light: light chain, VM env and tx pool

1 files changed, 505 insertions, 0 deletions

diff --git a/light/lightchain.go b/light/lightchain.go
new file mode 100644
index 000000000..88a25ba08
--- /dev/null
+++ b/light/lightchain.go
@@ -0,0 +1,505 @@
+// 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 light
+
+import (
+	"math/big"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/event"
+	"github.com/ethereum/go-ethereum/logger"
+	"github.com/ethereum/go-ethereum/logger/glog"
+	"github.com/ethereum/go-ethereum/pow"
+	"github.com/ethereum/go-ethereum/rlp"
+	"github.com/hashicorp/golang-lru"
+	"golang.org/x/net/context"
+)
+
+var (
+	bodyCacheLimit  = 256
+	blockCacheLimit = 256
+)
+
+// LightChain represents a canonical chain that by default only handles block
+// headers, downloading block bodies and receipts on demand through an ODR
+// interface. It only does header validation during chain insertion.
+type LightChain struct {
+	hc           *core.HeaderChain
+	chainDb      ethdb.Database
+	odr          OdrBackend
+	eventMux     *event.TypeMux
+	genesisBlock *types.Block
+
+	mu      sync.RWMutex
+	chainmu sync.RWMutex
+	procmu  sync.RWMutex
+
+	bodyCache    *lru.Cache // Cache for the most recent block bodies
+	bodyRLPCache *lru.Cache // Cache for the most recent block bodies in RLP encoded format
+	blockCache   *lru.Cache // Cache for the most recent entire blocks
+
+	quit    chan struct{}
+	running int32 // running must be called automically
+	// procInterrupt must be atomically called
+	procInterrupt int32 // interrupt signaler for block processing
+	wg            sync.WaitGroup
+
+	pow       pow.PoW
+	validator core.HeaderValidator
+}
+
+// NewLightChain returns a fully initialised light chain using information
+// available in the database. It initialises the default Ethereum header
+// validator.
+func NewLightChain(odr OdrBackend, config *core.ChainConfig, pow pow.PoW, mux *event.TypeMux) (*LightChain, error) {
+	bodyCache, _ := lru.New(bodyCacheLimit)
+	bodyRLPCache, _ := lru.New(bodyCacheLimit)
+	blockCache, _ := lru.New(blockCacheLimit)
+
+	bc := &LightChain{
+		chainDb:      odr.Database(),
+		odr:          odr,
+		eventMux:     mux,
+		quit:         make(chan struct{}),
+		bodyCache:    bodyCache,
+		bodyRLPCache: bodyRLPCache,
+		blockCache:   blockCache,
+		pow:          pow,
+	}
+
+	var err error
+	bc.hc, err = core.NewHeaderChain(odr.Database(), config, bc.Validator, bc.getProcInterrupt)
+	bc.SetValidator(core.NewHeaderValidator(config, bc.hc, pow))
+	if err != nil {
+		return nil, err
+	}
+
+	bc.genesisBlock, _ = bc.GetBlockByNumber(NoOdr, 0)
+	if bc.genesisBlock == nil {
+		bc.genesisBlock, err = core.WriteDefaultGenesisBlock(odr.Database())
+		if err != nil {
+			return nil, err
+		}
+		glog.V(logger.Info).Infoln("WARNING: Wrote default ethereum genesis block")
+	}
+
+	if bc.genesisBlock.Hash() == (common.Hash{212, 229, 103, 64, 248, 118, 174, 248, 192, 16, 184, 106, 64, 213, 245, 103, 69, 161, 24, 208, 144, 106, 52, 230, 154, 236, 140, 13, 177, 203, 143, 163}) {
+		// add trusted CHT
+		if config.DAOForkSupport {
+			WriteTrustedCht(bc.chainDb, TrustedCht{
+				Number: 564,
+				Root:   common.HexToHash("ee31f7fc21f627dc2b8d3ed8fed5b74dbc393d146a67249a656e163148e39016"),
+			})
+		} else {
+			WriteTrustedCht(bc.chainDb, TrustedCht{
+				Number: 523,
+				Root:   common.HexToHash("c035076523faf514038f619715de404a65398c51899b5dccca9c05b00bc79315"),
+			})
+		}
+		glog.V(logger.Info).Infoln("Added trusted CHT for mainnet")
+	} else {
+		if bc.genesisBlock.Hash() == (common.Hash{12, 215, 134, 162, 66, 93, 22, 241, 82, 198, 88, 49, 108, 66, 62, 108, 225, 24, 30, 21, 195, 41, 88, 38, 215, 201, 144, 76, 186, 156, 227, 3}) {
+			// add trusted CHT for testnet
+			WriteTrustedCht(bc.chainDb, TrustedCht{
+				Number: 319,
+				Root:   common.HexToHash("43b679ff9b4918b0b19e6256f20e35877365ec3e20b38e3b2a02cef5606176dc"),
+			})
+			glog.V(logger.Info).Infoln("Added trusted CHT for testnet")
+		} else {
+			DeleteTrustedCht(bc.chainDb)
+		}
+	}
+
+	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 core.BadHashes {
+		if header := bc.GetHeaderByHash(hash); header != nil {
+			glog.V(logger.Error).Infof("Found bad hash, rewinding chain to block #%d [%x…]", header.Number, header.ParentHash[:4])
+			bc.SetHead(header.Number.Uint64() - 1)
+			glog.V(logger.Error).Infoln("Chain rewind was successful, resuming normal operation")
+		}
+	}
+	return bc, nil
+}
+
+func (self *LightChain) getProcInterrupt() bool {
+	return atomic.LoadInt32(&self.procInterrupt) == 1
+}
+
+// Odr returns the ODR backend of the chain
+func (self *LightChain) Odr() OdrBackend {
+	return self.odr
+}
+
+// loadLastState loads the last known chain state from the database. This method
+// assumes that the chain manager mutex is held.
+func (self *LightChain) loadLastState() error {
+	if head := core.GetHeadHeaderHash(self.chainDb); head == (common.Hash{}) {
+		// Corrupt or empty database, init from scratch
+		self.Reset()
+	} else {
+		if header := self.GetHeaderByHash(head); header != nil {
+			self.hc.SetCurrentHeader(header)
+		}
+	}
+
+	// Issue a status log and return
+	header := self.hc.CurrentHeader()
+	headerTd := self.GetTd(header.Hash(), header.Number.Uint64())
+	glog.V(logger.Info).Infof("Last header: #%d [%x…] TD=%v", self.hc.CurrentHeader().Number, self.hc.CurrentHeader().Hash().Bytes()[:4], headerTd)
+
+	return nil
+}
+
+// SetHead rewinds the local chain to a new head. Everything above the new
+// head will be deleted and the new one set.
+func (bc *LightChain) SetHead(head uint64) {
+	bc.mu.Lock()
+	defer bc.mu.Unlock()
+
+	bc.hc.SetHead(head, nil)
+	bc.loadLastState()
+}
+
+// GasLimit returns the gas limit of the current HEAD block.
+func (self *LightChain) GasLimit() *big.Int {
+	self.mu.RLock()
+	defer self.mu.RUnlock()
+
+	return self.hc.CurrentHeader().GasLimit
+}
+
+// LastBlockHash return the hash of the HEAD block.
+func (self *LightChain) LastBlockHash() common.Hash {
+	self.mu.RLock()
+	defer self.mu.RUnlock()
+
+	return self.hc.CurrentHeader().Hash()
+}
+
+// Status returns status information about the current chain such as the HEAD Td,
+// the HEAD hash and the hash of the genesis block.
+func (self *LightChain) Status() (td *big.Int, currentBlock common.Hash, genesisBlock common.Hash) {
+	self.mu.RLock()
+	defer self.mu.RUnlock()
+
+	header := self.hc.CurrentHeader()
+	hash := header.Hash()
+	return self.GetTd(hash, header.Number.Uint64()), hash, self.genesisBlock.Hash()
+}
+
+// SetValidator sets the validator which is used to validate incoming headers.
+func (self *LightChain) SetValidator(validator core.HeaderValidator) {
+	self.procmu.Lock()
+	defer self.procmu.Unlock()
+	self.validator = validator
+}
+
+// Validator returns the current header validator.
+func (self *LightChain) Validator() core.HeaderValidator {
+	self.procmu.RLock()
+	defer self.procmu.RUnlock()
+	return self.validator
+}
+
+// State returns a new mutable state based on the current HEAD block.
+func (self *LightChain) State() *LightState {
+	return NewLightState(StateTrieID(self.hc.CurrentHeader()), self.odr)
+}
+
+// Reset purges the entire blockchain, restoring it to its genesis state.
+func (bc *LightChain) Reset() {
+	bc.ResetWithGenesisBlock(bc.genesisBlock)
+}
+
+// ResetWithGenesisBlock purges the entire blockchain, restoring it to the
+// specified genesis state.
+func (bc *LightChain) ResetWithGenesisBlock(genesis *types.Block) {
+	// Dump the entire block chain and purge the caches
+	bc.SetHead(0)
+
+	bc.mu.Lock()
+	defer bc.mu.Unlock()
+
+	// Prepare the genesis block and reinitialise the chain
+	if err := core.WriteTd(bc.chainDb, genesis.Hash(), genesis.NumberU64(), genesis.Difficulty()); err != nil {
+		glog.Fatalf("failed to write genesis block TD: %v", err)
+	}
+	if err := core.WriteBlock(bc.chainDb, genesis); err != nil {
+		glog.Fatalf("failed to write genesis block: %v", err)
+	}
+	bc.genesisBlock = genesis
+	bc.hc.SetGenesis(bc.genesisBlock.Header())
+	bc.hc.SetCurrentHeader(bc.genesisBlock.Header())
+}
+
+// Accessors
+
+// Genesis returns the genesis block
+func (bc *LightChain) Genesis() *types.Block {
+	return bc.genesisBlock
+}
+
+// GetBody retrieves a block body (transactions and uncles) from the database
+// or ODR service by hash, caching it if found.
+func (self *LightChain) GetBody(ctx context.Context, hash common.Hash) (*types.Body, error) {
+	// Short circuit if the body's already in the cache, retrieve otherwise
+	if cached, ok := self.bodyCache.Get(hash); ok {
+		body := cached.(*types.Body)
+		return body, nil
+	}
+	body, err := GetBody(ctx, self.odr, hash, self.hc.GetBlockNumber(hash))
+	if err != nil {
+		return nil, err
+	}
+	// Cache the found body for next time and return
+	self.bodyCache.Add(hash, body)
+	return body, nil
+}
+
+// GetBodyRLP retrieves a block body in RLP encoding from the database or
+// ODR service by hash, caching it if found.
+func (self *LightChain) GetBodyRLP(ctx context.Context, hash common.Hash) (rlp.RawValue, error) {
+	// Short circuit if the body's already in the cache, retrieve otherwise
+	if cached, ok := self.bodyRLPCache.Get(hash); ok {
+		return cached.(rlp.RawValue), nil
+	}
+	body, err := GetBodyRLP(ctx, self.odr, hash, self.hc.GetBlockNumber(hash))
+	if err != nil {
+		return nil, err
+	}
+	// Cache the found body for next time and return
+	self.bodyRLPCache.Add(hash, body)
+	return body, nil
+}
+
+// HasBlock checks if a block is fully present in the database or not, caching
+// it if present.
+func (bc *LightChain) HasBlock(hash common.Hash) bool {
+	blk, _ := bc.GetBlockByHash(NoOdr, hash)
+	return blk != nil
+}
+
+// GetBlock retrieves a block from the database or ODR service by hash and number,
+// caching it if found.
+func (self *LightChain) GetBlock(ctx context.Context, hash common.Hash, number uint64) (*types.Block, error) {
+	// Short circuit if the block's already in the cache, retrieve otherwise
+	if block, ok := self.blockCache.Get(hash); ok {
+		return block.(*types.Block), nil
+	}
+	block, err := GetBlock(ctx, self.odr, hash, number)
+	if err != nil {
+		return nil, err
+	}
+	// Cache the found block for next time and return
+	self.blockCache.Add(block.Hash(), block)
+	return block, nil
+}
+
+// GetBlockByHash retrieves a block from the database or ODR service by hash,
+// caching it if found.
+func (self *LightChain) GetBlockByHash(ctx context.Context, hash common.Hash) (*types.Block, error) {
+	return self.GetBlock(ctx, hash, self.hc.GetBlockNumber(hash))
+}
+
+// GetBlockByNumber retrieves a block from the database or ODR service by
+// number, caching it (associated with its hash) if found.
+func (self *LightChain) GetBlockByNumber(ctx context.Context, number uint64) (*types.Block, error) {
+	hash, err := GetCanonicalHash(ctx, self.odr, number)
+	if hash == (common.Hash{}) || err != nil {
+		return nil, err
+	}
+	return self.GetBlock(ctx, hash, number)
+}
+
+// Stop stops the blockchain service. If any imports are currently in progress
+// it will abort them using the procInterrupt.
+func (bc *LightChain) Stop() {
+	if !atomic.CompareAndSwapInt32(&bc.running, 0, 1) {
+		return
+	}
+	close(bc.quit)
+	atomic.StoreInt32(&bc.procInterrupt, 1)
+
+	bc.wg.Wait()
+
+	glog.V(logger.Info).Infoln("Chain manager stopped")
+}
+
+// Rollback is designed to remove a chain of links from the database that aren't
+// certain enough to be valid.
+func (self *LightChain) Rollback(chain []common.Hash) {
+	self.mu.Lock()
+	defer self.mu.Unlock()
+
+	for i := len(chain) - 1; i >= 0; i-- {
+		hash := chain[i]
+
+		if head := self.hc.CurrentHeader(); head.Hash() == hash {
+			self.hc.SetCurrentHeader(self.GetHeader(head.ParentHash, head.Number.Uint64()-1))
+		}
+	}
+}
+
+// postChainEvents iterates over the events generated by a chain insertion and
+// posts them into the event mux.
+func (self *LightChain) postChainEvents(events []interface{}) {
+	for _, event := range events {
+		if event, ok := event.(core.ChainEvent); ok {
+			if self.LastBlockHash() == event.Hash {
+				self.eventMux.Post(core.ChainHeadEvent{Block: event.Block})
+			}
+		}
+		// Fire the insertion events individually too
+		self.eventMux.Post(event)
+	}
+}
+
+// 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.
+//
+// In the case of a light chain, InsertHeaderChain also creates and posts light
+// chain events when necessary.
+func (self *LightChain) 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()
+
+	var events []interface{}
+	whFunc := func(header *types.Header) error {
+		self.mu.Lock()
+		defer self.mu.Unlock()
+
+		status, err := self.hc.WriteHeader(header)
+
+		switch status {
+		case core.CanonStatTy:
+			if glog.V(logger.Debug) {
+				glog.Infof("[%v] inserted header #%d (%x...).\n", time.Now().UnixNano(), header.Number, header.Hash().Bytes()[0:4])
+			}
+			events = append(events, core.ChainEvent{Block: types.NewBlockWithHeader(header), Hash: header.Hash()})
+
+		case core.SideStatTy:
+			if glog.V(logger.Detail) {
+				glog.Infof("inserted forked header #%d (TD=%v) (%x...).\n", header.Number, header.Difficulty, header.Hash().Bytes()[0:4])
+			}
+			events = append(events, core.ChainSideEvent{Block: types.NewBlockWithHeader(header)})
+
+		case core.SplitStatTy:
+			events = append(events, core.ChainSplitEvent{Block: types.NewBlockWithHeader(header)})
+		}
+
+		return err
+	}
+	i, err := self.hc.InsertHeaderChain(chain, checkFreq, whFunc)
+	go self.postChainEvents(events)
+	return i, err
+}
+
+// CurrentHeader retrieves the current head header of the canonical chain. The
+// header is retrieved from the HeaderChain's internal cache.
+func (self *LightChain) 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 and number, caching it if found.
+func (self *LightChain) GetTd(hash common.Hash, number uint64) *big.Int {
+	return self.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 (self *LightChain) GetTdByHash(hash common.Hash) *big.Int {
+	return self.hc.GetTdByHash(hash)
+}
+
+// GetHeader retrieves a block header from the database by hash and number,
+// caching it if found.
+func (self *LightChain) GetHeader(hash common.Hash, number uint64) *types.Header {
+	return self.hc.GetHeader(hash, number)
+}
+
+// GetHeaderByHash retrieves a block header from the database by hash, caching it if
+// found.
+func (self *LightChain) GetHeaderByHash(hash common.Hash) *types.Header {
+	return self.hc.GetHeaderByHash(hash)
+}
+
+// HasHeader checks if a block header is present in the database or not, caching
+// it if present.
+func (bc *LightChain) 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 *LightChain) 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 *LightChain) GetHeaderByNumber(number uint64) *types.Header {
+	return self.hc.GetHeaderByNumber(number)
+}
+
+// GetHeaderByNumberOdr retrieves a block header from the database or network
+// by number, caching it (associated with its hash) if found.
+func (self *LightChain) GetHeaderByNumberOdr(ctx context.Context, number uint64) (*types.Header, error) {
+	if header := self.hc.GetHeaderByNumber(number); header != nil {
+		return header, nil
+	}
+	return GetHeaderByNumber(ctx, self.odr, number)
+}
+
+func (self *LightChain) SyncCht(ctx context.Context) bool {
+	headNum := self.CurrentHeader().Number.Uint64()
+	cht := GetTrustedCht(self.chainDb)
+	if headNum+1 < cht.Number*ChtFrequency {
+		num := cht.Number*ChtFrequency - 1
+		header, err := GetHeaderByNumber(ctx, self.odr, num)
+		if header != nil && err == nil {
+			self.mu.Lock()
+			if self.hc.CurrentHeader().Number.Uint64() < header.Number.Uint64() {
+				self.hc.SetCurrentHeader(header)
+			}
+			self.mu.Unlock()
+			return true
+		}
+	}
+	return false
+}