neoneo-go/pkg/core/blockchain.go
2020-06-19 11:38:56 +03:00

1392 lines
42 KiB
Go

package core
import (
"fmt"
"math/big"
"sort"
"sync"
"sync/atomic"
"time"
"github.com/nspcc-dev/neo-go/pkg/config"
"github.com/nspcc-dev/neo-go/pkg/core/block"
"github.com/nspcc-dev/neo-go/pkg/core/dao"
"github.com/nspcc-dev/neo-go/pkg/core/interop"
"github.com/nspcc-dev/neo-go/pkg/core/mempool"
"github.com/nspcc-dev/neo-go/pkg/core/native"
"github.com/nspcc-dev/neo-go/pkg/core/state"
"github.com/nspcc-dev/neo-go/pkg/core/storage"
"github.com/nspcc-dev/neo-go/pkg/core/transaction"
"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
"github.com/nspcc-dev/neo-go/pkg/encoding/bigint"
"github.com/nspcc-dev/neo-go/pkg/io"
"github.com/nspcc-dev/neo-go/pkg/smartcontract"
"github.com/nspcc-dev/neo-go/pkg/smartcontract/trigger"
"github.com/nspcc-dev/neo-go/pkg/util"
"github.com/nspcc-dev/neo-go/pkg/vm"
"github.com/nspcc-dev/neo-go/pkg/vm/emit"
"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
"github.com/pkg/errors"
"go.uber.org/zap"
)
// Tuning parameters.
const (
headerBatchCount = 2000
version = "0.1.0"
defaultMemPoolSize = 50000
)
var (
// ErrAlreadyExists is returned when trying to add some already existing
// transaction into the pool (not specifying whether it exists in the
// chain or mempool).
ErrAlreadyExists = errors.New("already exists")
// ErrOOM is returned when adding transaction to the memory pool because
// it reached its full capacity.
ErrOOM = errors.New("no space left in the memory pool")
// ErrPolicy is returned on attempt to add transaction that doesn't
// comply with node's configured policy into the mempool.
ErrPolicy = errors.New("not allowed by policy")
// ErrInvalidBlockIndex is returned when trying to add block with index
// other than expected height of the blockchain.
ErrInvalidBlockIndex error = errors.New("invalid block index")
)
var (
genAmount = []int{8, 7, 6, 5, 4, 3, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}
decrementInterval = 2000000
persistInterval = 1 * time.Second
)
// Blockchain represents the blockchain. It maintans internal state representing
// the state of the ledger that can be accessed in various ways and changed by
// adding new blocks or headers.
type Blockchain struct {
config config.ProtocolConfiguration
// The only way chain state changes is by adding blocks, so we can't
// allow concurrent block additions. It differs from the next lock in
// that it's only for AddBlock method itself, the chain state is
// protected by the lock below, but holding it during all of AddBlock
// is too expensive (because the state only changes when persisting
// change cache).
addLock sync.Mutex
// This lock ensures blockchain immutability for operations that need
// that while performing their tasks. It's mostly used as a read lock
// with the only writer being the block addition logic.
lock sync.RWMutex
// Data access object for CRUD operations around storage.
dao *dao.Simple
// Current index/height of the highest block.
// Read access should always be called by BlockHeight().
// Write access should only happen in storeBlock().
blockHeight uint32
// Current top Block wrapped in an atomic.Value for safe access.
topBlock atomic.Value
// Current persisted block count.
persistedHeight uint32
// Number of headers stored in the chain file.
storedHeaderCount uint32
generationAmount []int
decrementInterval int
// All operations on headerList must be called from an
// headersOp to be routine safe.
headerList *HeaderHashList
// Only for operating on the headerList.
headersOp chan headersOpFunc
headersOpDone chan struct{}
// Stop synchronization mechanisms.
stopCh chan struct{}
runToExitCh chan struct{}
memPool mempool.Pool
// This lock protects concurrent access to keyCache.
keyCacheLock sync.RWMutex
// cache for block verification keys.
keyCache map[util.Uint160]map[string]*keys.PublicKey
log *zap.Logger
lastBatch *storage.MemBatch
contracts native.Contracts
// Notification subsystem.
events chan bcEvent
subCh chan interface{}
unsubCh chan interface{}
}
// bcEvent is an internal event generated by the Blockchain and then
// broadcasted to other parties. It joins the new block and associated
// invocation logs, all the other events visible from outside can be produced
// from this combination.
type bcEvent struct {
block *block.Block
appExecResults []*state.AppExecResult
}
type headersOpFunc func(headerList *HeaderHashList)
// NewBlockchain returns a new blockchain object the will use the
// given Store as its underlying storage. For it to work correctly you need
// to spawn a goroutine for its Run method after this initialization.
func NewBlockchain(s storage.Store, cfg config.ProtocolConfiguration, log *zap.Logger) (*Blockchain, error) {
if log == nil {
return nil, errors.New("empty logger")
}
if cfg.MemPoolSize <= 0 {
cfg.MemPoolSize = defaultMemPoolSize
log.Info("mempool size is not set or wrong, setting default value", zap.Int("MemPoolSize", cfg.MemPoolSize))
}
if cfg.MaxTransactionsPerBlock <= 0 {
cfg.MaxTransactionsPerBlock = 0
log.Info("MaxTransactionsPerBlock is not set or wrong, setting default value (unlimited)", zap.Int("MaxTransactionsPerBlock", cfg.MaxTransactionsPerBlock))
}
bc := &Blockchain{
config: cfg,
dao: dao.NewSimple(s, cfg.Magic),
headersOp: make(chan headersOpFunc),
headersOpDone: make(chan struct{}),
stopCh: make(chan struct{}),
runToExitCh: make(chan struct{}),
memPool: mempool.NewMemPool(cfg.MemPoolSize),
keyCache: make(map[util.Uint160]map[string]*keys.PublicKey),
log: log,
events: make(chan bcEvent),
subCh: make(chan interface{}),
unsubCh: make(chan interface{}),
generationAmount: genAmount,
decrementInterval: decrementInterval,
contracts: *native.NewContracts(),
}
if err := bc.init(); err != nil {
return nil, err
}
return bc, nil
}
func (bc *Blockchain) init() error {
// If we could not find the version in the Store, we know that there is nothing stored.
ver, err := bc.dao.GetVersion()
if err != nil {
bc.log.Info("no storage version found! creating genesis block")
if err = bc.dao.PutVersion(version); err != nil {
return err
}
genesisBlock, err := createGenesisBlock(bc.config)
if err != nil {
return err
}
bc.headerList = NewHeaderHashList(genesisBlock.Hash())
err = bc.dao.PutCurrentHeader(hashAndIndexToBytes(genesisBlock.Hash(), genesisBlock.Index))
if err != nil {
return err
}
return bc.storeBlock(genesisBlock)
}
if ver != version {
return fmt.Errorf("storage version mismatch betweeen %s and %s", version, ver)
}
// At this point there was no version found in the storage which
// implies a creating fresh storage with the version specified
// and the genesis block as first block.
bc.log.Info("restoring blockchain", zap.String("version", version))
bHeight, err := bc.dao.GetCurrentBlockHeight()
if err != nil {
return err
}
bc.blockHeight = bHeight
bc.persistedHeight = bHeight
hashes, err := bc.dao.GetHeaderHashes()
if err != nil {
return err
}
bc.headerList = NewHeaderHashList(hashes...)
bc.storedHeaderCount = uint32(len(hashes))
currHeaderHeight, currHeaderHash, err := bc.dao.GetCurrentHeaderHeight()
if err != nil {
return err
}
if bc.storedHeaderCount == 0 && currHeaderHeight == 0 {
bc.headerList.Add(currHeaderHash)
}
// There is a high chance that the Node is stopped before the next
// batch of 2000 headers was stored. Via the currentHeaders stored we can sync
// that with stored blocks.
if currHeaderHeight >= bc.storedHeaderCount {
hash := currHeaderHash
var targetHash util.Uint256
if bc.headerList.Len() > 0 {
targetHash = bc.headerList.Get(bc.headerList.Len() - 1)
} else {
genesisBlock, err := createGenesisBlock(bc.config)
if err != nil {
return err
}
targetHash = genesisBlock.Hash()
bc.headerList.Add(targetHash)
}
headers := make([]*block.Header, 0)
for hash != targetHash {
header, err := bc.GetHeader(hash)
if err != nil {
return fmt.Errorf("could not get header %s: %s", hash, err)
}
headers = append(headers, header)
hash = header.PrevHash
}
headerSliceReverse(headers)
for _, h := range headers {
if !h.Verify() {
return fmt.Errorf("bad header %d/%s in the storage", h.Index, h.Hash())
}
bc.headerList.Add(h.Hash())
}
}
return nil
}
// Run runs chain loop, it needs to be run as goroutine and executing it is
// critical for correct Blockchain operation.
func (bc *Blockchain) Run() {
persistTimer := time.NewTimer(persistInterval)
defer func() {
persistTimer.Stop()
if err := bc.persist(); err != nil {
bc.log.Warn("failed to persist", zap.Error(err))
}
if err := bc.dao.Store.Close(); err != nil {
bc.log.Warn("failed to close db", zap.Error(err))
}
close(bc.runToExitCh)
}()
go bc.notificationDispatcher()
for {
select {
case <-bc.stopCh:
return
case op := <-bc.headersOp:
op(bc.headerList)
bc.headersOpDone <- struct{}{}
case <-persistTimer.C:
go func() {
err := bc.persist()
if err != nil {
bc.log.Warn("failed to persist blockchain", zap.Error(err))
}
persistTimer.Reset(persistInterval)
}()
}
}
}
// notificationDispatcher manages subscription to events and broadcasts new events.
func (bc *Blockchain) notificationDispatcher() {
var (
// These are just sets of subscribers, though modelled as maps
// for ease of management (not a lot of subscriptions is really
// expected, but maps are convenient for adding/deleting elements).
blockFeed = make(map[chan<- *block.Block]bool)
txFeed = make(map[chan<- *transaction.Transaction]bool)
notificationFeed = make(map[chan<- *state.NotificationEvent]bool)
executionFeed = make(map[chan<- *state.AppExecResult]bool)
)
for {
select {
case <-bc.stopCh:
return
case sub := <-bc.subCh:
switch ch := sub.(type) {
case chan<- *block.Block:
blockFeed[ch] = true
case chan<- *transaction.Transaction:
txFeed[ch] = true
case chan<- *state.NotificationEvent:
notificationFeed[ch] = true
case chan<- *state.AppExecResult:
executionFeed[ch] = true
default:
panic(fmt.Sprintf("bad subscription: %T", sub))
}
case unsub := <-bc.unsubCh:
switch ch := unsub.(type) {
case chan<- *block.Block:
delete(blockFeed, ch)
case chan<- *transaction.Transaction:
delete(txFeed, ch)
case chan<- *state.NotificationEvent:
delete(notificationFeed, ch)
case chan<- *state.AppExecResult:
delete(executionFeed, ch)
default:
panic(fmt.Sprintf("bad unsubscription: %T", unsub))
}
case event := <-bc.events:
// We don't want to waste time looping through transactions when there are no
// subscribers.
if len(txFeed) != 0 || len(notificationFeed) != 0 || len(executionFeed) != 0 {
aer := event.appExecResults[0]
if !aer.TxHash.Equals(event.block.Hash()) {
panic("inconsistent application execution results")
}
for ch := range executionFeed {
ch <- aer
}
for i := range aer.Events {
for ch := range notificationFeed {
ch <- &aer.Events[i]
}
}
aerIdx := 1
for _, tx := range event.block.Transactions {
aer := event.appExecResults[aerIdx]
if !aer.TxHash.Equals(tx.Hash()) {
panic("inconsistent application execution results")
}
aerIdx++
for ch := range executionFeed {
ch <- aer
}
if aer.VMState == "HALT" {
for i := range aer.Events {
for ch := range notificationFeed {
ch <- &aer.Events[i]
}
}
}
for ch := range txFeed {
ch <- tx
}
}
}
for ch := range blockFeed {
ch <- event.block
}
}
}
}
// Close stops Blockchain's internal loop, syncs changes to persistent storage
// and closes it. The Blockchain is no longer functional after the call to Close.
func (bc *Blockchain) Close() {
// If there is a block addition in progress, wait for it to finish and
// don't allow new ones.
bc.addLock.Lock()
close(bc.stopCh)
<-bc.runToExitCh
bc.addLock.Unlock()
}
// AddBlock accepts successive block for the Blockchain, verifies it and
// stores internally. Eventually it will be persisted to the backing storage.
func (bc *Blockchain) AddBlock(block *block.Block) error {
bc.addLock.Lock()
defer bc.addLock.Unlock()
expectedHeight := bc.BlockHeight() + 1
if expectedHeight != block.Index {
return ErrInvalidBlockIndex
}
headerLen := bc.headerListLen()
if int(block.Index) == headerLen {
err := bc.addHeaders(bc.config.VerifyBlocks, block.Header())
if err != nil {
return err
}
}
if bc.config.VerifyBlocks {
err := block.Verify()
if err != nil {
return fmt.Errorf("block %s is invalid: %s", block.Hash().StringLE(), err)
}
if bc.config.VerifyTransactions {
for _, tx := range block.Transactions {
err := bc.VerifyTx(tx, block)
if err != nil {
return fmt.Errorf("transaction %s failed to verify: %s", tx.Hash().StringLE(), err)
}
}
}
}
return bc.storeBlock(block)
}
// AddHeaders processes the given headers and add them to the
// HeaderHashList. It expects headers to be sorted by index.
func (bc *Blockchain) AddHeaders(headers ...*block.Header) error {
return bc.addHeaders(bc.config.VerifyBlocks, headers...)
}
// addHeaders is an internal implementation of AddHeaders (`verify` parameter
// tells it to verify or not verify given headers).
func (bc *Blockchain) addHeaders(verify bool, headers ...*block.Header) (err error) {
var (
start = time.Now()
batch = bc.dao.Store.Batch()
)
if len(headers) > 0 {
var i int
curHeight := bc.HeaderHeight()
for i = range headers {
if headers[i].Index > curHeight {
break
}
}
headers = headers[i:]
}
if len(headers) == 0 {
return nil
} else if verify {
// Verify that the chain of the headers is consistent.
var lastHeader *block.Header
if lastHeader, err = bc.GetHeader(headers[0].PrevHash); err != nil {
return fmt.Errorf("previous header was not found: %v", err)
}
for _, h := range headers {
if err = bc.verifyHeader(h, lastHeader); err != nil {
return
}
lastHeader = h
}
}
bc.headersOp <- func(headerList *HeaderHashList) {
oldlen := headerList.Len()
for _, h := range headers {
if int(h.Index-1) >= headerList.Len() {
err = fmt.Errorf(
"height of received header %d is higher then the current header %d",
h.Index, headerList.Len(),
)
return
}
if int(h.Index) < headerList.Len() {
continue
}
if !h.Verify() {
err = fmt.Errorf("header %v is invalid", h)
return
}
if err = bc.processHeader(h, batch, headerList); err != nil {
return
}
}
if oldlen != headerList.Len() {
updateHeaderHeightMetric(headerList.Len() - 1)
if err = bc.dao.Store.PutBatch(batch); err != nil {
return
}
bc.log.Debug("done processing headers",
zap.Int("headerIndex", headerList.Len()-1),
zap.Uint32("blockHeight", bc.BlockHeight()),
zap.Duration("took", time.Since(start)))
}
}
<-bc.headersOpDone
return err
}
// processHeader processes the given header. Note that this is only thread safe
// if executed in headers operation.
func (bc *Blockchain) processHeader(h *block.Header, batch storage.Batch, headerList *HeaderHashList) error {
headerList.Add(h.Hash())
buf := io.NewBufBinWriter()
for int(h.Index)-headerBatchCount >= int(bc.storedHeaderCount) {
if err := headerList.Write(buf.BinWriter, int(bc.storedHeaderCount), headerBatchCount); err != nil {
return err
}
key := storage.AppendPrefixInt(storage.IXHeaderHashList, int(bc.storedHeaderCount))
batch.Put(key, buf.Bytes())
bc.storedHeaderCount += headerBatchCount
buf.Reset()
}
buf.Reset()
h.EncodeBinary(buf.BinWriter)
if buf.Err != nil {
return buf.Err
}
key := storage.AppendPrefix(storage.DataBlock, h.Hash().BytesLE())
batch.Put(key, buf.Bytes())
batch.Put(storage.SYSCurrentHeader.Bytes(), hashAndIndexToBytes(h.Hash(), h.Index))
return nil
}
// TODO: storeBlock needs some more love, its implemented as in the original
// project. This for the sake of development speed and understanding of what
// is happening here, quite allot as you can see :). If things are wired together
// and all tests are in place, we can make a more optimized and cleaner implementation.
func (bc *Blockchain) storeBlock(block *block.Block) error {
cache := dao.NewCached(bc.dao)
appExecResults := make([]*state.AppExecResult, 0, 1+len(block.Transactions))
if err := cache.StoreAsBlock(block); err != nil {
return err
}
if err := cache.StoreAsCurrentBlock(block); err != nil {
return err
}
if block.Index > 0 {
systemInterop := bc.newInteropContext(trigger.System, cache, block, nil)
v := SpawnVM(systemInterop)
v.LoadScriptWithFlags(bc.contracts.GetPersistScript(), smartcontract.AllowModifyStates|smartcontract.AllowCall)
v.SetPriceGetter(getPrice)
if err := v.Run(); err != nil {
return errors.Wrap(err, "can't persist native contracts")
} else if _, err := systemInterop.DAO.Persist(); err != nil {
return errors.Wrap(err, "can't persist `onPersist` changes")
}
for i := range systemInterop.Notifications {
bc.handleNotification(&systemInterop.Notifications[i], cache, block, block.Hash())
}
aer := &state.AppExecResult{
TxHash: block.Hash(), // application logs can be retrieved by block hash
Trigger: trigger.System,
VMState: v.State(),
GasConsumed: v.GasConsumed(),
Stack: v.Estack().ToContractParameters(),
Events: systemInterop.Notifications,
}
appExecResults = append(appExecResults, aer)
err := cache.PutAppExecResult(aer)
if err != nil {
return errors.Wrap(err, "failed to Store notifications")
}
}
for _, tx := range block.Transactions {
if err := cache.StoreAsTransaction(tx, block.Index); err != nil {
return err
}
systemInterop := bc.newInteropContext(trigger.Application, cache, block, tx)
v := SpawnVM(systemInterop)
v.LoadScriptWithFlags(tx.Script, smartcontract.All)
v.SetPriceGetter(getPrice)
v.GasLimit = tx.SystemFee
err := v.Run()
if !v.HasFailed() {
_, err := systemInterop.DAO.Persist()
if err != nil {
return errors.Wrap(err, "failed to persist invocation results")
}
for i := range systemInterop.Notifications {
bc.handleNotification(&systemInterop.Notifications[i], cache, block, tx.Hash())
}
} else {
bc.log.Warn("contract invocation failed",
zap.String("tx", tx.Hash().StringLE()),
zap.Uint32("block", block.Index),
zap.Error(err))
}
aer := &state.AppExecResult{
TxHash: tx.Hash(),
Trigger: trigger.Application,
VMState: v.State(),
GasConsumed: v.GasConsumed(),
Stack: v.Estack().ToContractParameters(),
Events: systemInterop.Notifications,
}
appExecResults = append(appExecResults, aer)
err = cache.PutAppExecResult(aer)
if err != nil {
return errors.Wrap(err, "failed to Store notifications")
}
}
if bc.config.SaveStorageBatch {
bc.lastBatch = cache.DAO.GetBatch()
}
bc.lock.Lock()
_, err := cache.Persist()
if err != nil {
bc.lock.Unlock()
return err
}
bc.topBlock.Store(block)
atomic.StoreUint32(&bc.blockHeight, block.Index)
bc.memPool.RemoveStale(bc.isTxStillRelevant, bc)
bc.lock.Unlock()
updateBlockHeightMetric(block.Index)
// Genesis block is stored when Blockchain is not yet running, so there
// is no one to read this event. And it doesn't make much sense as event
// anyway.
if block.Index != 0 {
bc.events <- bcEvent{block, appExecResults}
}
return nil
}
func (bc *Blockchain) handleNotification(note *state.NotificationEvent, d *dao.Cached, b *block.Block, h util.Uint256) {
arr, ok := note.Item.Value().([]stackitem.Item)
if !ok || len(arr) != 4 {
return
}
op, ok := arr[0].Value().([]byte)
if !ok || (string(op) != "transfer" && string(op) != "Transfer") {
return
}
var from []byte
fromValue := arr[1].Value()
// we don't have `from` set when we are minting tokens
if fromValue != nil {
from, ok = fromValue.([]byte)
if !ok {
return
}
}
var to []byte
toValue := arr[2].Value()
// we don't have `to` set when we are burning tokens
if toValue != nil {
to, ok = toValue.([]byte)
if !ok {
return
}
}
amount, ok := arr[3].Value().(*big.Int)
if !ok {
bs, ok := arr[3].Value().([]byte)
if !ok {
return
}
amount = bigint.FromBytes(bs)
}
bc.processNEP5Transfer(d, h, b, note.ScriptHash, from, to, amount.Int64())
}
func parseUint160(addr []byte) util.Uint160 {
if u, err := util.Uint160DecodeBytesBE(addr); err == nil {
return u
}
return util.Uint160{}
}
func (bc *Blockchain) processNEP5Transfer(cache *dao.Cached, h util.Uint256, b *block.Block, sc util.Uint160, from, to []byte, amount int64) {
toAddr := parseUint160(to)
fromAddr := parseUint160(from)
transfer := &state.NEP5Transfer{
Asset: sc,
From: fromAddr,
To: toAddr,
Block: b.Index,
Timestamp: b.Timestamp,
Tx: h,
}
if !fromAddr.Equals(util.Uint160{}) {
balances, err := cache.GetNEP5Balances(fromAddr)
if err != nil {
return
}
bs := balances.Trackers[sc]
bs.Balance -= amount
bs.LastUpdatedBlock = b.Index
balances.Trackers[sc] = bs
transfer.Amount = -amount
isBig, err := cache.AppendNEP5Transfer(fromAddr, balances.NextTransferBatch, transfer)
if err != nil {
return
}
if isBig {
balances.NextTransferBatch++
}
if err := cache.PutNEP5Balances(fromAddr, balances); err != nil {
return
}
}
if !toAddr.Equals(util.Uint160{}) {
balances, err := cache.GetNEP5Balances(toAddr)
if err != nil {
return
}
bs := balances.Trackers[sc]
bs.Balance += amount
bs.LastUpdatedBlock = b.Index
balances.Trackers[sc] = bs
transfer.Amount = amount
isBig, err := cache.AppendNEP5Transfer(toAddr, balances.NextTransferBatch, transfer)
if err != nil {
return
}
if isBig {
balances.NextTransferBatch++
}
if err := cache.PutNEP5Balances(toAddr, balances); err != nil {
return
}
}
}
// GetNEP5TransferLog returns NEP5 transfer log for the acc.
func (bc *Blockchain) GetNEP5TransferLog(acc util.Uint160) *state.NEP5TransferLog {
balances, err := bc.dao.GetNEP5Balances(acc)
if err != nil {
return nil
}
result := new(state.NEP5TransferLog)
for i := uint32(0); i <= balances.NextTransferBatch; i++ {
lg, err := bc.dao.GetNEP5TransferLog(acc, i)
if err != nil {
return nil
}
result.Raw = append(result.Raw, lg.Raw...)
}
return result
}
// GetNEP5Balances returns NEP5 balances for the acc.
func (bc *Blockchain) GetNEP5Balances(acc util.Uint160) *state.NEP5Balances {
bs, err := bc.dao.GetNEP5Balances(acc)
if err != nil {
return nil
}
return bs
}
// GetUtilityTokenBalance returns utility token (GAS) balance for the acc.
func (bc *Blockchain) GetUtilityTokenBalance(acc util.Uint160) util.Fixed8 {
bs, err := bc.dao.GetNEP5Balances(acc)
if err != nil {
return 0
}
return util.Fixed8(bs.Trackers[bc.contracts.GAS.Hash].Balance)
}
// GetGoverningTokenBalance returns governing token (NEO) balance and the height
// of the last balance change for the account.
func (bc *Blockchain) GetGoverningTokenBalance(acc util.Uint160) (util.Fixed8, uint32) {
bs, err := bc.dao.GetNEP5Balances(acc)
if err != nil {
return 0, 0
}
neo := bs.Trackers[bc.contracts.NEO.Hash]
return util.Fixed8(neo.Balance), neo.LastUpdatedBlock
}
// LastBatch returns last persisted storage batch.
func (bc *Blockchain) LastBatch() *storage.MemBatch {
return bc.lastBatch
}
// persist flushes current in-memory Store contents to the persistent storage.
func (bc *Blockchain) persist() error {
var (
start = time.Now()
persisted int
err error
)
persisted, err = bc.dao.Persist()
if err != nil {
return err
}
if persisted > 0 {
bHeight, err := bc.dao.GetCurrentBlockHeight()
if err != nil {
return err
}
oldHeight := atomic.SwapUint32(&bc.persistedHeight, bHeight)
diff := bHeight - oldHeight
storedHeaderHeight, _, err := bc.dao.GetCurrentHeaderHeight()
if err != nil {
return err
}
bc.log.Info("blockchain persist completed",
zap.Uint32("persistedBlocks", diff),
zap.Int("persistedKeys", persisted),
zap.Uint32("headerHeight", storedHeaderHeight),
zap.Uint32("blockHeight", bHeight),
zap.Duration("took", time.Since(start)))
// update monitoring metrics.
updatePersistedHeightMetric(bHeight)
}
return nil
}
func (bc *Blockchain) headerListLen() (n int) {
bc.headersOp <- func(headerList *HeaderHashList) {
n = headerList.Len()
}
<-bc.headersOpDone
return
}
// GetTransaction returns a TX and its height by the given hash.
func (bc *Blockchain) GetTransaction(hash util.Uint256) (*transaction.Transaction, uint32, error) {
if tx, ok := bc.memPool.TryGetValue(hash); ok {
return tx, 0, nil // the height is not actually defined for memPool transaction. Not sure if zero is a good number in this case.
}
return bc.dao.GetTransaction(hash)
}
// GetAppExecResult returns application execution result by the given
// tx hash.
func (bc *Blockchain) GetAppExecResult(hash util.Uint256) (*state.AppExecResult, error) {
return bc.dao.GetAppExecResult(hash)
}
// GetStorageItem returns an item from storage.
func (bc *Blockchain) GetStorageItem(scripthash util.Uint160, key []byte) *state.StorageItem {
return bc.dao.GetStorageItem(scripthash, key)
}
// GetStorageItems returns all storage items for a given scripthash.
func (bc *Blockchain) GetStorageItems(hash util.Uint160) (map[string]*state.StorageItem, error) {
return bc.dao.GetStorageItems(hash)
}
// GetBlock returns a Block by the given hash.
func (bc *Blockchain) GetBlock(hash util.Uint256) (*block.Block, error) {
topBlock := bc.topBlock.Load()
if topBlock != nil {
if tb, ok := topBlock.(*block.Block); ok && tb.Hash().Equals(hash) {
return tb, nil
}
}
block, err := bc.dao.GetBlock(hash)
if err != nil {
return nil, err
}
for _, tx := range block.Transactions {
stx, _, err := bc.dao.GetTransaction(tx.Hash())
if err != nil {
return nil, err
}
*tx = *stx
}
return block, nil
}
// GetHeader returns data block header identified with the given hash value.
func (bc *Blockchain) GetHeader(hash util.Uint256) (*block.Header, error) {
topBlock := bc.topBlock.Load()
if topBlock != nil {
if tb, ok := topBlock.(*block.Block); ok && tb.Hash().Equals(hash) {
return tb.Header(), nil
}
}
block, err := bc.dao.GetBlock(hash)
if err != nil {
return nil, err
}
return block.Header(), nil
}
// HasTransaction returns true if the blockchain contains he given
// transaction hash.
func (bc *Blockchain) HasTransaction(hash util.Uint256) bool {
return bc.memPool.ContainsKey(hash) || bc.dao.HasTransaction(hash)
}
// HasBlock returns true if the blockchain contains the given
// block hash.
func (bc *Blockchain) HasBlock(hash util.Uint256) bool {
if header, err := bc.GetHeader(hash); err == nil {
return header.Index <= bc.BlockHeight()
}
return false
}
// CurrentBlockHash returns the highest processed block hash.
func (bc *Blockchain) CurrentBlockHash() (hash util.Uint256) {
bc.headersOp <- func(headerList *HeaderHashList) {
hash = headerList.Get(int(bc.BlockHeight()))
}
<-bc.headersOpDone
return
}
// CurrentHeaderHash returns the hash of the latest known header.
func (bc *Blockchain) CurrentHeaderHash() (hash util.Uint256) {
bc.headersOp <- func(headerList *HeaderHashList) {
hash = headerList.Last()
}
<-bc.headersOpDone
return
}
// GetHeaderHash returns the hash from the headerList by its
// height/index.
func (bc *Blockchain) GetHeaderHash(i int) (hash util.Uint256) {
bc.headersOp <- func(headerList *HeaderHashList) {
hash = headerList.Get(i)
}
<-bc.headersOpDone
return
}
// BlockHeight returns the height/index of the highest block.
func (bc *Blockchain) BlockHeight() uint32 {
return atomic.LoadUint32(&bc.blockHeight)
}
// HeaderHeight returns the index/height of the highest header.
func (bc *Blockchain) HeaderHeight() uint32 {
return uint32(bc.headerListLen() - 1)
}
// GetContractState returns contract by its script hash.
func (bc *Blockchain) GetContractState(hash util.Uint160) *state.Contract {
contract, err := bc.dao.GetContractState(hash)
if contract == nil && err != storage.ErrKeyNotFound {
bc.log.Warn("failed to get contract state", zap.Error(err))
}
return contract
}
// GetAccountState returns the account state from its script hash.
func (bc *Blockchain) GetAccountState(scriptHash util.Uint160) *state.Account {
as, err := bc.dao.GetAccountState(scriptHash)
if as == nil && err != storage.ErrKeyNotFound {
bc.log.Warn("failed to get account state", zap.Error(err))
}
return as
}
// GetConfig returns the config stored in the blockchain.
func (bc *Blockchain) GetConfig() config.ProtocolConfiguration {
return bc.config
}
// SubscribeForBlocks adds given channel to new block event broadcasting, so when
// there is a new block added to the chain you'll receive it via this channel.
// Make sure it's read from regularly as not reading these events might affect
// other Blockchain functions.
func (bc *Blockchain) SubscribeForBlocks(ch chan<- *block.Block) {
bc.subCh <- ch
}
// SubscribeForTransactions adds given channel to new transaction event
// broadcasting, so when there is a new transaction added to the chain (in a
// block) you'll receive it via this channel. Make sure it's read from regularly
// as not reading these events might affect other Blockchain functions.
func (bc *Blockchain) SubscribeForTransactions(ch chan<- *transaction.Transaction) {
bc.subCh <- ch
}
// SubscribeForNotifications adds given channel to new notifications event
// broadcasting, so when an in-block transaction execution generates a
// notification you'll receive it via this channel. Only notifications from
// successful transactions are broadcasted, if you're interested in failed
// transactions use SubscribeForExecutions instead. Make sure this channel is
// read from regularly as not reading these events might affect other Blockchain
// functions.
func (bc *Blockchain) SubscribeForNotifications(ch chan<- *state.NotificationEvent) {
bc.subCh <- ch
}
// SubscribeForExecutions adds given channel to new transaction execution event
// broadcasting, so when an in-block transaction execution happens you'll receive
// the result of it via this channel. Make sure it's read from regularly as not
// reading these events might affect other Blockchain functions.
func (bc *Blockchain) SubscribeForExecutions(ch chan<- *state.AppExecResult) {
bc.subCh <- ch
}
// UnsubscribeFromBlocks unsubscribes given channel from new block notifications,
// you can close it afterwards. Passing non-subscribed channel is a no-op.
func (bc *Blockchain) UnsubscribeFromBlocks(ch chan<- *block.Block) {
bc.unsubCh <- ch
}
// UnsubscribeFromTransactions unsubscribes given channel from new transaction
// notifications, you can close it afterwards. Passing non-subscribed channel is
// a no-op.
func (bc *Blockchain) UnsubscribeFromTransactions(ch chan<- *transaction.Transaction) {
bc.unsubCh <- ch
}
// UnsubscribeFromNotifications unsubscribes given channel from new
// execution-generated notifications, you can close it afterwards. Passing
// non-subscribed channel is a no-op.
func (bc *Blockchain) UnsubscribeFromNotifications(ch chan<- *state.NotificationEvent) {
bc.unsubCh <- ch
}
// UnsubscribeFromExecutions unsubscribes given channel from new execution
// notifications, you can close it afterwards. Passing non-subscribed channel is
// a no-op.
func (bc *Blockchain) UnsubscribeFromExecutions(ch chan<- *state.AppExecResult) {
bc.unsubCh <- ch
}
// CalculateClaimable calculates the amount of GAS generated by owning specified
// amount of NEO between specified blocks. The amount of NEO being passed is in
// its natural non-divisible form (1 NEO as 1, 2 NEO as 2, no multiplication by
// 10⁸ is neeeded as for Fixed8).
func (bc *Blockchain) CalculateClaimable(value int64, startHeight, endHeight uint32) util.Fixed8 {
var amount util.Fixed8
di := uint32(bc.decrementInterval)
ustart := startHeight / di
if genSize := uint32(len(bc.generationAmount)); ustart < genSize {
uend := endHeight / di
iend := endHeight % di
if uend >= genSize {
uend = genSize - 1
iend = di
} else if iend == 0 {
uend--
iend = di
}
istart := startHeight % di
for ustart < uend {
amount += util.Fixed8(di-istart) * util.Fixed8(bc.generationAmount[ustart])
ustart++
istart = 0
}
amount += util.Fixed8(iend-istart) * util.Fixed8(bc.generationAmount[ustart])
}
return amount * util.Fixed8(value)
}
// FeePerByte returns transaction network fee per byte.
// TODO: should be implemented as part of PolicyContract
func (bc *Blockchain) FeePerByte() util.Fixed8 {
return util.Fixed8(1000)
}
// GetMemPool returns the memory pool of the blockchain.
func (bc *Blockchain) GetMemPool() *mempool.Pool {
return &bc.memPool
}
// ApplyPolicyToTxSet applies configured policies to given transaction set. It
// expects slice to be ordered by fee and returns a subslice of it.
func (bc *Blockchain) ApplyPolicyToTxSet(txes []*transaction.Transaction) []*transaction.Transaction {
if bc.config.MaxTransactionsPerBlock != 0 && len(txes) > bc.config.MaxTransactionsPerBlock {
txes = txes[:bc.config.MaxTransactionsPerBlock]
}
return txes
}
func (bc *Blockchain) verifyHeader(currHeader, prevHeader *block.Header) error {
if prevHeader.Hash() != currHeader.PrevHash {
return errors.New("previous header hash doesn't match")
}
if prevHeader.Index+1 != currHeader.Index {
return errors.New("previous header index doesn't match")
}
if prevHeader.Timestamp >= currHeader.Timestamp {
return errors.New("block is not newer than the previous one")
}
return bc.verifyHeaderWitnesses(currHeader, prevHeader)
}
// verifyTx verifies whether a transaction is bonafide or not.
func (bc *Blockchain) verifyTx(t *transaction.Transaction, block *block.Block) error {
height := bc.BlockHeight()
if t.ValidUntilBlock <= height || t.ValidUntilBlock > height+transaction.MaxValidUntilBlockIncrement {
return errors.Errorf("transaction has expired. ValidUntilBlock = %d, current height = %d", t.ValidUntilBlock, height)
}
balance := bc.GetUtilityTokenBalance(t.Sender)
need := t.SystemFee.Add(t.NetworkFee)
if balance.LessThan(need) {
return errors.Errorf("insufficient funds: balance is %v, need: %v", balance, need)
}
size := io.GetVarSize(t)
if size > transaction.MaxTransactionSize {
return errors.Errorf("invalid transaction size = %d. It shoud be less then MaxTransactionSize = %d", io.GetVarSize(t), transaction.MaxTransactionSize)
}
needNetworkFee := util.Fixed8(int64(size) * int64(bc.FeePerByte()))
netFee := t.NetworkFee.Sub(needNetworkFee)
if netFee < 0 {
return errors.Errorf("insufficient funds: net fee is %v, need %v", t.NetworkFee, needNetworkFee)
}
if block == nil {
if ok := bc.memPool.Verify(t, bc); !ok {
return errors.New("invalid transaction due to conflicts with the memory pool")
}
}
for _, a := range t.Attributes {
if a.Usage == transaction.ECDH02 || a.Usage == transaction.ECDH03 {
return errors.Errorf("invalid attribute's usage = %s ", a.Usage)
}
}
return bc.verifyTxWitnesses(t, block)
}
// isTxStillRelevant is a callback for mempool transaction filtering after the
// new block addition. It returns false for transactions already present in the
// chain (added by the new block), transactions using some inputs that are
// already used (double spends) and does witness reverification for non-standard
// contracts. It operates under the assumption that full transaction verification
// was already done so we don't need to check basic things like size, input/output
// correctness, etc.
func (bc *Blockchain) isTxStillRelevant(t *transaction.Transaction) bool {
var recheckWitness bool
if bc.dao.HasTransaction(t.Hash()) {
return false
}
for i := range t.Scripts {
if !vm.IsStandardContract(t.Scripts[i].VerificationScript) {
recheckWitness = true
break
}
}
if recheckWitness {
return bc.verifyTxWitnesses(t, nil) == nil
}
return true
}
// VerifyTx verifies whether a transaction is bonafide or not. Block parameter
// is used for easy interop access and can be omitted for transactions that are
// not yet added into any block.
// Golang implementation of Verify method in C# (https://github.com/neo-project/neo/blob/master/neo/Network/P2P/Payloads/Transaction.cs#L270).
func (bc *Blockchain) VerifyTx(t *transaction.Transaction, block *block.Block) error {
bc.lock.RLock()
defer bc.lock.RUnlock()
return bc.verifyTx(t, block)
}
// PoolTx verifies and tries to add given transaction into the mempool.
func (bc *Blockchain) PoolTx(t *transaction.Transaction) error {
bc.lock.RLock()
defer bc.lock.RUnlock()
if bc.HasTransaction(t.Hash()) {
return ErrAlreadyExists
}
if err := bc.verifyTx(t, nil); err != nil {
return err
}
// Policying.
if err := bc.memPool.Add(t, bc); err != nil {
switch err {
case mempool.ErrOOM:
return ErrOOM
case mempool.ErrConflict:
return ErrAlreadyExists
default:
return err
}
}
return nil
}
//GetStandByValidators returns validators from the configuration.
func (bc *Blockchain) GetStandByValidators() (keys.PublicKeys, error) {
return getValidators(bc.config)
}
// GetValidators returns next block validators.
func (bc *Blockchain) GetValidators() ([]*keys.PublicKey, error) {
return bc.contracts.NEO.GetNextBlockValidatorsInternal(bc, bc.dao)
}
// GetEnrollments returns all registered validators.
func (bc *Blockchain) GetEnrollments() ([]state.Validator, error) {
return bc.contracts.NEO.GetRegisteredValidators(bc.dao)
}
// GetScriptHashesForVerifying returns all the ScriptHashes of a transaction which will be use
// to verify whether the transaction is bonafide or not.
// Golang implementation of GetScriptHashesForVerifying method in C# (https://github.com/neo-project/neo/blob/master/neo/Network/P2P/Payloads/Transaction.cs#L190)
func (bc *Blockchain) GetScriptHashesForVerifying(t *transaction.Transaction) ([]util.Uint160, error) {
hashes := make(map[util.Uint160]bool)
hashes[t.Sender] = true
for _, c := range t.Cosigners {
hashes[c.Account] = true
}
// convert hashes to []util.Uint160
hashesResult := make([]util.Uint160, 0, len(hashes))
for h := range hashes {
hashesResult = append(hashesResult, h)
}
return hashesResult, nil
}
// GetTestVM returns a VM and a Store setup for a test run of some sort of code.
func (bc *Blockchain) GetTestVM(tx *transaction.Transaction) *vm.VM {
systemInterop := bc.newInteropContext(trigger.Application, bc.dao, nil, tx)
vm := SpawnVM(systemInterop)
vm.SetPriceGetter(getPrice)
return vm
}
// ScriptFromWitness returns verification script for provided witness.
// If hash is not equal to the witness script hash, error is returned.
func ScriptFromWitness(hash util.Uint160, witness *transaction.Witness) ([]byte, error) {
verification := witness.VerificationScript
if len(verification) == 0 {
bb := io.NewBufBinWriter()
emit.AppCall(bb.BinWriter, hash)
verification = bb.Bytes()
} else if h := witness.ScriptHash(); hash != h {
return nil, errors.New("witness hash mismatch")
}
return verification, nil
}
// verifyHashAgainstScript verifies given hash against the given witness.
func (bc *Blockchain) verifyHashAgainstScript(hash util.Uint160, witness *transaction.Witness, interopCtx *interop.Context, useKeys bool) error {
verification, err := ScriptFromWitness(hash, witness)
if err != nil {
return err
}
vm := SpawnVM(interopCtx)
vm.LoadScriptWithFlags(verification, smartcontract.ReadOnly)
vm.LoadScript(witness.InvocationScript)
if useKeys {
bc.keyCacheLock.RLock()
if bc.keyCache[hash] != nil {
vm.SetPublicKeys(bc.keyCache[hash])
}
bc.keyCacheLock.RUnlock()
}
err = vm.Run()
if vm.HasFailed() {
return errors.Errorf("vm failed to execute the script with error: %s", err)
}
resEl := vm.Estack().Pop()
if resEl != nil {
if !resEl.Bool() {
return errors.Errorf("signature check failed")
}
if useKeys {
bc.keyCacheLock.RLock()
_, ok := bc.keyCache[hash]
bc.keyCacheLock.RUnlock()
if !ok {
bc.keyCacheLock.Lock()
bc.keyCache[hash] = vm.GetPublicKeys()
bc.keyCacheLock.Unlock()
}
}
} else {
return errors.Errorf("no result returned from the script")
}
return nil
}
// verifyTxWitnesses verifies the scripts (witnesses) that come with a given
// transaction. It can reorder them by ScriptHash, because that's required to
// match a slice of script hashes from the Blockchain. Block parameter
// is used for easy interop access and can be omitted for transactions that are
// not yet added into any block.
// Golang implementation of VerifyWitnesses method in C# (https://github.com/neo-project/neo/blob/master/neo/SmartContract/Helper.cs#L87).
func (bc *Blockchain) verifyTxWitnesses(t *transaction.Transaction, block *block.Block) error {
hashes, err := bc.GetScriptHashesForVerifying(t)
if err != nil {
return err
}
witnesses := t.Scripts
if len(hashes) != len(witnesses) {
return errors.Errorf("expected len(hashes) == len(witnesses). got: %d != %d", len(hashes), len(witnesses))
}
sort.Slice(hashes, func(i, j int) bool { return hashes[i].Less(hashes[j]) })
sort.Slice(witnesses, func(i, j int) bool { return witnesses[i].ScriptHash().Less(witnesses[j].ScriptHash()) })
interopCtx := bc.newInteropContext(trigger.Verification, bc.dao, block, t)
for i := 0; i < len(hashes); i++ {
err := bc.verifyHashAgainstScript(hashes[i], &witnesses[i], interopCtx, false)
if err != nil {
numStr := fmt.Sprintf("witness #%d", i)
return errors.Wrap(err, numStr)
}
}
return nil
}
// verifyHeaderWitnesses is a block-specific implementation of VerifyWitnesses logic.
func (bc *Blockchain) verifyHeaderWitnesses(currHeader, prevHeader *block.Header) error {
var hash util.Uint160
if prevHeader == nil && currHeader.PrevHash.Equals(util.Uint256{}) {
hash = currHeader.Script.ScriptHash()
} else {
hash = prevHeader.NextConsensus
}
interopCtx := bc.newInteropContext(trigger.Verification, bc.dao, nil, nil)
interopCtx.Container = currHeader
return bc.verifyHashAgainstScript(hash, &currHeader.Script, interopCtx, true)
}
// GoverningTokenHash returns the governing token (NEO) native contract hash.
func (bc *Blockchain) GoverningTokenHash() util.Uint160 {
return bc.contracts.NEO.Hash
}
// UtilityTokenHash returns the utility token (GAS) native contract hash.
func (bc *Blockchain) UtilityTokenHash() util.Uint160 {
return bc.contracts.GAS.Hash
}
func hashAndIndexToBytes(h util.Uint256, index uint32) []byte {
buf := io.NewBufBinWriter()
buf.WriteBytes(h.BytesLE())
buf.WriteU32LE(index)
return buf.Bytes()
}
func (bc *Blockchain) secondsPerBlock() int {
return bc.config.SecondsPerBlock
}
func (bc *Blockchain) newInteropContext(trigger trigger.Type, d dao.DAO, block *block.Block, tx *transaction.Transaction) *interop.Context {
ic := interop.NewContext(trigger, bc, d, bc.contracts.Contracts, block, tx, bc.log)
switch {
case tx != nil:
ic.Container = tx
case block != nil:
ic.Container = block
}
return ic
}