// dbIndexDisconnectBlock removes all of the index entries associated with the
// given block using the provided indexer and updates the tip of the indexer
// accordingly. An error will be returned if the current tip for the indexer is
// not the passed block.
func dbIndexDisconnectBlock(dbTx database.Tx, indexer Indexer, block, parent *dcrutil.Block, view *blockchain.UtxoViewpoint) error {
// Assert that the block being disconnected is the current tip of the
// index.
idxKey := indexer.Key()
curTipHash, _, err := dbFetchIndexerTip(dbTx, idxKey)
if err != nil {
return err
}
if !curTipHash.IsEqual(block.Sha()) {
return AssertError(fmt.Sprintf("dbIndexDisconnectBlock must "+
"be called with the block at the current index tip "+
"(%s, tip %s, block %s)", indexer.Name(),
curTipHash, block.Sha()))
}
// Notify the indexer with the disconnected block so it can remove all
// of the appropriate entries.
if err := indexer.DisconnectBlock(dbTx, block, parent, view); err != nil {
return err
}
// Update the current index tip.
prevHash := &block.MsgBlock().Header.PrevBlock
return dbPutIndexerTip(dbTx, idxKey, prevHash, uint32(block.Height())-1)
}
// submitBlock submits the passed block to network after ensuring it passes all
// of the consensus validation rules.
func (m *CPUMiner) submitBlock(block *dcrutil.Block) bool {
m.submitBlockLock.Lock()
defer m.submitBlockLock.Unlock()
_, latestHeight := m.server.blockManager.chainState.Best()
// Be sure to set this so ProcessBlock doesn't fail! - Decred
block.SetHeight(latestHeight + 1)
// Process this block using the same rules as blocks coming from other
// nodes. This will in turn relay it to the network like normal.
isOrphan, err := m.server.blockManager.ProcessBlock(block, blockchain.BFNone)
if err != nil {
// Anything other than a rule violation is an unexpected error,
// so log that error as an internal error.
if rErr, ok := err.(blockchain.RuleError); !ok {
minrLog.Errorf("Unexpected error while processing "+
"block submitted via CPU miner: %v", err)
return false
} else {
// Occasionally errors are given out for timing errors with
// ResetMinDifficulty and high block works that is above
// the target. Feed these to debug.
if m.server.chainParams.ResetMinDifficulty &&
rErr.ErrorCode == blockchain.ErrHighHash {
minrLog.Debugf("Block submitted via CPU miner rejected "+
"because of ResetMinDifficulty time sync failure: %v",
err)
return false
} else {
// Other rule errors should be reported.
minrLog.Errorf("Block submitted via CPU miner rejected: %v", err)
return false
}
}
}
if isOrphan {
minrLog.Errorf("Block submitted via CPU miner is an orphan building "+
"on parent %v", block.MsgBlock().Header.PrevBlock)
return false
}
// The block was accepted.
coinbaseTxOuts := block.MsgBlock().Transactions[0].TxOut
coinbaseTxGenerated := int64(0)
for _, out := range coinbaseTxOuts {
coinbaseTxGenerated += out.Value
}
minrLog.Infof("Block submitted via CPU miner accepted (hash %s, "+
"height %v, amount %v)",
block.Sha(),
block.Height(),
dcrutil.Amount(coinbaseTxGenerated))
return true
}
// DebugBlockString dumps a verbose message containing information about
// the transactions of a block.
func DebugBlockString(block *dcrutil.Block) string {
if block == nil {
return "block pointer nil"
}
var buffer bytes.Buffer
hash := block.Sha()
str := fmt.Sprintf("Block Header: %v Height: %v \n",
hash, block.Height())
buffer.WriteString(str)
str = fmt.Sprintf("Block contains %v regular transactions "+
"and %v stake transactions \n",
len(block.Transactions()),
len(block.STransactions()))
buffer.WriteString(str)
str = fmt.Sprintf("List of regular transactions \n")
buffer.WriteString(str)
for i, tx := range block.Transactions() {
str = fmt.Sprintf("Index: %v, Hash: %v \n", i, tx.Sha())
buffer.WriteString(str)
}
if len(block.STransactions()) == 0 {
return buffer.String()
}
str = fmt.Sprintf("List of stake transactions \n")
buffer.WriteString(str)
for i, stx := range block.STransactions() {
txTypeStr := ""
txType := stake.DetermineTxType(stx)
switch txType {
case stake.TxTypeSStx:
txTypeStr = "SStx"
case stake.TxTypeSSGen:
txTypeStr = "SSGen"
case stake.TxTypeSSRtx:
txTypeStr = "SSRtx"
default:
txTypeStr = "Error"
}
str = fmt.Sprintf("Index: %v, Type: %v, Hash: %v \n",
i, txTypeStr, stx.Sha())
buffer.WriteString(str)
}
return buffer.String()
}
// DisconnectBlock is invoked by the index manager when a block has been
// disconnected from the main chain. This indexer removes the
// hash-to-transaction mapping for every transaction in the block.
//
// This is part of the Indexer interface.
func (idx *TxIndex) DisconnectBlock(dbTx database.Tx, block, parent *dcrutil.Block, view *blockchain.UtxoViewpoint) error {
// Remove all of the transactions in the block from the index.
if err := dbRemoveTxIndexEntries(dbTx, block, parent); err != nil {
return err
}
// Remove the block ID index entry for the block being disconnected and
// decrement the current internal block ID to account for it.
blockSha := block.Sha()
if err := dbRemoveBlockIDIndexEntry(dbTx, *blockSha); err != nil {
return err
}
idx.curBlockID--
return nil
}
// InsertBlock synchronously queues a newly solved block to have its
// transactions indexed by address.
func (a *addrIndexer) InsertBlock(block *dcrutil.Block, parent *dcrutil.Block) error {
addrIndex, err := a.indexBlockAddrs(block, parent)
if err != nil {
return fmt.Errorf("Unable to index transactions of"+
" block: %v", err)
}
err = a.server.db.UpdateAddrIndexForBlock(block.Sha(),
block.Height(),
addrIndex)
if err != nil {
return fmt.Errorf("Unable to insert block: %v", err.Error())
}
return nil
}
// checkCoinbaseUniqueHeight checks to ensure that for all blocks height > 1
// that the coinbase contains the height encoding to make coinbase hash collisions
// impossible.
func checkCoinbaseUniqueHeight(blockHeight int64, block *dcrutil.Block) error {
if !(len(block.MsgBlock().Transactions) > 0) {
str := fmt.Sprintf("block %v has no coinbase", block.Sha())
return ruleError(ErrNoTransactions, str)
}
// Coinbase TxOut[0] is always tax, TxOut[1] is always
// height + extranonce, so at least two outputs must
// exist.
if !(len(block.MsgBlock().Transactions[0].TxOut) > 1) {
str := fmt.Sprintf("block %v is missing necessary coinbase "+
"outputs", block.Sha())
return ruleError(ErrFirstTxNotCoinbase, str)
}
// The first 4 bytes of the NullData output must be the
// encoded height of the block, so that every coinbase
// created has a unique transaction hash.
nullData, err := txscript.GetNullDataContent(
block.MsgBlock().Transactions[0].TxOut[1].Version,
block.MsgBlock().Transactions[0].TxOut[1].PkScript)
if err != nil {
str := fmt.Sprintf("block %v txOut 1 has wrong pkScript "+
"type", block.Sha())
return ruleError(ErrFirstTxNotCoinbase, str)
}
if len(nullData) < 4 {
str := fmt.Sprintf("block %v txOut 1 has too short nullData "+
"push to contain height", block.Sha())
return ruleError(ErrFirstTxNotCoinbase, str)
}
// Check the height and ensure it is correct.
cbHeight := binary.LittleEndian.Uint32(nullData[0:4])
if cbHeight != uint32(blockHeight) {
prevBlock := block.MsgBlock().Header.PrevBlock
str := fmt.Sprintf("block %v txOut 1 has wrong height in "+
"coinbase; want %v, got %v; prevBlock %v, header height %v",
block.Sha(), blockHeight, cbHeight, prevBlock,
block.MsgBlock().Header.Height)
return ruleError(ErrCoinbaseHeight, str)
}
return nil
}
// connectTransactions updates the view by adding all new utxos created by all
// of the transactions in the passed block, marking all utxos the transactions
// spend as spent, and setting the best hash for the view to the passed block.
// In addition, when the 'stxos' argument is not nil, it will be updated to
// append an entry for each spent txout.
func (b *BlockChain) connectTransactions(view *UtxoViewpoint, block *dcrutil.Block,
parent *dcrutil.Block, stxos *[]spentTxOut) error {
regularTxTreeValid := dcrutil.IsFlagSet16(block.MsgBlock().Header.VoteBits,
dcrutil.BlockValid)
thisNodeStakeViewpoint := ViewpointPrevInvalidStake
if regularTxTreeValid {
thisNodeStakeViewpoint = ViewpointPrevValidStake
}
if parent != nil && block.Height() != 0 {
view.SetStakeViewpoint(ViewpointPrevValidInitial)
err := view.fetchInputUtxos(b.db, block, parent)
if err != nil {
return err
}
mBlock := block.MsgBlock()
votebits := mBlock.Header.VoteBits
regularTxTreeValid := dcrutil.IsFlagSet16(votebits, dcrutil.BlockValid)
if regularTxTreeValid {
for i, tx := range parent.Transactions() {
err := view.connectTransaction(tx, parent.Height(), uint32(i),
stxos)
if err != nil {
return err
}
}
}
}
for i, stx := range block.STransactions() {
view.SetStakeViewpoint(thisNodeStakeViewpoint)
err := view.fetchInputUtxos(b.db, block, parent)
if err != nil {
return err
}
err = view.connectTransaction(stx, block.Height(), uint32(i), stxos)
if err != nil {
return err
}
}
// Update the best hash for view to include this block since all of its
// transactions have been connected.
view.SetBestHash(block.Sha())
return nil
}
// ConnectBlock is invoked by the index manager when a new block has been
// connected to the main chain. This indexer adds a hash-to-transaction mapping
// for every transaction in the passed block.
//
// This is part of the Indexer interface.
func (idx *TxIndex) ConnectBlock(dbTx database.Tx, block, parent *dcrutil.Block, view *blockchain.UtxoViewpoint) error {
// Increment the internal block ID to use for the block being connected
// and add all of the transactions in the block to the index.
newBlockID := idx.curBlockID + 1
if err := dbAddTxIndexEntries(dbTx, block, parent, newBlockID); err != nil {
return err
}
// Add the new block ID index entry for the block being connected and
// update the current internal block ID accordingly.
blockSha := block.Sha()
err := dbPutBlockIDIndexEntry(dbTx, *blockSha, newBlockID)
if err != nil {
return err
}
idx.curBlockID = newBlockID
return nil
}
// dbIndexConnectBlock adds all of the index entries associated with the
// given block using the provided indexer and updates the tip of the indexer
// accordingly. An error will be returned if the current tip for the indexer is
// not the previous block for the passed block.
func dbIndexConnectBlock(dbTx database.Tx, indexer Indexer, block, parent *dcrutil.Block, view *blockchain.UtxoViewpoint) error {
// Assert that the block being connected properly connects to the
// current tip of the index.
idxKey := indexer.Key()
curTipHash, _, err := dbFetchIndexerTip(dbTx, idxKey)
if err != nil {
return err
}
if !curTipHash.IsEqual(&block.MsgBlock().Header.PrevBlock) {
return AssertError(fmt.Sprintf("dbIndexConnectBlock must be "+
"called with a block that extends the current index "+
"tip (%s, tip %s, block %s)", indexer.Name(),
curTipHash, block.Sha()))
}
// Notify the indexer with the connected block so it can index it.
if err := indexer.ConnectBlock(dbTx, block, parent, view); err != nil {
return err
}
// Update the current index tip.
return dbPutIndexerTip(dbTx, idxKey, block.Sha(), uint32(block.Height()))
}
// dbAddTxIndexEntries uses an existing database transaction to add a
// transaction index entry for every transaction in the passed block.
func dbAddTxIndexEntries(dbTx database.Tx, block, parent *dcrutil.Block, blockID uint32) error {
// The offset and length of the transactions within the serialized
// block, for the regular transactions of the parent (if added)
// and the stake transactions of the current block.
regularTxTreeValid := dcrutil.IsFlagSet16(block.MsgBlock().Header.VoteBits,
dcrutil.BlockValid)
var parentRegularTxs []*dcrutil.Tx
var parentTxLocs []wire.TxLoc
var parentBlockID uint32
if regularTxTreeValid && block.Height() > 1 {
var err error
parentRegularTxs = parent.Transactions()
parentTxLocs, _, err = parent.TxLoc()
if err != nil {
return err
}
parentSha := parent.Sha()
parentBlockID, err = dbFetchBlockIDByHash(dbTx, *parentSha)
if err != nil {
return err
}
}
_, blockStxLocs, err := block.TxLoc()
if err != nil {
return err
}
allTxs := append(parentRegularTxs, block.STransactions()...)
allTxsLocs := append(parentTxLocs, blockStxLocs...)
stakeTxStartIdx := len(parentRegularTxs)
// As an optimization, allocate a single slice big enough to hold all
// of the serialized transaction index entries for the block and
// serialize them directly into the slice. Then, pass the appropriate
// subslice to the database to be written. This approach significantly
// cuts down on the number of required allocations.
offset := 0
serializedValues := make([]byte, len(allTxs)*txEntrySize)
blockIDToUse := parentBlockID
for i, tx := range allTxs {
// Switch to using the newest block ID for the stake transactions,
// since these are not from the parent.
if i == stakeTxStartIdx {
blockIDToUse = blockID
}
putTxIndexEntry(serializedValues[offset:], blockIDToUse, allTxsLocs[i])
endOffset := offset + txEntrySize
txSha := tx.Sha()
err := dbPutTxIndexEntry(dbTx, *txSha,
serializedValues[offset:endOffset:endOffset])
if err != nil {
return err
}
offset += txEntrySize
}
return nil
}
// fetchInputTransactions fetches the input transactions referenced by the
// transactions in the given block from its point of view. See fetchTxList
// for more details on what the point of view entails.
// Decred: This function is for verifying the validity of the regular tx tree in
// this block for the case that it does get accepted in the next block.
func (b *BlockChain) fetchInputTransactions(node *blockNode, block *dcrutil.Block, viewpoint int8) (TxStore, error) {
// Verify we have the same node as we do block.
blockHash := block.Sha()
if !node.hash.IsEqual(blockHash) {
return nil, fmt.Errorf("node and block hash are different!")
}
// If we need the previous block, grab it.
var parentBlock *dcrutil.Block
if viewpoint == ViewpointPrevValidInitial ||
viewpoint == ViewpointPrevValidStake ||
viewpoint == ViewpointPrevValidRegular {
var errFetchBlock error
parentBlock, errFetchBlock = b.getBlockFromHash(node.parentHash)
if errFetchBlock != nil {
return nil, errFetchBlock
}
}
txInFlight := map[chainhash.Hash]int{}
txNeededSet := make(map[chainhash.Hash]struct{})
txStore := make(TxStore)
// Case 1: ViewpointPrevValidInitial. We need the viewpoint of the
// current chain without the TxTreeRegular of the previous block
// added so we can validate that.
if viewpoint == ViewpointPrevValidInitial {
// Build a map of in-flight transactions because some of the inputs in
// this block could be referencing other transactions earlier in this
// block which are not yet in the chain.
transactions := parentBlock.Transactions()
for i, tx := range transactions {
txInFlight[*tx.Sha()] = i
}
// Loop through all of the transaction inputs (except for the coinbase
// which has no inputs) collecting them into sets of what is needed and
// what is already known (in-flight).
for i, tx := range transactions[1:] {
for _, txIn := range tx.MsgTx().TxIn {
// Add an entry to the transaction store for the needed
// transaction with it set to missing by default.
originHash := &txIn.PreviousOutPoint.Hash
txD := &TxData{Hash: originHash, Err: database.ErrTxShaMissing}
txStore[*originHash] = txD
// It is acceptable for a transaction input to reference
// the output of another transaction in this block only
// if the referenced transaction comes before the
// current one in this block. Update the transaction
// store acccordingly when this is the case. Otherwise,
// we still need the transaction.
//
// NOTE: The >= is correct here because i is one less
// than the actual position of the transaction within
// the block due to skipping the coinbase.
if inFlightIndex, ok := txInFlight[*originHash]; ok &&
i >= inFlightIndex {
originTx := transactions[inFlightIndex]
txD.Tx = originTx
txD.BlockHeight = node.height - 1
txD.BlockIndex = uint32(inFlightIndex)
txD.Spent = make([]bool, len(originTx.MsgTx().TxOut))
txD.Err = nil
} else {
txNeededSet[*originHash] = struct{}{}
}
}
}
// Request the input transactions from the point of view of the node.
txNeededStore, err := b.fetchTxStore(node, block, txNeededSet, viewpoint)
if err != nil {
return nil, err
}
// Merge the results of the requested transactions and the in-flight
// transactions.
for _, txD := range txNeededStore {
txStore[*txD.Hash] = txD
}
return txStore, nil
}
// Case 2+3: ViewpointPrevValidStake and ViewpointPrevValidStake.
// For ViewpointPrevValidStake, we need the viewpoint of the
// current chain with the TxTreeRegular of the previous block
// added so we can validate the TxTreeStake of the current block.
// For ViewpointPrevInvalidStake, we need the viewpoint of the
// current chain with the TxTreeRegular of the previous block
// missing so we can validate the TxTreeStake of the current block.
if viewpoint == ViewpointPrevValidStake ||
viewpoint == ViewpointPrevInvalidStake {
// We need all of the stake tx txins. None of these are considered
// in-flight in relation to the regular tx tree or to other tx in
// the stake tx tree, so don't do any of those expensive checks and
// just append it to the tx slice.
stransactions := block.STransactions()
for _, tx := range stransactions {
isSSGen, _ := stake.IsSSGen(tx)
for i, txIn := range tx.MsgTx().TxIn {
// Ignore stakebases.
if isSSGen && i == 0 {
continue
}
// Add an entry to the transaction store for the needed
// transaction with it set to missing by default.
originHash := &txIn.PreviousOutPoint.Hash
txD := &TxData{Hash: originHash, Err: database.ErrTxShaMissing}
txStore[*originHash] = txD
txNeededSet[*originHash] = struct{}{}
}
}
// Request the input transactions from the point of view of the node.
txNeededStore, err := b.fetchTxStore(node, block, txNeededSet, viewpoint)
if err != nil {
return nil, err
}
return txNeededStore, nil
}
// Case 4+5: ViewpointPrevValidRegular and
// ViewpointPrevInvalidRegular.
// For ViewpointPrevValidRegular, we need the viewpoint of the
// current chain with the TxTreeRegular of the previous block
// and the TxTreeStake of the current block added so we can
// validate the TxTreeRegular of the current block.
// For ViewpointPrevInvalidRegular, we need the viewpoint of the
// current chain with the TxTreeRegular of the previous block
// missing and the TxTreeStake of the current block added so we
// can validate the TxTreeRegular of the current block.
if viewpoint == ViewpointPrevValidRegular ||
viewpoint == ViewpointPrevInvalidRegular {
transactions := block.Transactions()
for i, tx := range transactions {
txInFlight[*tx.Sha()] = i
}
// Loop through all of the transaction inputs (except for the coinbase
// which has no inputs) collecting them into sets of what is needed and
// what is already known (in-flight).
txNeededSet := make(map[chainhash.Hash]struct{})
txStore = make(TxStore)
for i, tx := range transactions[1:] {
for _, txIn := range tx.MsgTx().TxIn {
// Add an entry to the transaction store for the needed
// transaction with it set to missing by default.
originHash := &txIn.PreviousOutPoint.Hash
txD := &TxData{Hash: originHash, Err: database.ErrTxShaMissing}
txStore[*originHash] = txD
// It is acceptable for a transaction input to reference
// the output of another transaction in this block only
// if the referenced transaction comes before the
// current one in this block. Update the transaction
// store acccordingly when this is the case. Otherwise,
// we still need the transaction.
//
// NOTE: The >= is correct here because i is one less
// than the actual position of the transaction within
// the block due to skipping the coinbase.
if inFlightIndex, ok := txInFlight[*originHash]; ok &&
i >= inFlightIndex {
originTx := transactions[inFlightIndex]
txD.Tx = originTx
txD.BlockHeight = node.height
txD.BlockIndex = uint32(inFlightIndex)
txD.Spent = make([]bool, len(originTx.MsgTx().TxOut))
txD.Err = nil
} else {
txNeededSet[*originHash] = struct{}{}
}
}
}
// Request the input transactions from the point of view of the node.
txNeededStore, err := b.fetchTxStore(node, block, txNeededSet, viewpoint)
if err != nil {
return nil, err
}
// Merge the results of the requested transactions and the in-flight
// transactions.
for _, txD := range txNeededStore {
txStore[*txD.Hash] = txD
}
return txStore, nil
}
return nil, fmt.Errorf("Invalid viewpoint passed to fetchInputTransactions")
}
// IsCheckpointCandidate returns whether or not the passed block is a good
// checkpoint candidate.
//
// The factors used to determine a good checkpoint are:
// - The block must be in the main chain
// - The block must be at least 'CheckpointConfirmations' blocks prior to the
// current end of the main chain
// - The timestamps for the blocks before and after the checkpoint must have
// timestamps which are also before and after the checkpoint, respectively
// (due to the median time allowance this is not always the case)
// - The block must not contain any strange transaction such as those with
// nonstandard scripts
//
// The intent is that candidates are reviewed by a developer to make the final
// decision and then manually added to the list of checkpoints for a network.
//
// This function is safe for concurrent access.
func (b *BlockChain) IsCheckpointCandidate(block *dcrutil.Block) (bool, error) {
b.chainLock.RLock()
defer b.chainLock.RUnlock()
// Checkpoints must be enabled.
if b.noCheckpoints {
return false, fmt.Errorf("checkpoints are disabled")
}
var isCandidate bool
err := b.db.View(func(dbTx database.Tx) error {
// A checkpoint must be in the main chain.
blockHeight, err := dbFetchHeightByHash(dbTx, block.Sha())
if err != nil {
// Only return an error if it's not due to the block not
// being in the main chain.
if !isNotInMainChainErr(err) {
return err
}
return nil
}
// Ensure the height of the passed block and the entry for the
// block in the main chain match. This should always be the
// case unless the caller provided an invalid block.
if blockHeight != block.Height() {
return fmt.Errorf("passed block height of %d does not "+
"match the main chain height of %d",
block.Height(), blockHeight)
}
// A checkpoint must be at least CheckpointConfirmations blocks
// before the end of the main chain.
mainChainHeight := b.bestNode.height
if blockHeight > (mainChainHeight - CheckpointConfirmations) {
return nil
}
// Get the previous block header.
prevHash := &block.MsgBlock().Header.PrevBlock
prevHeader, err := dbFetchHeaderByHash(dbTx, prevHash)
if err != nil {
return err
}
// Get the next block header.
nextHeader, err := dbFetchHeaderByHeight(dbTx, blockHeight+1)
if err != nil {
return err
}
// A checkpoint must have timestamps for the block and the
// blocks on either side of it in order (due to the median time
// allowance this is not always the case).
prevTime := prevHeader.Timestamp
curTime := block.MsgBlock().Header.Timestamp
nextTime := nextHeader.Timestamp
if prevTime.After(curTime) || nextTime.Before(curTime) {
return nil
}
// A checkpoint must have transactions that only contain
// standard scripts.
for _, tx := range block.Transactions() {
if isNonstandardTransaction(tx) {
return nil
}
}
// All of the checks passed, so the block is a candidate.
isCandidate = true
return nil
})
return isCandidate, err
}
// ConnectBlock is invoked by the index manager when a new block has been
// connected to the main chain. This indexer adds a mapping for each address
// the transactions in the block involve.
//
// This is part of the Indexer interface.
func (idx *AddrIndex) ConnectBlock(dbTx database.Tx, block, parent *dcrutil.Block,
view *blockchain.UtxoViewpoint) error {
// The offset and length of the transactions within the serialized
// block for the regular transactions of the previous block, if
// applicable.
regularTxTreeValid := dcrutil.IsFlagSet16(block.MsgBlock().Header.VoteBits,
dcrutil.BlockValid)
var parentTxLocs []wire.TxLoc
var parentBlockID uint32
if regularTxTreeValid && block.Height() > 1 {
var err error
parentTxLocs, _, err = parent.TxLoc()
if err != nil {
return err
}
parentSha := parent.Sha()
parentBlockID, err = dbFetchBlockIDByHash(dbTx, *parentSha)
if err != nil {
return err
}
}
// The offset and length of the transactions within the serialized
// block for the added stake transactions.
_, blockStxLocs, err := block.TxLoc()
if err != nil {
return err
}
// Nothing to index, just return.
if len(parentTxLocs)+len(blockStxLocs) == 0 {
return nil
}
// Get the internal block ID associated with the block.
blockSha := block.Sha()
blockID, err := dbFetchBlockIDByHash(dbTx, *blockSha)
if err != nil {
return err
}
// Build all of the address to transaction mappings in a local map.
addrsToTxns := make(writeIndexData)
idx.indexBlock(addrsToTxns, block, parent, view)
// Add all of the index entries for each address.
stakeIdxsStart := len(parentTxLocs)
allTxLocs := append(parentTxLocs, blockStxLocs...)
addrIdxBucket := dbTx.Metadata().Bucket(addrIndexKey)
for addrKey, txIdxs := range addrsToTxns {
for _, txIdx := range txIdxs {
// Switch to using the newest block ID for the stake transactions,
// since these are not from the parent. Offset the index to be
// correct for the location in this given block.
blockIDToUse := parentBlockID
if txIdx >= stakeIdxsStart {
blockIDToUse = blockID
}
err := dbPutAddrIndexEntry(addrIdxBucket, addrKey,
blockIDToUse, allTxLocs[txIdx])
if err != nil {
return err
}
}
}
return nil
}
// insertBlock is the internal function which implements the public
// InsertBlock. See the comment for InsertBlock for more details.
//
// This function MUST be called with the tmdb lock held (for writes).
func (tmdb *TicketDB) insertBlock(block *dcrutil.Block) (SStxMemMap,
SStxMemMap, SStxMemMap, error) {
height := block.Height()
if height < tmdb.StakeEnabledHeight {
return nil, nil, nil, nil
}
// Sanity check: Does the number of tickets in ticketMap equal the number
// of tickets indicated in the header?
poolSizeBlock := int(block.MsgBlock().Header.PoolSize)
poolSize := 0
for i := 0; i < BucketsSize; i++ {
poolSize += len(tmdb.maps.ticketMap[i])
}
if poolSize != poolSizeBlock {
return nil, nil, nil, fmt.Errorf("ticketpoolsize in block %v not "+
"equal to the calculated ticketpoolsize, indicating database "+
"corruption (got %v, want %v)",
block.Sha(),
poolSizeBlock,
poolSize)
}
// Create the block in the spentTicketMap.
tmdb.maybeInsertBlock(block.Height())
// Iterate through all the SSGen (vote) tx in the block and add them to
// a map of tickets that were actually used. The rest of the tickets in
// the buckets were then considered missed --> missedTicketMap.
// Note that it doesn't really matter what value you set usedTickets to,
// it's just a map of tickets that were actually used in the block. It
// would probably be more efficient to use an array.
usedTickets := make(map[chainhash.Hash]struct{})
spendingHashes := make(map[chainhash.Hash]chainhash.Hash)
revocations := make(map[chainhash.Hash]struct{})
for _, staketx := range block.STransactions() {
if is, _ := IsSSGen(staketx); is {
msgTx := staketx.MsgTx()
sstxIn := msgTx.TxIn[1] // sstx input
sstxHash := sstxIn.PreviousOutPoint.Hash
usedTickets[sstxHash] = struct{}{}
spendingHashes[sstxHash] = *staketx.Sha()
}
if is, _ := IsSSRtx(staketx); is {
msgTx := staketx.MsgTx()
sstxIn := msgTx.TxIn[0] // sstx input
sstxHash := sstxIn.PreviousOutPoint.Hash
revocations[sstxHash] = struct{}{}
}
}
// Spend or miss all the necessary tickets and do some sanity checks.
parentBlock, err := tmdb.database.FetchBlockBySha(
&block.MsgBlock().Header.PrevBlock)
if err != nil {
return nil, nil, nil, err
}
spentAndMissedTickets, err := tmdb.spendTickets(parentBlock,
usedTickets,
spendingHashes)
if err != nil {
return nil, nil, nil, err
}
// Expire all old tickets, and stick them into the spent and missed ticket
// map too.
expiredTickets, err := tmdb.expireTickets(height)
if err != nil {
return nil, nil, nil, err
}
if len(expiredTickets) > 0 && len(spentAndMissedTickets) == 0 {
return nil, nil, nil, fmt.Errorf("tried to expire tickets before " +
"stake validation height! TicketExpiry may be too small")
}
if len(expiredTickets) > 0 {
for hash, ticket := range expiredTickets {
spentAndMissedTickets[hash] = ticket
}
}
revokedTickets, err := tmdb.revokeTickets(revocations)
if err != nil {
return nil, nil, nil, err
}
newTickets, err := tmdb.pushMatureTicketsAtHeight(block.Height())
if err != nil {
return nil, nil, nil, err
}
log.Debugf("Connected block %v (height %v) to the ticket database",
block.Sha(), block.Height())
return cloneSStxMemMap(spentAndMissedTickets), cloneSStxMemMap(newTickets),
cloneSStxMemMap(revokedTickets), nil
}
// maybeAcceptBlock potentially accepts a block into the memory block chain.
// It performs several validation checks which depend on its position within
// the block chain before adding it. The block is expected to have already gone
// through ProcessBlock before calling this function with it.
//
// The flags modify the behavior of this function as follows:
// - BFDryRun: The memory chain index will not be pruned and no accept
// notification will be sent since the block is not being accepted.
//
// This function MUST be called with the chain state lock held (for writes).
func (b *BlockChain) maybeAcceptBlock(block *dcrutil.Block,
flags BehaviorFlags) (bool, error) {
dryRun := flags&BFDryRun == BFDryRun
// Get a block node for the block previous to this one. Will be nil
// if this is the genesis block.
prevNode, err := b.getPrevNodeFromBlock(block)
if err != nil {
log.Debugf("getPrevNodeFromBlock: %v", err)
return false, err
}
// The height of this block is one more than the referenced previous
// block.
blockHeight := int64(0)
if prevNode != nil {
blockHeight = prevNode.height + 1
}
block.SetHeight(blockHeight)
// The block must pass all of the validation rules which depend on the
// position of the block within the block chain.
err = b.checkBlockContext(block, prevNode, flags)
if err != nil {
return false, err
}
// Prune stake nodes and block nodes which are no longer needed before
// creating a new node.
if !dryRun {
err := b.pruner.pruneChainIfNeeded()
if err != nil {
return false, err
}
}
// Create a new block node for the block and add it to the in-memory
// block chain (could be either a side chain or the main chain).
blockHeader := &block.MsgBlock().Header
newNode := newBlockNode(blockHeader, block.Sha(), blockHeight,
ticketsSpentInBlock(block), ticketsRevokedInBlock(block),
voteVersionsInBlock(block, b.chainParams))
if prevNode != nil {
newNode.parent = prevNode
newNode.height = blockHeight
newNode.workSum.Add(prevNode.workSum, newNode.workSum)
}
// Fetching a stake node could enable a new DoS vector, so restrict
// this only to blocks that are recent in history.
if newNode.height < b.bestNode.height-minMemoryNodes {
newNode.stakeNode, err = b.fetchStakeNode(newNode)
if err != nil {
return false, err
}
newNode.stakeUndoData = newNode.stakeNode.UndoData()
}
// Connect the passed block to the chain while respecting proper chain
// selection according to the chain with the most proof of work. This
// also handles validation of the transaction scripts.
var onMainChain bool
onMainChain, err = b.connectBestChain(newNode, block, flags)
if err != nil {
return false, err
}
// Notify the caller that the new block was accepted into the block
// chain. The caller would typically want to react by relaying the
// inventory to other peers.
if !dryRun {
b.chainLock.Unlock()
b.sendNotification(NTBlockAccepted,
&BlockAcceptedNtfnsData{onMainChain, block})
b.chainLock.Lock()
}
return onMainChain, nil
}
// maybeAcceptBlock potentially accepts a block into the memory block chain.
// It performs several validation checks which depend on its position within
// the block chain before adding it. The block is expected to have already gone
// through ProcessBlock before calling this function with it.
//
// The flags modify the behavior of this function as follows:
// - BFDryRun: The memory chain index will not be pruned and no accept
// notification will be sent since the block is not being accepted.
func (b *BlockChain) maybeAcceptBlock(block *dcrutil.Block,
flags BehaviorFlags) (bool, error) {
dryRun := flags&BFDryRun == BFDryRun
// Get a block node for the block previous to this one. Will be nil
// if this is the genesis block.
prevNode, err := b.getPrevNodeFromBlock(block)
if err != nil {
log.Debugf("getPrevNodeFromBlock: %v", err)
return false, err
}
// The height of this block is one more than the referenced previous
// block.
blockHeight := int64(0)
if prevNode != nil {
blockHeight = prevNode.height + 1
}
block.SetHeight(blockHeight)
// The block must pass all of the validation rules which depend on the
// position of the block within the block chain.
err = b.checkBlockContext(block, prevNode, flags)
if err != nil {
return false, err
}
// Prune block nodes which are no longer needed before creating
// a new node.
if !dryRun {
err = b.pruneBlockNodes()
if err != nil {
return false, err
}
}
// Create a new block node for the block and add it to the in-memory
// block chain (could be either a side chain or the main chain).
blockHeader := &block.MsgBlock().Header
var voteBitsStake []uint16
for _, stx := range block.STransactions() {
if is, _ := stake.IsSSGen(stx); is {
vb := stake.GetSSGenVoteBits(stx)
voteBitsStake = append(voteBitsStake, vb)
}
}
newNode := newBlockNode(blockHeader, block.Sha(), blockHeight, voteBitsStake)
if prevNode != nil {
newNode.parent = prevNode
newNode.height = blockHeight
newNode.workSum.Add(prevNode.workSum, newNode.workSum)
}
// Connect the passed block to the chain while respecting proper chain
// selection according to the chain with the most proof of work. This
// also handles validation of the transaction scripts.
var onMainChain bool
onMainChain, err = b.connectBestChain(newNode, block, flags)
if err != nil {
return false, err
}
// Notify the caller that the new block was accepted into the block
// chain. The caller would typically want to react by relaying the
// inventory to other peers.
if !dryRun {
b.sendNotification(NTBlockAccepted,
&BlockAcceptedNtfnsData{onMainChain, block})
}
return onMainChain, nil
}
// disconnectTransactions updates the view by removing all of the transactions
// created by the passed block, restoring all utxos the transactions spent by
// using the provided spent txo information, and setting the best hash for the
// view to the block before the passed block.
//
// This function will ONLY work correctly for a single transaction tree at a
// time because of index tracking.
func (b *BlockChain) disconnectTransactions(view *UtxoViewpoint,
block *dcrutil.Block, parent *dcrutil.Block, stxos []spentTxOut) error {
// Sanity check the correct number of stxos are provided.
if len(stxos) != countSpentOutputs(block, parent) {
return AssertError(fmt.Sprintf("disconnectTransactions "+
"called with bad spent transaction out information "+
"(len stxos %v, count is %v)", len(stxos),
countSpentOutputs(block, parent)))
}
// Loop backwards through all transactions so everything is unspent in
// reverse order. This is necessary since transactions later in a block
// can spend from previous ones.
regularTxTreeValid := dcrutil.IsFlagSet16(block.MsgBlock().Header.VoteBits,
dcrutil.BlockValid)
thisNodeStakeViewpoint := ViewpointPrevInvalidStake
if regularTxTreeValid {
thisNodeStakeViewpoint = ViewpointPrevValidStake
}
view.SetStakeViewpoint(thisNodeStakeViewpoint)
err := view.fetchInputUtxos(b.db, block, parent)
if err != nil {
return err
}
stxoIdx := len(stxos) - 1
transactions := block.STransactions()
for txIdx := len(transactions) - 1; txIdx > -1; txIdx-- {
tx := transactions[txIdx]
msgTx := tx.MsgTx()
tt := stake.DetermineTxType(msgTx)
// Clear this transaction from the view if it already exists or
// create a new empty entry for when it does not. This is done
// because the code relies on its existence in the view in order
// to signal modifications have happened.
entry := view.entries[*tx.Sha()]
if entry == nil {
entry = newUtxoEntry(msgTx.Version, uint32(block.Height()),
uint32(txIdx), IsCoinBaseTx(msgTx), msgTx.Expiry != 0, tt)
if tt == stake.TxTypeSStx {
stakeExtra := make([]byte, serializeSizeForMinimalOutputs(tx))
putTxToMinimalOutputs(stakeExtra, tx)
entry.stakeExtra = stakeExtra
}
view.entries[*tx.Sha()] = entry
}
entry.modified = true
entry.sparseOutputs = make(map[uint32]*utxoOutput)
// Loop backwards through all of the transaction inputs (except
// for the coinbase which has no inputs) and unspend the
// referenced txos. This is necessary to match the order of the
// spent txout entries.
for txInIdx := len(tx.MsgTx().TxIn) - 1; txInIdx > -1; txInIdx-- {
// Skip empty vote stakebases.
if txInIdx == 0 && (tt == stake.TxTypeSSGen) {
continue
}
// Ensure the spent txout index is decremented to stay
// in sync with the transaction input.
stxo := &stxos[stxoIdx]
stxoIdx--
// When there is not already an entry for the referenced
// transaction in the view, it means it was fully spent,
// so create a new utxo entry in order to resurrect it.
txIn := tx.MsgTx().TxIn[txInIdx]
originHash := &txIn.PreviousOutPoint.Hash
originIndex := txIn.PreviousOutPoint.Index
entry := view.LookupEntry(originHash)
if entry == nil {
if !stxo.txFullySpent {
return AssertError(fmt.Sprintf("tried to revive utx %v from "+
"non-fully spent stx entry", originHash))
}
entry = newUtxoEntry(tx.MsgTx().Version, stxo.height,
stxo.index, stxo.isCoinBase, stxo.hasExpiry,
stxo.txType)
if stxo.txType == stake.TxTypeSStx {
entry.stakeExtra = stxo.stakeExtra
}
view.entries[*originHash] = entry
}
// Mark the entry as modified since it is either new
// or will be changed below.
entry.modified = true
// Restore the specific utxo using the stxo data from
// the spend journal if it doesn't already exist in the
// view.
output, ok := entry.sparseOutputs[originIndex]
if !ok {
// Add the unspent transaction output.
entry.sparseOutputs[originIndex] = &utxoOutput{
compressed: stxo.compressed,
spent: false,
amount: txIn.ValueIn,
scriptVersion: stxo.scriptVersion,
pkScript: stxo.pkScript,
}
continue
}
// Mark the existing referenced transaction output as
// unspent.
output.spent = false
}
}
// There is no regular tx from before the genesis block, so ignore the genesis
// block for the next step.
if parent != nil && block.Height() != 0 {
// Only bother to unspend transactions if the parent's tx tree was
// validated. Otherwise, these transactions were never in the blockchain's
// history in the first place.
if regularTxTreeValid {
view.SetStakeViewpoint(ViewpointPrevValidInitial)
err = view.fetchInputUtxos(b.db, block, parent)
if err != nil {
return err
}
transactions := parent.Transactions()
for txIdx := len(transactions) - 1; txIdx > -1; txIdx-- {
tx := transactions[txIdx]
// Clear this transaction from the view if it already exists or
// create a new empty entry for when it does not. This is done
// because the code relies on its existence in the view in order
// to signal modifications have happened.
isCoinbase := txIdx == 0
entry := view.entries[*tx.Sha()]
if entry == nil {
entry = newUtxoEntry(tx.MsgTx().Version,
uint32(parent.Height()), uint32(txIdx), isCoinbase,
tx.MsgTx().Expiry != 0, stake.TxTypeRegular)
view.entries[*tx.Sha()] = entry
}
entry.modified = true
entry.sparseOutputs = make(map[uint32]*utxoOutput)
// Loop backwards through all of the transaction inputs (except
// for the coinbase which has no inputs) and unspend the
// referenced txos. This is necessary to match the order of the
// spent txout entries.
if isCoinbase {
continue
}
for txInIdx := len(tx.MsgTx().TxIn) - 1; txInIdx > -1; txInIdx-- {
// Ensure the spent txout index is decremented to stay
// in sync with the transaction input.
stxo := &stxos[stxoIdx]
stxoIdx--
// When there is not already an entry for the referenced
// transaction in the view, it means it was fully spent,
// so create a new utxo entry in order to resurrect it.
txIn := tx.MsgTx().TxIn[txInIdx]
originHash := &txIn.PreviousOutPoint.Hash
originIndex := txIn.PreviousOutPoint.Index
entry := view.entries[*originHash]
if entry == nil {
if !stxo.txFullySpent {
return AssertError(fmt.Sprintf("tried to "+
"revive utx %v from non-fully spent stx entry",
originHash))
}
entry = newUtxoEntry(tx.MsgTx().Version,
stxo.height, stxo.index, stxo.isCoinBase,
stxo.hasExpiry, stxo.txType)
if stxo.txType == stake.TxTypeSStx {
entry.stakeExtra = stxo.stakeExtra
}
view.entries[*originHash] = entry
}
// Mark the entry as modified since it is either new
// or will be changed below.
entry.modified = true
// Restore the specific utxo using the stxo data from
// the spend journal if it doesn't already exist in the
// view.
output, ok := entry.sparseOutputs[originIndex]
if !ok {
// Add the unspent transaction output.
entry.sparseOutputs[originIndex] = &utxoOutput{
compressed: stxo.compressed,
spent: false,
amount: txIn.ValueIn,
scriptVersion: stxo.scriptVersion,
pkScript: stxo.pkScript,
}
continue
}
// Mark the existing referenced transaction output as
// unspent.
output.spent = false
}
}
}
}
// Update the best hash for view to the previous block since all of the
// transactions for the current block have been disconnected.
view.SetBestHash(parent.Sha())
return nil
}
// InsertBlock inserts raw block and transaction data from a block into the
// database. The first block inserted into the database will be treated as the
// genesis block. Every subsequent block insert requires the referenced parent
// block to already exist.
func (db *LevelDb) InsertBlock(block *dcrutil.Block) (height int64, rerr error) {
// Be careful with this function on syncs. It contains decred changes.
// Obtain the previous block first so long as it's not the genesis block
var blockPrev *dcrutil.Block
// Decred: WARNING. This function assumes that all block insertion calls have
// dcrutil.blocks passed to them with block.blockHeight set correctly. However,
// loading the genesis block in btcd didn't do this (via block manager); pre-
// production it should be established that all calls to this function pass
// blocks with block.blockHeight set correctly.
if block.Height() != 0 {
var errBlockPrev error
blockPrev, errBlockPrev = db.FetchBlockBySha(&block.MsgBlock().Header.PrevBlock)
if errBlockPrev != nil {
blockSha := block.Sha()
log.Warnf("Failed to fetch parent block of block %v", blockSha)
return 0, errBlockPrev
}
}
db.dbLock.Lock()
defer db.dbLock.Unlock()
defer func() {
if rerr == nil {
rerr = db.processBatches()
} else {
db.lBatch().Reset()
}
}()
blocksha := block.Sha()
mblock := block.MsgBlock()
rawMsg, err := block.Bytes()
if err != nil {
log.Warnf("Failed to obtain raw block sha %v", blocksha)
return 0, err
}
_, sTxLoc, err := block.TxLoc()
if err != nil {
log.Warnf("Failed to obtain raw block sha %v, stxloc %v", blocksha, sTxLoc)
return 0, err
}
// Insert block into database
newheight, err := db.insertBlockData(blocksha, &mblock.Header.PrevBlock,
rawMsg)
if err != nil {
log.Warnf("Failed to insert block %v %v %v", blocksha,
&mblock.Header.PrevBlock, err)
return 0, err
}
// Get data necessary to process regular tx tree of parent block if it's not
// the genesis block.
var mBlockPrev *wire.MsgBlock
var txLoc []wire.TxLoc
if blockPrev != nil {
blockShaPrev := blockPrev.Sha()
mBlockPrev = blockPrev.MsgBlock()
txLoc, _, err = blockPrev.TxLoc()
if err != nil {
log.Warnf("Failed to obtain raw block sha %v, txloc %v", blockShaPrev, txLoc)
return 0, err
}
}
// Insert the regular tx of the parent block into the tx database if the vote
// bits enable it, and if it's not the genesis block.
votebits := mblock.Header.VoteBits
if dcrutil.IsFlagSet16(votebits, dcrutil.BlockValid) && blockPrev != nil {
for txidx, tx := range mBlockPrev.Transactions {
txsha, err := blockPrev.TxSha(txidx)
if err != nil {
log.Warnf("failed to compute tx name block %v idx %v err %v", blocksha, txidx, err)
return 0, err
}
spentbuflen := (len(tx.TxOut) + 7) / 8
spentbuf := make([]byte, spentbuflen, spentbuflen)
if len(tx.TxOut)%8 != 0 {
for i := uint(len(tx.TxOut) % 8); i < 8; i++ {
spentbuf[spentbuflen-1] |= (byte(1) << i)
}
}
// newheight-1 instead of newheight below, as the tx is actually found
// in the parent.
//fmt.Printf("insert tx %v into db at height %v\n", txsha, newheight)
err = db.insertTx(txsha, newheight-1, uint32(txidx), txLoc[txidx].TxStart, txLoc[txidx].TxLen, spentbuf)
if err != nil {
log.Warnf("block %v idx %v failed to insert tx %v %v err %v", blocksha, newheight-1, &txsha, txidx, err)
return 0, err
}
err = db.doSpend(tx)
if err != nil {
log.Warnf("block %v idx %v failed to spend tx %v %v err %v", blocksha, newheight, txsha, txidx, err)
return 0, err
}
}
}
// Insert the stake tx of the current block into the tx database.
if len(mblock.STransactions) != 0 {
for txidx, tx := range mblock.STransactions {
txsha, err := block.STxSha(txidx)
if err != nil {
log.Warnf("failed to compute stake tx name block %v idx %v err %v", blocksha, txidx, err)
return 0, err
}
spentbuflen := (len(tx.TxOut) + 7) / 8
spentbuf := make([]byte, spentbuflen, spentbuflen)
if len(tx.TxOut)%8 != 0 {
for i := uint(len(tx.TxOut) % 8); i < 8; i++ {
spentbuf[spentbuflen-1] |= (byte(1) << i)
}
}
err = db.insertTx(txsha, newheight, uint32(txidx), sTxLoc[txidx].TxStart, sTxLoc[txidx].TxLen, spentbuf)
if err != nil {
log.Warnf("block %v idx %v failed to insert stake tx %v %v err %v", blocksha, newheight, &txsha, txidx, err)
return 0, err
}
err = db.doSpend(tx)
if err != nil {
log.Warnf("block %v idx %v failed to spend stx %v %v err %v", blocksha, newheight, txsha, txidx, err)
return 0, err
}
}
}
return newheight, nil
}
// ProcessBlock is the main workhorse for handling insertion of new blocks into
// the block chain. It includes functionality such as rejecting duplicate
// blocks, ensuring blocks follow all rules, orphan handling, and insertion into
// the block chain along with best chain selection and reorganization.
//
// It returns a first bool specifying whether or not the block is on on a fork
// or on a side chain. True means it's on the main chain.
//
// It returns a second bool which indicates whether or not the block is an orphan
// and any errors that occurred during processing. The returned bool is only
// valid when the error is nil.
func (b *BlockChain) ProcessBlock(block *dcrutil.Block,
timeSource MedianTimeSource, flags BehaviorFlags) (bool, bool, error) {
fastAdd := flags&BFFastAdd == BFFastAdd
dryRun := flags&BFDryRun == BFDryRun
blockHash := block.Sha()
log.Tracef("Processing block %v", blockHash)
// The block must not already exist in the main chain or side chains.
exists, err := b.blockExists(blockHash)
if err != nil {
return false, false, err
}
if exists {
str := fmt.Sprintf("already have block %v", blockHash)
return false, false, ruleError(ErrDuplicateBlock, str)
}
// The block must not already exist as an orphan.
if _, exists := b.orphans[*blockHash]; exists {
str := fmt.Sprintf("already have block (orphan) %v", blockHash)
return false, false, ruleError(ErrDuplicateBlock, str)
}
// Perform preliminary sanity checks on the block and its transactions.
err = checkBlockSanity(block, timeSource, flags, b.chainParams)
if err != nil {
return false, false, err
}
// Find the previous checkpoint and perform some additional checks based
// on the checkpoint. This provides a few nice properties such as
// preventing old side chain blocks before the last checkpoint,
// rejecting easy to mine, but otherwise bogus, blocks that could be
// used to eat memory, and ensuring expected (versus claimed) proof of
// work requirements since the previous checkpoint are met.
blockHeader := &block.MsgBlock().Header
checkpointBlock, err := b.findPreviousCheckpoint()
if err != nil {
return false, false, err
}
if checkpointBlock != nil {
// Ensure the block timestamp is after the checkpoint timestamp.
checkpointHeader := &checkpointBlock.MsgBlock().Header
checkpointTime := checkpointHeader.Timestamp
if blockHeader.Timestamp.Before(checkpointTime) {
str := fmt.Sprintf("block %v has timestamp %v before "+
"last checkpoint timestamp %v", blockHash,
blockHeader.Timestamp, checkpointTime)
return false, false, ruleError(ErrCheckpointTimeTooOld, str)
}
if !fastAdd {
// Even though the checks prior to now have already ensured the
// proof of work exceeds the claimed amount, the claimed amount
// is a field in the block header which could be forged. This
// check ensures the proof of work is at least the minimum
// expected based on elapsed time since the last checkpoint and
// maximum adjustment allowed by the retarget rules.
duration := blockHeader.Timestamp.Sub(checkpointTime)
requiredTarget := CompactToBig(b.calcEasiestDifficulty(
checkpointHeader.Bits, duration))
currentTarget := CompactToBig(blockHeader.Bits)
if currentTarget.Cmp(requiredTarget) > 0 {
str := fmt.Sprintf("block target difficulty of %064x "+
"is too low when compared to the previous "+
"checkpoint", currentTarget)
return false, false, ruleError(ErrDifficultyTooLow, str)
}
}
}
// Handle orphan blocks.
prevHash := &blockHeader.PrevBlock
if !prevHash.IsEqual(zeroHash) {
prevHashExists, err := b.blockExists(prevHash)
if err != nil {
return false, false, err
}
if !prevHashExists {
if !dryRun {
log.Infof("Adding orphan block %v with parent %v",
blockHash, prevHash)
b.addOrphanBlock(block)
}
return false, true, err
}
}
// The block has passed all context independent checks and appears sane
// enough to potentially accept it into the block chain.
var onMainChain bool
onMainChain, err = b.maybeAcceptBlock(block, flags)
if err != nil {
return false, false, err
}
// Don't process any orphans or log when the dry run flag is set.
if !dryRun {
// Accept any orphan blocks that depend on this block (they are
// no longer orphans) and repeat for those accepted blocks until
// there are no more.
err := b.processOrphans(blockHash, flags)
if err != nil {
return false, false, err
}
log.Debugf("Accepted block %v", blockHash)
}
return onMainChain, false, err
}
// connectTickets updates the passed map by removing removing any tickets
// from the ticket pool that have been considered spent or missed in this block
// according to the block header. Then, it connects all the newly mature tickets
// to the passed map.
func (b *BlockChain) connectTickets(tixStore TicketStore,
node *blockNode,
block *dcrutil.Block) error {
if tixStore == nil {
return fmt.Errorf("nil ticket store!")
}
// Nothing to do if tickets haven't yet possibly matured.
height := node.height
if height < b.chainParams.StakeEnabledHeight {
return nil
}
parentBlock, err := b.GetBlockFromHash(node.parentHash)
if err != nil {
return err
}
revocations := node.header.Revocations
tM := int64(b.chainParams.TicketMaturity)
// Skip a number of validation steps before we requiring chain
// voting.
if node.height >= b.chainParams.StakeValidationHeight {
regularTxTreeValid := dcrutil.IsFlagSet16(node.header.VoteBits,
dcrutil.BlockValid)
thisNodeStakeViewpoint := ViewpointPrevInvalidStake
if regularTxTreeValid {
thisNodeStakeViewpoint = ViewpointPrevValidStake
}
// We need the missed tickets bucket from the original perspective of
// the node.
missedTickets, err := b.GenerateMissedTickets(tixStore)
if err != nil {
return err
}
// TxStore at blockchain HEAD + TxTreeRegular of prevBlock (if
// validated) for this node.
txInputStoreStake, err := b.fetchInputTransactions(node, block,
thisNodeStakeViewpoint)
if err != nil {
errStr := fmt.Sprintf("fetchInputTransactions failed for incoming "+
"node %v; error given: %v", node.hash, err)
return errors.New(errStr)
}
// PART 1: Spend/miss winner tickets
// Iterate through all the SSGen (vote) tx in the block and add them to
// a map of tickets that were actually used.
spentTicketsFromBlock := make(map[chainhash.Hash]bool)
numberOfSSgen := 0
for _, staketx := range block.STransactions() {
if is, _ := stake.IsSSGen(staketx); is {
msgTx := staketx.MsgTx()
sstxIn := msgTx.TxIn[1] // sstx input
sstxHash := sstxIn.PreviousOutPoint.Hash
originTx, exists := txInputStoreStake[sstxHash]
if !exists {
str := fmt.Sprintf("unable to find input transaction "+
"%v for transaction %v", sstxHash, staketx.Sha())
return ruleError(ErrMissingTx, str)
}
sstxHeight := originTx.BlockHeight
// Check maturity of ticket; we can only spend the ticket after it
// hits maturity at height + tM + 1.
if (height - sstxHeight) < (tM + 1) {
blockSha := block.Sha()
errStr := fmt.Sprintf("Error: A ticket spend as an SSGen in "+
"block height %v was immature! Block sha %v",
height,
blockSha)
return errors.New(errStr)
}
// Fill out the ticket data.
spentTicketsFromBlock[sstxHash] = true
numberOfSSgen++
}
}
// Obtain the TicketsPerBlock many tickets that were selected this round,
// then check these against the tickets that were actually used to make
// sure that any SSGen actually match the selected tickets. Commit the
// spent or missed tickets to the ticket store after.
spentAndMissedTickets := make(TicketStore)
tixSpent := 0
tixMissed := 0
// Sort the entire list of tickets lexicographically by sorting
// each bucket and then appending it to the list. Start by generating
// a prefix matched map of tickets to speed up the lookup.
tpdBucketMap := make(map[uint8][]*TicketPatchData)
for _, tpd := range tixStore {
// Bucket does not exist.
if _, ok := tpdBucketMap[tpd.td.Prefix]; !ok {
tpdBucketMap[tpd.td.Prefix] = make([]*TicketPatchData, 1)
tpdBucketMap[tpd.td.Prefix][0] = tpd
} else {
// Bucket exists.
data := tpdBucketMap[tpd.td.Prefix]
tpdBucketMap[tpd.td.Prefix] = append(data, tpd)
}
}
totalTickets := 0
sortedSlice := make([]*stake.TicketData, 0)
for i := 0; i < stake.BucketsSize; i++ {
ltb, err := b.GenerateLiveTicketBucket(tixStore, tpdBucketMap,
uint8(i))
if err != nil {
h := node.hash
str := fmt.Sprintf("Failed to generate live ticket bucket "+
"%v for node %v, height %v! Error: %v",
i,
h,
node.height,
err.Error())
return fmt.Errorf(str)
}
mapLen := len(ltb)
tempTdSlice := stake.NewTicketDataSlice(mapLen)
itr := 0 // Iterator
for _, td := range ltb {
tempTdSlice[itr] = td
itr++
totalTickets++
}
sort.Sort(tempTdSlice)
sortedSlice = append(sortedSlice, tempTdSlice...)
}
// Use the parent block's header to seed a PRNG that picks the
// lottery winners.
ticketsPerBlock := int(b.chainParams.TicketsPerBlock)
pbhB, err := parentBlock.MsgBlock().Header.Bytes()
if err != nil {
return err
}
prng := stake.NewHash256PRNG(pbhB)
ts, err := stake.FindTicketIdxs(int64(totalTickets), ticketsPerBlock, prng)
if err != nil {
return err
}
ticketsToSpendOrMiss := make([]*stake.TicketData, ticketsPerBlock,
ticketsPerBlock)
for i, idx := range ts {
ticketsToSpendOrMiss[i] = sortedSlice[idx]
}
// Spend or miss these tickets by checking for their existence in the
// passed spentTicketsFromBlock map.
for _, ticket := range ticketsToSpendOrMiss {
// Move the ticket from active tickets map into the used tickets
// map if the ticket was spent.
wasSpent, _ := spentTicketsFromBlock[ticket.SStxHash]
if wasSpent {
tpd := NewTicketPatchData(ticket, TiSpent, nil)
spentAndMissedTickets[ticket.SStxHash] = tpd
tixSpent++
} else { // Ticket missed being spent and --> false or nil
tpd := NewTicketPatchData(ticket, TiMissed, nil)
spentAndMissedTickets[ticket.SStxHash] = tpd
tixMissed++
}
}
// This error is thrown if for some reason there exists an SSGen in
// the block that doesn't spend a ticket from the eligible list of
// tickets, thus making it invalid.
if tixSpent != numberOfSSgen {
errStr := fmt.Sprintf("an invalid number %v "+
"tickets was spent, but %v many tickets should "+
"have been spent!", tixSpent, numberOfSSgen)
return errors.New(errStr)
}
if tixMissed != (ticketsPerBlock - numberOfSSgen) {
errStr := fmt.Sprintf("an invalid number %v "+
"tickets was missed, but %v many tickets should "+
"have been missed!", tixMissed,
ticketsPerBlock-numberOfSSgen)
return errors.New(errStr)
}
if (tixSpent + tixMissed) != int(b.chainParams.TicketsPerBlock) {
errStr := fmt.Sprintf("an invalid number %v "+
"tickets was spent and missed, but TicketsPerBlock %v many "+
"tickets should have been spent!", tixSpent,
ticketsPerBlock)
return errors.New(errStr)
}
// Calculate all the tickets expiring this block and mark them as missed.
tpdBucketMap = make(map[uint8][]*TicketPatchData)
for _, tpd := range tixStore {
// Bucket does not exist.
if _, ok := tpdBucketMap[tpd.td.Prefix]; !ok {
tpdBucketMap[tpd.td.Prefix] = make([]*TicketPatchData, 1)
tpdBucketMap[tpd.td.Prefix][0] = tpd
} else {
// Bucket exists.
data := tpdBucketMap[tpd.td.Prefix]
tpdBucketMap[tpd.td.Prefix] = append(data, tpd)
}
}
toExpireHeight := node.height - int64(b.chainParams.TicketExpiry)
if !(toExpireHeight < int64(b.chainParams.StakeEnabledHeight)) {
for i := 0; i < stake.BucketsSize; i++ {
// Generate the live ticket bucket.
ltb, err := b.GenerateLiveTicketBucket(tixStore,
tpdBucketMap, uint8(i))
if err != nil {
return err
}
for _, ticket := range ltb {
if ticket.BlockHeight == toExpireHeight {
tpd := NewTicketPatchData(ticket, TiMissed, nil)
spentAndMissedTickets[ticket.SStxHash] = tpd
}
}
}
}
// Merge the ticket store patch containing the spent and missed tickets
// with the ticket store.
for hash, tpd := range spentAndMissedTickets {
tixStore[hash] = tpd
}
// At this point our tixStore now contains all the spent and missed tx
// as per this block.
// PART 2: Remove tickets that were missed and are now revoked.
// Iterate through all the SSGen (vote) tx in the block and add them to
// a map of tickets that were actually used.
revocationsFromBlock := make(map[chainhash.Hash]struct{})
numberOfSSRtx := 0
for _, staketx := range block.STransactions() {
if is, _ := stake.IsSSRtx(staketx); is {
msgTx := staketx.MsgTx()
sstxIn := msgTx.TxIn[0] // sstx input
sstxHash := sstxIn.PreviousOutPoint.Hash
// Fill out the ticket data.
revocationsFromBlock[sstxHash] = struct{}{}
numberOfSSRtx++
}
}
if numberOfSSRtx != int(revocations) {
errStr := fmt.Sprintf("an invalid revocations %v was calculated "+
"the block header indicates %v instead", numberOfSSRtx,
revocations)
return errors.New(errStr)
}
// Lookup the missed ticket. If we find it in the patch data,
// modify the patch data so that it doesn't exist.
// Otherwise, just modify load the missed ticket data from
// the ticket db and create patch data based on that.
for hash, _ := range revocationsFromBlock {
ticketWasMissed := false
if td, is := missedTickets[hash]; is {
maturedHeight := td.BlockHeight
// Check maturity of ticket; we can only spend the ticket after it
// hits maturity at height + tM + 2.
if height < maturedHeight+2 {
blockSha := block.Sha()
errStr := fmt.Sprintf("Error: A ticket spend as an "+
"SSRtx in block height %v was immature! Block sha %v",
height,
blockSha)
return errors.New(errStr)
}
ticketWasMissed = true
}
if !ticketWasMissed {
errStr := fmt.Sprintf("SSRtx spent missed sstx %v, "+
"but that missed sstx could not be found!",
hash)
return errors.New(errStr)
}
}
}
// PART 3: Add newly maturing tickets
// This is the only chunk we need to do for blocks appearing before
// stake validation height.
// Calculate block number for where new tickets are maturing from and retrieve
// this block from db.
// Get the block that is maturing.
matureNode, err := b.getNodeAtHeightFromTopNode(node, tM)
if err != nil {
return err
}
matureBlock, errBlock := b.getBlockFromHash(matureNode.hash)
if errBlock != nil {
return errBlock
}
// Maturing tickets are from the maturingBlock; fill out the ticket patch data
// and then push them to the tixStore.
for _, stx := range matureBlock.STransactions() {
if is, _ := stake.IsSStx(stx); is {
// Calculate the prefix for pre-sort.
sstxHash := *stx.Sha()
prefix := uint8(sstxHash[0])
// Fill out the ticket data.
td := stake.NewTicketData(sstxHash,
prefix,
chainhash.Hash{},
height,
false, // not missed
false) // not expired
tpd := NewTicketPatchData(td,
TiAvailable,
nil)
tixStore[*stx.Sha()] = tpd
}
}
return nil
}
// IsCheckpointCandidate returns whether or not the passed block is a good
// checkpoint candidate.
//
// The factors used to determine a good checkpoint are:
// - The block must be in the main chain
// - The block must be at least 'CheckpointConfirmations' blocks prior to the
// current end of the main chain
// - The timestamps for the blocks before and after the checkpoint must have
// timestamps which are also before and after the checkpoint, respectively
// (due to the median time allowance this is not always the case)
// - The block must not contain any strange transaction such as those with
// nonstandard scripts
//
// The intent is that candidates are reviewed by a developer to make the final
// decision and then manually added to the list of checkpoints for a network.
func (b *BlockChain) IsCheckpointCandidate(block *dcrutil.Block) (bool, error) {
// Checkpoints must be enabled.
if b.noCheckpoints {
return false, fmt.Errorf("checkpoints are disabled")
}
// A checkpoint must be in the main chain.
exists, err := b.db.ExistsSha(block.Sha())
if err != nil {
return false, err
}
if !exists {
return false, nil
}
// A checkpoint must be at least CheckpointConfirmations blocks before
// the end of the main chain.
blockHeight := block.Height()
_, mainChainHeight, err := b.db.NewestSha()
if err != nil {
return false, err
}
if blockHeight > (mainChainHeight - CheckpointConfirmations) {
return false, nil
}
// Get the previous block.
prevHash := &block.MsgBlock().Header.PrevBlock
prevBlock, err := b.db.FetchBlockBySha(prevHash)
if err != nil {
return false, err
}
// Get the next block.
nextHash, err := b.db.FetchBlockShaByHeight(blockHeight + 1)
if err != nil {
return false, err
}
nextBlock, err := b.db.FetchBlockBySha(nextHash)
if err != nil {
return false, err
}
// A checkpoint must have timestamps for the block and the blocks on
// either side of it in order (due to the median time allowance this is
// not always the case).
prevTime := prevBlock.MsgBlock().Header.Timestamp
curTime := block.MsgBlock().Header.Timestamp
nextTime := nextBlock.MsgBlock().Header.Timestamp
if prevTime.After(curTime) || nextTime.Before(curTime) {
return false, nil
}
// A checkpoint must have transactions that only contain standard
// scripts.
for _, tx := range block.Transactions() {
if isNonstandardTransaction(tx) {
return false, nil
}
}
return true, nil
}
// InsertBlock inserts raw block and transaction data from a block into the
// database. The first block inserted into the database will be treated as the
// genesis block. Every subsequent block insert requires the referenced parent
// block to already exist. This is part of the database.Db interface
// implementation.
func (db *MemDb) InsertBlock(block *dcrutil.Block) (int64, error) {
db.Lock()
defer db.Unlock()
if db.closed {
return 0, ErrDbClosed
}
// Reject the insert if the previously reference block does not exist
// except in the case there are no blocks inserted yet where the first
// inserted block is assumed to be a genesis block.
msgBlock := block.MsgBlock()
if _, exists := db.blocksBySha[msgBlock.Header.PrevBlock]; !exists {
if len(db.blocks) > 0 {
return 0, database.ErrPrevShaMissing
}
}
var blockPrev *dcrutil.Block = nil
// Decred: WARNING. This function assumes that all block insertion calls have
// dcrutil.blocks passed to them with block.blockHeight set correctly. However,
// loading the genesis block in dcrd didn't do this (via block manager); pre-
// production it should be established that all calls to this function pass
// blocks with block.blockHeight set correctly.
if len(db.blocks) > 0 {
var errBlockPrev error
blockPrev, errBlockPrev = db.fetchBlockBySha(&msgBlock.Header.PrevBlock)
if errBlockPrev != nil {
blockSha := block.Sha()
log.Warnf("Failed to fetch parent block of block %v", blockSha)
return 0, errBlockPrev
}
}
// Build a map of in-flight transactions because some of the inputs in
// this block could be referencing other transactions earlier in this
// block which are not yet in the chain.
newHeight := int64(len(db.blocks))
txInFlight := map[chainhash.Hash]int{}
// Loop through all transactions and inputs to ensure there are no error
// conditions that would prevent them from be inserted into the db.
// Although these checks could could be done in the loop below, checking
// for error conditions up front means the code below doesn't have to
// deal with rollback on errors.
votebits := block.MsgBlock().Header.VoteBits
if dcrutil.IsFlagSet16(votebits, dcrutil.BlockValid) && blockPrev != nil {
transactions := blockPrev.Transactions()
for i, tx := range transactions {
txInFlight[*tx.Sha()] = i
}
for i, tx := range transactions {
for _, txIn := range tx.MsgTx().TxIn {
if isCoinbaseInput(txIn) {
continue
}
// It is acceptable for a transaction input to reference
// the output of another transaction in this block only
// if the referenced transaction comes before the
// current one in this block.
prevOut := &txIn.PreviousOutPoint
if inFlightIndex, ok := txInFlight[prevOut.Hash]; ok {
if i <= inFlightIndex {
log.Warnf("InsertBlock: requested hash "+
" of %s does not exist in-flight",
tx.Sha())
return 0, database.ErrTxShaMissing
}
} else {
originTxns, exists := db.txns[prevOut.Hash]
if !exists {
log.Warnf("InsertBlock: requested hash "+
"of %s by %s does not exist",
prevOut.Hash, tx.Sha())
return 0, database.ErrTxShaMissing
}
originTxD := originTxns[len(originTxns)-1]
if prevOut.Index > uint32(len(originTxD.spentBuf)) {
log.Warnf("InsertBlock: requested hash "+
"of %s with index %d does not "+
"exist", tx.Sha(), prevOut.Index)
return 0, database.ErrTxShaMissing
}
}
}
// Prevent duplicate transactions in the same block.
if inFlightIndex, exists := txInFlight[*tx.Sha()]; exists &&
inFlightIndex < i {
log.Warnf("Block contains duplicate transaction %s",
tx.Sha())
return 0, database.ErrDuplicateSha
}
// Prevent duplicate transactions unless the old one is fully
// spent.
if txns, exists := db.txns[*tx.Sha()]; exists {
txD := txns[len(txns)-1]
if !isFullySpent(txD) {
log.Warnf("Attempt to insert duplicate "+
"transaction %s", tx.Sha())
return 0, database.ErrDuplicateSha
}
}
}
}
db.blocks = append(db.blocks, msgBlock)
db.blocksBySha[msgBlock.Header.BlockSha()] = newHeight
if dcrutil.IsFlagSet16(votebits, dcrutil.BlockValid) && blockPrev != nil {
// Insert information about eacj transaction and spend all of the
// outputs referenced by the inputs to the transactions.
for i, tx := range blockPrev.Transactions() {
// Insert the transaction data.
txD := tTxInsertData{
tree: dcrutil.TxTreeRegular,
blockHeight: newHeight - 1,
offset: i,
spentBuf: make([]bool, len(tx.MsgTx().TxOut)),
}
db.txns[*tx.Sha()] = append(db.txns[*tx.Sha()], &txD)
// Spend all of the inputs.
for _, txIn := range tx.MsgTx().TxIn {
// Coinbase transaction has no inputs.
if isCoinbaseInput(txIn) {
continue
}
// Already checked for existing and valid ranges above.
prevOut := &txIn.PreviousOutPoint
originTxns := db.txns[prevOut.Hash]
originTxD := originTxns[len(originTxns)-1]
originTxD.spentBuf[prevOut.Index] = true
}
}
}
for i, tx := range block.STransactions() {
// Insert the transaction data.
txD := tTxInsertData{
tree: dcrutil.TxTreeStake,
blockHeight: newHeight,
offset: i,
spentBuf: make([]bool, len(tx.MsgTx().TxOut)),
}
db.txns[*tx.Sha()] = append(db.txns[*tx.Sha()], &txD)
// Spend all of the inputs.
for _, txIn := range tx.MsgTx().TxIn {
// Coinbase transaction has no inputs.
if isCoinbaseInput(txIn) {
continue
}
// Already checked for existing and valid ranges above.
prevOut := &txIn.PreviousOutPoint
originTxns := db.txns[prevOut.Hash]
originTxD := originTxns[len(originTxns)-1]
originTxD.spentBuf[prevOut.Index] = true
}
}
return newHeight, nil
}
// indexBlock extract all of the standard addresses from all of the transactions
// in the passed block and maps each of them to the assocaited transaction using
// the passed map.
func (idx *AddrIndex) indexBlock(data writeIndexData, block, parent *dcrutil.Block, view *blockchain.UtxoViewpoint) {
regularTxTreeValid := dcrutil.IsFlagSet16(block.MsgBlock().Header.VoteBits,
dcrutil.BlockValid)
var stakeStartIdx int
if regularTxTreeValid {
for txIdx, tx := range parent.Transactions() {
// Coinbases do not reference any inputs. Since the block is
// required to have already gone through full validation, it has
// already been proven on the first transaction in the block is
// a coinbase.
if txIdx != 0 {
for _, txIn := range tx.MsgTx().TxIn {
// The view should always have the input since
// the index contract requires it, however, be
// safe and simply ignore any missing entries.
origin := &txIn.PreviousOutPoint
entry := view.LookupEntry(&origin.Hash)
if entry == nil {
log.Warnf("Missing input %v for tx %v while "+
"indexing block %v (height %v)\n", origin.Hash,
tx.Sha(), block.Sha(), block.Height())
continue
}
version := entry.ScriptVersionByIndex(origin.Index)
pkScript := entry.PkScriptByIndex(origin.Index)
txType := entry.TransactionType()
idx.indexPkScript(data, version, pkScript, txIdx,
txType == stake.TxTypeSStx)
}
}
for _, txOut := range tx.MsgTx().TxOut {
idx.indexPkScript(data, txOut.Version, txOut.PkScript, txIdx,
false)
}
}
stakeStartIdx = len(parent.Transactions())
}
for txIdx, tx := range block.STransactions() {
msgTx := tx.MsgTx()
thisTxOffset := txIdx + stakeStartIdx
isSSGen, _ := stake.IsSSGen(msgTx)
for i, txIn := range msgTx.TxIn {
// Skip stakebases.
if isSSGen && i == 0 {
continue
}
// The view should always have the input since
// the index contract requires it, however, be
// safe and simply ignore any missing entries.
origin := &txIn.PreviousOutPoint
entry := view.LookupEntry(&origin.Hash)
if entry == nil {
log.Warnf("Missing input %v for tx %v while "+
"indexing block %v (height %v)\n", origin.Hash,
tx.Sha(), block.Sha(), block.Height())
continue
}
version := entry.ScriptVersionByIndex(origin.Index)
pkScript := entry.PkScriptByIndex(origin.Index)
txType := entry.TransactionType()
idx.indexPkScript(data, version, pkScript, thisTxOffset,
txType == stake.TxTypeSStx)
}
isSStx, _ := stake.IsSStx(msgTx)
for _, txOut := range msgTx.TxOut {
idx.indexPkScript(data, txOut.Version, txOut.PkScript,
thisTxOffset, isSStx)
}
}
}