// Copyright 2014 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
// Package core implements the Ethereum consensus protocol.
package core
import (
"bytes"
"errors"
"fmt"
"io"
"math/big"
mrand "math/rand"
"sync"
"sync/atomic"
"time"
coreCommon "github.com/dexon-foundation/dexon-consensus-core/common"
coreTypes "github.com/dexon-foundation/dexon-consensus-core/core/types"
"github.com/dexon-foundation/dexon/common"
"github.com/dexon-foundation/dexon/common/mclock"
"github.com/dexon-foundation/dexon/common/prque"
"github.com/dexon-foundation/dexon/consensus"
"github.com/dexon-foundation/dexon/core/rawdb"
"github.com/dexon-foundation/dexon/core/state"
"github.com/dexon-foundation/dexon/core/types"
"github.com/dexon-foundation/dexon/core/vm"
"github.com/dexon-foundation/dexon/crypto"
"github.com/dexon-foundation/dexon/ethdb"
"github.com/dexon-foundation/dexon/event"
"github.com/dexon-foundation/dexon/log"
"github.com/dexon-foundation/dexon/metrics"
"github.com/dexon-foundation/dexon/params"
"github.com/dexon-foundation/dexon/rlp"
"github.com/dexon-foundation/dexon/trie"
"github.com/hashicorp/golang-lru"
)
var (
blockInsertTimer = metrics.NewRegisteredTimer("chain/inserts", nil)
blockValidationTimer = metrics.NewRegisteredTimer("chain/validation", nil)
blockExecutionTimer = metrics.NewRegisteredTimer("chain/execution", nil)
blockWriteTimer = metrics.NewRegisteredTimer("chain/write", nil)
ErrNoGenesis = errors.New("Genesis not found in chain")
)
const (
bodyCacheLimit = 256
blockCacheLimit = 256
receiptsCacheLimit = 32
maxFutureBlocks = 256
maxTimeFutureBlocks = 30
badBlockLimit = 10
triesInMemory = 128
// BlockChainVersion ensures that an incompatible database forces a resync from scratch.
BlockChainVersion uint64 = 3
)
// CacheConfig contains the configuration values for the trie caching/pruning
// that's resident in a blockchain.
type CacheConfig struct {
Disabled bool // Whether to disable trie write caching (archive node)
TrieCleanLimit int // Memory allowance (MB) to use for caching trie nodes in memory
TrieDirtyLimit int // Memory limit (MB) at which to start flushing dirty trie nodes to disk
TrieTimeLimit time.Duration // Time limit after which to flush the current in-memory trie to disk
}
// BlockChain represents the canonical chain given a database with a genesis
// block. The Blockchain manages chain imports, reverts, chain reorganisations.
//
// Importing blocks in to the block chain happens according to the set of rules
// defined by the two stage Validator. Processing of blocks is done using the
// Processor which processes the included transaction. The validation of the state
// is done in the second part of the Validator. Failing results in aborting of
// the import.
//
// The BlockChain also helps in returning blocks from **any** chain included
// in the database as well as blocks that represents the canonical chain. It's
// important to note that GetBlock can return any block and does not need to be
// included in the canonical one where as GetBlockByNumber always represents the
// canonical chain.
type BlockChain struct {
chainConfig *params.ChainConfig // Chain & network configuration
cacheConfig *CacheConfig // Cache configuration for pruning
db ethdb.Database // Low level persistent database to store final content in
triegc *prque.Prque // Priority queue mapping block numbers to tries to gc
gcproc time.Duration // Accumulates canonical block processing for trie dumping
hc *HeaderChain
rmLogsFeed event.Feed
chainFeed event.Feed
chainSideFeed event.Feed
chainHeadFeed event.Feed
logsFeed event.Feed
scope event.SubscriptionScope
genesisBlock *types.Block
mu sync.RWMutex // global mutex for locking chain operations
chainmu sync.RWMutex // blockchain insertion lock
procmu sync.RWMutex // block processor lock
checkpoint int // checkpoint counts towards the new checkpoint
currentBlock atomic.Value // Current head of the block chain
currentFastBlock atomic.Value // Current head of the fast-sync chain (may be above the block chain!)
stateCache state.Database // State database to reuse between imports (contains state cache)
bodyCache *lru.Cache // Cache for the most recent block bodies
bodyRLPCache *lru.Cache // Cache for the most recent block bodies in RLP encoded format
receiptsCache *lru.Cache // Cache for the most recent receipts per block
blockCache *lru.Cache // Cache for the most recent entire blocks
futureBlocks *lru.Cache // future blocks are blocks added for later processing
quit chan struct{} // blockchain quit channel
running int32 // running must be called atomically
// procInterrupt must be atomically called
procInterrupt int32 // interrupt signaler for block processing
wg sync.WaitGroup // chain processing wait group for shutting down
engine consensus.Engine
processor Processor // block processor interface
validator Validator // block and state validator interface
vmConfig vm.Config
badBlocks *lru.Cache // Bad block cache
shouldPreserve func(*types.Block) bool // Function used to determine whether should preserve the given block.
confirmedBlockMu sync.Mutex
confirmedBlocks map[coreCommon.Hash]*coreTypes.Block
chainConfirmedBlocks map[uint32][]*coreTypes.Block
}
// NewBlockChain returns a fully initialised block chain using information
// available in the database. It initialises the default Ethereum Validator and
// Processor.
func NewBlockChain(db ethdb.Database, cacheConfig *CacheConfig, chainConfig *params.ChainConfig, engine consensus.Engine, vmConfig vm.Config, shouldPreserve func(block *types.Block) bool) (*BlockChain, error) {
if cacheConfig == nil {
cacheConfig = &CacheConfig{
TrieCleanLimit: 256,
TrieDirtyLimit: 256,
TrieTimeLimit: 5 * time.Minute,
}
}
bodyCache, _ := lru.New(bodyCacheLimit)
bodyRLPCache, _ := lru.New(bodyCacheLimit)
receiptsCache, _ := lru.New(receiptsCacheLimit)
blockCache, _ := lru.New(blockCacheLimit)
futureBlocks, _ := lru.New(maxFutureBlocks)
badBlocks, _ := lru.New(badBlockLimit)
bc := &BlockChain{
chainConfig: chainConfig,
cacheConfig: cacheConfig,
db: db,
triegc: prque.New(nil),
stateCache: state.NewDatabase(db),
stateCache: state.NewDatabaseWithCache(db, cacheConfig.TrieCleanLimit),
quit: make(chan struct{}),
shouldPreserve: shouldPreserve,
bodyCache: bodyCache,
bodyRLPCache: bodyRLPCache,
receiptsCache: receiptsCache,
blockCache: blockCache,
futureBlocks: futureBlocks,
engine: engine,
vmConfig: vmConfig,
badBlocks: badBlocks,
confirmedBlocks: make(map[coreCommon.Hash]*coreTypes.Block),
chainConfirmedBlocks: make(map[uint32][]*coreTypes.Block),
}
bc.SetValidator(NewBlockValidator(chainConfig, bc, engine))
bc.SetProcessor(NewStateProcessor(chainConfig, bc, engine))
var err error
bc.hc, err = NewHeaderChain(db, chainConfig, engine, bc.getProcInterrupt)
if err != nil {
return nil, err
}
bc.genesisBlock = bc.GetBlockByNumber(0)
if bc.genesisBlock == nil {
return nil, ErrNoGenesis
}
if err := bc.loadLastState(); err != nil {
return nil, err
}
// Check the current state of the block hashes and make sure that we do not have any of the bad blocks in our chain
for hash := range BadHashes {
if header := bc.GetHeaderByHash(hash); header != nil {
// get the canonical block corresponding to the offending header's number
headerByNumber := bc.GetHeaderByNumber(header.Number.Uint64())
// make sure the headerByNumber (if present) is in our current canonical chain
if headerByNumber != nil && headerByNumber.Hash() == header.Hash() {
log.Error("Found bad hash, rewinding chain", "number", header.Number, "hash", header.ParentHash)
bc.SetHead(header.Number.Uint64() - 1)
log.Error("Chain rewind was successful, resuming normal operation")
}
}
}
// Take ownership of this particular state
go bc.update()
return bc, nil
}
func (bc *BlockChain) getProcInterrupt() bool {
return atomic.LoadInt32(&bc.procInterrupt) == 1
}
// GetVMConfig returns the block chain VM config.
func (bc *BlockChain) GetVMConfig() *vm.Config {
return &bc.vmConfig
}
func (bc *BlockChain) AddConfirmedBlock(block *coreTypes.Block) {
bc.confirmedBlockMu.Lock()
defer bc.confirmedBlockMu.Unlock()
bc.confirmedBlocks[block.Hash] = block
chainBlocks := bc.chainConfirmedBlocks[block.Position.ChainID]
bc.chainConfirmedBlocks[block.Position.ChainID] = append(chainBlocks, block)
}
func (bc *BlockChain) RemoveConfirmedBlock(hash coreCommon.Hash) {
bc.confirmedBlockMu.Lock()
defer bc.confirmedBlockMu.Unlock()
block := bc.confirmedBlocks[hash]
delete(bc.confirmedBlocks, block.Hash)
chainBlocks := bc.chainConfirmedBlocks[block.Position.ChainID]
bc.chainConfirmedBlocks[block.Position.ChainID] = chainBlocks[1:]
}
func (bc *BlockChain) GetConfirmedBlockByHash(hash coreCommon.Hash) *coreTypes.Block {
return bc.confirmedBlocks[hash]
}
func (bc *BlockChain) GetConfirmedTxsByAddress(chainID uint32, address common.Address) (types.Transactions, error) {
var addressTxs types.Transactions
for _, block := range bc.chainConfirmedBlocks[chainID] {
var transactions types.Transactions
err := rlp.Decode(bytes.NewReader(block.Payload), &transactions)
if err != nil {
return nil, err
}
for _, tx := range transactions {
msg, err := tx.AsMessage(types.MakeSigner(bc.chainConfig, new(big.Int)))
if err != nil {
return nil, err
}
if msg.From() == address {
addressTxs = append(addressTxs, tx)
}
}
}
return addressTxs, nil
}
// loadLastState loads the last known chain state from the database. This method
// assumes that the chain manager mutex is held.
func (bc *BlockChain) loadLastState() error {
// Restore the last known head block
head := rawdb.ReadHeadBlockHash(bc.db)
if head == (common.Hash{}) {
// Corrupt or empty database, init from scratch
log.Warn("Empty database, resetting chain")
return bc.Reset()
}
// Make sure the entire head block is available
currentBlock := bc.GetBlockByHash(head)
if currentBlock == nil {
// Corrupt or empty database, init from scratch
log.Warn("Head block missing, resetting chain", "hash", head)
return bc.Reset()
}
// Make sure the state associated with the block is available
if _, err := state.New(currentBlock.Root(), bc.stateCache); err != nil {
// Dangling block without a state associated, init from scratch
log.Warn("Head state missing, repairing chain", "number", currentBlock.Number(), "hash", currentBlock.Hash())
if err := bc.repair(¤tBlock); err != nil {
return err
}
}
// Everything seems to be fine, set as the head block
bc.currentBlock.Store(currentBlock)
// Restore the last known head header
currentHeader := currentBlock.Header()
if head := rawdb.ReadHeadHeaderHash(bc.db); head != (common.Hash{}) {
if header := bc.GetHeaderByHash(head); header != nil {
currentHeader = header
}
}
bc.hc.SetCurrentHeader(currentHeader)
// Restore the last known head fast block
bc.currentFastBlock.Store(currentBlock)
if head := rawdb.ReadHeadFastBlockHash(bc.db); head != (common.Hash{}) {
if block := bc.GetBlockByHash(head); block != nil {
bc.currentFastBlock.Store(block)
}
}
// Issue a status log for the user
currentFastBlock := bc.CurrentFastBlock()
headerTd := bc.GetTd(currentHeader.Hash(), currentHeader.Number.Uint64())
blockTd := bc.GetTd(currentBlock.Hash(), currentBlock.NumberU64())
fastTd := bc.GetTd(currentFastBlock.Hash(), currentFastBlock.NumberU64())
log.Info("Loaded most recent local header", "number", currentHeader.Number, "hash", currentHeader.Hash(), "td", headerTd, "age", common.PrettyAge(time.Unix(int64(currentHeader.Time), 0)))
log.Info("Loaded most recent local full block", "number", currentBlock.Number(), "hash", currentBlock.Hash(), "td", blockTd, "age", common.PrettyAge(time.Unix(int64(currentBlock.Time()), 0)))
log.Info("Loaded most recent local fast block", "number", currentFastBlock.Number(), "hash", currentFastBlock.Hash(), "td", fastTd, "age", common.PrettyAge(time.Unix(int64(currentFastBlock.Time()), 0)))
return nil
}
// SetHead rewinds the local chain to a new head. In the case of headers, everything
// above the new head will be deleted and the new one set. In the case of blocks
// though, the head may be further rewound if block bodies are missing (non-archive
// nodes after a fast sync).
func (bc *BlockChain) SetHead(head uint64) error {
log.Warn("Rewinding blockchain", "target", head)
bc.mu.Lock()
defer bc.mu.Unlock()
// Rewind the header chain, deleting all block bodies until then
delFn := func(db rawdb.DatabaseDeleter, hash common.Hash, num uint64) {
rawdb.DeleteBody(db, hash, num)
}
bc.hc.SetHead(head, delFn)
currentHeader := bc.hc.CurrentHeader()
// Clear out any stale content from the caches
bc.bodyCache.Purge()
bc.bodyRLPCache.Purge()
bc.receiptsCache.Purge()
bc.blockCache.Purge()
bc.futureBlocks.Purge()
// Rewind the block chain, ensuring we don't end up with a stateless head block
if currentBlock := bc.CurrentBlock(); currentBlock != nil && currentHeader.Number.Uint64() < currentBlock.NumberU64() {
bc.currentBlock.Store(bc.GetBlock(currentHeader.Hash(), currentHeader.Number.Uint64()))
}
if currentBlock := bc.CurrentBlock(); currentBlock != nil {
if _, err := state.New(currentBlock.Root(), bc.stateCache); err != nil {
// Rewound state missing, rolled back to before pivot, reset to genesis
bc.currentBlock.Store(bc.genesisBlock)
}
}
// Rewind the fast block in a simpleton way to the target head
if currentFastBlock := bc.CurrentFastBlock(); currentFastBlock != nil && currentHeader.Number.Uint64() < currentFastBlock.NumberU64() {
bc.currentFastBlock.Store(bc.GetBlock(currentHeader.Hash(), currentHeader.Number.Uint64()))
}
// If either blocks reached nil, reset to the genesis state
if currentBlock := bc.CurrentBlock(); currentBlock == nil {
bc.currentBlock.Store(bc.genesisBlock)
}
if currentFastBlock := bc.CurrentFastBlock(); currentFastBlock == nil {
bc.currentFastBlock.Store(bc.genesisBlock)
}
currentBlock := bc.CurrentBlock()
currentFastBlock := bc.CurrentFastBlock()
rawdb.WriteHeadBlockHash(bc.db, currentBlock.Hash())
rawdb.WriteHeadFastBlockHash(bc.db, currentFastBlock.Hash())
return bc.loadLastState()
}
// FastSyncCommitHead sets the current head block to the one defined by the hash
// irrelevant what the chain contents were prior.
func (bc *BlockChain) FastSyncCommitHead(hash common.Hash) error {
// Make sure that both the block as well at its state trie exists
block := bc.GetBlockByHash(hash)
if block == nil {
return fmt.Errorf("non existent block [%x…]", hash[:4])
}
if _, err := trie.NewSecure(block.Root(), bc.stateCache.TrieDB(), 0); err != nil {
return err
}
// If all checks out, manually set the head block
bc.mu.Lock()
bc.currentBlock.Store(block)
bc.mu.Unlock()
log.Info("Committed new head block", "number", block.Number(), "hash", hash)
return nil
}
// GasLimit returns the gas limit of the current HEAD block.
func (bc *BlockChain) GasLimit() uint64 {
return bc.CurrentBlock().GasLimit()
}
// CurrentBlock retrieves the current head block of the canonical chain. The
// block is retrieved from the blockchain's internal cache.
func (bc *BlockChain) CurrentBlock() *types.Block {
return bc.currentBlock.Load().(*types.Block)
}
// CurrentFastBlock retrieves the current fast-sync head block of the canonical
// chain. The block is retrieved from the blockchain's internal cache.
func (bc *BlockChain) CurrentFastBlock() *types.Block {
return bc.currentFastBlock.Load().(*types.Block)
}
// SetProcessor sets the processor required for making state modifications.
func (bc *BlockChain) SetProcessor(processor Processor) {
bc.procmu.Lock()
defer bc.procmu.Unlock()
bc.processor = processor
}
// SetValidator sets the validator which is used to validate incoming blocks.
func (bc *BlockChain) SetValidator(validator Validator) {
bc.procmu.Lock()
defer bc.procmu.Unlock()
bc.validator = validator
}
// Validator returns the current validator.
func (bc *BlockChain) Validator() Validator {
bc.procmu.RLock()
defer bc.procmu.RUnlock()
return bc.validator
}
// Processor returns the current processor.
func (bc *BlockChain) Processor() Processor {
bc.procmu.RLock()
defer bc.procmu.RUnlock()
return bc.processor
}
// State returns a new mutable state based on the current HEAD block.
func (bc *BlockChain) State() (*state.StateDB, error) {
return bc.StateAt(bc.CurrentBlock().Root())
}
// StateAt returns a new mutable state based on a particular point in time.
func (bc *BlockChain) StateAt(root common.Hash) (*state.StateDB, error) {
return state.New(root, bc.stateCache)
}
// StateCache returns the caching database underpinning the blockchain instance.
func (bc *BlockChain) StateCache() state.Database {
return bc.stateCache
}
// Reset purges the entire blockchain, restoring it to its genesis state.
func (bc *BlockChain) Reset() error {
return bc.ResetWithGenesisBlock(bc.genesisBlock)
}
// ResetWithGenesisBlock purges the entire blockchain, restoring it to the
// specified genesis state.
func (bc *BlockChain) ResetWithGenesisBlock(genesis *types.Block) error {
// Dump the entire block chain and purge the caches
if err := bc.SetHead(0); err != nil {
return err
}
bc.mu.Lock()
defer bc.mu.Unlock()
// Prepare the genesis block and reinitialise the chain
if err := bc.hc.WriteTd(genesis.Hash(), genesis.NumberU64(), genesis.Difficulty()); err != nil {
log.Crit("Failed to write genesis block TD", "err", err)
}
rawdb.WriteBlock(bc.db, genesis)
bc.genesisBlock = genesis
bc.insert(bc.genesisBlock)
bc.currentBlock.Store(bc.genesisBlock)
bc.hc.SetGenesis(bc.genesisBlock.Header())
bc.hc.SetCurrentHeader(bc.genesisBlock.Header())
bc.currentFastBlock.Store(bc.genesisBlock)
return nil
}
// repair tries to repair the current blockchain by rolling back the current block
// until one with associated state is found. This is needed to fix incomplete db
// writes caused either by crashes/power outages, or simply non-committed tries.
//
// This method only rolls back the current block. The current header and current
// fast block are left intact.
func (bc *BlockChain) repair(head **types.Block) error {
for {
// Abort if we've rewound to a head block that does have associated state
if _, err := state.New((*head).Root(), bc.stateCache); err == nil {
log.Info("Rewound blockchain to past state", "number", (*head).Number(), "hash", (*head).Hash())
return nil
}
// Otherwise rewind one block and recheck state availability there
block := bc.GetBlock((*head).ParentHash(), (*head).NumberU64()-1)
if block == nil {
return fmt.Errorf("missing block %d [%x]", (*head).NumberU64()-1, (*head).ParentHash())
}
(*head) = block
}
}
// Export writes the active chain to the given writer.
func (bc *BlockChain) Export(w io.Writer) error {
return bc.ExportN(w, uint64(0), bc.CurrentBlock().NumberU64())
}
// ExportN writes a subset of the active chain to the given writer.
func (bc *BlockChain) ExportN(w io.Writer, first uint64, last uint64) error {
bc.mu.RLock()
defer bc.mu.RUnlock()
if first > last {
return fmt.Errorf("export failed: first (%d) is greater than last (%d)", first, last)
}
log.Info("Exporting batch of blocks", "count", last-first+1)
start, reported := time.Now(), time.Now()
for nr := first; nr <= last; nr++ {
block := bc.GetBlockByNumber(nr)
if block == nil {
return fmt.Errorf("export failed on #%d: not found", nr)
}
if err := block.EncodeRLP(w); err != nil {
return err
}
if time.Since(reported) >= statsReportLimit {
log.Info("Exporting blocks", "exported", block.NumberU64()-first, "elapsed", common.PrettyDuration(time.Since(start)))
reported = time.Now()
}
}
return nil
}
// insert injects a new head block into the current block chain. This method
// assumes that the block is indeed a true head. It will also reset the head
// header and the head fast sync block to this very same block if they are older
// or if they are on a different side chain.
//
// Note, this function assumes that the `mu` mutex is held!
func (bc *BlockChain) insert(block *types.Block) {
// If the block is on a side chain or an unknown one, force other heads onto it too
updateHeads := rawdb.ReadCanonicalHash(bc.db, block.NumberU64()) != block.Hash()
// Add the block to the canonical chain number scheme and mark as the head
rawdb.WriteCanonicalHash(bc.db, block.Hash(), block.NumberU64())
rawdb.WriteHeadBlockHash(bc.db, block.Hash())
bc.currentBlock.Store(block)
// If the block is better than our head or is on a different chain, force update heads
if updateHeads {
bc.hc.SetCurrentHeader(block.Header())
rawdb.WriteHeadFastBlockHash(bc.db, block.Hash())
bc.currentFastBlock.Store(block)
}
}
// Genesis retrieves the chain's genesis block.
func (bc *BlockChain) Genesis() *types.Block {
return bc.genesisBlock
}
// GetBody retrieves a block body (transactions and uncles) from the database by
// hash, caching it if found.
func (bc *BlockChain) GetBody(hash common.Hash) *types.Body {
// Short circuit if the body's already in the cache, retrieve otherwise
if cached, ok := bc.bodyCache.Get(hash); ok {
body := cached.(*types.Body)
return body
}
number := bc.hc.GetBlockNumber(hash)
if number == nil {
return nil
}
body := rawdb.ReadBody(bc.db, hash, *number)
if body == nil {
return nil
}
// Cache the found body for next time and return
bc.bodyCache.Add(hash, body)
return body
}
// GetBodyRLP retrieves a block body in RLP encoding from the database by hash,
// caching it if found.
func (bc *BlockChain) GetBodyRLP(hash common.Hash) rlp.RawValue {
// Short circuit if the body's already in the cache, retrieve otherwise
if cached, ok := bc.bodyRLPCache.Get(hash); ok {
return cached.(rlp.RawValue)
}
number := bc.hc.GetBlockNumber(hash)
if number == nil {
return nil
}
body := rawdb.ReadBodyRLP(bc.db, hash, *number)
if len(body) == 0 {
return nil
}
// Cache the found body for next time and return
bc.bodyRLPCache.Add(hash, body)
return body
}
// HasBlock checks if a block is fully present in the database or not.
func (bc *BlockChain) HasBlock(hash common.Hash, number uint64) bool {
if bc.blockCache.Contains(hash) {
return true
}
return rawdb.HasBody(bc.db, hash, number)
}
// HasFastBlock checks if a fast block is fully present in the database or not.
func (bc *BlockChain) HasFastBlock(hash common.Hash, number uint64) bool {
if !bc.HasBlock(hash, number) {
return false
}
if bc.receiptsCache.Contains(hash) {
return true
}
return rawdb.HasReceipts(bc.db, hash, number)
}
// HasState checks if state trie is fully present in the database or not.
func (bc *BlockChain) HasState(hash common.Hash) bool {
_, err := bc.stateCache.OpenTrie(hash)
return err == nil
}
// HasBlockAndState checks if a block and associated state trie is fully present
// in the database or not, caching it if present.
func (bc *BlockChain) HasBlockAndState(hash common.Hash, number uint64) bool {
// Check first that the block itself is known
block := bc.GetBlock(hash, number)
if block == nil {
return false
}
return bc.HasState(block.Root())
}
// GetBlock retrieves a block from the database by hash and number,
// caching it if found.
func (bc *BlockChain) GetBlock(hash common.Hash, number uint64) *types.Block {
// Short circuit if the block's already in the cache, retrieve otherwise
if block, ok := bc.blockCache.Get(hash); ok {
return block.(*types.Block)
}
block := rawdb.ReadBlock(bc.db, hash, number)
if block == nil {
return nil
}
// Cache the found block for next time and return
bc.blockCache.Add(block.Hash(), block)
return block
}
// GetBlockByHash retrieves a block from the database by hash, caching it if found.
func (bc *BlockChain) GetBlockByHash(hash common.Hash) *types.Block {
number := bc.hc.GetBlockNumber(hash)
if number == nil {
return nil
}
return bc.GetBlock(hash, *number)
}
// GetBlockByNumber retrieves a block from the database by number, caching it
// (associated with its hash) if found.
func (bc *BlockChain) GetBlockByNumber(number uint64) *types.Block {
hash := rawdb.ReadCanonicalHash(bc.db, number)
if hash == (common.Hash{}) {
return nil
}
return bc.GetBlock(hash, number)
}
// GetReceiptsByHash retrieves the receipts for all transactions in a given block.
func (bc *BlockChain) GetReceiptsByHash(hash common.Hash) types.Receipts {
if receipts, ok := bc.receiptsCache.Get(hash); ok {
return receipts.(types.Receipts)
}
number := rawdb.ReadHeaderNumber(bc.db, hash)
if number == nil {
return nil
}
receipts := rawdb.ReadReceipts(bc.db, hash, *number)
bc.receiptsCache.Add(hash, receipts)
return receipts
}
// GetBlocksFromHash returns the block corresponding to hash and up to n-1 ancestors.
// [deprecated by eth/62]
func (bc *BlockChain) GetBlocksFromHash(hash common.Hash, n int) (blocks []*types.Block) {
number := bc.hc.GetBlockNumber(hash)
if number == nil {
return nil
}
for i := 0; i < n; i++ {
block := bc.GetBlock(hash, *number)
if block == nil {
break
}
blocks = append(blocks, block)
hash = block.ParentHash()
*number--
}
return
}
// GetUnclesInChain retrieves all the uncles from a given block backwards until
// a specific distance is reached.
func (bc *BlockChain) GetUnclesInChain(block *types.Block, length int) []*types.Header {
uncles := []*types.Header{}
for i := 0; block != nil && i < length; i++ {
uncles = append(uncles, block.Uncles()...)
block = bc.GetBlock(block.ParentHash(), block.NumberU64()-1)
}
return uncles
}
// TrieNode retrieves a blob of data associated with a trie node (or code hash)
// either from ephemeral in-memory cache, or from persistent storage.
func (bc *BlockChain) TrieNode(hash common.Hash) ([]byte, error) {
return bc.stateCache.TrieDB().Node(hash)
}
// Stop stops the blockchain service. If any imports are currently in progress
// it will abort them using the procInterrupt.
func (bc *BlockChain) Stop() {
if !atomic.CompareAndSwapInt32(&bc.running, 0, 1) {
return
}
// Unsubscribe all subscriptions registered from blockchain
bc.scope.Close()
close(bc.quit)
atomic.StoreInt32(&bc.procInterrupt, 1)
bc.wg.Wait()
// Ensure the state of a recent block is also stored to disk before exiting.
// We're writing three different states to catch different restart scenarios:
// - HEAD: So we don't need to reprocess any blocks in the general case
// - HEAD-1: So we don't do large reorgs if our HEAD becomes an uncle
// - HEAD-127: So we have a hard limit on the number of blocks reexecuted
if !bc.cacheConfig.Disabled {
triedb := bc.stateCache.TrieDB()
for _, offset := range []uint64{0, 1, triesInMemory - 1} {
if number := bc.CurrentBlock().NumberU64(); number > offset {
recent := bc.GetBlockByNumber(number - offset)
log.Info("Writing cached state to disk", "block", recent.Number(), "hash", recent.Hash(), "root", recent.Root())
if err := triedb.Commit(recent.Root(), true); err != nil {
log.Error("Failed to commit recent state trie", "err", err)
}
}
}
for !bc.triegc.Empty() {
triedb.Dereference(bc.triegc.PopItem().(common.Hash))
}
if size, _ := triedb.Size(); size != 0 {
log.Error("Dangling trie nodes after full cleanup")
}
}
log.Info("Blockchain manager stopped")
}
func (bc *BlockChain) procFutureBlocks() {
blocks := make([]*types.Block, 0, bc.futureBlocks.Len())
for _, hash := range bc.futureBlocks.Keys() {
if block, exist := bc.futureBlocks.Peek(hash); exist {
blocks = append(blocks, block.(*types.Block))
}
}
if len(blocks) > 0 {
types.BlockBy(types.Number).Sort(blocks)
// Insert one by one as chain insertion needs contiguous ancestry between blocks
for i := range blocks {
bc.InsertChain(blocks[i : i+1])
}
}
}
// WriteStatus status of write
type WriteStatus byte
const (
NonStatTy WriteStatus = iota
CanonStatTy
SideStatTy
)
// Rollback is designed to remove a chain of links from the database that aren't
// certain enough to be valid.
func (bc *BlockChain) Rollback(chain []common.Hash) {
bc.mu.Lock()
defer bc.mu.Unlock()
for i := len(chain) - 1; i >= 0; i-- {
hash := chain[i]
currentHeader := bc.hc.CurrentHeader()
if currentHeader.Hash() == hash {
bc.hc.SetCurrentHeader(bc.GetHeader(currentHeader.ParentHash, currentHeader.Number.Uint64()-1))
}
if currentFastBlock := bc.CurrentFastBlock(); currentFastBlock.Hash() == hash {
newFastBlock := bc.GetBlock(currentFastBlock.ParentHash(), currentFastBlock.NumberU64()-1)
bc.currentFastBlock.Store(newFastBlock)
rawdb.WriteHeadFastBlockHash(bc.db, newFastBlock.Hash())
}
if currentBlock := bc.CurrentBlock(); currentBlock.Hash() == hash {
newBlock := bc.GetBlock(currentBlock.ParentHash(), currentBlock.NumberU64()-1)
bc.currentBlock.Store(newBlock)
rawdb.WriteHeadBlockHash(bc.db, newBlock.Hash())
}
}
}
// SetReceiptsData computes all the non-consensus fields of the receipts
func SetReceiptsData(config *params.ChainConfig, block *types.Block, receipts types.Receipts) error {
signer := types.MakeSigner(config, block.Number())
transactions, logIndex := block.Transactions(), uint(0)
if len(transactions) != len(receipts) {
return errors.New("transaction and receipt count mismatch")
}
for j := 0; j < len(receipts); j++ {
// The transaction hash can be retrieved from the transaction itself
receipts[j].TxHash = transactions[j].Hash()
// The contract address can be derived from the transaction itself
if transactions[j].To() == nil {
// Deriving the signer is expensive, only do if it's actually needed
from, _ := types.Sender(signer, transactions[j])
receipts[j].ContractAddress = crypto.CreateAddress(from, transactions[j].Nonce())
}
// The used gas can be calculated based on previous receipts
if j == 0 {
receipts[j].GasUsed = receipts[j].CumulativeGasUsed
} else {
receipts[j].GasUsed = receipts[j].CumulativeGasUsed - receipts[j-1].CumulativeGasUsed
}
// The derived log fields can simply be set from the block and transaction
for k := 0; k < len(receipts[j].Logs); k++ {
receipts[j].Logs[k].BlockNumber = block.NumberU64()
receipts[j].Logs[k].BlockHash = block.Hash()
receipts[j].Logs[k].TxHash = receipts[j].TxHash
receipts[j].Logs[k].TxIndex = uint(j)
receipts[j].Logs[k].Index = logIndex
logIndex++
}
}
return nil
}
// InsertReceiptChain attempts to complete an already existing header chain with
// transaction and receipt data.
func (bc *BlockChain) InsertReceiptChain(blockChain types.Blocks, receiptChain []types.Receipts) (int, error) {
bc.wg.Add(1)
defer bc.wg.Done()
// Do a sanity check that the provided chain is actually ordered and linked
for i := 1; i < len(blockChain); i++ {
if blockChain[i].NumberU64() != blockChain[i-1].NumberU64()+1 || blockChain[i].ParentHash() != blockChain[i-1].Hash() {
log.Error("Non contiguous receipt insert", "number", blockChain[i].Number(), "hash", blockChain[i].Hash(), "parent", blockChain[i].ParentHash(),
"prevnumber", blockChain[i-1].Number(), "prevhash", blockChain[i-1].Hash())
return 0, fmt.Errorf("non contiguous insert: item %d is #%d [%x…], item %d is #%d [%x…] (parent [%x…])", i-1, blockChain[i-1].NumberU64(),
blockChain[i-1].Hash().Bytes()[:4], i, blockChain[i].NumberU64(), blockChain[i].Hash().Bytes()[:4], blockChain[i].ParentHash().Bytes()[:4])
}
}
var (
stats = struct{ processed, ignored int32 }{}
start = time.Now()
bytes = 0
batch = bc.db.NewBatch()
)
for i, block := range blockChain {
receipts := receiptChain[i]
// Short circuit insertion if shutting down or processing failed
if atomic.LoadInt32(&bc.procInterrupt) == 1 {
return 0, nil
}
// Short circuit if the owner header is unknown
if !bc.HasHeader(block.Hash(), block.NumberU64()) {
return i, fmt.Errorf("containing header #%d [%x…] unknown", block.Number(), block.Hash().Bytes()[:4])
}
// Skip if the entire data is already known
if bc.HasBlock(block.Hash(), block.NumberU64()) {
stats.ignored++
continue
}
// Compute all the non-consensus fields of the receipts
if err := SetReceiptsData(bc.chainConfig, block, receipts); err != nil {
return i, fmt.Errorf("failed to set receipts data: %v", err)
}
// Write all the data out into the database
rawdb.WriteBody(batch, block.Hash(), block.NumberU64(), block.Body())
rawdb.WriteReceipts(batch, block.Hash(), block.NumberU64(), receipts)
rawdb.WriteTxLookupEntries(batch, block)
stats.processed++
if batch.ValueSize() >= ethdb.IdealBatchSize {
if err := batch.Write(); err != nil {
return 0, err
}
bytes += batch.ValueSize()
batch.Reset()
}
}
if batch.ValueSize() > 0 {
bytes += batch.ValueSize()
if err := batch.Write(); err != nil {
return 0, err
}
}
// Update the head fast sync block if better
bc.mu.Lock()
head := blockChain[len(blockChain)-1]
if td := bc.GetTd(head.Hash(), head.NumberU64()); td != nil { // Rewind may have occurred, skip in that case
currentFastBlock := bc.CurrentFastBlock()
if bc.GetTd(currentFastBlock.Hash(), currentFastBlock.NumberU64()).Cmp(td) < 0 {
rawdb.WriteHeadFastBlockHash(bc.db, head.Hash())
bc.currentFastBlock.Store(head)
}
}
bc.mu.Unlock()
context := []interface{}{
"count", stats.processed, "elapsed", common.PrettyDuration(time.Since(start)),
"number", head.Number(), "hash", head.Hash(), "age", common.PrettyAge(time.Unix(int64(head.Time()), 0)),
"size", common.StorageSize(bytes),
}
if stats.ignored > 0 {
context = append(context, []interface{}{"ignored", stats.ignored}...)
}
log.Info("Imported new block receipts", context...)
return 0, nil
}
var lastWrite uint64
// WriteBlockWithoutState writes only the block and its metadata to the database,
// but does not write any state. This is used to construct competing side forks
// up to the point where they exceed the canonical total difficulty.
func (bc *BlockChain) WriteBlockWithoutState(block *types.Block, td *big.Int) (err error) {
bc.wg.Add(1)
defer bc.wg.Done()
if err := bc.hc.WriteTd(block.Hash(), block.NumberU64(), td); err != nil {
return err
}
rawdb.WriteBlock(bc.db, block)
return nil
}
// WriteBlockWithState writes the block and all associated state to the database.
func (bc *BlockChain) WriteBlockWithState(block *types.Block, receipts []*types.Receipt, state *state.StateDB) (status WriteStatus, err error) {
bc.wg.Add(1)
defer bc.wg.Done()
// Calculate the total difficulty of the block
ptd := bc.GetTd(block.ParentHash(), block.NumberU64()-1)
if ptd == nil {
return NonStatTy, consensus.ErrUnknownAncestor
}
// Make sure no inconsistent state is leaked during insertion
bc.mu.Lock()
defer bc.mu.Unlock()
currentBlock := bc.CurrentBlock()
localTd := bc.GetTd(currentBlock.Hash(), currentBlock.NumberU64())
externTd := new(big.Int).Add(block.Difficulty(), ptd)
// Irrelevant of the canonical status, write the block itself to the database
if err := bc.hc.WriteTd(block.Hash(), block.NumberU64(), externTd); err != nil {
return NonStatTy, err
}
rawdb.WriteBlock(bc.db, block)
root, err := state.Commit(bc.chainConfig.IsEIP158(block.Number()))
if err != nil {
return NonStatTy, err
}
triedb := bc.stateCache.TrieDB()
// If we're running an archive node, always flush
if bc.cacheConfig.Disabled {
if err := triedb.Commit(root, false); err != nil {
return NonStatTy, err
}
} else {
// Full but not archive node, do proper garbage collection
triedb.Reference(root, common.Hash{}) // metadata reference to keep trie alive
bc.triegc.Push(root, -int64(block.NumberU64()))
if current := block.NumberU64(); current > triesInMemory {
// If we exceeded our memory allowance, flush matured singleton nodes to disk
var (
nodes, imgs = triedb.Size()
limit = common.StorageSize(bc.cacheConfig.TrieDirtyLimit) * 1024 * 1024
)
if nodes > limit || imgs > 4*1024*1024 {
triedb.Cap(limit - ethdb.IdealBatchSize)
}
// Find the next state trie we need to commit
chosen := current - triesInMemory
// If we exceeded out time allowance, flush an entire trie to disk
if bc.gcproc > bc.cacheConfig.TrieTimeLimit {
// If the header is missing (canonical chain behind), we're reorging a low
// diff sidechain. Suspend committing until this operation is completed.
header := bc.GetHeaderByNumber(chosen)
if header == nil {
log.Warn("Reorg in progress, trie commit postponed", "number", chosen)
} else {
// If we're exceeding limits but haven't reached a large enough memory gap,
// warn the user that the system is becoming unstable.
if chosen < lastWrite+triesInMemory && bc.gcproc >= 2*bc.cacheConfig.TrieTimeLimit {
log.Info("State in memory for too long, committing", "time", bc.gcproc, "allowance", bc.cacheConfig.TrieTimeLimit, "optimum", float64(chosen-lastWrite)/triesInMemory)
}
// Flush an entire trie and restart the counters
triedb.Commit(header.Root, true)
lastWrite = chosen
bc.gcproc = 0
}
}
// Garbage collect anything below our required write retention
for !bc.triegc.Empty() {
root, number := bc.triegc.Pop()
if uint64(-number) > chosen {
bc.triegc.Push(root, number)
break
}
triedb.Dereference(root.(common.Hash))
}
}
}
// Write other block data using a batch.
batch := bc.db.NewBatch()
rawdb.WriteReceipts(batch, block.Hash(), block.NumberU64(), receipts)
// If the total difficulty is higher than our known, add it to the canonical chain
// Second clause in the if statement reduces the vulnerability to selfish mining.
// Please refer to http://www.cs.cornell.edu/~ie53/publications/btcProcFC.pdf
reorg := externTd.Cmp(localTd) > 0
currentBlock = bc.CurrentBlock()
if !reorg && externTd.Cmp(localTd) == 0 {
// Split same-difficulty blocks by number, then preferentially select
// the block generated by the local miner as the canonical block.
if block.NumberU64() < currentBlock.NumberU64() {
reorg = true
} else if block.NumberU64() == currentBlock.NumberU64() {
var currentPreserve, blockPreserve bool
if bc.shouldPreserve != nil {
currentPreserve, blockPreserve = bc.shouldPreserve(currentBlock), bc.shouldPreserve(block)
}
reorg = !currentPreserve && (blockPreserve || mrand.Float64() < 0.5)
}
}
if reorg {
// Reorganise the chain if the parent is not the head block
if block.ParentHash() != currentBlock.Hash() {
if err := bc.reorg(currentBlock, block); err != nil {
return NonStatTy, err
}
}
// Write the positional metadata for transaction/receipt lookups and preimages
rawdb.WriteTxLookupEntries(batch, block)
rawdb.WritePreimages(batch, state.Preimages())
status = CanonStatTy
} else {
status = SideStatTy
}
if err := batch.Write(); err != nil {
return NonStatTy, err
}
// Set new head.
if status == CanonStatTy {
bc.insert(block)
}
bc.futureBlocks.Remove(block.Hash())
return status, nil
}
// addFutureBlock checks if the block is within the max allowed window to get
// accepted for future processing, and returns an error if the block is too far
// ahead and was not added.
func (bc *BlockChain) addFutureBlock(block *types.Block) error {
max := uint64(time.Now().Unix() + maxTimeFutureBlocks)
if block.Time() > max {
return fmt.Errorf("future block timestamp %v > allowed %v", block.Time(), max)
}
bc.futureBlocks.Add(block.Hash(), block)
return nil
}
// InsertChain attempts to insert the given batch of blocks in to the canonical
// chain or, otherwise, create a fork. If an error is returned it will return
// the index number of the failing block as well an error describing what went
// wrong.
//
// After insertion is done, all accumulated events will be fired.
func (bc *BlockChain) InsertChain(chain types.Blocks) (int, error) {
// Sanity check that we have something meaningful to import
if len(chain) == 0 {
return 0, nil
}
// Do a sanity check that the provided chain is actually ordered and linked
for i := 1; i < len(chain); i++ {
if chain[i].NumberU64() != chain[i-1].NumberU64()+1 || chain[i].ParentHash() != chain[i-1].Hash() {
// Chain broke ancestry, log a message (programming error) and skip insertion
log.Error("Non contiguous block insert", "number", chain[i].Number(), "hash", chain[i].Hash(),
"parent", chain[i].ParentHash(), "prevnumber", chain[i-1].Number(), "prevhash", chain[i-1].Hash())
return 0, fmt.Errorf("non contiguous insert: item %d is #%d [%x…], item %d is #%d [%x…] (parent [%x…])", i-1, chain[i-1].NumberU64(),
chain[i-1].Hash().Bytes()[:4], i, chain[i].NumberU64(), chain[i].Hash().Bytes()[:4], chain[i].ParentHash().Bytes()[:4])
}
}
// Pre-checks passed, start the full block imports
bc.wg.Add(1)
bc.chainmu.Lock()
n, events, logs, err := bc.insertChain(chain, true)
bc.chainmu.Unlock()
bc.wg.Done()
bc.PostChainEvents(events, logs)
return n, err
}
// insertChain is the internal implementation of insertChain, which assumes that
// 1) chains are contiguous, and 2) The chain mutex is held.
//
// This method is split out so that import batches that require re-injecting
// historical blocks can do so without releasing the lock, which could lead to
// racey behaviour. If a sidechain import is in progress, and the historic state
// is imported, but then new canon-head is added before the actual sidechain
// completes, then the historic state could be pruned again
func (bc *BlockChain) insertChain(chain types.Blocks, verifySeals bool) (int, []interface{}, []*types.Log, error) {
// If the chain is terminating, don't even bother starting u
if atomic.LoadInt32(&bc.procInterrupt) == 1 {
return 0, nil, nil, nil
}
// Start a parallel signature recovery (signer will fluke on fork transition, minimal perf loss)
senderCacher.recoverFromBlocks(types.MakeSigner(bc.chainConfig, chain[0].Number()), chain)
// A queued approach to delivering events. This is generally
// faster than direct delivery and requires much less mutex
// acquiring.
var (
stats = insertStats{startTime: mclock.Now()}
events = make([]interface{}, 0, len(chain))
lastCanon *types.Block
coalescedLogs []*types.Log
)
// Start the parallel header verifier
headers := make([]*types.Header, len(chain))
seals := make([]bool, len(chain))
for i, block := range chain {
headers[i] = block.Header()
seals[i] = verifySeals
}
abort, results := bc.engine.VerifyHeaders(bc, headers, seals)
defer close(abort)
// Peek the error for the first block to decide the directing import logic
it := newInsertIterator(chain, results, bc.Validator())
block, err := it.next()
switch {
// First block is pruned, insert as sidechain and reorg only if TD grows enough
case err == consensus.ErrPrunedAncestor:
return bc.insertSidechain(block, it)
// First block is future, shove it (and all children) to the future queue (unknown ancestor)
case err == consensus.ErrFutureBlock || (err == consensus.ErrUnknownAncestor && bc.futureBlocks.Contains(it.first().ParentHash())):
for block != nil && (it.index == 0 || err == consensus.ErrUnknownAncestor) {
if err := bc.addFutureBlock(block); err != nil {
return it.index, events, coalescedLogs, err
}
block, err = it.next()
}
stats.queued += it.processed()
stats.ignored += it.remaining()
// If there are any still remaining, mark as ignored
return it.index, events, coalescedLogs, err
// First block (and state) is known
// 1. We did a roll-back, and should now do a re-import
// 2. The block is stored as a sidechain, and is lying about it's stateroot, and passes a stateroot
// from the canonical chain, which has not been verified.
case err == ErrKnownBlock:
// Skip all known blocks that behind us
current := bc.CurrentBlock().NumberU64()
for block != nil && err == ErrKnownBlock && current >= block.NumberU64() {
stats.ignored++
block, err = it.next()
}
// Falls through to the block import
// Some other error occurred, abort
case err != nil:
stats.ignored += len(it.chain)
bc.reportBlock(block, nil, err)
return it.index, events, coalescedLogs, err
}
// No validation errors for the first block (or chain prefix skipped)
for ; block != nil && err == nil; block, err = it.next() {
// If the chain is terminating, stop processing blocks
if atomic.LoadInt32(&bc.procInterrupt) == 1 {
log.Debug("Premature abort during blocks processing")
break
}
// If the header is a banned one, straight out abort
if BadHashes[block.Hash()] {
bc.reportBlock(block, nil, ErrBlacklistedHash)
return it.index, events, coalescedLogs, ErrBlacklistedHash
}
// Retrieve the parent block and it's state to execute on top
start := time.Now()
parent := it.previous()
if parent == nil {
parent = bc.GetBlock(block.ParentHash(), block.NumberU64()-1)
}
state, err := state.New(parent.Root(), bc.stateCache)
if err != nil {
return it.index, events, coalescedLogs, err
}
// Process block using the parent state as reference point.
t0 := time.Now()
receipts, logs, usedGas, err := bc.processor.Process(block, state, bc.vmConfig)
t1 := time.Now()
if err != nil {
bc.reportBlock(block, receipts, err)
return it.index, events, coalescedLogs, err
}
// Validate the state using the default validator
if err := bc.Validator().ValidateState(block, parent, state, receipts, usedGas); err != nil {
bc.reportBlock(block, receipts, err)
return it.index, events, coalescedLogs, err
}
t2 := time.Now()
proctime := time.Since(start)
// Write the block to the chain and get the status.
status, err := bc.WriteBlockWithState(block, receipts, state)
t3 := time.Now()
if err != nil {
return it.index, events, coalescedLogs, err
}
blockInsertTimer.UpdateSince(start)
blockExecutionTimer.Update(t1.Sub(t0))
blockValidationTimer.Update(t2.Sub(t1))
blockWriteTimer.Update(t3.Sub(t2))
switch status {
case CanonStatTy:
log.Debug("Inserted new block", "number", block.Number(), "hash", block.Hash(),
"uncles", len(block.Uncles()), "txs", len(block.Transactions()), "gas", block.GasUsed(),
"elapsed", common.PrettyDuration(time.Since(start)),
"root", block.Root())
coalescedLogs = append(coalescedLogs, logs...)
events = append(events, ChainEvent{block, block.Hash(), logs})
lastCanon = block
// Only count canonical blocks for GC processing time
bc.gcproc += proctime
case SideStatTy:
log.Debug("Inserted forked block", "number", block.Number(), "hash", block.Hash(),
"diff", block.Difficulty(), "elapsed", common.PrettyDuration(time.Since(start)),
"txs", len(block.Transactions()), "gas", block.GasUsed(), "uncles", len(block.Uncles()),
"root", block.Root())
events = append(events, ChainSideEvent{block})
}
blockInsertTimer.UpdateSince(start)
stats.processed++
stats.usedGas += usedGas
cache, _ := bc.stateCache.TrieDB().Size()
stats.report(chain, it.index, cache)
}
// Any blocks remaining here? The only ones we care about are the future ones
if block != nil && err == consensus.ErrFutureBlock {
if err := bc.addFutureBlock(block); err != nil {
return it.index, events, coalescedLogs, err
}
block, err = it.next()
for ; block != nil && err == consensus.ErrUnknownAncestor; block, err = it.next() {
if err := bc.addFutureBlock(block); err != nil {
return it.index, events, coalescedLogs, err
}
stats.queued++
}
}
stats.ignored += it.remaining()
// Append a single chain head event if we've progressed the chain
if lastCanon != nil && bc.CurrentBlock().Hash() == lastCanon.Hash() {
events = append(events, ChainHeadEvent{lastCanon})
}
return it.index, events, coalescedLogs, err
}
// insertSidechain is called when an import batch hits upon a pruned ancestor
// error, which happens when a sidechain with a sufficiently old fork-block is
// found.
//
// The method writes all (header-and-body-valid) blocks to disk, then tries to
// switch over to the new chain if the TD exceeded the current chain.
func (bc *BlockChain) insertSidechain(block *types.Block, it *insertIterator) (int, []interface{}, []*types.Log, error) {
var (
externTd *big.Int
current = bc.CurrentBlock().NumberU64()
)
// The first sidechain block error is already verified to be ErrPrunedAncestor.
// Since we don't import them here, we expect ErrUnknownAncestor for the remaining
// ones. Any other errors means that the block is invalid, and should not be written
// to disk.
err := consensus.ErrPrunedAncestor
for ; block != nil && (err == consensus.ErrPrunedAncestor); block, err = it.next() {
// Check the canonical state root for that number
if number := block.NumberU64(); current >= number {
if canonical := bc.GetBlockByNumber(number); canonical != nil && canonical.Root() == block.Root() {
// This is most likely a shadow-state attack. When a fork is imported into the
// database, and it eventually reaches a block height which is not pruned, we
// just found that the state already exist! This means that the sidechain block
// refers to a state which already exists in our canon chain.
//
// If left unchecked, we would now proceed importing the blocks, without actually
// having verified the state of the previous blocks.
log.Warn("Sidechain ghost-state attack detected", "number", block.NumberU64(), "sideroot", block.Root(), "canonroot", canonical.Root())
// If someone legitimately side-mines blocks, they would still be imported as usual. However,
// we cannot risk writing unverified blocks to disk when they obviously target the pruning
// mechanism.
return it.index, nil, nil, errors.New("sidechain ghost-state attack")
}
}
if externTd == nil {
externTd = bc.GetTd(block.ParentHash(), block.NumberU64()-1)
}
externTd = new(big.Int).Add(externTd, block.Difficulty())
if !bc.HasBlock(block.Hash(), block.NumberU64()) {
start := time.Now()
if err := bc.WriteBlockWithoutState(block, externTd); err != nil {
return it.index, nil, nil, err
}
log.Debug("Injected sidechain block", "number", block.Number(), "hash", block.Hash(),
"diff", block.Difficulty(), "elapsed", common.PrettyDuration(time.Since(start)),
"txs", len(block.Transactions()), "gas", block.GasUsed(), "uncles", len(block.Uncles()),
"root", block.Root())
}
}
// At this point, we've written all sidechain blocks to database. Loop ended
// either on some other error or all were processed. If there was some other
// error, we can ignore the rest of those blocks.
//
// If the externTd was larger than our local TD, we now need to reimport the previous
// blocks to regenerate the required state
localTd := bc.GetTd(bc.CurrentBlock().Hash(), current)
if localTd.Cmp(externTd) > 0 {
log.Info("Sidechain written to disk", "start", it.first().NumberU64(), "end", it.previous().NumberU64(), "sidetd", externTd, "localtd", localTd)
return it.index, nil, nil, err
}
// Gather all the sidechain hashes (full blocks may be memory heavy)
var (
hashes []common.Hash
numbers []uint64
)
parent := bc.GetHeader(it.previous().Hash(), it.previous().NumberU64())
for parent != nil && !bc.HasState(parent.Root) {
hashes = append(hashes, parent.Hash())
numbers = append(numbers, parent.Number.Uint64())
parent = bc.GetHeader(parent.ParentHash, parent.Number.Uint64()-1)
}
if parent == nil {
return it.index, nil, nil, errors.New("missing parent")
}
// Import all the pruned blocks to make the state available
var (
blocks []*types.Block
memory common.StorageSize
)
for i := len(hashes) - 1; i >= 0; i-- {
// Append the next block to our batch
block := bc.GetBlock(hashes[i], numbers[i])
blocks = append(blocks, block)
memory += block.Size()
// If memory use grew too large, import and continue. Sadly we need to discard
// all raised events and logs from notifications since we're too heavy on the
// memory here.
if len(blocks) >= 2048 || memory > 64*1024*1024 {
log.Info("Importing heavy sidechain segment", "blocks", len(blocks), "start", blocks[0].NumberU64(), "end", block.NumberU64())
if _, _, _, err := bc.insertChain(blocks, false); err != nil {
return 0, nil, nil, err
}
blocks, memory = blocks[:0], 0
// If the chain is terminating, stop processing blocks
if atomic.LoadInt32(&bc.procInterrupt) == 1 {
log.Debug("Premature abort during blocks processing")
return 0, nil, nil, nil
}
}
}
if len(blocks) > 0 {
log.Info("Importing sidechain segment", "start", blocks[0].NumberU64(), "end", blocks[len(blocks)-1].NumberU64())
return bc.insertChain(blocks, false)
}
return 0, nil, nil, nil
}
// reorg takes two blocks, an old chain and a new chain and will reconstruct the
// blocks and inserts them to be part of the new canonical chain and accumulates
// potential missing transactions and post an event about them.
func (bc *BlockChain) reorg(oldBlock, newBlock *types.Block) error {
var (
newChain types.Blocks
oldChain types.Blocks
commonBlock *types.Block
deletedTxs types.Transactions
addedTxs types.Transactions
deletedLogs []*types.Log
rebirthLogs []*types.Log
// collectLogs collects the logs that were generated during the
// processing of the block that corresponds with the given hash.
// These logs are later announced as deleted or reborn
collectLogs = func(hash common.Hash, removed bool) {
number := bc.hc.GetBlockNumber(hash)
if number == nil {
return
}
receipts := rawdb.ReadReceipts(bc.db, hash, *number)
for _, receipt := range receipts {
for _, log := range receipt.Logs {
l := *log
if removed {
l.Removed = true
deletedLogs = append(deletedLogs, &l)
} else {
rebirthLogs = append(rebirthLogs, &l)
}
}
}
}
)
// Reduce the longer chain to the same number as the shorter one
if oldBlock.NumberU64() > newBlock.NumberU64() {
// Old chain is longer, gather all transactions and logs as deleted ones
for ; oldBlock != nil && oldBlock.NumberU64() != newBlock.NumberU64(); oldBlock = bc.GetBlock(oldBlock.ParentHash(), oldBlock.NumberU64()-1) {
oldChain = append(oldChain, oldBlock)
deletedTxs = append(deletedTxs, oldBlock.Transactions()...)
collectLogs(oldBlock.Hash(), true)
}
} else {
// New chain is longer, stash all blocks away for subsequent insertion
for ; newBlock != nil && newBlock.NumberU64() != oldBlock.NumberU64(); newBlock = bc.GetBlock(newBlock.ParentHash(), newBlock.NumberU64()-1) {
newChain = append(newChain, newBlock)
}
}
if oldBlock == nil {
return fmt.Errorf("invalid old chain")
}
if newBlock == nil {
return fmt.Errorf("invalid new chain")
}
// Both sides of the reorg are at the same number, reduce both until the common
// ancestor is found
for {
// If the common ancestor was found, bail out
if oldBlock.Hash() == newBlock.Hash() {
commonBlock = oldBlock
break
}
// Remove an old block as well as stash away a new block
oldChain = append(oldChain, oldBlock)
deletedTxs = append(deletedTxs, oldBlock.Transactions()...)
collectLogs(oldBlock.Hash(), true)
newChain = append(newChain, newBlock)
// Step back with both chains
oldBlock = bc.GetBlock(oldBlock.ParentHash(), oldBlock.NumberU64()-1)
if oldBlock == nil {
return fmt.Errorf("invalid old chain")
}
newBlock = bc.GetBlock(newBlock.ParentHash(), newBlock.NumberU64()-1)
if newBlock == nil {
return fmt.Errorf("invalid new chain")
}
}
// Ensure the user sees large reorgs
if len(oldChain) > 0 && len(newChain) > 0 {
logFn := log.Debug
if len(oldChain) > 63 {
logFn = log.Warn
}
logFn("Chain split detected", "number", commonBlock.Number(), "hash", commonBlock.Hash(),
"drop", len(oldChain), "dropfrom", oldChain[0].Hash(), "add", len(newChain), "addfrom", newChain[0].Hash())
} else {
log.Error("Impossible reorg, please file an issue", "oldnum", oldBlock.Number(), "oldhash", oldBlock.Hash(), "newnum", newBlock.Number(), "newhash", newBlock.Hash())
}
// Insert the new chain, taking care of the proper incremental order
for i := len(newChain) - 1; i >= 0; i-- {
// Insert the block in the canonical way, re-writing history
bc.insert(newChain[i])
// Collect reborn logs due to chain reorg (except head block (reverse order))
if i != 0 {
collectLogs(newChain[i].Hash(), false)
}
// Write lookup entries for hash based transaction/receipt searches
rawdb.WriteTxLookupEntries(bc.db, newChain[i])
addedTxs = append(addedTxs, newChain[i].Transactions()...)
}
// When transactions get deleted from the database, the receipts that were
// created in the fork must also be deleted
batch := bc.db.NewBatch()
for _, tx := range types.TxDifference(deletedTxs, addedTxs) {
rawdb.DeleteTxLookupEntry(batch, tx.Hash())
}
batch.Write()
// If any logs need to be fired, do it now. In theory we could avoid creating
// this goroutine if there are no events to fire, but realistcally that only
// ever happens if we're reorging empty blocks, which will only happen on idle
// networks where performance is not an issue either way.
//
// TODO(karalabe): Can we get rid of the goroutine somehow to guarantee correct
// event ordering?
go func() {
if len(deletedLogs) > 0 {
bc.rmLogsFeed.Send(RemovedLogsEvent{deletedLogs})
}
if len(rebirthLogs) > 0 {
bc.logsFeed.Send(rebirthLogs)
}
if len(oldChain) > 0 {
for _, block := range oldChain {
bc.chainSideFeed.Send(ChainSideEvent{Block: block})
}
}
}()
return nil
}
// PostChainEvents iterates over the events generated by a chain insertion and
// posts them into the event feed.
// TODO: Should not expose PostChainEvents. The chain events should be posted in WriteBlock.
func (bc *BlockChain) PostChainEvents(events []interface{}, logs []*types.Log) {
// post event logs for further processing
if logs != nil {
bc.logsFeed.Send(logs)
}
for _, event := range events {
switch ev := event.(type) {
case ChainEvent:
bc.chainFeed.Send(ev)
case ChainHeadEvent:
bc.chainHeadFeed.Send(ev)
case ChainSideEvent:
bc.chainSideFeed.Send(ev)
}
}
}
func (bc *BlockChain) update() {
futureTimer := time.NewTicker(5 * time.Second)
defer futureTimer.Stop()
for {
select {
case <-futureTimer.C:
bc.procFutureBlocks()
case <-bc.quit:
return
}
}
}
// BadBlocks returns a list of the last 'bad blocks' that the client has seen on the network
func (bc *BlockChain) BadBlocks() []*types.Block {
blocks := make([]*types.Block, 0, bc.badBlocks.Len())
for _, hash := range bc.badBlocks.Keys() {
if blk, exist := bc.badBlocks.Peek(hash); exist {
block := blk.(*types.Block)
blocks = append(blocks, block)
}
}
return blocks
}
// addBadBlock adds a bad block to the bad-block LRU cache
func (bc *BlockChain) addBadBlock(block *types.Block) {
bc.badBlocks.Add(block.Hash(), block)
}
// reportBlock logs a bad block error.
func (bc *BlockChain) reportBlock(block *types.Block, receipts types.Receipts, err error) {
bc.addBadBlock(block)
var receiptString string
for i, receipt := range receipts {
receiptString += fmt.Sprintf("\t %d: cumulative: %v gas: %v contract: %v status: %v tx: %v logs: %v bloom: %x state: %x\n",
i, receipt.CumulativeGasUsed, receipt.GasUsed, receipt.ContractAddress.Hex(),
receipt.Status, receipt.TxHash.Hex(), receipt.Logs, receipt.Bloom, receipt.PostState)
}
log.Error(fmt.Sprintf(`
########## BAD BLOCK #########
Chain config: %v
Number: %v
Hash: 0x%x
%v
Error: %v
##############################
`, bc.chainConfig, block.Number(), block.Hash(), receiptString, err))
}
// InsertHeaderChain attempts to insert the given header chain in to the local
// chain, possibly creating a reorg. If an error is returned, it will return the
// index number of the failing header as well an error describing what went wrong.
//
// The verify parameter can be used to fine tune whether nonce verification
// should be done or not. The reason behind the optional check is because some
// of the header retrieval mechanisms already need to verify nonces, as well as
// because nonces can be verified sparsely, not needing to check each.
func (bc *BlockChain) InsertHeaderChain(chain []*types.Header, checkFreq int) (int, error) {
start := time.Now()
if i, err := bc.hc.ValidateHeaderChain(chain, checkFreq); err != nil {
return i, err
}
// Make sure only one thread manipulates the chain at once
bc.chainmu.Lock()
defer bc.chainmu.Unlock()
bc.wg.Add(1)
defer bc.wg.Done()
whFunc := func(header *types.Header) error {
bc.mu.Lock()
defer bc.mu.Unlock()
_, err := bc.hc.WriteHeader(header)
return err
}
return bc.hc.InsertHeaderChain(chain, whFunc, start)
}
// writeHeader writes a header into the local chain, given that its parent is
// already known. If the total difficulty of the newly inserted header becomes
// greater than the current known TD, the canonical chain is re-routed.
//
// Note: This method is not concurrent-safe with inserting blocks simultaneously
// into the chain, as side effects caused by reorganisations cannot be emulated
// without the real blocks. Hence, writing headers directly should only be done
// in two scenarios: pure-header mode of operation (light clients), or properly
// separated header/block phases (non-archive clients).
func (bc *BlockChain) writeHeader(header *types.Header) error {
bc.wg.Add(1)
defer bc.wg.Done()
bc.mu.Lock()
defer bc.mu.Unlock()
_, err := bc.hc.WriteHeader(header)
return err
}
// CurrentHeader retrieves the current head header of the canonical chain. The
// header is retrieved from the HeaderChain's internal cache.
func (bc *BlockChain) CurrentHeader() *types.Header {
return bc.hc.CurrentHeader()
}
// GetTd retrieves a block's total difficulty in the canonical chain from the
// database by hash and number, caching it if found.
func (bc *BlockChain) GetTd(hash common.Hash, number uint64) *big.Int {
return bc.hc.GetTd(hash, number)
}
// GetTdByHash retrieves a block's total difficulty in the canonical chain from the
// database by hash, caching it if found.
func (bc *BlockChain) GetTdByHash(hash common.Hash) *big.Int {
return bc.hc.GetTdByHash(hash)
}
// GetHeader retrieves a block header from the database by hash and number,
// caching it if found.
func (bc *BlockChain) GetHeader(hash common.Hash, number uint64) *types.Header {
return bc.hc.GetHeader(hash, number)
}
// GetHeaderByHash retrieves a block header from the database by hash, caching it if
// found.
func (bc *BlockChain) GetHeaderByHash(hash common.Hash) *types.Header {
return bc.hc.GetHeaderByHash(hash)
}
// HasHeader checks if a block header is present in the database or not, caching
// it if present.
func (bc *BlockChain) HasHeader(hash common.Hash, number uint64) bool {
return bc.hc.HasHeader(hash, number)
}
// GetBlockHashesFromHash retrieves a number of block hashes starting at a given
// hash, fetching towards the genesis block.
func (bc *BlockChain) GetBlockHashesFromHash(hash common.Hash, max uint64) []common.Hash {
return bc.hc.GetBlockHashesFromHash(hash, max)
}
// GetAncestor retrieves the Nth ancestor of a given block. It assumes that either the given block or
// a close ancestor of it is canonical. maxNonCanonical points to a downwards counter limiting the
// number of blocks to be individually checked before we reach the canonical chain.
//
// Note: ancestor == 0 returns the same block, 1 returns its parent and so on.
func (bc *BlockChain) GetAncestor(hash common.Hash, number, ancestor uint64, maxNonCanonical *uint64) (common.Hash, uint64) {
bc.chainmu.Lock()
defer bc.chainmu.Unlock()
return bc.hc.GetAncestor(hash, number, ancestor, maxNonCanonical)
}
// GetHeaderByNumber retrieves a block header from the database by number,
// caching it (associated with its hash) if found.
func (bc *BlockChain) GetHeaderByNumber(number uint64) *types.Header {
return bc.hc.GetHeaderByNumber(number)
}
// Config retrieves the blockchain's chain configuration.
func (bc *BlockChain) Config() *params.ChainConfig { return bc.chainConfig }
// Engine retrieves the blockchain's consensus engine.
func (bc *BlockChain) Engine() consensus.Engine { return bc.engine }
// SubscribeRemovedLogsEvent registers a subscription of RemovedLogsEvent.
func (bc *BlockChain) SubscribeRemovedLogsEvent(ch chan<- RemovedLogsEvent) event.Subscription {
return bc.scope.Track(bc.rmLogsFeed.Subscribe(ch))
}
// SubscribeChainEvent registers a subscription of ChainEvent.
func (bc *BlockChain) SubscribeChainEvent(ch chan<- ChainEvent) event.Subscription {
return bc.scope.Track(bc.chainFeed.Subscribe(ch))
}
// SubscribeChainHeadEvent registers a subscription of ChainHeadEvent.
func (bc *BlockChain) SubscribeChainHeadEvent(ch chan<- ChainHeadEvent) event.Subscription {
return bc.scope.Track(bc.chainHeadFeed.Subscribe(ch))
}
// SubscribeChainSideEvent registers a subscription of ChainSideEvent.
func (bc *BlockChain) SubscribeChainSideEvent(ch chan<- ChainSideEvent) event.Subscription {
return bc.scope.Track(bc.chainSideFeed.Subscribe(ch))
}
// SubscribeLogsEvent registers a subscription of []*types.Log.
func (bc *BlockChain) SubscribeLogsEvent(ch chan<- []*types.Log) event.Subscription {
return bc.scope.Track(bc.logsFeed.Subscribe(ch))
}
