neoneo-go/pkg/core/blockchain.go
Roman Khimov 44ae9086b6 core: improve and fix locking in storeBlock
Getting batch, updating Prometheus metrics and pushing events doesn't require
any locking: batch is a local cache batch that no one outside cares about,
Prometheus metrics are not critical to be in perfect sync and events are
asynchronous anyway.

Native contracts also don't require any locks and they should be processed
before dumping storage changes.
2020-05-26 11:36:47 +03:00

1901 lines
58 KiB
Go

package core
import (
"fmt"
"math"
"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/io"
"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/pkg/errors"
"go.uber.org/zap"
)
// Tuning parameters.
const (
headerBatchCount = 2000
version = "0.1.0"
// This one comes from C# code and it's different from the constant used
// when creating an asset with Neo.Asset.Create interop call. It looks
// like 2000000 is coming from the decrementInterval, but C# code doesn't
// contain any relationship between the two, so we should follow this
// behavior.
registeredAssetLifetime = 2 * 2000000
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))
}
if cfg.MaxFreeTransactionsPerBlock <= 0 {
cfg.MaxFreeTransactionsPerBlock = 0
log.Info("MaxFreeTransactionsPerBlock is not set or wrong, setting default value (unlimited)", zap.Int("MaxFreeTransactionsPerBlock", cfg.MaxFreeTransactionsPerBlock))
}
if cfg.MaxFreeTransactionSize <= 0 {
cfg.MaxFreeTransactionSize = 0
log.Info("MaxFreeTransactionSize is not set or wrong, setting default value (unlimited)", zap.Int("MaxFreeTransactionSize", cfg.MaxFreeTransactionSize))
}
if cfg.FeePerExtraByte <= 0 {
cfg.FeePerExtraByte = 0
log.Info("FeePerExtraByte is not set or wrong, setting default value", zap.Float64("FeePerExtraByte", cfg.FeePerExtraByte))
}
bc := &Blockchain{
config: cfg,
dao: dao.NewSimple(s),
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 {
var aerIdx int
for _, tx := range event.block.Transactions {
if tx.Type == transaction.InvocationType {
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() {
close(bc.stopCh)
<-bc.runToExitCh
}
// 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()
buf.BinWriter.WriteU32LE(0) // sys fee is yet to be calculated
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
}
// getSystemFeeAmount returns sum of all system fees for blocks up to h.
// and 0 if no such block exists.
func (bc *Blockchain) getSystemFeeAmount(h util.Uint256) uint32 {
_, sf, _ := bc.dao.GetBlock(h)
return sf
}
// 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, len(block.Transactions))
fee := bc.getSystemFeeAmount(block.PrevHash)
for _, tx := range block.Transactions {
fee += uint32(tx.SystemFee.IntegralValue())
}
if err := cache.StoreAsBlock(block, fee); err != nil {
return err
}
if err := cache.StoreAsCurrentBlock(block); err != nil {
return err
}
for _, tx := range block.Transactions {
if err := cache.StoreAsTransaction(tx, block.Index); err != nil {
return err
}
if err := cache.PutUnspentCoinState(tx.Hash(), state.NewUnspentCoin(block.Index, tx)); err != nil {
return err
}
// Process TX outputs.
if err := processOutputs(tx, cache); err != nil {
return err
}
// Process TX inputs that are grouped by previous hash.
for _, inputs := range transaction.GroupInputsByPrevHash(tx.Inputs) {
prevHash := inputs[0].PrevHash
unspent, err := cache.GetUnspentCoinState(prevHash)
if err != nil {
return err
}
for _, input := range inputs {
if len(unspent.States) <= int(input.PrevIndex) {
return fmt.Errorf("bad input: %s/%d", input.PrevHash.StringLE(), input.PrevIndex)
}
if unspent.States[input.PrevIndex].State&state.CoinSpent != 0 {
return fmt.Errorf("double spend: %s/%d", input.PrevHash.StringLE(), input.PrevIndex)
}
unspent.States[input.PrevIndex].State |= state.CoinSpent
unspent.States[input.PrevIndex].SpendHeight = block.Index
prevTXOutput := &unspent.States[input.PrevIndex].Output
account, err := cache.GetAccountStateOrNew(prevTXOutput.ScriptHash)
if err != nil {
return err
}
if prevTXOutput.AssetID.Equals(GoverningTokenID()) {
err = account.Unclaimed.Put(&state.UnclaimedBalance{
Tx: input.PrevHash,
Index: input.PrevIndex,
Start: unspent.Height,
End: block.Index,
Value: prevTXOutput.Amount,
})
if err != nil {
return err
}
}
balancesLen := len(account.Balances[prevTXOutput.AssetID])
if balancesLen <= 1 {
delete(account.Balances, prevTXOutput.AssetID)
} else {
var index = -1
for i, balance := range account.Balances[prevTXOutput.AssetID] {
if balance.Tx.Equals(input.PrevHash) && balance.Index == input.PrevIndex {
index = i
break
}
}
if index >= 0 {
last := balancesLen - 1
if last > index {
account.Balances[prevTXOutput.AssetID][index] = account.Balances[prevTXOutput.AssetID][last]
}
account.Balances[prevTXOutput.AssetID] = account.Balances[prevTXOutput.AssetID][:last]
}
}
if err = cache.PutAccountState(account); err != nil {
return err
}
}
if err = cache.PutUnspentCoinState(prevHash, unspent); err != nil {
return err
}
}
// Process the underlying type of the TX.
switch t := tx.Data.(type) {
case *transaction.RegisterTX:
err := cache.PutAssetState(&state.Asset{
ID: tx.Hash(),
AssetType: t.AssetType,
Name: t.Name,
Amount: t.Amount,
Precision: t.Precision,
Owner: t.Owner,
Admin: t.Admin,
Expiration: bc.BlockHeight() + registeredAssetLifetime,
})
if err != nil {
return err
}
case *transaction.IssueTX:
for _, res := range bc.GetTransactionResults(tx) {
if res.Amount < 0 {
asset, err := cache.GetAssetState(res.AssetID)
if asset == nil || err != nil {
return fmt.Errorf("issue failed: no asset %s or error %s", res.AssetID, err)
}
asset.Available -= res.Amount
if err := cache.PutAssetState(asset); err != nil {
return err
}
}
}
case *transaction.ClaimTX:
// Remove claimed NEO from spent coins making it unavalaible for
// additional claims.
for _, input := range t.Claims {
scs, err := cache.GetUnspentCoinState(input.PrevHash)
if err == nil {
if len(scs.States) <= int(input.PrevIndex) {
err = errors.New("invalid claim index")
} else if scs.States[input.PrevIndex].State&state.CoinClaimed != 0 {
err = errors.New("double claim")
}
}
if err != nil {
// We can't really do anything about it
// as it's a transaction in a signed block.
bc.log.Warn("FALSE OR DOUBLE CLAIM",
zap.String("PrevHash", input.PrevHash.StringLE()),
zap.Uint16("PrevIndex", input.PrevIndex),
zap.String("tx", tx.Hash().StringLE()),
zap.Uint32("block", block.Index),
)
// "Strict" mode.
if bc.config.VerifyTransactions {
return err
}
break
}
acc, err := cache.GetAccountState(scs.States[input.PrevIndex].ScriptHash)
if err != nil {
return err
}
scs.States[input.PrevIndex].State |= state.CoinClaimed
if err = cache.PutUnspentCoinState(input.PrevHash, scs); err != nil {
return err
}
changed := acc.Unclaimed.Remove(input.PrevHash, input.PrevIndex)
if !changed {
bc.log.Warn("no spent coin in the account",
zap.String("tx", tx.Hash().StringLE()),
zap.String("input", input.PrevHash.StringLE()),
zap.String("account", acc.ScriptHash.String()))
} else if err := cache.PutAccountState(acc); err != nil {
return err
}
}
case *transaction.InvocationTX:
systemInterop := bc.newInteropContext(trigger.Application, cache, block, tx)
v := SpawnVM(systemInterop)
v.LoadScript(t.Script)
v.SetPriceGetter(getPrice)
if bc.config.FreeGasLimit > 0 {
v.SetGasLimit(bc.config.FreeGasLimit + t.Gas)
}
err := v.Run()
if !v.HasFailed() {
_, err := systemInterop.DAO.Persist()
if err != nil {
return errors.Wrap(err, "failed to persist invocation results")
}
for _, note := range systemInterop.Notifications {
arr, ok := note.Item.Value().([]vm.StackItem)
if !ok || len(arr) != 4 {
continue
}
op, ok := arr[0].Value().([]byte)
if !ok || (string(op) != "transfer" && string(op) != "Transfer") {
continue
}
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 {
continue
}
}
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 {
continue
}
}
amount, ok := arr[3].Value().(*big.Int)
if !ok {
bs, ok := arr[3].Value().([]byte)
if !ok {
continue
}
amount = emit.BytesToInt(bs)
}
bc.processNEP5Transfer(cache, tx, block, note.ScriptHash, from, to, amount.Int64())
}
} 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")
}
}
}
for i := range bc.contracts.Contracts {
systemInterop := bc.newInteropContext(trigger.Application, cache, block, nil)
if err := bc.contracts.Contracts[i].OnPersist(systemInterop); err != nil {
return err
}
}
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 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, tx *transaction.Transaction, 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: tx.Hash(),
}
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 {
return util.Fixed8FromInt64(bc.GetNEP5Balances(acc).Trackers[bc.contracts.GAS.Hash].Balance)
}
// LastBatch returns last persisted storage batch.
func (bc *Blockchain) LastBatch() *storage.MemBatch {
return bc.lastBatch
}
// processOutputs processes transaction outputs.
func processOutputs(tx *transaction.Transaction, dao *dao.Cached) error {
for index, output := range tx.Outputs {
account, err := dao.GetAccountStateOrNew(output.ScriptHash)
if err != nil {
return err
}
account.Balances[output.AssetID] = append(account.Balances[output.AssetID], state.UnspentBalance{
Tx: tx.Hash(),
Index: uint16(index),
Value: output.Amount,
})
if err = dao.PutAccountState(account); err != nil {
return err
}
}
return nil
}
// 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)
}
// GetAssetState returns asset state from its assetID.
func (bc *Blockchain) GetAssetState(assetID util.Uint256) *state.Asset {
asset, err := bc.dao.GetAssetState(assetID)
if asset == nil && err != storage.ErrKeyNotFound {
bc.log.Warn("failed to get asset state",
zap.Stringer("asset", assetID),
zap.Error(err))
}
return asset
}
// 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
}
// GetUnspentCoinState returns unspent coin state for given tx hash.
func (bc *Blockchain) GetUnspentCoinState(hash util.Uint256) *state.UnspentCoin {
ucs, err := bc.dao.GetUnspentCoinState(hash)
if ucs == nil && err != storage.ErrKeyNotFound {
bc.log.Warn("failed to get unspent coin state", zap.Error(err))
}
return ucs
}
// 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 which can be claimed for a transaction with value.
// First return value is GAS generated between startHeight and endHeight.
// Second return value is GAS returned from accumulated SystemFees between startHeight and endHeight.
func (bc *Blockchain) CalculateClaimable(value util.Fixed8, startHeight, endHeight uint32) (util.Fixed8, util.Fixed8, error) {
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])
}
if startHeight == 0 {
startHeight++
}
h := bc.GetHeaderHash(int(startHeight - 1))
feeStart := bc.getSystemFeeAmount(h)
h = bc.GetHeaderHash(int(endHeight - 1))
feeEnd := bc.getSystemFeeAmount(h)
sysFeeTotal := util.Fixed8(feeEnd - feeStart)
ratio := value / 100000000
return amount * ratio, sysFeeTotal * ratio, nil
}
// References maps transaction's inputs into a slice of InOuts, effectively
// joining each Input with the corresponding Output.
// @TODO: unfortunately we couldn't attach this method to the Transaction struct in the
// transaction package because of a import cycle problem. Perhaps we should think to re-design
// the code base to avoid this situation.
func (bc *Blockchain) References(t *transaction.Transaction) ([]transaction.InOut, error) {
return bc.references(t.Inputs)
}
// references is an internal implementation of References that operates directly
// on a slice of Input.
func (bc *Blockchain) references(ins []transaction.Input) ([]transaction.InOut, error) {
references := make([]transaction.InOut, 0, len(ins))
for _, inputs := range transaction.GroupInputsByPrevHash(ins) {
prevHash := inputs[0].PrevHash
unspent, err := bc.dao.GetUnspentCoinState(prevHash)
if err != nil {
return nil, errors.New("bad input reference")
}
for _, in := range inputs {
if int(in.PrevIndex) > len(unspent.States)-1 {
return nil, errors.New("bad input reference")
}
references = append(references, transaction.InOut{In: *in, Out: unspent.States[in.PrevIndex].Output})
}
}
return references, nil
}
// 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)
}
// IsLowPriority checks given fee for being less than configured
// LowPriorityThreshold.
func (bc *Blockchain) IsLowPriority(fee util.Fixed8) bool {
return fee < util.Fixed8FromFloat(bc.GetConfig().LowPriorityThreshold)
}
// 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 []mempool.TxWithFee) []mempool.TxWithFee {
if bc.config.MaxTransactionsPerBlock != 0 && len(txes) > bc.config.MaxTransactionsPerBlock {
txes = txes[:bc.config.MaxTransactionsPerBlock]
}
maxFree := bc.config.MaxFreeTransactionsPerBlock
if maxFree != 0 {
lowStart := sort.Search(len(txes), func(i int) bool {
return bc.IsLowPriority(txes[i].Fee)
})
if lowStart+maxFree < len(txes) {
txes = txes[:lowStart+maxFree]
}
}
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 transaction.HaveDuplicateInputs(t.Inputs) {
return errors.New("invalid transaction's inputs")
}
if block == nil {
if ok := bc.memPool.Verify(t, bc); !ok {
return errors.New("invalid transaction due to conflicts with the memory pool")
}
}
if bc.dao.IsDoubleSpend(t) {
return errors.New("invalid transaction caused by double spending")
}
if err := bc.verifyOutputs(t); err != nil {
return errors.Wrap(err, "wrong outputs")
}
refs, err := bc.References(t)
if err != nil {
return err
}
results := refsAndOutsToResults(refs, t.Outputs)
if err := bc.verifyResults(t, results); err != nil {
return err
}
for _, a := range t.Attributes {
if a.Usage == transaction.ECDH02 || a.Usage == transaction.ECDH03 {
return errors.Errorf("invalid attribute's usage = %s ", a.Usage)
}
}
switch t.Type {
case transaction.ClaimType:
claim := t.Data.(*transaction.ClaimTX)
if transaction.HaveDuplicateInputs(claim.Claims) {
return errors.New("duplicate claims")
}
if bc.dao.IsDoubleClaim(claim) {
return errors.New("double claim")
}
if err := bc.verifyClaims(t, results); err != nil {
return err
}
case transaction.InvocationType:
inv := t.Data.(*transaction.InvocationTX)
if inv.Gas.FractionalValue() != 0 {
return errors.New("invocation gas can only be integer")
}
}
return bc.verifyTxWitnesses(t, block)
}
func (bc *Blockchain) verifyClaims(tx *transaction.Transaction, results []*transaction.Result) (err error) {
t := tx.Data.(*transaction.ClaimTX)
var result *transaction.Result
for i := range results {
if results[i].AssetID == UtilityTokenID() {
result = results[i]
break
}
}
if result == nil || result.Amount.GreaterThan(0) {
return errors.New("invalid output in claim tx")
}
bonus, err := bc.calculateBonus(t.Claims)
if err == nil && bonus != -result.Amount {
return fmt.Errorf("wrong bonus calculated in claim tx: %s != %s",
bonus.String(), (-result.Amount).String())
}
return err
}
func (bc *Blockchain) calculateBonus(claims []transaction.Input) (util.Fixed8, error) {
unclaimed := []*spentCoin{}
inputs := transaction.GroupInputsByPrevHash(claims)
for _, group := range inputs {
h := group[0].PrevHash
unspent, err := bc.dao.GetUnspentCoinState(h)
if err != nil {
return 0, err
}
for _, c := range group {
if len(unspent.States) <= int(c.PrevIndex) {
return 0, fmt.Errorf("can't find spent coins for %s (%d)", c.PrevHash.StringLE(), c.PrevIndex)
}
if unspent.States[c.PrevIndex].State&state.CoinSpent == 0 {
return 0, fmt.Errorf("not spent yet: %s/%d", c.PrevHash.StringLE(), c.PrevIndex)
}
if unspent.States[c.PrevIndex].State&state.CoinClaimed != 0 {
return 0, fmt.Errorf("already claimed: %s/%d", c.PrevHash.StringLE(), c.PrevIndex)
}
unclaimed = append(unclaimed, &spentCoin{
Output: &unspent.States[c.PrevIndex].Output,
StartHeight: unspent.Height,
EndHeight: unspent.States[c.PrevIndex].SpendHeight,
})
}
}
return bc.calculateBonusInternal(unclaimed)
}
func (bc *Blockchain) calculateBonusInternal(scs []*spentCoin) (util.Fixed8, error) {
var claimed util.Fixed8
for _, sc := range scs {
gen, sys, err := bc.CalculateClaimable(sc.Output.Amount, sc.StartHeight, sc.EndHeight)
if err != nil {
return 0, err
}
claimed += gen + sys
}
return claimed, nil
}
// 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
}
if bc.dao.IsDoubleSpend(t) {
return false
}
if t.Type == transaction.ClaimType {
claim := t.Data.(*transaction.ClaimTX)
if bc.dao.IsDoubleClaim(claim) {
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 t.Type != transaction.ClaimType {
txSize := io.GetVarSize(t)
maxFree := bc.config.MaxFreeTransactionSize
if maxFree != 0 && txSize > maxFree {
if bc.IsLowPriority(t.NetworkFee) ||
t.NetworkFee < util.Fixed8FromFloat(bc.config.FeePerExtraByte)*util.Fixed8(txSize-maxFree) {
return ErrPolicy
}
}
}
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
}
func (bc *Blockchain) verifyOutputs(t *transaction.Transaction) error {
for assetID, outputs := range t.GroupOutputByAssetID() {
assetState := bc.GetAssetState(assetID)
if assetState == nil {
return fmt.Errorf("no asset state for %s", assetID.StringLE())
}
if assetState.Expiration < bc.blockHeight+1 && assetState.AssetType != transaction.GoverningToken && assetState.AssetType != transaction.UtilityToken {
return fmt.Errorf("asset %s expired", assetID.StringLE())
}
for _, out := range outputs {
if int64(out.Amount)%int64(math.Pow10(8-int(assetState.Precision))) != 0 {
return fmt.Errorf("output is not compliant with %s asset precision", assetID.StringLE())
}
}
}
return nil
}
func (bc *Blockchain) verifyResults(t *transaction.Transaction, results []*transaction.Result) error {
var resultsDestroy []*transaction.Result
var resultsIssue []*transaction.Result
for _, re := range results {
if re.Amount.GreaterThan(util.Fixed8(0)) {
resultsDestroy = append(resultsDestroy, re)
}
if re.Amount.LessThan(util.Fixed8(0)) {
resultsIssue = append(resultsIssue, re)
}
}
if len(resultsDestroy) > 1 {
return errors.New("tx has more than 1 destroy output")
}
if len(resultsDestroy) == 1 && resultsDestroy[0].AssetID != UtilityTokenID() {
return errors.New("tx destroys non-utility token")
}
sysfee := t.SystemFee
if sysfee.GreaterThan(util.Fixed8(0)) {
if len(resultsDestroy) == 0 {
return fmt.Errorf("system requires to pay %s fee, but tx pays nothing", sysfee.String())
}
if resultsDestroy[0].Amount.LessThan(sysfee) {
return fmt.Errorf("system requires to pay %s fee, but tx pays %s only", sysfee.String(), resultsDestroy[0].Amount.String())
}
}
switch t.Type {
case transaction.ClaimType:
for _, r := range resultsIssue {
if r.AssetID != UtilityTokenID() {
return errors.New("miner or claim tx issues non-utility tokens")
}
}
break
case transaction.IssueType:
for _, r := range resultsIssue {
if r.AssetID == UtilityTokenID() {
return errors.New("issue tx issues utility tokens")
}
asset, err := bc.dao.GetAssetState(r.AssetID)
if asset == nil || err != nil {
return errors.New("invalid asset in issue tx")
}
if asset.Available < r.Amount {
return errors.New("trying to issue more than available")
}
}
break
default:
if len(resultsIssue) > 0 {
return errors.New("non issue/miner/claim tx issues tokens")
}
break
}
return nil
}
// GetTransactionResults returns the transaction results aggregate by assetID.
// Golang of GetTransationResults method in C# (https://github.com/neo-project/neo/blob/master/neo/Network/P2P/Payloads/Transaction.cs#L207)
func (bc *Blockchain) GetTransactionResults(t *transaction.Transaction) []*transaction.Result {
references, err := bc.References(t)
if err != nil {
return nil
}
return refsAndOutsToResults(references, t.Outputs)
}
// mapReferencesToResults returns cumulative results of transaction based in its
// references and outputs.
func refsAndOutsToResults(references []transaction.InOut, outputs []transaction.Output) []*transaction.Result {
var results []*transaction.Result
tempResult := make(map[util.Uint256]util.Fixed8)
for _, inout := range references {
c := tempResult[inout.Out.AssetID]
tempResult[inout.Out.AssetID] = c.Add(inout.Out.Amount)
}
for _, output := range outputs {
c := tempResult[output.AssetID]
tempResult[output.AssetID] = c.Sub(output.Amount)
}
results = []*transaction.Result{} // this assignment is necessary. (Most of the time amount == 0 and results is the empty slice.)
for assetID, amount := range tempResult {
if amount != util.Fixed8(0) {
results = append(results, &transaction.Result{
AssetID: assetID,
Amount: amount,
})
}
}
return results
}
//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) {
references, err := bc.References(t)
if err != nil {
return nil, err
}
hashes := make(map[util.Uint160]bool)
for i := range references {
hashes[references[i].Out.ScriptHash] = true
}
for a, outputs := range t.GroupOutputByAssetID() {
as := bc.GetAssetState(a)
if as == nil {
return nil, errors.New("Invalid operation")
}
if as.AssetType&transaction.DutyFlag != 0 {
for _, o := range outputs {
h := o.ScriptHash
if _, ok := hashes[h]; !ok {
hashes[h] = true
}
}
}
}
hashes[t.Sender] = true
for _, c := range t.Cosigners {
hashes[c.Account] = true
}
switch t.Type {
case transaction.ClaimType:
claim := t.Data.(*transaction.ClaimTX)
refs, err := bc.references(claim.Claims)
if err != nil {
return nil, err
}
for i := range refs {
hashes[refs[i].Out.ScriptHash] = true
}
case transaction.IssueType:
for _, res := range refsAndOutsToResults(references, t.Outputs) {
if res.Amount < 0 {
asset, err := bc.dao.GetAssetState(res.AssetID)
if asset == nil || err != nil {
return nil, errors.New("invalid asset in issue tx")
}
hashes[asset.Issuer] = true
}
}
case transaction.RegisterType:
reg := t.Data.(*transaction.RegisterTX)
hashes[reg.Owner.GetScriptHash()] = 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() *vm.VM {
systemInterop := bc.newInteropContext(trigger.Application, bc.dao, nil, nil)
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.LoadScript(verification)
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).
// Unfortunately the IVerifiable interface could not be implemented because we can't move the References method in blockchain.go to the transaction.go file.
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
}