Merge pull request #2081 from zsfelfoldi/light-chain

core: create a header chain structure shared by full and light clients
This commit is contained in:
Jeffrey Wilcke 2016-03-10 15:16:11 +01:00
commit 8b58cd0190
4 changed files with 575 additions and 345 deletions

View File

@ -18,11 +18,9 @@
package core
import (
crand "crypto/rand"
"errors"
"fmt"
"io"
"math"
"math/big"
mrand "math/rand"
"runtime"
@ -82,24 +80,22 @@ const (
// included in the canonical one where as GetBlockByNumber always represents the
// canonical chain.
type BlockChain struct {
hc *HeaderChain
chainDb ethdb.Database
eventMux *event.TypeMux
genesisBlock *types.Block
// Last known total difficulty
mu sync.RWMutex
chainmu sync.RWMutex
tsmu sync.RWMutex
procmu sync.RWMutex
checkpoint int // checkpoint counts towards the new checkpoint
currentHeader *types.Header // Current head of the header chain (may be above the block chain!)
currentBlock *types.Block // Current head of the block chain
currentFastBlock *types.Block // Current head of the fast-sync chain (may be above the block chain!)
checkpoint int // checkpoint counts towards the new checkpoint
currentBlock *types.Block // Current head of the block chain
currentFastBlock *types.Block // Current head of the fast-sync chain (may be above the block chain!)
headerCache *lru.Cache // Cache for the most recent block headers
bodyCache *lru.Cache // Cache for the most recent block bodies
bodyRLPCache *lru.Cache // Cache for the most recent block bodies in RLP encoded format
tdCache *lru.Cache // Cache for the most recent block total difficulties
blockCache *lru.Cache // Cache for the most recent entire blocks
futureBlocks *lru.Cache // future blocks are blocks added for later processing
@ -110,7 +106,6 @@ type BlockChain struct {
wg sync.WaitGroup
pow pow.PoW
rand *mrand.Rand
processor Processor
validator Validator
}
@ -119,10 +114,8 @@ type BlockChain struct {
// available in the database. It initialiser the default Ethereum Validator and
// Processor.
func NewBlockChain(chainDb ethdb.Database, pow pow.PoW, mux *event.TypeMux) (*BlockChain, error) {
headerCache, _ := lru.New(headerCacheLimit)
bodyCache, _ := lru.New(bodyCacheLimit)
bodyRLPCache, _ := lru.New(bodyCacheLimit)
tdCache, _ := lru.New(tdCacheLimit)
blockCache, _ := lru.New(blockCacheLimit)
futureBlocks, _ := lru.New(maxFutureBlocks)
@ -130,22 +123,21 @@ func NewBlockChain(chainDb ethdb.Database, pow pow.PoW, mux *event.TypeMux) (*Bl
chainDb: chainDb,
eventMux: mux,
quit: make(chan struct{}),
headerCache: headerCache,
bodyCache: bodyCache,
bodyRLPCache: bodyRLPCache,
tdCache: tdCache,
blockCache: blockCache,
futureBlocks: futureBlocks,
pow: pow,
}
// Seed a fast but crypto originating random generator
seed, err := crand.Int(crand.Reader, big.NewInt(math.MaxInt64))
bc.SetValidator(NewBlockValidator(bc, pow))
bc.SetProcessor(NewStateProcessor(bc))
gv := func() HeaderValidator { return bc.Validator() }
var err error
bc.hc, err = NewHeaderChain(chainDb, gv, bc.getProcInterrupt)
if err != nil {
return nil, err
}
bc.rand = mrand.New(mrand.NewSource(seed.Int64()))
bc.SetValidator(NewBlockValidator(bc, pow))
bc.SetProcessor(NewStateProcessor(bc))
bc.genesisBlock = bc.GetBlockByNumber(0)
if bc.genesisBlock == nil {
@ -171,6 +163,10 @@ func NewBlockChain(chainDb ethdb.Database, pow pow.PoW, mux *event.TypeMux) (*Bl
return bc, nil
}
func (self *BlockChain) getProcInterrupt() bool {
return atomic.LoadInt32(&self.procInterrupt) == 1
}
// loadLastState loads the last known chain state from the database. This method
// assumes that the chain manager mutex is held.
func (self *BlockChain) loadLastState() error {
@ -189,12 +185,13 @@ func (self *BlockChain) loadLastState() error {
}
}
// Restore the last known head header
self.currentHeader = self.currentBlock.Header()
currentHeader := self.currentBlock.Header()
if head := GetHeadHeaderHash(self.chainDb); head != (common.Hash{}) {
if header := self.GetHeader(head); header != nil {
self.currentHeader = header
currentHeader = header
}
}
self.hc.SetCurrentHeader(currentHeader)
// Restore the last known head fast block
self.currentFastBlock = self.currentBlock
if head := GetHeadFastBlockHash(self.chainDb); head != (common.Hash{}) {
@ -203,11 +200,11 @@ func (self *BlockChain) loadLastState() error {
}
}
// Issue a status log and return
headerTd := self.GetTd(self.currentHeader.Hash())
headerTd := self.GetTd(self.hc.CurrentHeader().Hash())
blockTd := self.GetTd(self.currentBlock.Hash())
fastTd := self.GetTd(self.currentFastBlock.Hash())
glog.V(logger.Info).Infof("Last header: #%d [%x…] TD=%v", self.currentHeader.Number, self.currentHeader.Hash().Bytes()[:4], headerTd)
glog.V(logger.Info).Infof("Last header: #%d [%x…] TD=%v", self.hc.CurrentHeader().Number, self.hc.CurrentHeader().Hash().Bytes()[:4], headerTd)
glog.V(logger.Info).Infof("Last block: #%d [%x…] TD=%v", self.currentBlock.Number(), self.currentBlock.Hash().Bytes()[:4], blockTd)
glog.V(logger.Info).Infof("Fast block: #%d [%x…] TD=%v", self.currentFastBlock.Number(), self.currentFastBlock.Hash().Bytes()[:4], fastTd)
@ -222,71 +219,35 @@ func (bc *BlockChain) SetHead(head uint64) {
bc.mu.Lock()
defer bc.mu.Unlock()
// Figure out the highest known canonical headers and/or blocks
height := uint64(0)
if bc.currentHeader != nil {
if hh := bc.currentHeader.Number.Uint64(); hh > height {
height = hh
}
}
if bc.currentBlock != nil {
if bh := bc.currentBlock.NumberU64(); bh > height {
height = bh
}
}
if bc.currentFastBlock != nil {
if fbh := bc.currentFastBlock.NumberU64(); fbh > height {
height = fbh
}
}
// Gather all the hashes that need deletion
drop := make(map[common.Hash]struct{})
for bc.currentHeader != nil && bc.currentHeader.Number.Uint64() > head {
drop[bc.currentHeader.Hash()] = struct{}{}
bc.currentHeader = bc.GetHeader(bc.currentHeader.ParentHash)
}
for bc.currentBlock != nil && bc.currentBlock.NumberU64() > head {
drop[bc.currentBlock.Hash()] = struct{}{}
bc.currentBlock = bc.GetBlock(bc.currentBlock.ParentHash())
}
for bc.currentFastBlock != nil && bc.currentFastBlock.NumberU64() > head {
drop[bc.currentFastBlock.Hash()] = struct{}{}
bc.currentFastBlock = bc.GetBlock(bc.currentFastBlock.ParentHash())
}
// Roll back the canonical chain numbering
for i := height; i > head; i-- {
DeleteCanonicalHash(bc.chainDb, i)
}
// Delete everything found by the above rewind
for hash, _ := range drop {
DeleteHeader(bc.chainDb, hash)
delFn := func(hash common.Hash) {
DeleteBody(bc.chainDb, hash)
DeleteTd(bc.chainDb, hash)
}
bc.hc.SetHead(head, delFn)
// Clear out any stale content from the caches
bc.headerCache.Purge()
bc.bodyCache.Purge()
bc.bodyRLPCache.Purge()
bc.blockCache.Purge()
bc.futureBlocks.Purge()
// Update all computed fields to the new head
if bc.currentBlock != nil && bc.hc.CurrentHeader().Number.Uint64() < bc.currentBlock.NumberU64() {
bc.currentBlock = bc.GetBlock(bc.hc.CurrentHeader().Hash())
}
if bc.currentFastBlock != nil && bc.hc.CurrentHeader().Number.Uint64() < bc.currentFastBlock.NumberU64() {
bc.currentFastBlock = bc.GetBlock(bc.hc.CurrentHeader().Hash())
}
if bc.currentBlock == nil {
bc.currentBlock = bc.genesisBlock
}
if bc.currentHeader == nil {
bc.currentHeader = bc.genesisBlock.Header()
}
if bc.currentFastBlock == nil {
bc.currentFastBlock = bc.genesisBlock
}
if err := WriteHeadBlockHash(bc.chainDb, bc.currentBlock.Hash()); err != nil {
glog.Fatalf("failed to reset head block hash: %v", err)
}
if err := WriteHeadHeaderHash(bc.chainDb, bc.currentHeader.Hash()); err != nil {
glog.Fatalf("failed to reset head header hash: %v", err)
}
if err := WriteHeadFastBlockHash(bc.chainDb, bc.currentFastBlock.Hash()); err != nil {
glog.Fatalf("failed to reset head fast block hash: %v", err)
}
@ -329,15 +290,6 @@ func (self *BlockChain) LastBlockHash() common.Hash {
return self.currentBlock.Hash()
}
// CurrentHeader retrieves the current head header of the canonical chain. The
// header is retrieved from the blockchain's internal cache.
func (self *BlockChain) CurrentHeader() *types.Header {
self.mu.RLock()
defer self.mu.RUnlock()
return self.currentHeader
}
// CurrentBlock retrieves the current head block of the canonical chain. The
// block is retrieved from the blockchain's internal cache.
func (self *BlockChain) CurrentBlock() *types.Block {
@ -425,7 +377,8 @@ func (bc *BlockChain) ResetWithGenesisBlock(genesis *types.Block) {
bc.genesisBlock = genesis
bc.insert(bc.genesisBlock)
bc.currentBlock = bc.genesisBlock
bc.currentHeader = bc.genesisBlock.Header()
bc.hc.SetGenesis(bc.genesisBlock.Header())
bc.hc.SetCurrentHeader(bc.genesisBlock.Header())
bc.currentFastBlock = bc.genesisBlock
}
@ -483,10 +436,7 @@ func (bc *BlockChain) insert(block *types.Block) {
// If the block is better than out head or is on a different chain, force update heads
if updateHeads {
if err := WriteHeadHeaderHash(bc.chainDb, block.Hash()); err != nil {
glog.Fatalf("failed to insert head header hash: %v", err)
}
bc.currentHeader = block.Header()
bc.hc.SetCurrentHeader(block.Header())
if err := WriteHeadFastBlockHash(bc.chainDb, block.Hash()); err != nil {
glog.Fatalf("failed to insert head fast block hash: %v", err)
@ -500,38 +450,6 @@ func (bc *BlockChain) Genesis() *types.Block {
return bc.genesisBlock
}
// HasHeader checks if a block header is present in the database or not, caching
// it if present.
func (bc *BlockChain) HasHeader(hash common.Hash) bool {
return bc.GetHeader(hash) != nil
}
// GetHeader retrieves a block header from the database by hash, caching it if
// found.
func (self *BlockChain) GetHeader(hash common.Hash) *types.Header {
// Short circuit if the header's already in the cache, retrieve otherwise
if header, ok := self.headerCache.Get(hash); ok {
return header.(*types.Header)
}
header := GetHeader(self.chainDb, hash)
if header == nil {
return nil
}
// Cache the found header for next time and return
self.headerCache.Add(header.Hash(), header)
return header
}
// GetHeaderByNumber retrieves a block header from the database by number,
// caching it (associated with its hash) if found.
func (self *BlockChain) GetHeaderByNumber(number uint64) *types.Header {
hash := GetCanonicalHash(self.chainDb, number)
if hash == (common.Hash{}) {
return nil
}
return self.GetHeader(hash)
}
// GetBody retrieves a block body (transactions and uncles) from the database by
// hash, caching it if found.
func (self *BlockChain) GetBody(hash common.Hash) *types.Body {
@ -565,22 +483,6 @@ func (self *BlockChain) GetBodyRLP(hash common.Hash) rlp.RawValue {
return body
}
// GetTd retrieves a block's total difficulty in the canonical chain from the
// database by hash, caching it if found.
func (self *BlockChain) GetTd(hash common.Hash) *big.Int {
// Short circuit if the td's already in the cache, retrieve otherwise
if cached, ok := self.tdCache.Get(hash); ok {
return cached.(*big.Int)
}
td := GetTd(self.chainDb, hash)
if td == nil {
return nil
}
// Cache the found body for next time and return
self.tdCache.Add(hash, td)
return td
}
// HasBlock checks if a block is fully present in the database or not, caching
// it if present.
func (bc *BlockChain) HasBlock(hash common.Hash) bool {
@ -625,28 +527,6 @@ func (self *BlockChain) GetBlockByNumber(number uint64) *types.Block {
return self.GetBlock(hash)
}
// GetBlockHashesFromHash retrieves a number of block hashes starting at a given
// hash, fetching towards the genesis block.
func (self *BlockChain) GetBlockHashesFromHash(hash common.Hash, max uint64) []common.Hash {
// Get the origin header from which to fetch
header := self.GetHeader(hash)
if header == nil {
return nil
}
// Iterate the headers until enough is collected or the genesis reached
chain := make([]common.Hash, 0, max)
for i := uint64(0); i < max; i++ {
if header = self.GetHeader(header.ParentHash); header == nil {
break
}
chain = append(chain, header.Hash())
if header.Number.Cmp(common.Big0) == 0 {
break
}
}
return chain
}
// [deprecated by eth/62]
// GetBlocksFromHash returns the block corresponding to hash and up to n-1 ancestors.
func (self *BlockChain) GetBlocksFromHash(hash common.Hash, n int) (blocks []*types.Block) {
@ -698,195 +578,15 @@ func (self *BlockChain) procFutureBlocks() {
}
}
type writeStatus byte
type WriteStatus byte
const (
NonStatTy writeStatus = iota
NonStatTy WriteStatus = iota
CanonStatTy
SplitStatTy
SideStatTy
)
// 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 (self *BlockChain) writeHeader(header *types.Header) error {
self.wg.Add(1)
defer self.wg.Done()
// Calculate the total difficulty of the header
ptd := self.GetTd(header.ParentHash)
if ptd == nil {
return ParentError(header.ParentHash)
}
localTd := self.GetTd(self.currentHeader.Hash())
externTd := new(big.Int).Add(header.Difficulty, ptd)
// Make sure no inconsistent state is leaked during insertion
self.mu.Lock()
defer self.mu.Unlock()
// 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
if externTd.Cmp(localTd) > 0 || (externTd.Cmp(localTd) == 0 && mrand.Float64() < 0.5) {
// Delete any canonical number assignments above the new head
for i := header.Number.Uint64() + 1; GetCanonicalHash(self.chainDb, i) != (common.Hash{}); i++ {
DeleteCanonicalHash(self.chainDb, i)
}
// Overwrite any stale canonical number assignments
head := self.GetHeader(header.ParentHash)
for GetCanonicalHash(self.chainDb, head.Number.Uint64()) != head.Hash() {
WriteCanonicalHash(self.chainDb, head.Hash(), head.Number.Uint64())
head = self.GetHeader(head.ParentHash)
}
// Extend the canonical chain with the new header
if err := WriteCanonicalHash(self.chainDb, header.Hash(), header.Number.Uint64()); err != nil {
glog.Fatalf("failed to insert header number: %v", err)
}
if err := WriteHeadHeaderHash(self.chainDb, header.Hash()); err != nil {
glog.Fatalf("failed to insert head header hash: %v", err)
}
self.currentHeader = types.CopyHeader(header)
}
// Irrelevant of the canonical status, write the header itself to the database
if err := WriteTd(self.chainDb, header.Hash(), externTd); err != nil {
glog.Fatalf("failed to write header total difficulty: %v", err)
}
if err := WriteHeader(self.chainDb, header); err != nil {
glog.Fatalf("filed to write header contents: %v", err)
}
return nil
}
// 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 verfy nonces, as well as
// because nonces can be verified sparsely, not needing to check each.
func (self *BlockChain) InsertHeaderChain(chain []*types.Header, checkFreq int) (int, error) {
self.wg.Add(1)
defer self.wg.Done()
// Make sure only one thread manipulates the chain at once
self.chainmu.Lock()
defer self.chainmu.Unlock()
// Collect some import statistics to report on
stats := struct{ processed, ignored int }{}
start := time.Now()
// Generate the list of headers that should be POW verified
verify := make([]bool, len(chain))
for i := 0; i < len(verify)/checkFreq; i++ {
index := i*checkFreq + self.rand.Intn(checkFreq)
if index >= len(verify) {
index = len(verify) - 1
}
verify[index] = true
}
verify[len(verify)-1] = true // Last should always be verified to avoid junk
// Create the header verification task queue and worker functions
tasks := make(chan int, len(chain))
for i := 0; i < len(chain); i++ {
tasks <- i
}
close(tasks)
errs, failed := make([]error, len(tasks)), int32(0)
process := func(worker int) {
for index := range tasks {
header, hash := chain[index], chain[index].Hash()
// Short circuit insertion if shutting down or processing failed
if atomic.LoadInt32(&self.procInterrupt) == 1 {
return
}
if atomic.LoadInt32(&failed) > 0 {
return
}
// Short circuit if the header is bad or already known
if BadHashes[hash] {
errs[index] = BadHashError(hash)
atomic.AddInt32(&failed, 1)
return
}
if self.HasHeader(hash) {
continue
}
// Verify that the header honors the chain parameters
checkPow := verify[index]
var err error
if index == 0 {
err = self.Validator().ValidateHeader(header, self.GetHeader(header.ParentHash), checkPow)
} else {
err = self.Validator().ValidateHeader(header, chain[index-1], checkPow)
}
if err != nil {
errs[index] = err
atomic.AddInt32(&failed, 1)
return
}
}
}
// Start as many worker threads as goroutines allowed
pending := new(sync.WaitGroup)
for i := 0; i < runtime.GOMAXPROCS(0); i++ {
pending.Add(1)
go func(id int) {
defer pending.Done()
process(id)
}(i)
}
pending.Wait()
// If anything failed, report
if failed > 0 {
for i, err := range errs {
if err != nil {
return i, err
}
}
}
// All headers passed verification, import them into the database
for i, header := range chain {
// Short circuit insertion if shutting down
if atomic.LoadInt32(&self.procInterrupt) == 1 {
glog.V(logger.Debug).Infoln("premature abort during header chain processing")
break
}
hash := header.Hash()
// If the header's already known, skip it, otherwise store
if self.HasHeader(hash) {
stats.ignored++
continue
}
if err := self.writeHeader(header); err != nil {
return i, err
}
stats.processed++
}
// Report some public statistics so the user has a clue what's going on
first, last := chain[0], chain[len(chain)-1]
glog.V(logger.Info).Infof("imported %d header(s) (%d ignored) in %v. #%v [%x… / %x…]", stats.processed, stats.ignored,
time.Since(start), last.Number, first.Hash().Bytes()[:4], last.Hash().Bytes()[:4])
return 0, nil
}
// Rollback is designed to remove a chain of links from the database that aren't
// certain enough to be valid.
func (self *BlockChain) Rollback(chain []common.Hash) {
@ -896,9 +596,8 @@ func (self *BlockChain) Rollback(chain []common.Hash) {
for i := len(chain) - 1; i >= 0; i-- {
hash := chain[i]
if self.currentHeader.Hash() == hash {
self.currentHeader = self.GetHeader(self.currentHeader.ParentHash)
WriteHeadHeaderHash(self.chainDb, self.currentHeader.Hash())
if self.hc.CurrentHeader().Hash() == hash {
self.hc.SetCurrentHeader(self.GetHeader(self.hc.CurrentHeader().ParentHash))
}
if self.currentFastBlock.Hash() == hash {
self.currentFastBlock = self.GetBlock(self.currentFastBlock.ParentHash())
@ -1055,7 +754,7 @@ func (self *BlockChain) InsertReceiptChain(blockChain types.Blocks, receiptChain
}
// WriteBlock writes the block to the chain.
func (self *BlockChain) WriteBlock(block *types.Block) (status writeStatus, err error) {
func (self *BlockChain) WriteBlock(block *types.Block) (status WriteStatus, err error) {
self.wg.Add(1)
defer self.wg.Done()
@ -1427,3 +1126,89 @@ func reportBlock(block *types.Block, err error) {
}
go ReportBlock(block, 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 verfy nonces, as well as
// because nonces can be verified sparsely, not needing to check each.
func (self *BlockChain) InsertHeaderChain(chain []*types.Header, checkFreq int) (int, error) {
// Make sure only one thread manipulates the chain at once
self.chainmu.Lock()
defer self.chainmu.Unlock()
self.wg.Add(1)
defer self.wg.Done()
whFunc := func(header *types.Header) error {
self.mu.Lock()
defer self.mu.Unlock()
_, err := self.hc.WriteHeader(header)
return err
}
return self.hc.InsertHeaderChain(chain, checkFreq, whFunc)
}
// 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 (self *BlockChain) writeHeader(header *types.Header) error {
self.wg.Add(1)
defer self.wg.Done()
self.mu.Lock()
defer self.mu.Unlock()
_, err := self.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 (self *BlockChain) CurrentHeader() *types.Header {
self.mu.RLock()
defer self.mu.RUnlock()
return self.hc.CurrentHeader()
}
// GetTd retrieves a block's total difficulty in the canonical chain from the
// database by hash, caching it if found.
func (self *BlockChain) GetTd(hash common.Hash) *big.Int {
return self.hc.GetTd(hash)
}
// GetHeader retrieves a block header from the database by hash, caching it if
// found.
func (self *BlockChain) GetHeader(hash common.Hash) *types.Header {
return self.hc.GetHeader(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) bool {
return bc.hc.HasHeader(hash)
}
// GetBlockHashesFromHash retrieves a number of block hashes starting at a given
// hash, fetching towards the genesis block.
func (self *BlockChain) GetBlockHashesFromHash(hash common.Hash, max uint64) []common.Hash {
return self.hc.GetBlockHashesFromHash(hash, max)
}
// GetHeaderByNumber retrieves a block header from the database by number,
// caching it (associated with its hash) if found.
func (self *BlockChain) GetHeaderByNumber(number uint64) *types.Header {
return self.hc.GetHeaderByNumber(number)
}

View File

@ -472,11 +472,16 @@ func makeBlockChainWithDiff(genesis *types.Block, d []int, seed byte) []*types.B
func chm(genesis *types.Block, db ethdb.Database) *BlockChain {
var eventMux event.TypeMux
bc := &BlockChain{chainDb: db, genesisBlock: genesis, eventMux: &eventMux, pow: FakePow{}, rand: rand.New(rand.NewSource(0))}
bc.headerCache, _ = lru.New(100)
bc := &BlockChain{
chainDb: db,
genesisBlock: genesis,
eventMux: &eventMux,
pow: FakePow{},
}
valFn := func() HeaderValidator { return bc.Validator() }
bc.hc, _ = NewHeaderChain(db, valFn, bc.getProcInterrupt)
bc.bodyCache, _ = lru.New(100)
bc.bodyRLPCache, _ = lru.New(100)
bc.tdCache, _ = lru.New(100)
bc.blockCache, _ = lru.New(100)
bc.futureBlocks, _ = lru.New(100)
bc.SetValidator(bproc{})

432
core/headerchain.go Normal file
View File

@ -0,0 +1,432 @@
// Copyright 2015 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
import (
crand "crypto/rand"
"math"
"math/big"
mrand "math/rand"
"runtime"
"sync"
"sync/atomic"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/logger"
"github.com/ethereum/go-ethereum/logger/glog"
"github.com/ethereum/go-ethereum/pow"
"github.com/hashicorp/golang-lru"
)
// HeaderChain implements the basic block header chain logic that is shared by
// core.BlockChain and light.LightChain. It is not usable in itself, only as
// a part of either structure.
// It is not thread safe either, the encapsulating chain structures should do
// the necessary mutex locking/unlocking.
type HeaderChain struct {
chainDb ethdb.Database
genesisHeader *types.Header
currentHeader *types.Header // Current head of the header chain (may be above the block chain!)
headerCache *lru.Cache // Cache for the most recent block headers
tdCache *lru.Cache // Cache for the most recent block total difficulties
procInterrupt func() bool
rand *mrand.Rand
getValidator getHeaderValidatorFn
}
// getHeaderValidatorFn returns a HeaderValidator interface
type getHeaderValidatorFn func() HeaderValidator
// NewHeaderChain creates a new HeaderChain structure.
// getValidator should return the parent's validator
// procInterrupt points to the parent's interrupt semaphore
// wg points to the parent's shutdown wait group
func NewHeaderChain(chainDb ethdb.Database, getValidator getHeaderValidatorFn, procInterrupt func() bool) (*HeaderChain, error) {
headerCache, _ := lru.New(headerCacheLimit)
tdCache, _ := lru.New(tdCacheLimit)
// Seed a fast but crypto originating random generator
seed, err := crand.Int(crand.Reader, big.NewInt(math.MaxInt64))
if err != nil {
return nil, err
}
hc := &HeaderChain{
chainDb: chainDb,
headerCache: headerCache,
tdCache: tdCache,
procInterrupt: procInterrupt,
rand: mrand.New(mrand.NewSource(seed.Int64())),
getValidator: getValidator,
}
hc.genesisHeader = hc.GetHeaderByNumber(0)
if hc.genesisHeader == nil {
genesisBlock, err := WriteDefaultGenesisBlock(chainDb)
if err != nil {
return nil, err
}
glog.V(logger.Info).Infoln("WARNING: Wrote default ethereum genesis block")
hc.genesisHeader = genesisBlock.Header()
}
hc.currentHeader = hc.genesisHeader
if head := GetHeadBlockHash(chainDb); head != (common.Hash{}) {
if chead := hc.GetHeader(head); chead != nil {
hc.currentHeader = chead
}
}
return hc, nil
}
// 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 (hc *HeaderChain) WriteHeader(header *types.Header) (status WriteStatus, err error) {
// Calculate the total difficulty of the header
ptd := hc.GetTd(header.ParentHash)
if ptd == nil {
return NonStatTy, ParentError(header.ParentHash)
}
localTd := hc.GetTd(hc.currentHeader.Hash())
externTd := new(big.Int).Add(header.Difficulty, ptd)
// 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
if externTd.Cmp(localTd) > 0 || (externTd.Cmp(localTd) == 0 && mrand.Float64() < 0.5) {
// Delete any canonical number assignments above the new head
for i := header.Number.Uint64() + 1; GetCanonicalHash(hc.chainDb, i) != (common.Hash{}); i++ {
DeleteCanonicalHash(hc.chainDb, i)
}
// Overwrite any stale canonical number assignments
head := hc.GetHeader(header.ParentHash)
for GetCanonicalHash(hc.chainDb, head.Number.Uint64()) != head.Hash() {
WriteCanonicalHash(hc.chainDb, head.Hash(), head.Number.Uint64())
head = hc.GetHeader(head.ParentHash)
}
// Extend the canonical chain with the new header
if err := WriteCanonicalHash(hc.chainDb, header.Hash(), header.Number.Uint64()); err != nil {
glog.Fatalf("failed to insert header number: %v", err)
}
if err := WriteHeadHeaderHash(hc.chainDb, header.Hash()); err != nil {
glog.Fatalf("failed to insert head header hash: %v", err)
}
hc.currentHeader = types.CopyHeader(header)
status = CanonStatTy
} else {
status = SideStatTy
}
// Irrelevant of the canonical status, write the header itself to the database
if err := WriteTd(hc.chainDb, header.Hash(), externTd); err != nil {
glog.Fatalf("failed to write header total difficulty: %v", err)
}
if err := WriteHeader(hc.chainDb, header); err != nil {
glog.Fatalf("failed to write header contents: %v", err)
}
return
}
// WhCallback is a callback function for inserting individual headers.
// A callback is used for two reasons: first, in a LightChain, status should be
// processed and light chain events sent, while in a BlockChain this is not
// necessary since chain events are sent after inserting blocks. Second, the
// header writes should be protected by the parent chain mutex individually.
type WhCallback func(*types.Header) error
// 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 verfy nonces, as well as
// because nonces can be verified sparsely, not needing to check each.
func (hc *HeaderChain) InsertHeaderChain(chain []*types.Header, checkFreq int, writeHeader WhCallback) (int, error) {
// Collect some import statistics to report on
stats := struct{ processed, ignored int }{}
start := time.Now()
// Generate the list of headers that should be POW verified
verify := make([]bool, len(chain))
for i := 0; i < len(verify)/checkFreq; i++ {
index := i*checkFreq + hc.rand.Intn(checkFreq)
if index >= len(verify) {
index = len(verify) - 1
}
verify[index] = true
}
verify[len(verify)-1] = true // Last should always be verified to avoid junk
// Create the header verification task queue and worker functions
tasks := make(chan int, len(chain))
for i := 0; i < len(chain); i++ {
tasks <- i
}
close(tasks)
errs, failed := make([]error, len(tasks)), int32(0)
process := func(worker int) {
for index := range tasks {
header, hash := chain[index], chain[index].Hash()
// Short circuit insertion if shutting down or processing failed
if hc.procInterrupt() {
return
}
if atomic.LoadInt32(&failed) > 0 {
return
}
// Short circuit if the header is bad or already known
if BadHashes[hash] {
errs[index] = BadHashError(hash)
atomic.AddInt32(&failed, 1)
return
}
if hc.HasHeader(hash) {
continue
}
// Verify that the header honors the chain parameters
checkPow := verify[index]
var err error
if index == 0 {
err = hc.getValidator().ValidateHeader(header, hc.GetHeader(header.ParentHash), checkPow)
} else {
err = hc.getValidator().ValidateHeader(header, chain[index-1], checkPow)
}
if err != nil {
errs[index] = err
atomic.AddInt32(&failed, 1)
return
}
}
}
// Start as many worker threads as goroutines allowed
pending := new(sync.WaitGroup)
for i := 0; i < runtime.GOMAXPROCS(0); i++ {
pending.Add(1)
go func(id int) {
defer pending.Done()
process(id)
}(i)
}
pending.Wait()
// If anything failed, report
if failed > 0 {
for i, err := range errs {
if err != nil {
return i, err
}
}
}
// All headers passed verification, import them into the database
for i, header := range chain {
// Short circuit insertion if shutting down
if hc.procInterrupt() {
glog.V(logger.Debug).Infoln("premature abort during header chain processing")
break
}
hash := header.Hash()
// If the header's already known, skip it, otherwise store
if hc.HasHeader(hash) {
stats.ignored++
continue
}
if err := writeHeader(header); err != nil {
return i, err
}
stats.processed++
}
// Report some public statistics so the user has a clue what's going on
first, last := chain[0], chain[len(chain)-1]
glog.V(logger.Info).Infof("imported %d header(s) (%d ignored) in %v. #%v [%x… / %x…]", stats.processed, stats.ignored,
time.Since(start), last.Number, first.Hash().Bytes()[:4], last.Hash().Bytes()[:4])
return 0, nil
}
// GetBlockHashesFromHash retrieves a number of block hashes starting at a given
// hash, fetching towards the genesis block.
func (hc *HeaderChain) GetBlockHashesFromHash(hash common.Hash, max uint64) []common.Hash {
// Get the origin header from which to fetch
header := hc.GetHeader(hash)
if header == nil {
return nil
}
// Iterate the headers until enough is collected or the genesis reached
chain := make([]common.Hash, 0, max)
for i := uint64(0); i < max; i++ {
if header = hc.GetHeader(header.ParentHash); header == nil {
break
}
chain = append(chain, header.Hash())
if header.Number.Cmp(common.Big0) == 0 {
break
}
}
return chain
}
// GetTd retrieves a block's total difficulty in the canonical chain from the
// database by hash, caching it if found.
func (hc *HeaderChain) GetTd(hash common.Hash) *big.Int {
// Short circuit if the td's already in the cache, retrieve otherwise
if cached, ok := hc.tdCache.Get(hash); ok {
return cached.(*big.Int)
}
td := GetTd(hc.chainDb, hash)
if td == nil {
return nil
}
// Cache the found body for next time and return
hc.tdCache.Add(hash, td)
return td
}
// GetHeader retrieves a block header from the database by hash, caching it if
// found.
func (hc *HeaderChain) GetHeader(hash common.Hash) *types.Header {
// Short circuit if the header's already in the cache, retrieve otherwise
if header, ok := hc.headerCache.Get(hash); ok {
return header.(*types.Header)
}
header := GetHeader(hc.chainDb, hash)
if header == nil {
return nil
}
// Cache the found header for next time and return
hc.headerCache.Add(header.Hash(), header)
return header
}
// HasHeader checks if a block header is present in the database or not, caching
// it if present.
func (hc *HeaderChain) HasHeader(hash common.Hash) bool {
return hc.GetHeader(hash) != nil
}
// GetHeaderByNumber retrieves a block header from the database by number,
// caching it (associated with its hash) if found.
func (hc *HeaderChain) GetHeaderByNumber(number uint64) *types.Header {
hash := GetCanonicalHash(hc.chainDb, number)
if hash == (common.Hash{}) {
return nil
}
return hc.GetHeader(hash)
}
// CurrentHeader retrieves the current head header of the canonical chain. The
// header is retrieved from the HeaderChain's internal cache.
func (hc *HeaderChain) CurrentHeader() *types.Header {
return hc.currentHeader
}
// SetCurrentHeader sets the current head header of the canonical chain.
func (hc *HeaderChain) SetCurrentHeader(head *types.Header) {
if err := WriteHeadHeaderHash(hc.chainDb, head.Hash()); err != nil {
glog.Fatalf("failed to insert head header hash: %v", err)
}
hc.currentHeader = head
}
// DeleteCallback is a callback function that is called by SetHead before
// each header is deleted.
type DeleteCallback func(common.Hash)
// SetHead rewinds the local chain to a new head. Everything above the new head
// will be deleted and the new one set.
func (hc *HeaderChain) SetHead(head uint64, delFn DeleteCallback) {
height := uint64(0)
if hc.currentHeader != nil {
height = hc.currentHeader.Number.Uint64()
}
for hc.currentHeader != nil && hc.currentHeader.Number.Uint64() > head {
hash := hc.currentHeader.Hash()
if delFn != nil {
delFn(hash)
}
DeleteHeader(hc.chainDb, hash)
DeleteTd(hc.chainDb, hash)
hc.currentHeader = hc.GetHeader(hc.currentHeader.ParentHash)
}
// Roll back the canonical chain numbering
for i := height; i > head; i-- {
DeleteCanonicalHash(hc.chainDb, i)
}
// Clear out any stale content from the caches
hc.headerCache.Purge()
hc.tdCache.Purge()
if hc.currentHeader == nil {
hc.currentHeader = hc.genesisHeader
}
if err := WriteHeadHeaderHash(hc.chainDb, hc.currentHeader.Hash()); err != nil {
glog.Fatalf("failed to reset head header hash: %v", err)
}
}
// SetGenesis sets a new genesis block header for the chain
func (hc *HeaderChain) SetGenesis(head *types.Header) {
hc.genesisHeader = head
}
// headerValidator is responsible for validating block headers
//
// headerValidator implements HeaderValidator.
type headerValidator struct {
hc *HeaderChain // Canonical header chain
Pow pow.PoW // Proof of work used for validating
}
// NewBlockValidator returns a new block validator which is safe for re-use
func NewHeaderValidator(chain *HeaderChain, pow pow.PoW) HeaderValidator {
return &headerValidator{
Pow: pow,
hc: chain,
}
}
// ValidateHeader validates the given header and, depending on the pow arg,
// checks the proof of work of the given header. Returns an error if the
// validation failed.
func (v *headerValidator) ValidateHeader(header, parent *types.Header, checkPow bool) error {
// Short circuit if the parent is missing.
if parent == nil {
return ParentError(header.ParentHash)
}
// Short circuit if the header's already known or its parent missing
if v.hc.HasHeader(header.Hash()) {
return nil
}
return ValidateHeader(v.Pow, header, parent, checkPow, false)
}

View File

@ -38,14 +38,22 @@ import (
// ValidateHeader validates the given header and parent and returns an error
// if it failed to do so.
//
// ValidateStack validates the given statedb and optionally the receipts and
// ValidateState validates the given statedb and optionally the receipts and
// gas used. The implementor should decide what to do with the given input.
type Validator interface {
HeaderValidator
ValidateBlock(block *types.Block) error
ValidateHeader(header, parent *types.Header, checkPow bool) error
ValidateState(block, parent *types.Block, state *state.StateDB, receipts types.Receipts, usedGas *big.Int) error
}
// HeaderValidator is an interface for validating headers only
//
// ValidateHeader validates the given header and parent and returns an error
// if it failed to do so.
type HeaderValidator interface {
ValidateHeader(header, parent *types.Header, checkPow bool) error
}
// Processor is an interface for processing blocks using a given initial state.
//
// Process takes the block to be processed and the statedb upon which the