package dummy import ( "errors" "fmt" "golang.org/x/crypto/sha3" "math/big" "runtime" "time" "github.com/ava-labs/coreth/consensus" "github.com/ava-labs/coreth/core/state" "github.com/ava-labs/coreth/core/types" "github.com/ava-labs/coreth/params" "github.com/ava-labs/coreth/rpc" "github.com/ava-labs/go-ethereum/common" "github.com/ava-labs/go-ethereum/rlp" mapset "github.com/deckarep/golang-set" ) type OnFinalizeCallbackType = func(chain consensus.ChainReader, header *types.Header, state *state.StateDB, txs []*types.Transaction, uncles []*types.Header) type OnFinalizeAndAssembleCallbackType = func(state *state.StateDB, txs []*types.Transaction) ([]byte, error) type OnAPIsCallbackType = func(consensus.ChainReader) []rpc.API type OnExtraStateChangeType = func(block *types.Block, statedb *state.StateDB) error type ConsensusCallbacks struct { OnSeal func(*types.Block) error OnSealHash func(*types.Header) OnAPIs OnAPIsCallbackType OnFinalize OnFinalizeCallbackType OnFinalizeAndAssemble OnFinalizeAndAssembleCallbackType OnExtraStateChange OnExtraStateChangeType } type DummyEngine struct { cb *ConsensusCallbacks } func NewDummyEngine(cb *ConsensusCallbacks) *DummyEngine { return &DummyEngine{cb: cb} } var ( allowedFutureBlockTime = 15 * time.Second // Max time from current time allowed for blocks, before they're considered future blocks ) var ( maxUncles = 2 // Maximum number of uncles allowed in a single block errTooManyUncles = errors.New("too many uncles") errZeroBlockTime = errors.New("timestamp equals parent's") errDuplicateUncle = errors.New("duplicate uncle") errUncleIsAncestor = errors.New("uncle is ancestor") errDanglingUncle = errors.New("uncle's parent is not ancestor") ) // modified from consensus.go func (self *DummyEngine) verifyHeader(chain consensus.ChainReader, header, parent *types.Header, uncle bool, seal bool) error { // Ensure that the header's extra-data section is of a reasonable size if uint64(len(header.Extra)) > params.MaximumExtraDataSize { return fmt.Errorf("extra-data too long: %d > %d", len(header.Extra), params.MaximumExtraDataSize) } // Verify the header's timestamp if !uncle { if header.Time > uint64(time.Now().Add(allowedFutureBlockTime).Unix()) { return consensus.ErrFutureBlock } } //if header.Time <= parent.Time { if header.Time < parent.Time { return errZeroBlockTime } // Verify that the gas limit is <= 2^63-1 cap := uint64(0x7fffffffffffffff) if header.GasLimit > cap { return fmt.Errorf("invalid gasLimit: have %v, max %v", header.GasLimit, cap) } // Verify that the gasUsed is <= gasLimit if header.GasUsed > header.GasLimit { return fmt.Errorf("invalid gasUsed: have %d, gasLimit %d", header.GasUsed, header.GasLimit) } // Verify that the gas limit remains within allowed bounds diff := int64(parent.GasLimit) - int64(header.GasLimit) if diff < 0 { diff *= -1 } limit := parent.GasLimit / params.GasLimitBoundDivisor if uint64(diff) >= limit || header.GasLimit < params.MinGasLimit { return fmt.Errorf("invalid gas limit: have %d, want %d += %d", header.GasLimit, parent.GasLimit, limit) } // Verify that the block number is parent's +1 if diff := new(big.Int).Sub(header.Number, parent.Number); diff.Cmp(big.NewInt(1)) != 0 { return consensus.ErrInvalidNumber } // Verify the engine specific seal securing the block if seal { if err := self.VerifySeal(chain, header); err != nil { return err } } return nil } func (self *DummyEngine) verifyHeaderWorker(chain consensus.ChainReader, headers []*types.Header, seals []bool, index int) error { var parent *types.Header if index == 0 { parent = chain.GetHeader(headers[0].ParentHash, headers[0].Number.Uint64()-1) } else if headers[index-1].Hash() == headers[index].ParentHash { parent = headers[index-1] } if parent == nil { return consensus.ErrUnknownAncestor } if chain.GetHeader(headers[index].Hash(), headers[index].Number.Uint64()) != nil { return nil // known block } return self.verifyHeader(chain, headers[index], parent, false, seals[index]) } func (self *DummyEngine) Author(header *types.Header) (common.Address, error) { return header.Coinbase, nil } func (self *DummyEngine) VerifyHeader(chain consensus.ChainReader, header *types.Header, seal bool) error { // Short circuit if the header is known, or it's parent not number := header.Number.Uint64() if chain.GetHeader(header.Hash(), number) != nil { return nil } parent := chain.GetHeader(header.ParentHash, number-1) if parent == nil { return consensus.ErrUnknownAncestor } // Sanity checks passed, do a proper verification return self.verifyHeader(chain, header, parent, false, seal) } func (self *DummyEngine) VerifyHeaders(chain consensus.ChainReader, headers []*types.Header, seals []bool) (chan<- struct{}, <-chan error) { // Spawn as many workers as allowed threads workers := runtime.GOMAXPROCS(0) if len(headers) < workers { workers = len(headers) } // Create a task channel and spawn the verifiers var ( inputs = make(chan int) done = make(chan int, workers) errors = make([]error, len(headers)) abort = make(chan struct{}) ) for i := 0; i < workers; i++ { go func() { for index := range inputs { errors[index] = self.verifyHeaderWorker(chain, headers, seals, index) done <- index } }() } errorsOut := make(chan error, len(headers)) go func() { defer close(inputs) var ( in, out = 0, 0 checked = make([]bool, len(headers)) inputs = inputs ) for { select { case inputs <- in: if in++; in == len(headers) { // Reached end of headers. Stop sending to workers. inputs = nil } case index := <-done: for checked[index] = true; checked[out]; out++ { errorsOut <- errors[out] if out == len(headers)-1 { return } } case <-abort: return } } }() return abort, errorsOut } func (self *DummyEngine) VerifyUncles(chain consensus.ChainReader, block *types.Block) error { // Verify that there are at most 2 uncles included in this block if len(block.Uncles()) > maxUncles { return errTooManyUncles } if len(block.Uncles()) == 0 { return nil } // Gather the set of past uncles and ancestors uncles, ancestors := mapset.NewSet(), make(map[common.Hash]*types.Header) number, parent := block.NumberU64()-1, block.ParentHash() for i := 0; i < 7; i++ { ancestor := chain.GetBlock(parent, number) if ancestor == nil { break } ancestors[ancestor.Hash()] = ancestor.Header() for _, uncle := range ancestor.Uncles() { uncles.Add(uncle.Hash()) } parent, number = ancestor.ParentHash(), number-1 } ancestors[block.Hash()] = block.Header() uncles.Add(block.Hash()) // Verify each of the uncles that it's recent, but not an ancestor for _, uncle := range block.Uncles() { // Make sure every uncle is rewarded only once hash := uncle.Hash() if uncles.Contains(hash) { return errDuplicateUncle } uncles.Add(hash) // Make sure the uncle has a valid ancestry if ancestors[hash] != nil { return errUncleIsAncestor } if ancestors[uncle.ParentHash] == nil || uncle.ParentHash == block.ParentHash() { return errDanglingUncle } if err := self.verifyHeader(chain, uncle, ancestors[uncle.ParentHash], true, true); err != nil { return err } } return nil } func (self *DummyEngine) VerifySeal(chain consensus.ChainReader, header *types.Header) error { return nil } func (self *DummyEngine) Prepare(chain consensus.ChainReader, header *types.Header) error { header.Difficulty = big.NewInt(1) return nil } func (self *DummyEngine) Finalize( chain consensus.ChainReader, header *types.Header, state *state.StateDB, txs []*types.Transaction, uncles []*types.Header) { if self.cb.OnFinalize != nil { self.cb.OnFinalize(chain, header, state, txs, uncles) } // commit the final state root header.Root = state.IntermediateRoot(chain.Config().IsEIP158(header.Number)) } func (self *DummyEngine) FinalizeAndAssemble(chain consensus.ChainReader, header *types.Header, state *state.StateDB, txs []*types.Transaction, uncles []*types.Header, receipts []*types.Receipt) (*types.Block, error) { var extdata []byte if self.cb.OnFinalizeAndAssemble != nil { ret, err := self.cb.OnFinalizeAndAssemble(state, txs) extdata = ret if err != nil { return nil, err } } // commit the final state root header.Root = state.IntermediateRoot(chain.Config().IsEIP158(header.Number)) // Header seems complete, assemble into a block and return return types.NewBlock(header, txs, uncles, receipts, extdata), nil } func (self *DummyEngine) Seal(chain consensus.ChainReader, block *types.Block, results chan<- *types.Block, stop <-chan struct{}) (err error) { if self.cb.OnSeal != nil { err = self.cb.OnSeal(block) } else { err = nil } if err == nil { results <- block } return } func (self *DummyEngine) SealHash(header *types.Header) (hash common.Hash) { if self.cb.OnSealHash != nil { self.cb.OnSealHash(header) } hasher := sha3.NewLegacyKeccak256() rlp.Encode(hasher, []interface{}{ header.ParentHash, header.UncleHash, header.Coinbase, header.Root, header.TxHash, header.ReceiptHash, header.Bloom, header.Difficulty, header.Number, header.GasLimit, header.GasUsed, header.Time, header.Extra, }) hasher.Sum(hash[:0]) return hash } func (self *DummyEngine) CalcDifficulty(chain consensus.ChainReader, time uint64, parent *types.Header) *big.Int { return big.NewInt(1) } func (self *DummyEngine) APIs(chain consensus.ChainReader) (res []rpc.API) { res = nil if self.cb.OnAPIs != nil { res = self.cb.OnAPIs(chain) } return } func (self *DummyEngine) Close() error { return nil } func (self *DummyEngine) ExtraStateChange(block *types.Block, statedb *state.StateDB) error { if self.cb.OnExtraStateChange != nil { return self.cb.OnExtraStateChange(block, statedb) } return nil }