package state import ( "fmt" "strings" "time" abci "github.com/tendermint/tendermint/abci/types" dbm "github.com/tendermint/tendermint/libs/db" "github.com/tendermint/tendermint/libs/fail" "github.com/tendermint/tendermint/libs/log" "github.com/tendermint/tendermint/proxy" "github.com/tendermint/tendermint/types" ) //----------------------------------------------------------------------------- // BlockExecutor handles block execution and state updates. // It exposes ApplyBlock(), which validates & executes the block, updates state w/ ABCI responses, // then commits and updates the mempool atomically, then saves state. // BlockExecutor provides the context and accessories for properly executing a block. type BlockExecutor struct { // save state, validators, consensus params, abci responses here db dbm.DB // execute the app against this proxyApp proxy.AppConnConsensus // events eventBus types.BlockEventPublisher // update these with block results after commit mempool Mempool evpool EvidencePool logger log.Logger metrics *Metrics } type BlockExecutorOption func(executor *BlockExecutor) func BlockExecutorWithMetrics(metrics *Metrics) BlockExecutorOption { return func(blockExec *BlockExecutor) { blockExec.metrics = metrics } } // NewBlockExecutor returns a new BlockExecutor with a NopEventBus. // Call SetEventBus to provide one. func NewBlockExecutor(db dbm.DB, logger log.Logger, proxyApp proxy.AppConnConsensus, mempool Mempool, evpool EvidencePool, options ...BlockExecutorOption) *BlockExecutor { res := &BlockExecutor{ db: db, proxyApp: proxyApp, eventBus: types.NopEventBus{}, mempool: mempool, evpool: evpool, logger: logger, metrics: NopMetrics(), } for _, option := range options { option(res) } return res } // SetEventBus - sets the event bus for publishing block related events. // If not called, it defaults to types.NopEventBus. func (blockExec *BlockExecutor) SetEventBus(eventBus types.BlockEventPublisher) { blockExec.eventBus = eventBus } // ValidateBlock validates the given block against the given state. // If the block is invalid, it returns an error. // Validation does not mutate state, but does require historical information from the stateDB, // ie. to verify evidence from a validator at an old height. func (blockExec *BlockExecutor) ValidateBlock(state State, block *types.Block) error { return validateBlock(blockExec.db, state, block) } // ApplyBlock validates the block against the state, executes it against the app, // fires the relevant events, commits the app, and saves the new state and responses. // It's the only function that needs to be called // from outside this package to process and commit an entire block. // It takes a blockID to avoid recomputing the parts hash. func (blockExec *BlockExecutor) ApplyBlock(state State, blockID types.BlockID, block *types.Block) (State, error) { if err := blockExec.ValidateBlock(state, block); err != nil { return state, ErrInvalidBlock(err) } startTime := time.Now().UnixNano() abciResponses, err := execBlockOnProxyApp(blockExec.logger, blockExec.proxyApp, block, state.LastValidators, blockExec.db) endTime := time.Now().UnixNano() blockExec.metrics.BlockProcessingTime.Observe(float64(endTime-startTime) / 1000000) if err != nil { return state, ErrProxyAppConn(err) } fail.Fail() // XXX // Save the results before we commit. saveABCIResponses(blockExec.db, block.Height, abciResponses) fail.Fail() // XXX // validate the validator updates and convert to tendermint types abciValUpdates := abciResponses.EndBlock.ValidatorUpdates err = validateValidatorUpdates(abciValUpdates, state.ConsensusParams.Validator) if err != nil { return state, fmt.Errorf("Error in validator updates: %v", err) } validatorUpdates, err := types.PB2TM.ValidatorUpdates(abciValUpdates) if err != nil { return state, err } if len(validatorUpdates) > 0 { blockExec.logger.Info("Updates to validators", "updates", makeValidatorUpdatesLogString(validatorUpdates)) } // Update the state with the block and responses. state, err = updateState(state, blockID, &block.Header, abciResponses, validatorUpdates) if err != nil { return state, fmt.Errorf("Commit failed for application: %v", err) } // Lock mempool, commit app state, update mempoool. appHash, err := blockExec.Commit(state, block) if err != nil { return state, fmt.Errorf("Commit failed for application: %v", err) } // Update evpool with the block and state. blockExec.evpool.Update(block, state) fail.Fail() // XXX // Update the app hash and save the state. state.AppHash = appHash SaveState(blockExec.db, state) fail.Fail() // XXX // Events are fired after everything else. // NOTE: if we crash between Commit and Save, events wont be fired during replay fireEvents(blockExec.logger, blockExec.eventBus, block, abciResponses, validatorUpdates) return state, nil } // Commit locks the mempool, runs the ABCI Commit message, and updates the // mempool. // It returns the result of calling abci.Commit (the AppHash), and an error. // The Mempool must be locked during commit and update because state is // typically reset on Commit and old txs must be replayed against committed // state before new txs are run in the mempool, lest they be invalid. func (blockExec *BlockExecutor) Commit( state State, block *types.Block, ) ([]byte, error) { blockExec.mempool.Lock() defer blockExec.mempool.Unlock() // while mempool is Locked, flush to ensure all async requests have completed // in the ABCI app before Commit. err := blockExec.mempool.FlushAppConn() if err != nil { blockExec.logger.Error("Client error during mempool.FlushAppConn", "err", err) return nil, err } // Commit block, get hash back res, err := blockExec.proxyApp.CommitSync() if err != nil { blockExec.logger.Error( "Client error during proxyAppConn.CommitSync", "err", err, ) return nil, err } // ResponseCommit has no error code - just data blockExec.logger.Info( "Committed state", "height", block.Height, "txs", block.NumTxs, "appHash", fmt.Sprintf("%X", res.Data), ) // Update mempool. err = blockExec.mempool.Update( block.Height, block.Txs, TxPreCheck(state), TxPostCheck(state), ) return res.Data, err } //--------------------------------------------------------- // Helper functions for executing blocks and updating state // Executes block's transactions on proxyAppConn. // Returns a list of transaction results and updates to the validator set func execBlockOnProxyApp( logger log.Logger, proxyAppConn proxy.AppConnConsensus, block *types.Block, lastValSet *types.ValidatorSet, stateDB dbm.DB, ) (*ABCIResponses, error) { var validTxs, invalidTxs = 0, 0 txIndex := 0 abciResponses := NewABCIResponses(block) // Execute transactions and get hash. proxyCb := func(req *abci.Request, res *abci.Response) { switch r := res.Value.(type) { case *abci.Response_DeliverTx: // TODO: make use of res.Log // TODO: make use of this info // Blocks may include invalid txs. txRes := r.DeliverTx if txRes.Code == abci.CodeTypeOK { validTxs++ } else { logger.Debug("Invalid tx", "code", txRes.Code, "log", txRes.Log) invalidTxs++ } abciResponses.DeliverTx[txIndex] = txRes txIndex++ } } proxyAppConn.SetResponseCallback(proxyCb) commitInfo, byzVals := getBeginBlockValidatorInfo(block, lastValSet, stateDB) // Begin block var err error abciResponses.BeginBlock, err = proxyAppConn.BeginBlockSync(abci.RequestBeginBlock{ Hash: block.Hash(), Header: types.TM2PB.Header(&block.Header), LastCommitInfo: commitInfo, ByzantineValidators: byzVals, }) if err != nil { logger.Error("Error in proxyAppConn.BeginBlock", "err", err) return nil, err } // Run txs of block. for _, tx := range block.Txs { proxyAppConn.DeliverTxAsync(tx) if err := proxyAppConn.Error(); err != nil { return nil, err } } // End block. abciResponses.EndBlock, err = proxyAppConn.EndBlockSync(abci.RequestEndBlock{Height: block.Height}) if err != nil { logger.Error("Error in proxyAppConn.EndBlock", "err", err) return nil, err } logger.Info("Executed block", "height", block.Height, "validTxs", validTxs, "invalidTxs", invalidTxs) return abciResponses, nil } func getBeginBlockValidatorInfo(block *types.Block, lastValSet *types.ValidatorSet, stateDB dbm.DB) (abci.LastCommitInfo, []abci.Evidence) { // Sanity check that commit length matches validator set size - // only applies after first block if block.Height > 1 { precommitLen := len(block.LastCommit.Precommits) valSetLen := len(lastValSet.Validators) if precommitLen != valSetLen { // sanity check panic(fmt.Sprintf("precommit length (%d) doesn't match valset length (%d) at height %d\n\n%v\n\n%v", precommitLen, valSetLen, block.Height, block.LastCommit.Precommits, lastValSet.Validators)) } } // Collect the vote info (list of validators and whether or not they signed). voteInfos := make([]abci.VoteInfo, len(lastValSet.Validators)) for i, val := range lastValSet.Validators { var vote *types.Vote if i < len(block.LastCommit.Precommits) { vote = block.LastCommit.Precommits[i] } voteInfo := abci.VoteInfo{ Validator: types.TM2PB.Validator(val), SignedLastBlock: vote != nil, } voteInfos[i] = voteInfo } commitInfo := abci.LastCommitInfo{ Round: int32(block.LastCommit.Round()), Votes: voteInfos, } byzVals := make([]abci.Evidence, len(block.Evidence.Evidence)) for i, ev := range block.Evidence.Evidence { // We need the validator set. We already did this in validateBlock. // TODO: Should we instead cache the valset in the evidence itself and add // `SetValidatorSet()` and `ToABCI` methods ? valset, err := LoadValidators(stateDB, ev.Height()) if err != nil { panic(err) // shouldn't happen } byzVals[i] = types.TM2PB.Evidence(ev, valset, block.Time) } return commitInfo, byzVals } func validateValidatorUpdates(abciUpdates []abci.ValidatorUpdate, params types.ValidatorParams) error { for _, valUpdate := range abciUpdates { if valUpdate.GetPower() < 0 { return fmt.Errorf("Voting power can't be negative %v", valUpdate) } else if valUpdate.GetPower() == 0 { // continue, since this is deleting the validator, and thus there is no // pubkey to check continue } // Check if validator's pubkey matches an ABCI type in the consensus params thisKeyType := valUpdate.PubKey.Type if !params.IsValidPubkeyType(thisKeyType) { return fmt.Errorf("Validator %v is using pubkey %s, which is unsupported for consensus", valUpdate, thisKeyType) } } return nil } // If more or equal than 1/3 of total voting power changed in one block, then // a light client could never prove the transition externally. See // ./lite/doc.go for details on how a light client tracks validators. func updateValidators(currentSet *types.ValidatorSet, updates []*types.Validator) error { for _, valUpdate := range updates { // should already have been checked if valUpdate.VotingPower < 0 { return fmt.Errorf("Voting power can't be negative %v", valUpdate) } address := valUpdate.Address _, val := currentSet.GetByAddress(address) // valUpdate.VotingPower is ensured to be non-negative in validation method if valUpdate.VotingPower == 0 { // remove val _, removed := currentSet.Remove(address) if !removed { return fmt.Errorf("Failed to remove validator %X", address) } } else if val == nil { // add val // make sure we do not exceed MaxTotalVotingPower by adding this validator: totalVotingPower := currentSet.TotalVotingPower() updatedVotingPower := valUpdate.VotingPower + totalVotingPower overflow := updatedVotingPower > types.MaxTotalVotingPower || updatedVotingPower < 0 if overflow { return fmt.Errorf( "Failed to add new validator %v. Adding it would exceed max allowed total voting power %v", valUpdate, types.MaxTotalVotingPower) } // TODO: issue #1558 update spec according to the following: // Set ProposerPriority to -C*totalVotingPower (with C ~= 1.125) to make sure validators can't // unbond/rebond to reset their (potentially previously negative) ProposerPriority to zero. // // Contract: totalVotingPower < MaxTotalVotingPower to ensure ProposerPriority does // not exceed the bounds of int64. // // Compute ProposerPriority = -1.125*totalVotingPower == -(totalVotingPower + (totalVotingPower >> 3)). valUpdate.ProposerPriority = -(totalVotingPower + (totalVotingPower >> 3)) added := currentSet.Add(valUpdate) if !added { return fmt.Errorf("Failed to add new validator %v", valUpdate) } } else { // update val // make sure we do not exceed MaxTotalVotingPower by updating this validator: totalVotingPower := currentSet.TotalVotingPower() curVotingPower := val.VotingPower updatedVotingPower := totalVotingPower - curVotingPower + valUpdate.VotingPower overflow := updatedVotingPower > types.MaxTotalVotingPower || updatedVotingPower < 0 if overflow { return fmt.Errorf( "Failed to update existing validator %v. Updating it would exceed max allowed total voting power %v", valUpdate, types.MaxTotalVotingPower) } updated := currentSet.Update(valUpdate) if !updated { return fmt.Errorf("Failed to update validator %X to %v", address, valUpdate) } } } return nil } // updateState returns a new State updated according to the header and responses. func updateState( state State, blockID types.BlockID, header *types.Header, abciResponses *ABCIResponses, validatorUpdates []*types.Validator, ) (State, error) { // Copy the valset so we can apply changes from EndBlock // and update s.LastValidators and s.Validators. nValSet := state.NextValidators.Copy() // Update the validator set with the latest abciResponses. lastHeightValsChanged := state.LastHeightValidatorsChanged if len(validatorUpdates) > 0 { err := updateValidators(nValSet, validatorUpdates) if err != nil { return state, fmt.Errorf("Error changing validator set: %v", err) } // Change results from this height but only applies to the next next height. lastHeightValsChanged = header.Height + 1 + 1 } // Update validator proposer priority and set state variables. nValSet.IncrementProposerPriority(1) // Update the params with the latest abciResponses. nextParams := state.ConsensusParams lastHeightParamsChanged := state.LastHeightConsensusParamsChanged if abciResponses.EndBlock.ConsensusParamUpdates != nil { // NOTE: must not mutate s.ConsensusParams nextParams = state.ConsensusParams.Update(abciResponses.EndBlock.ConsensusParamUpdates) err := nextParams.Validate() if err != nil { return state, fmt.Errorf("Error updating consensus params: %v", err) } // Change results from this height but only applies to the next height. lastHeightParamsChanged = header.Height + 1 } // TODO: allow app to upgrade version nextVersion := state.Version // NOTE: the AppHash has not been populated. // It will be filled on state.Save. return State{ Version: nextVersion, ChainID: state.ChainID, LastBlockHeight: header.Height, LastBlockTotalTx: state.LastBlockTotalTx + header.NumTxs, LastBlockID: blockID, LastBlockTime: header.Time, NextValidators: nValSet, Validators: state.NextValidators.Copy(), LastValidators: state.Validators.Copy(), LastHeightValidatorsChanged: lastHeightValsChanged, ConsensusParams: nextParams, LastHeightConsensusParamsChanged: lastHeightParamsChanged, LastResultsHash: abciResponses.ResultsHash(), AppHash: nil, }, nil } // Fire NewBlock, NewBlockHeader. // Fire TxEvent for every tx. // NOTE: if Tendermint crashes before commit, some or all of these events may be published again. func fireEvents(logger log.Logger, eventBus types.BlockEventPublisher, block *types.Block, abciResponses *ABCIResponses, validatorUpdates []*types.Validator) { eventBus.PublishEventNewBlock(types.EventDataNewBlock{ Block: block, ResultBeginBlock: *abciResponses.BeginBlock, ResultEndBlock: *abciResponses.EndBlock, }) eventBus.PublishEventNewBlockHeader(types.EventDataNewBlockHeader{ Header: block.Header, ResultBeginBlock: *abciResponses.BeginBlock, ResultEndBlock: *abciResponses.EndBlock, }) for i, tx := range block.Data.Txs { eventBus.PublishEventTx(types.EventDataTx{types.TxResult{ Height: block.Height, Index: uint32(i), Tx: tx, Result: *(abciResponses.DeliverTx[i]), }}) } if len(validatorUpdates) > 0 { eventBus.PublishEventValidatorSetUpdates( types.EventDataValidatorSetUpdates{ValidatorUpdates: validatorUpdates}) } } //---------------------------------------------------------------------------------------------------- // Execute block without state. TODO: eliminate // ExecCommitBlock executes and commits a block on the proxyApp without validating or mutating the state. // It returns the application root hash (result of abci.Commit). func ExecCommitBlock( appConnConsensus proxy.AppConnConsensus, block *types.Block, logger log.Logger, lastValSet *types.ValidatorSet, stateDB dbm.DB, ) ([]byte, error) { _, err := execBlockOnProxyApp(logger, appConnConsensus, block, lastValSet, stateDB) if err != nil { logger.Error("Error executing block on proxy app", "height", block.Height, "err", err) return nil, err } // Commit block, get hash back res, err := appConnConsensus.CommitSync() if err != nil { logger.Error("Client error during proxyAppConn.CommitSync", "err", res) return nil, err } // ResponseCommit has no error or log, just data return res.Data, nil } // Make pretty string for validatorUpdates logging func makeValidatorUpdatesLogString(vals []*types.Validator) string { chunks := make([]string, len(vals)) for i, val := range vals { chunks[i] = fmt.Sprintf("%s:%d", val.Address, val.VotingPower) } return strings.Join(chunks, ",") }