentKVStoreApplication{ app: &KVStoreApplication{state: state}, logger: log.NewNopLogger(), } } func (app *PersistentKVStoreApplication) SetLogger(l log.Logger) { app.logger = l } func (app *PersistentKVStoreApplication) Info(req types.RequestInfo) types.ResponseInfo { res := app.app.Info(req) res.LastBlockHeight = app.app.state.Height res.LastBlockAppHash = app.app.state.AppHash return res } func (app *PersistentKVStoreApplication) SetOption(req types.RequestSetOption) types.ResponseSetOption { return app.app.SetOption(req) } // tx is either "val:pubkey/power" or "key=value" or just arbitrary bytes func (app *PersistentKVStoreApplication) DeliverTx(tx []byte) types.ResponseDeliverTx { // if it starts with "val:", update the validator set // format is "val:pubkey/power" if isValidatorTx(tx) { // update validators in the merkle tree // and in app.ValUpdates return app.execValidatorTx(tx) } // otherwise, update the key-value store return app.app.DeliverTx(tx) } func (app *PersistentKVStoreApplication) CheckTx(tx []byte) types.ResponseCheckTx { return app.app.CheckTx(tx) } // Commit will panic if InitChain was not called func (app *PersistentKVStoreApplication) Commit() types.ResponseCommit { return app.app.Commit() } func (app *PersistentKVStoreApplication) Query(reqQuery types.RequestQuery) types.ResponseQuery { return app.app.Query(reqQuery) } // Save the validators in the merkle tree func (app *PersistentKVStoreApplication) InitChain(req types.RequestInitChain) types.ResponseInitChain { for _, v := range req.Validators { r := app.updateValidator(v) if r.IsErr() { app.logger.Error("Error updating validators", "r", r) } } return types.ResponseInitChain{} } // Track the block hash and header information func (app *PersistentKVStoreApplication) BeginBlock(req types.RequestBeginBlock) types.ResponseBeginBlock { // reset valset changes app.ValUpdates = make([]types.Validator, 0) return types.ResponseBeginBlock{} } // Update the validator set func (app *PersistentKVStoreApplication) EndBlock(req types.RequestEndBlock) types.ResponseEndBlock { return types.ResponseEndBlock{ValidatorUpdates: app.ValUpdates} } //--------------------------------------------- // update validators func (app *PersistentKVStoreApplication) Validators() (validators []types.Validator) { itr := app.app.state.db.Iterator(nil, nil) for ; itr.Valid(); itr.Next() { if isValidatorTx(itr.Key()) { validator := new(types.Validator) err := types.ReadMessage(bytes.NewBuffer(itr.Value()), validator) if err != nil { panic(err) } validators = append(validators, *validator) } } return } func MakeValSetChangeTx(pubkey types.PubKey, power int64) []byte { return []byte(cmn.Fmt("val:%X/%d", pubkey.Data, power)) } func isValidatorTx(tx []byte) bool { return strings.HasPrefix(string(tx), ValidatorSetChangePrefix) } // format is "val:pubkey/power" // pubkey is raw 32-byte ed25519 key func (app *PersistentKVStoreApplication) execValidatorTx(tx []byte) types.ResponseDeliverTx { tx = tx[len(ValidatorSetChangePrefix):] //get the pubkey and power pubKeyAndPower := strings.Split(string(tx), "/") if len(pubKeyAndPower) != 2 { return types.ResponseDeliverTx{ Code: code.CodeTypeEncodingError, Log: fmt.Sprintf("Expected 'pubkey/power'. Got %v", pubKeyAndPower)} } pubkeyS, powerS := pubKeyAndPower[0], pubKeyAndPower[1] // decode the pubkey pubkey, err := hex.DecodeString(pubkeyS) if err != nil { return types.ResponseDeliverTx{ Code: code.CodeTypeEncodingError, Log: fmt.Sprintf("Pubkey (%s) is invalid hex", pubkeyS)} } // decode the power power, err := strconv.ParseInt(powerS, 10, 64) if err != nil { return types.ResponseDeliverTx{ Code: code.CodeTypeEncodingError, Log: fmt.Sprintf("Power (%s) is not an int", powerS)} } // update return app.updateValidator(types.Ed25519Validator(pubkey, int64(power))) } // add, update, or remove a validator func (app *PersistentKVStoreApplication) updateValidator(v types.Validator) types.ResponseDeliverTx { key := []byte("val:" + string(v.PubKey.Data)) if v.Power == 0 { // remove validator if !app.app.state.db.Has(key) { return types.ResponseDeliverTx{ Code: code.CodeTypeUnauthorized, Log: fmt.Sprintf("Cannot remove non-existent validator %X", key)} } app.app.state.db.Delete(key) } else { // add or update validator value := bytes.NewBuffer(make([]byte, 0)) if err := types.WriteMessage(&v, value); err != nil { return types.ResponseDeliverTx{ Code: code.CodeTypeEncodingError, Log: fmt.Sprintf("Error encoding validator: %v", err)} } app.app.state.db.Set(key, value.Bytes()) } // we only update the changes array if we successfully updated the tree app.ValUpdates = append(app.ValUpdates, v) return types.ResponseDeliverTx{Code: code.CodeTypeOK} }