neoneo-go/pkg/core/blockchain.go
2020-01-22 14:32:21 +03:00

1500 lines
44 KiB
Go

package core
import (
"bytes"
"fmt"
"math"
"math/big"
"sort"
"strconv"
"sync/atomic"
"time"
"github.com/CityOfZion/neo-go/config"
"github.com/CityOfZion/neo-go/pkg/core/block"
"github.com/CityOfZion/neo-go/pkg/core/mempool"
"github.com/CityOfZion/neo-go/pkg/core/state"
"github.com/CityOfZion/neo-go/pkg/core/storage"
"github.com/CityOfZion/neo-go/pkg/core/transaction"
"github.com/CityOfZion/neo-go/pkg/crypto/keys"
"github.com/CityOfZion/neo-go/pkg/io"
"github.com/CityOfZion/neo-go/pkg/smartcontract"
"github.com/CityOfZion/neo-go/pkg/smartcontract/trigger"
"github.com/CityOfZion/neo-go/pkg/util"
"github.com/CityOfZion/neo-go/pkg/vm"
"github.com/pkg/errors"
"go.uber.org/zap"
)
// Tuning parameters.
const (
headerBatchCount = 2000
version = "0.0.3"
// 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
)
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.
type Blockchain struct {
config config.ProtocolConfiguration
// Data access object for CRUD operations around storage.
dao *dao
// 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
// 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
// cache for block verification keys.
keyCache map[util.Uint160]map[string]*keys.PublicKey
log *zap.Logger
}
type headersOpFunc func(headerList *HeaderHashList)
// NewBlockchain returns a new blockchain object the will use the
// given Store as its underlying storage.
func NewBlockchain(s storage.Store, cfg config.ProtocolConfiguration, log *zap.Logger) (*Blockchain, error) {
if log == nil {
return nil, errors.New("empty logger")
}
bc := &Blockchain{
config: cfg,
dao: newDao(s),
headersOp: make(chan headersOpFunc),
headersOpDone: make(chan struct{}),
stopCh: make(chan struct{}),
runToExitCh: make(chan struct{}),
memPool: mempool.NewMemPool(50000),
keyCache: make(map[util.Uint160]map[string]*keys.PublicKey),
log: log,
}
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.
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)
}()
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)
}
}
}
// 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 {
expectedHeight := bc.BlockHeight() + 1
if expectedHeight != block.Index {
return fmt.Errorf("expected block %d, but passed block %d", expectedHeight, block.Index)
}
if bc.config.VerifyBlocks {
err := block.Verify()
if err == nil {
err = bc.VerifyBlock(block)
}
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)
}
}
}
}
headerLen := bc.headerListLen()
if int(block.Index) == headerLen {
err := bc.AddHeaders(block.Header())
if err != nil {
return err
}
}
return bc.storeBlock(block)
}
// AddHeaders processes the given headers and add them to the
// HeaderHashList.
func (bc *Blockchain) AddHeaders(headers ...*block.Header) (err error) {
var (
start = time.Now()
batch = bc.dao.store.Batch()
)
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 := newCachedDao(bc.dao.store)
if err := cache.StoreAsBlock(block, 0); 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(), NewUnspentCoinState(len(tx.Outputs))); 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 prevHash, inputs := range tx.GroupInputsByPrevHash() {
prevTX, prevTXHeight, err := bc.GetTransaction(prevHash)
if err != nil {
return fmt.Errorf("could not find previous TX: %s", prevHash)
}
for _, input := range inputs {
unspent, err := cache.GetUnspentCoinStateOrNew(input.PrevHash)
if err != nil {
return err
}
unspent.states[input.PrevIndex] = state.CoinSpent
if err = cache.PutUnspentCoinState(input.PrevHash, unspent); err != nil {
return err
}
prevTXOutput := prevTX.Outputs[input.PrevIndex]
account, err := cache.GetAccountStateOrNew(prevTXOutput.ScriptHash)
if err != nil {
return err
}
if prevTXOutput.AssetID.Equals(governingTokenTX().Hash()) {
spentCoin := NewSpentCoinState(input.PrevHash, prevTXHeight)
spentCoin.items[input.PrevIndex] = block.Index
if err = cache.PutSpentCoinState(input.PrevHash, spentCoin); err != nil {
return err
}
if err = processTXWithValidatorsSubtract(account, cache, prevTXOutput.Amount); 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 {
copy(account.Balances[prevTXOutput.AssetID][index:], account.Balances[prevTXOutput.AssetID][index+1:])
account.Balances[prevTXOutput.AssetID] = account.Balances[prevTXOutput.AssetID][:balancesLen-1]
}
}
if err = cache.PutAccountState(account); 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.GetSpentCoinsOrNew(input.PrevHash)
if err != nil {
return err
}
if scs.txHash == input.PrevHash {
// Existing scs.
delete(scs.items, input.PrevIndex)
if err = cache.PutSpentCoinState(input.PrevHash, scs); err != nil {
return err
}
} else {
// Uninitialized, new, forget about it.
if err = cache.DeleteSpentCoinState(input.PrevHash); err != nil {
return err
}
}
}
case *transaction.EnrollmentTX:
if err := processEnrollmentTX(cache, t); err != nil {
return err
}
case *transaction.StateTX:
if err := processStateTX(cache, t); err != nil {
return err
}
case *transaction.PublishTX:
var properties smartcontract.PropertyState
if t.NeedStorage {
properties |= smartcontract.HasStorage
}
contract := &state.Contract{
Script: t.Script,
ParamList: t.ParamList,
ReturnType: t.ReturnType,
Properties: properties,
Name: t.Name,
CodeVersion: t.CodeVersion,
Author: t.Author,
Email: t.Email,
Description: t.Description,
}
if err := cache.PutContractState(contract); err != nil {
return err
}
case *transaction.InvocationTX:
systemInterop := bc.newInteropContext(trigger.Application, cache.store, block, tx)
v := bc.spawnVMWithInterops(systemInterop)
v.SetCheckedHash(tx.VerificationHash().BytesBE())
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" {
continue
}
from, ok := arr[1].Value().([]byte)
if !ok {
continue
}
to, ok := arr[2].Value().([]byte)
if !ok {
continue
}
amount, ok := arr[3].Value().(*big.Int)
if !ok {
continue
}
// TODO: #498
_, _, _, _ = op, from, to, amount
}
} 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.Stack("estack"),
Events: systemInterop.notifications,
}
err = cache.PutAppExecResult(aer)
if err != nil {
return errors.Wrap(err, "failed to store notifications")
}
}
}
_, err := cache.Persist()
if err != nil {
return err
}
bc.topBlock.Store(block)
atomic.StoreUint32(&bc.blockHeight, block.Index)
updateBlockHeightMetric(block.Index)
for _, tx := range block.Transactions {
bc.memPool.Remove(tx.Hash())
}
return nil
}
// processOutputs processes transaction outputs.
func processOutputs(tx *transaction.Transaction, dao *cachedDao) 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
}
if err = processTXWithValidatorsAdd(&output, account, dao); err != nil {
return err
}
}
return nil
}
func processTXWithValidatorsAdd(output *transaction.Output, account *state.Account, dao *cachedDao) error {
if output.AssetID.Equals(governingTokenTX().Hash()) && len(account.Votes) > 0 {
for _, vote := range account.Votes {
validatorState, err := dao.GetValidatorStateOrNew(vote)
if err != nil {
return err
}
validatorState.Votes += output.Amount
if err = dao.PutValidatorState(validatorState); err != nil {
return err
}
}
}
return nil
}
func processTXWithValidatorsSubtract(account *state.Account, dao *cachedDao, toSubtract util.Fixed8) error {
for _, vote := range account.Votes {
validator, err := dao.GetValidatorStateOrNew(vote)
if err != nil {
return err
}
validator.Votes -= toSubtract
if !validator.RegisteredAndHasVotes() {
if err := dao.DeleteValidatorState(validator); err != nil {
return err
}
} else {
if err := dao.PutValidatorState(validator); err != nil {
return err
}
}
}
return nil
}
func processValidatorStateDescriptor(descriptor *transaction.StateDescriptor, dao *cachedDao) error {
publicKey := &keys.PublicKey{}
err := publicKey.DecodeBytes(descriptor.Key)
if err != nil {
return err
}
validatorState, err := dao.GetValidatorStateOrNew(publicKey)
if err != nil {
return err
}
if descriptor.Field == "Registered" {
isRegistered, err := strconv.ParseBool(string(descriptor.Value))
if err != nil {
return err
}
validatorState.Registered = isRegistered
return dao.PutValidatorState(validatorState)
}
return nil
}
func processAccountStateDescriptor(descriptor *transaction.StateDescriptor, dao *cachedDao) error {
hash, err := util.Uint160DecodeBytesBE(descriptor.Key)
if err != nil {
return err
}
account, err := dao.GetAccountStateOrNew(hash)
if err != nil {
return err
}
if descriptor.Field == "Votes" {
balance := account.GetBalanceValues()[governingTokenTX().Hash()]
if err = processTXWithValidatorsSubtract(account, dao, balance); err != nil {
return err
}
votes := keys.PublicKeys{}
err := votes.DecodeBytes(descriptor.Value)
if err != nil {
return err
}
if votes.Len() != len(account.Votes) {
account.Votes = votes
for _, vote := range votes {
validator, err := dao.GetValidatorStateOrNew(vote)
if err != nil {
return err
}
if err := dao.PutValidatorState(validator); 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)
}
// 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
}
if len(block.Transactions) == 0 {
return nil, fmt.Errorf("only header is available")
}
for _, tx := range block.Transactions {
stx, _, err := bc.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) *UnspentCoinState {
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
}
// References returns a map with input coin reference (prevhash and index) as key
// and transaction output as value from a transaction t.
// @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) map[transaction.Input]*transaction.Output {
references := make(map[transaction.Input]*transaction.Output)
for prevHash, inputs := range t.GroupInputsByPrevHash() {
if tx, _, err := bc.GetTransaction(prevHash); err != nil {
tx = nil
} else if tx != nil {
for _, in := range inputs {
references[*in] = &tx.Outputs[in.PrevIndex]
}
} else {
references = nil
}
}
return references
}
// FeePerByte returns network fee divided by the size of the transaction.
func (bc *Blockchain) FeePerByte(t *transaction.Transaction) util.Fixed8 {
return bc.NetworkFee(t).Div(int64(io.GetVarSize(t)))
}
// NetworkFee returns network fee.
func (bc *Blockchain) NetworkFee(t *transaction.Transaction) util.Fixed8 {
inputAmount := util.Fixed8FromInt64(0)
for _, txOutput := range bc.References(t) {
if txOutput.AssetID == utilityTokenTX().Hash() {
inputAmount.Add(txOutput.Amount)
}
}
outputAmount := util.Fixed8FromInt64(0)
for _, txOutput := range t.Outputs {
if txOutput.AssetID == utilityTokenTX().Hash() {
outputAmount.Add(txOutput.Amount)
}
}
return inputAmount.Sub(outputAmount).Sub(bc.SystemFee(t))
}
// SystemFee returns system fee.
func (bc *Blockchain) SystemFee(t *transaction.Transaction) util.Fixed8 {
return bc.GetConfig().SystemFee.TryGetValue(t.Type)
}
// IsLowPriority flags a transaction as low priority if the network fee is less than
// LowPriorityThreshold.
func (bc *Blockchain) IsLowPriority(t *transaction.Transaction) bool {
return bc.NetworkFee(t) < util.Fixed8FromFloat(bc.GetConfig().LowPriorityThreshold)
}
// GetMemPool returns the memory pool of the blockchain.
func (bc *Blockchain) GetMemPool() mempool.Pool {
return bc.memPool
}
// VerifyBlock verifies block against its current state.
func (bc *Blockchain) VerifyBlock(block *block.Block) error {
prevHeader, err := bc.GetHeader(block.PrevHash)
if err != nil {
return errors.Wrap(err, "unable to get previous header")
}
if prevHeader.Index+1 != block.Index {
return errors.New("previous header index doesn't match")
}
if prevHeader.Timestamp >= block.Timestamp {
return errors.New("block is not newer than the previous one")
}
return bc.verifyBlockWitnesses(block, prevHeader)
}
// 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 {
if io.GetVarSize(t) > transaction.MaxTransactionSize {
return errors.Errorf("invalid transaction size = %d. It shoud be less then MaxTransactionSize = %d", io.GetVarSize(t), transaction.MaxTransactionSize)
}
if ok := bc.verifyInputs(t); !ok {
return errors.New("invalid transaction's inputs")
}
if block == nil {
if ok := bc.memPool.Verify(t); !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")
}
if err := bc.verifyResults(t); 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)
}
}
return bc.verifyTxWitnesses(t, block)
}
func (bc *Blockchain) verifyInputs(t *transaction.Transaction) bool {
for i := 1; i < len(t.Inputs); i++ {
for j := 0; j < i; j++ {
if t.Inputs[i].PrevHash == t.Inputs[j].PrevHash && t.Inputs[i].PrevIndex == t.Inputs[j].PrevIndex {
return false
}
}
}
return true
}
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) error {
results := bc.GetTransactionResults(t)
if results == nil {
return errors.New("tx has no results")
}
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 != utilityTokenTX().Hash() {
return errors.New("tx destroys non-utility token")
}
sysfee := bc.SystemFee(t)
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.MinerType, transaction.ClaimType:
for _, r := range resultsIssue {
if r.AssetID != utilityTokenTX().Hash() {
return errors.New("miner or claim tx issues non-utility tokens")
}
}
break
case transaction.IssueType:
for _, r := range resultsIssue {
if r.AssetID == utilityTokenTX().Hash() {
return errors.New("issue tx issues utility tokens")
}
}
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 {
var tempResults []*transaction.Result
var results []*transaction.Result
tempGroupResult := make(map[util.Uint256]util.Fixed8)
references := bc.References(t)
if references == nil {
return nil
}
for _, output := range references {
tempResults = append(tempResults, &transaction.Result{
AssetID: output.AssetID,
Amount: output.Amount,
})
}
for _, output := range t.Outputs {
tempResults = append(tempResults, &transaction.Result{
AssetID: output.AssetID,
Amount: -output.Amount,
})
}
for _, r := range tempResults {
if amount, ok := tempGroupResult[r.AssetID]; ok {
tempGroupResult[r.AssetID] = amount.Add(r.Amount)
} else {
tempGroupResult[r.AssetID] = r.Amount
}
}
results = []*transaction.Result{} // this assignment is necessary. (Most of the time amount == 0 and results is the empty slice.)
for assetID, amount := range tempGroupResult {
if amount != util.Fixed8(0) {
results = append(results, &transaction.Result{
AssetID: assetID,
Amount: amount,
})
}
}
return results
}
// GetScriptHashesForVerifyingClaim returns all ScriptHashes of Claim transaction
// which has a different implementation from generic GetScriptHashesForVerifying.
func (bc *Blockchain) GetScriptHashesForVerifyingClaim(t *transaction.Transaction) ([]util.Uint160, error) {
// Avoiding duplicates.
hashmap := make(map[util.Uint160]bool)
claim := t.Data.(*transaction.ClaimTX)
clGroups := make(map[util.Uint256][]*transaction.Input)
for _, in := range claim.Claims {
clGroups[in.PrevHash] = append(clGroups[in.PrevHash], in)
}
for group, inputs := range clGroups {
refTx, _, err := bc.GetTransaction(group)
if err != nil {
return nil, err
}
for _, input := range inputs {
if len(refTx.Outputs) <= int(input.PrevIndex) {
return nil, fmt.Errorf("wrong PrevIndex reference")
}
hashmap[refTx.Outputs[input.PrevIndex].ScriptHash] = true
}
}
if len(hashmap) > 0 {
hashes := make([]util.Uint160, 0, len(hashmap))
for k := range hashmap {
hashes = append(hashes, k)
}
return hashes, nil
}
return nil, fmt.Errorf("no hashes found")
}
//GetStandByValidators returns validators from the configuration.
func (bc *Blockchain) GetStandByValidators() (keys.PublicKeys, error) {
return getValidators(bc.config)
}
// GetValidators returns validators.
// Golang implementation of GetValidators method in C# (https://github.com/neo-project/neo/blob/c64748ecbac3baeb8045b16af0d518398a6ced24/neo/Persistence/Snapshot.cs#L182)
func (bc *Blockchain) GetValidators(txes ...*transaction.Transaction) ([]*keys.PublicKey, error) {
cache := newCachedDao(bc.dao.store)
if len(txes) > 0 {
for _, tx := range txes {
// iterate through outputs
for index, output := range tx.Outputs {
accountState, err := cache.GetAccountState(output.ScriptHash)
if err != nil {
return nil, err
}
accountState.Balances[output.AssetID] = append(accountState.Balances[output.AssetID], state.UnspentBalance{
Tx: tx.Hash(),
Index: uint16(index),
Value: output.Amount,
})
if err := cache.PutAccountState(accountState); err != nil {
return nil, err
}
if err = processTXWithValidatorsAdd(&output, accountState, cache); err != nil {
return nil, err
}
}
// group inputs by the same previous hash and iterate through inputs
group := make(map[util.Uint256][]*transaction.Input)
for i := range tx.Inputs {
hash := tx.Inputs[i].PrevHash
group[hash] = append(group[hash], &tx.Inputs[i])
}
for hash, inputs := range group {
prevTx, _, err := cache.GetTransaction(hash)
if err != nil {
return nil, err
}
// process inputs
for _, input := range inputs {
prevOutput := prevTx.Outputs[input.PrevIndex]
accountState, err := cache.GetAccountStateOrNew(prevOutput.ScriptHash)
if err != nil {
return nil, err
}
// process account state votes: if there are any -> validators will be updated.
if err = processTXWithValidatorsSubtract(accountState, cache, prevOutput.Amount); err != nil {
return nil, err
}
delete(accountState.Balances, prevOutput.AssetID)
if err = cache.PutAccountState(accountState); err != nil {
return nil, err
}
}
}
switch t := tx.Data.(type) {
case *transaction.EnrollmentTX:
if err := processEnrollmentTX(cache, t); err != nil {
return nil, err
}
case *transaction.StateTX:
if err := processStateTX(cache, t); err != nil {
return nil, err
}
}
}
}
validators := cache.GetValidators()
count := state.GetValidatorsWeightedAverage(validators)
standByValidators, err := bc.GetStandByValidators()
if err != nil {
return nil, err
}
if count < len(standByValidators) {
count = len(standByValidators)
}
uniqueSBValidators := standByValidators.Unique()
pubKeys := keys.PublicKeys{}
for _, validator := range validators {
if validator.RegisteredAndHasVotes() || uniqueSBValidators.Contains(validator.PublicKey) {
pubKeys = append(pubKeys, validator.PublicKey)
}
}
sort.Sort(sort.Reverse(pubKeys))
if pubKeys.Len() >= count {
return pubKeys[:count], nil
}
result := pubKeys.Unique()
for i := 0; i < uniqueSBValidators.Len() && result.Len() < count; i++ {
result = append(result, uniqueSBValidators[i])
}
return result, nil
}
func processStateTX(dao *cachedDao, tx *transaction.StateTX) error {
for _, desc := range tx.Descriptors {
switch desc.Type {
case transaction.Account:
if err := processAccountStateDescriptor(desc, dao); err != nil {
return err
}
case transaction.Validator:
if err := processValidatorStateDescriptor(desc, dao); err != nil {
return err
}
}
}
return nil
}
func processEnrollmentTX(dao *cachedDao, tx *transaction.EnrollmentTX) error {
validatorState, err := dao.GetValidatorStateOrNew(&tx.PublicKey)
if err != nil {
return err
}
validatorState.Registered = true
return dao.PutValidatorState(validatorState)
}
// 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) {
if t.Type == transaction.ClaimType {
return bc.GetScriptHashesForVerifyingClaim(t)
}
references := bc.References(t)
if references == nil {
return nil, errors.New("Invalid operation")
}
hashes := make(map[util.Uint160]bool)
for _, i := range t.Inputs {
h := references[i].ScriptHash
if _, ok := hashes[h]; !ok {
hashes[h] = true
}
}
for _, a := range t.Attributes {
if a.Usage == transaction.Script {
h, err := util.Uint160DecodeBytesBE(a.Data)
if err != nil {
return nil, err
}
if _, ok := hashes[h]; !ok {
hashes[h] = 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
}
}
}
}
// convert hashes to []util.Uint160
hashesResult := make([]util.Uint160, 0, len(hashes))
for h := range hashes {
hashesResult = append(hashesResult, h)
}
return hashesResult, nil
}
// spawnVMWithInterops returns a VM with script getter and interop functions set
// up for current blockchain.
func (bc *Blockchain) spawnVMWithInterops(interopCtx *interopContext) *vm.VM {
vm := vm.New()
vm.SetScriptGetter(func(hash util.Uint160) []byte {
cs, err := interopCtx.dao.GetContractState(hash)
if err != nil {
return nil
}
return cs.Script
})
vm.RegisterInteropGetter(interopCtx.getSystemInterop)
vm.RegisterInteropGetter(interopCtx.getNeoInterop)
return vm
}
// GetTestVM returns a VM and a Store setup for a test run of some sort of code.
func (bc *Blockchain) GetTestVM() (*vm.VM, storage.Store) {
tmpStore := storage.NewMemCachedStore(bc.dao.store)
systemInterop := bc.newInteropContext(trigger.Application, tmpStore, nil, nil)
vm := bc.spawnVMWithInterops(systemInterop)
vm.SetPriceGetter(getPrice)
return vm, tmpStore
}
// 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 := new(bytes.Buffer)
err := vm.EmitAppCall(bb, hash, false)
if err != nil {
return nil, err
}
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, checkedHash util.Uint256, interopCtx *interopContext, useKeys bool) error {
verification, err := ScriptFromWitness(hash, witness)
if err != nil {
return err
}
vm := bc.spawnVMWithInterops(interopCtx)
vm.SetCheckedHash(checkedHash.BytesBE())
vm.LoadScript(verification)
vm.LoadScript(witness.InvocationScript)
if useKeys && bc.keyCache[hash] != nil {
vm.SetPublicKeys(bc.keyCache[hash])
}
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 {
res, err := resEl.TryBool()
if err != nil {
return err
}
if !res {
return errors.Errorf("signature check failed")
}
if useKeys && bc.keyCache[hash] == nil {
bc.keyCache[hash] = vm.GetPublicKeys()
}
} 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.store, block, t)
for i := 0; i < len(hashes); i++ {
err := bc.verifyHashAgainstScript(hashes[i], &witnesses[i], t.VerificationHash(), interopCtx, false)
if err != nil {
numStr := fmt.Sprintf("witness #%d", i)
return errors.Wrap(err, numStr)
}
}
return nil
}
// verifyBlockWitnesses is a block-specific implementation of VerifyWitnesses logic.
func (bc *Blockchain) verifyBlockWitnesses(block *block.Block, prevHeader *block.Header) error {
var hash util.Uint160
if prevHeader == nil && block.PrevHash.Equals(util.Uint256{}) {
hash = block.Script.ScriptHash()
} else {
hash = prevHeader.NextConsensus
}
interopCtx := bc.newInteropContext(trigger.Verification, bc.dao.store, nil, nil)
return bc.verifyHashAgainstScript(hash, &block.Script, block.VerificationHash(), interopCtx, true)
}
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 byte, s storage.Store, block *block.Block, tx *transaction.Transaction) *interopContext {
return newInteropContext(trigger, bc, s, block, tx, bc.log)
}