// PushGetBlocksMsg sends a getblocks message for the provided block locator
// and stop hash. It will ignore back-to-back duplicate requests.
func (p *peer) PushGetBlocksMsg(locator btcchain.BlockLocator, stopHash *btcwire.ShaHash) error {
// Extract the begin hash from the block locator, if one was specified,
// to use for filtering duplicate getblocks requests.
// request.
var beginHash *btcwire.ShaHash
if len(locator) > 0 {
beginHash = locator[0]
}
// Filter duplicate getblocks requests.
if p.prevGetBlocksStop != nil && p.prevGetBlocksBegin != nil &&
beginHash != nil && stopHash.IsEqual(p.prevGetBlocksStop) &&
beginHash.IsEqual(p.prevGetBlocksBegin) {
log.Tracef("PEER: Filtering duplicate [getblocks] with begin "+
"hash %v, stop hash %v", beginHash, stopHash)
return nil
}
// Construct the getblocks request and queue it to be sent.
msg := btcwire.NewMsgGetBlocks(stopHash)
for _, hash := range locator {
err := msg.AddBlockLocatorHash(hash)
if err != nil {
return err
}
}
p.QueueMessage(msg, nil)
// Update the previous getblocks request information for filtering
// duplicates.
p.prevGetBlocksBegin = beginHash
p.prevGetBlocksStop = stopHash
return nil
}
// FetchTxUsedBySha returns the used/spent buffer for a given transaction.
func (db *SqliteDb) FetchTxUsedBySha(txsha *btcwire.ShaHash) (spentbuf []byte, err error) {
var row *sql.Row
db.dbLock.Lock()
defer db.dbLock.Unlock()
rowBytes := txsha.String()
txop := db.txop(txFetchUsedByShaStmt)
row = txop.QueryRow(rowBytes)
var databytes []byte
err = row.Scan(&databytes)
if err == sql.ErrNoRows {
txop := db.txop(txtmpFetchUsedByShaStmt)
row = txop.QueryRow(rowBytes)
err = row.Scan(&databytes)
if err == sql.ErrNoRows {
err = btcdb.TxShaMissing
return
}
if err != nil {
log.Warnf("txtmp FetchLocationBySha: fail %v",
err)
return
}
}
if err != nil {
log.Warnf("FetchUsedBySha: fail %v", err)
return
}
spentbuf = databytes
return
}
// fetchLocationBySha look up the Tx sha information by name.
// Must be called with db lock held.
func (db *SqliteDb) fetchLocationBySha(txsha *btcwire.ShaHash) (blockidx int64, txoff int, txlen int, err error) {
var row *sql.Row
var blockid int64
var ttxoff int
var ttxlen int
rowBytes := txsha.String()
txop := db.txop(txFetchLocationByShaStmt)
row = txop.QueryRow(rowBytes)
err = row.Scan(&blockid, &ttxoff, &ttxlen)
if err == sql.ErrNoRows {
txop = db.txop(txtmpFetchLocationByShaStmt)
row = txop.QueryRow(rowBytes)
err = row.Scan(&blockid, &ttxoff, &ttxlen)
if err == sql.ErrNoRows {
err = btcdb.TxShaMissing
return
}
if err != nil {
log.Warnf("txtmp FetchLocationBySha: fail %v",
err)
return
}
}
if err != nil {
log.Warnf("FetchLocationBySha: fail %v", err)
return
}
blockidx = blockid - 1
txoff = ttxoff
txlen = ttxlen
return
}
// FetchHeightRange looks up a range of blocks by the start and ending
// heights. Fetch is inclusive of the start height and exclusive of the
// ending height. To fetch all hashes from the start height until no
// more are present, use the special id `AllShas'.
func (db *LevelDb) FetchHeightRange(startHeight, endHeight int64) (rshalist []btcwire.ShaHash, err error) {
db.dbLock.Lock()
defer db.dbLock.Unlock()
var endidx int64
if endHeight == btcdb.AllShas {
endidx = startHeight + 500
} else {
endidx = endHeight
}
shalist := make([]btcwire.ShaHash, 0, endidx-startHeight)
for height := startHeight; height < endidx; height++ {
// TODO(drahn) fix blkFile from height
key := int64ToKey(height)
blkVal, lerr := db.lDb.Get(key, db.ro)
if lerr != nil {
break
}
var sha btcwire.ShaHash
sha.SetBytes(blkVal[0:32])
shalist = append(shalist, sha)
}
if err != nil {
return
}
//log.Tracef("FetchIdxRange idx %v %v returned %v shas err %v", startHeight, endHeight, len(shalist), err)
return shalist, nil
}
// RecordMinedTx searches through each account's TxStore, searching for a
// sent transaction with the same txid as from a txmined notification. If
// the transaction IDs match, the record in the TxStore is updated with
// the full information about the newly-mined tx, and the TxStore is
// scheduled to be written to disk..
func (am *AccountManager) RecordMinedTx(txid *btcwire.ShaHash,
blkhash *btcwire.ShaHash, blkheight int32, blkindex int,
blktime int64) error {
for _, a := range am.AllAccounts() {
// Search in reverse order. Since more recently-created
// transactions are appended to the end of the store, it's
// more likely to find it when searching from the end.
for i := len(a.TxStore) - 1; i >= 0; i-- {
sendtx, ok := a.TxStore[i].(*tx.SendTx)
if ok {
if bytes.Equal(txid.Bytes(), sendtx.TxID[:]) {
copy(sendtx.BlockHash[:], blkhash.Bytes())
sendtx.BlockHeight = blkheight
sendtx.BlockIndex = int32(blkindex)
sendtx.BlockTime = blktime
am.ds.ScheduleTxStoreWrite(a)
return nil
}
}
}
}
return errors.New("txid does not match any recorded sent transaction")
}
func parsesha(argstr string) (argtype int, height int64, psha *btcwire.ShaHash, err error) {
var sha btcwire.ShaHash
var hashbuf string
switch len(argstr) {
case 64:
hashbuf = argstr
case 66:
if argstr[0:2] != "0x" {
log.Infof("prefix is %v", argstr[0:2])
err = ErrBadShaPrefix
return
}
hashbuf = argstr[2:]
default:
if len(argstr) <= 16 {
// assume value is height
argtype = ArgHeight
var h int
h, err = strconv.Atoi(argstr)
if err == nil {
height = int64(h)
return
}
log.Infof("Unable to parse height %v, err %v", height, err)
}
err = ErrBadShaLen
return
}
var buf [32]byte
for idx, ch := range hashbuf {
var val rune
switch {
case ch >= '0' && ch <= '9':
val = ch - '0'
case ch >= 'a' && ch <= 'f':
val = ch - 'a' + rune(10)
case ch >= 'A' && ch <= 'F':
val = ch - 'A' + rune(10)
default:
err = ErrBadShaChar
return
}
b := buf[31-idx/2]
if idx&1 == 1 {
b |= byte(val)
} else {
b |= (byte(val) << 4)
}
buf[31-idx/2] = b
}
sha.SetBytes(buf[0:32])
psha = &sha
return
}
// Row returns row data for block iterator.
func (bi *SqliteBlockIterator) Row() (key *btcwire.ShaHash, pver uint32,
buf []byte, err error) {
var keybytes []byte
err = bi.rows.Scan(&keybytes, &pver, &buf)
if err == nil {
var retkey btcwire.ShaHash
retkey.SetBytes(keybytes)
key = &retkey
}
return
}
// ShaHashToBig converts a btcwire.ShaHash into a big.Int that can be used to
// perform math comparisons.
func ShaHashToBig(hash *btcwire.ShaHash) *big.Int {
// A ShaHash is in little-endian, but the big package wants the bytes
// in big-endian. Reverse them. ShaHash.Bytes makes a copy, so it
// is safe to modify the returned buffer.
buf := hash.Bytes()
blen := len(buf)
for i := 0; i < blen/2; i++ {
buf[i], buf[blen-1-i] = buf[blen-1-i], buf[i]
}
return new(big.Int).SetBytes(buf)
}
// VerboseGetRawTransaction sends the verbose version of a getrawtransaction
// request to receive details about a transaction.
func VerboseGetRawTransaction(rpc ServerConn, txsha *btcwire.ShaHash) (*btcjson.TxRawResult, *btcjson.Error) {
// NewGetRawTransactionCmd cannot fail with a single optarg.
cmd, _ := btcjson.NewGetRawTransactionCmd(<-NewJSONID, txsha.String(), 1)
response := <-rpc.SendRequest(NewServerRequest(cmd))
var resultData btcjson.TxRawResult
_, jsonErr := response.FinishUnmarshal(&resultData)
if jsonErr != nil {
return nil, jsonErr
}
return &resultData, nil
}
// hashMerkleBranches takes two hashes, treated as the left and right tree
// nodes, and returns the hash of their concatenation. This is a helper
// function used to during generatation of a merkle tree.
func hashMerkleBranches(left *btcwire.ShaHash, right *btcwire.ShaHash) *btcwire.ShaHash {
// Concatenate the left and right nodes.
var sha [btcwire.HashSize * 2]byte
copy(sha[:btcwire.HashSize], left.Bytes())
copy(sha[btcwire.HashSize:], right.Bytes())
// Create a new sha hash from the double sha 256. Ignore the error
// here since SetBytes can't fail here due to the fact DoubleSha256
// always returns a []byte of the right size regardless of input.
newSha, _ := btcwire.NewShaHash(btcwire.DoubleSha256(sha[:]))
return newSha
}
func notifySpentData(n ntfnChan, txhash *btcwire.ShaHash, index uint32,
spender *btcutil.Tx) {
var buf bytes.Buffer
// Ignore Serialize's error, as writing to a bytes.buffer
// cannot fail.
spender.MsgTx().Serialize(&buf)
txStr := hex.EncodeToString(buf.Bytes())
ntfn := btcws.NewTxSpentNtfn(txhash.String(), int(index), txStr)
n <- ntfn
}
// GetBlockAsync returns an instance of a type that can be used to get the
// result of the RPC at some future time by invoking the Receive function on the
// returned instance.
//
// See GetBlock for the blocking version and more details.
func (c *Client) GetBlockAsync(blockHash *btcwire.ShaHash) FutureGetBlockResult {
hash := ""
if blockHash != nil {
hash = blockHash.String()
}
id := c.NextID()
cmd, err := btcjson.NewGetBlockCmd(id, hash, false)
if err != nil {
return newFutureError(err)
}
return c.sendCmd(cmd)
}
// GetBlockVerboseAsync returns an instance of a type that can be used to get
// the result of the RPC at some future time by invoking the Receive function on
// the returned instance.
//
// See GetBlockVerbose for the blocking version and more details.
func (c *Client) GetBlockVerboseAsync(blockHash *btcwire.ShaHash, verboseTx bool) FutureGetBlockVerboseResult {
hash := ""
if blockHash != nil {
hash = blockHash.String()
}
id := c.NextID()
cmd, err := btcjson.NewGetBlockCmd(id, hash, true, verboseTx)
if err != nil {
return newFutureError(err)
}
return c.sendCmd(cmd)
}
// fetchBlockShaByHeight returns a block hash based on its height in the
// block chain.
func (db *LevelDb) fetchBlockShaByHeight(height int64) (rsha *btcwire.ShaHash, err error) {
key := int64ToKey(height)
blkVal, err := db.lDb.Get(key, db.ro)
if err != nil {
log.Tracef("failed to find height %v", height)
return // exists ???
}
var sha btcwire.ShaHash
sha.SetBytes(blkVal[0:32])
return &sha, nil
}
func notifySpentData(wallet walletChan, txhash *btcwire.ShaHash, index uint32,
spender *btcutil.Tx) {
var buf bytes.Buffer
// Ignore Serialize's error, as writing to a bytes.buffer
// cannot fail.
spender.MsgTx().Serialize(&buf)
txStr := hex.EncodeToString(buf.Bytes())
// TODO(jrick): create a new notification in btcws and use that.
ntfn := btcws.NewTxSpentNtfn(txhash.String(), int(index), txStr)
mntfn, _ := ntfn.MarshalJSON()
wallet <- mntfn
}
// GetRawTransactionAsync returns an instance of a type that can be used to get
// the result of the RPC at some future time by invoking the Receive function on
// the returned instance.
//
// See GetRawTransaction for the blocking version and more details.
func (c *Client) GetRawTransactionAsync(txHash *btcwire.ShaHash) FutureGetRawTransactionResult {
hash := ""
if txHash != nil {
hash = txHash.String()
}
id := c.NextID()
cmd, err := btcjson.NewGetRawTransactionCmd(id, hash, 0)
if err != nil {
return newFutureError(err)
}
return c.sendCmd(cmd)
}
// insertTx inserts a tx hash and its associated data into the database.
// Must be called with db lock held.
func (db *SqliteDb) insertTx(txsha *btcwire.ShaHash, blockidx int64, txoff int, txlen int, usedbuf []byte) (err error) {
tx := &db.txState
if tx.tx == nil {
err = db.startTx()
if err != nil {
return
}
}
blockid := blockidx + 1
txd := tTxInsertData{txsha: txsha, blockid: blockid, txoff: txoff, txlen: txlen, usedbuf: usedbuf}
log.Tracef("inserting tx %v for block %v off %v len %v",
txsha, blockid, txoff, txlen)
rowBytes := txsha.String()
var op int // which table to insert data into.
if db.UseTempTX {
var tblockid int64
var ttxoff int
var ttxlen int
txop := db.txop(txFetchLocationByShaStmt)
row := txop.QueryRow(rowBytes)
err = row.Scan(&tblockid, &ttxoff, &ttxlen)
if err != sql.ErrNoRows {
// sha already present
err = btcdb.DuplicateSha
return
}
op = txtmpInsertStmt
} else {
op = txInsertStmt
}
txop := db.txop(op)
_, err = txop.Exec(rowBytes, blockid, txoff, txlen, usedbuf)
if err != nil {
log.Warnf("failed to insert %v %v %v", txsha, blockid, err)
return
}
if db.UseTempTX {
db.TempTblSz++
}
// put in insert list for replay
tx.txInsertList = append(tx.txInsertList, txd)
return
}
func (db *LevelDb) setBlk(sha *btcwire.ShaHash, blkHeight int64, buf []byte) {
// serialize
var lw [8]byte
binary.LittleEndian.PutUint64(lw[0:8], uint64(blkHeight))
shaKey := shaBlkToKey(sha)
blkKey := int64ToKey(blkHeight)
shaB := sha.Bytes()
blkVal := make([]byte, len(shaB)+len(buf))
copy(blkVal[0:], shaB)
copy(blkVal[len(shaB):], buf)
db.lBatch().Put(shaKey, lw[:])
db.lBatch().Put(blkKey, blkVal)
}
// blkExistsSha looks up the given block hash
// returns true if it is present in the database.
// CALLED WITH LOCK HELD
func (db *SqliteDb) blkExistsSha(sha *btcwire.ShaHash) bool {
var pver uint32
row := db.blkStmts[blkExistsSha].QueryRow(sha.Bytes())
err := row.Scan(&pver)
if err == sql.ErrNoRows {
return false
}
if err != nil {
// ignore real errors?
log.Warnf("blkExistsSha: fail %v", err)
return false
}
return true
}
// RescanEndBlockAsync returns an instance of a type that can be used to get
// the result of the RPC at some future time by invoking the Receive function on
// the returned instance.
//
// See RescanEndBlock for the blocking version and more details.
//
// NOTE: This is a btcd extension and requires a websocket connection.
func (c *Client) RescanEndBlockAsync(startBlock *btcwire.ShaHash,
addresses []btcutil.Address, outpoints []*btcwire.OutPoint,
endBlock *btcwire.ShaHash) FutureRescanResult {
// Not supported in HTTP POST mode.
if c.config.HttpPostMode {
return newFutureError(ErrNotificationsNotSupported)
}
// Ignore the notification if the client is not interested in
// notifications.
if c.ntfnHandlers == nil {
return newNilFutureResult()
}
// Convert block hashes to strings.
var startBlockShaStr, endBlockShaStr string
if startBlock != nil {
startBlockShaStr = startBlock.String()
}
if endBlock != nil {
endBlockShaStr = endBlock.String()
}
// Convert addresses to strings.
addrs := make([]string, 0, len(addresses))
for _, addr := range addresses {
addrs = append(addrs, addr.String())
}
// Convert outpoints.
ops := make([]btcws.OutPoint, 0, len(outpoints))
for _, op := range outpoints {
ops = append(ops, *btcws.NewOutPointFromWire(op))
}
id := c.NextID()
cmd, err := btcws.NewRescanCmd(id, startBlockShaStr, addrs, ops,
endBlockShaStr)
if err != nil {
return newFutureError(err)
}
return c.sendCmd(cmd)
}
// FetchBlockShaByHeight returns a block hash based on its height in the
// block chain.
func (db *SqliteDb) FetchBlockShaByHeight(height int64) (sha *btcwire.ShaHash, err error) {
var row *sql.Row
db.dbLock.Lock()
defer db.dbLock.Unlock()
blockidx := height + 1 // skew between btc blockid and sql
row = db.blkStmts[blkFetchIdx].QueryRow(blockidx)
var shabytes []byte
err = row.Scan(&shabytes)
if err != nil {
return
}
var shaval btcwire.ShaHash
shaval.SetBytes(shabytes)
return &shaval, nil
}
// insertSha stores a block hash and its associated data block with a
// previous sha of `prevSha' and a version of `pver'.
// insertSha shall be called with db lock held
func (db *SqliteDb) insertBlockData(sha *btcwire.ShaHash, prevSha *btcwire.ShaHash, pver uint32, buf []byte) (blockid int64, err error) {
tx := &db.txState
if tx.tx == nil {
err = db.startTx()
if err != nil {
return
}
}
var prevOk bool
var blkid int64
prevOk = db.blkExistsSha(prevSha) // exists -> ok
if !prevOk {
return 0, btcdb.PrevShaMissing
}
result, err := db.blkStmts[blkInsertSha].Exec(sha.Bytes(), pver, buf)
if err != nil {
return
}
blkid, err = result.LastInsertId()
if err != nil {
return 0, err
}
blkid -= 1 // skew between btc blockid and sql
// Because we don't know know what the last idx is, we don't
// cache unless already cached
if db.lastBlkShaCached == true {
db.lastBlkSha = *sha
db.lastBlkIdx++
}
bid := tBlockInsertData{*sha, pver, buf}
tx.txInsertList = append(tx.txInsertList, bid)
tx.txDataSz += len(buf)
blockid = blkid
return
}
func (db *LevelDb) getBlkByHeight(blkHeight int64) (rsha *btcwire.ShaHash, rbuf []byte, err error) {
var blkVal []byte
key := int64ToKey(blkHeight)
blkVal, err = db.lDb.Get(key, db.ro)
if err != nil {
log.Tracef("failed to find height %v", blkHeight)
return // exists ???
}
var sha btcwire.ShaHash
sha.SetBytes(blkVal[0:32])
blockdata := make([]byte, len(blkVal[32:]))
copy(blockdata[:], blkVal[32:])
return &sha, blockdata, nil
}
// RecordMinedTx searches through each account's TxStore, searching for a
// sent transaction with the same txid as from a txmined notification. If
// the transaction IDs match, the record in the TxStore is updated with
// the full information about the newly-mined tx, and the TxStore is
// scheduled to be written to disk..
func (store *AccountStore) RecordMinedTx(txid *btcwire.ShaHash,
blkhash *btcwire.ShaHash, blkheight int32, blkindex int,
blktime int64) error {
store.RLock()
defer store.RUnlock()
for _, account := range store.accounts {
// The tx stores will be searched through while holding the
// reader lock, and the writer will only be grabbed if necessary.
account.TxStore.RLock()
// Search in reverse order. Since more recently-created
// transactions are appended to the end of the store, it's
// more likely to find it when searching from the end.
for i := len(account.TxStore.s) - 1; i >= 0; i-- {
sendtx, ok := account.TxStore.s[i].(*tx.SendTx)
if ok {
if bytes.Equal(txid.Bytes(), sendtx.TxID[:]) {
account.TxStore.RUnlock()
account.TxStore.Lock()
copy(sendtx.BlockHash[:], blkhash.Bytes())
sendtx.BlockHeight = blkheight
sendtx.BlockIndex = int32(blkindex)
sendtx.BlockTime = blktime
account.TxStore.Unlock()
account.ScheduleTxStoreWrite()
return nil
}
}
}
account.TxStore.RUnlock()
}
return errors.New("txid does not match any recorded sent transaction")
}
// fetchSha returns the datablock and pver for the given ShaHash.
func (db *SqliteDb) fetchSha(sha btcwire.ShaHash) (buf []byte, pver uint32,
blkid int64, err error) {
db.dbLock.Lock()
defer db.dbLock.Unlock()
row := db.blkStmts[blkFetchSha].QueryRow(sha.Bytes())
var blockidx int64
var databytes []byte
err = row.Scan(&pver, &databytes, &blockidx)
if err == sql.ErrNoRows {
return // no warning
}
if err != nil {
log.Warnf("fail 2 %v", err)
return
}
buf = databytes
blkid = blockidx - 1 // skew between btc blockid and sql
return
}
// FetchHeightRange looks up a range of blocks by the start and ending
// heights. Fetch is inclusive of the start height and exclusive of the
// ending height. To fetch all hashes from the start height until no
// more are present, use the special id `AllShas'.
func (db *SqliteDb) FetchHeightRange(startHeight, endHeight int64) (rshalist []btcwire.ShaHash, err error) {
db.dbLock.Lock()
defer db.dbLock.Unlock()
startidx := startHeight + 1 // skew between btc block height and sql
var endidx int64
if endHeight == btcdb.AllShas {
endidx = btcdb.AllShas // no skew if asking for all
} else {
endidx = endHeight + 1 // skew between btc block height and sql
}
rows, err := db.blkStmts[blkFetchIdxList].Query(startidx, endidx)
if err != nil {
log.Warnf("query failed %v", err)
return
}
var shalist []btcwire.ShaHash
for rows.Next() {
var sha btcwire.ShaHash
var shabytes []byte
err = rows.Scan(&shabytes)
if err != nil {
log.Warnf("wtf? %v", err)
break
}
sha.SetBytes(shabytes)
shalist = append(shalist, sha)
}
rows.Close()
if err == nil {
rshalist = shalist
}
log.Tracef("FetchIdxRange idx %v %v returned %v shas err %v", startHeight, endHeight, len(shalist), err)
return
}
// createTxRawResult converts the passed transaction and associated parameters
// to a raw transaction JSON object.
func createTxRawResult(net btcwire.BitcoinNet, txSha string, mtx *btcwire.MsgTx, blk *btcutil.Block, maxidx int64, blksha *btcwire.ShaHash) (*btcjson.TxRawResult, error) {
mtxHex, err := messageToHex(mtx)
if err != nil {
return nil, err
}
vin, err := createVinList(mtx)
if err != nil {
return nil, err
}
vout, err := createVoutList(mtx, net)
if err != nil {
return nil, err
}
txReply := &btcjson.TxRawResult{
Hex: mtxHex,
Txid: txSha,
Vout: vout,
Vin: vin,
Version: mtx.Version,
LockTime: mtx.LockTime,
}
if blk != nil {
blockHeader := &blk.MsgBlock().Header
idx := blk.Height()
// This is not a typo, they are identical in bitcoind as well.
txReply.Time = blockHeader.Timestamp.Unix()
txReply.Blocktime = blockHeader.Timestamp.Unix()
txReply.BlockHash = blksha.String()
txReply.Confirmations = uint64(1 + maxidx - idx)
}
return txReply, nil
}
// NewestSha provides an interface to quickly look up the sha of
// the most recent (end) of the block chain.
func (db *SqliteDb) NewestSha() (sha *btcwire.ShaHash, blkid int64, err error) {
var row *sql.Row
var blockidx int64
db.dbLock.Lock()
defer db.dbLock.Unlock()
// answer may be cached
if db.lastBlkShaCached == true {
shacopy := db.lastBlkSha
sha = &shacopy
blkid = db.lastBlkIdx - 1 // skew between btc blockid and sql
return
}
querystr := "SELECT key, blockid FROM block ORDER BY blockid DESC;"
tx := &db.txState
if tx.tx != nil {
row = tx.tx.QueryRow(querystr)
} else {
row = db.sqldb.QueryRow(querystr)
}
var shabytes []byte
err = row.Scan(&shabytes, &blockidx)
if err == nil {
var retsha btcwire.ShaHash
retsha.SetBytes(shabytes)
sha = &retsha
blkid = blockidx - 1 // skew between btc blockid and sql
db.lastBlkSha = retsha
db.lastBlkIdx = blockidx
db.lastBlkShaCached = true
}
return
}
func (db *LevelDb) setBlk(sha *btcwire.ShaHash, blkHeight int64, buf []byte) error {
// serialize
var lw bytes.Buffer
err := binary.Write(&lw, binary.LittleEndian, blkHeight)
if err != nil {
err = fmt.Errorf("Write Fail")
return err
}
shaKey := shaBlkToKey(sha)
blkKey := int64ToKey(blkHeight)
shaB := sha.Bytes()
blkVal := make([]byte, len(shaB)+len(buf))
copy(blkVal[0:], shaB)
copy(blkVal[len(shaB):], buf)
db.lBatch().Put(shaKey, lw.Bytes())
db.lBatch().Put(blkKey, blkVal)
return nil
}
// BlockLocatorFromHash returns a block locator for the passed block hash.
// See BlockLocator for details on the algotirhm used to create a block locator.
//
// In addition to the general algorithm referenced above, there are a couple of
// special cases which are handled:
//
// - If the genesis hash is passed, there are no previous hashes to add and
// therefore the block locator will only consist of the genesis hash
// - If the passed hash is not currently known, the block locator will only
// consist of the passed hash
func (b *BlockChain) BlockLocatorFromHash(hash *btcwire.ShaHash) BlockLocator {
// The locator contains the requested hash at the very least.
locator := make(BlockLocator, 0, btcwire.MaxBlockLocatorsPerMsg)
locator = append(locator, hash)
// Nothing more to do if a locator for the genesis hash was requested.
if hash.IsEqual(b.chainParams().GenesisHash) {
return locator
}
// Attempt to find the height of the block that corresponds to the
// passed hash, and if it's on a side chain, also find the height at
// which it forks from the main chain.
blockHeight := int64(-1)
forkHeight := int64(-1)
node, exists := b.index[*hash]
if !exists {
// Try to look up the height for passed block hash. Assume an
// error means it doesn't exist and just return the locator for
// the block itself.
block, err := b.db.FetchBlockBySha(hash)
if err != nil {
return locator
}
blockHeight = block.Height()
} else {
blockHeight = node.height
// Find the height at which this node forks from the main chain
// if the node is on a side chain.
if !node.inMainChain {
for n := node; n.parent != nil; n = n.parent {
if n.inMainChain {
forkHeight = n.height
break
}
}
}
}
// Generate the block locators according to the algorithm described in
// in the BlockLocator comment and make sure to leave room for the
// final genesis hash.
iterNode := node
increment := int64(1)
for len(locator) < btcwire.MaxBlockLocatorsPerMsg-1 {
// Once there are 10 locators, exponentially increase the
// distance between each block locator.
if len(locator) > 10 {
increment *= 2
}
blockHeight -= increment
if blockHeight < 1 {
break
}
// As long as this is still on the side chain, walk backwards
// along the side chain nodes to each block height.
if forkHeight != -1 && blockHeight > forkHeight {
// Intentionally use parent field instead of the
// getPrevNodeFromNode function since we don't want to
// dynamically load nodes when building block locators.
// Side chain blocks should always be in memory already,
// and if they aren't for some reason it's ok to skip
// them.
for iterNode != nil && blockHeight > iterNode.height {
iterNode = iterNode.parent
}
if iterNode != nil && iterNode.height == blockHeight {
locator = append(locator, iterNode.hash)
}
continue
}
// The desired block height is in the main chain, so look it up
// from the main chain database.
h, err := b.db.FetchBlockShaByHeight(blockHeight)
if err != nil {
// This shouldn't happen and it's ok to ignore block
// locators, so just continue to the next one.
log.Warnf("Lookup of known valid height failed %v",
blockHeight)
continue
}
locator = append(locator, h)
}
// Append the appropriate genesis block.
locator = append(locator, b.chainParams().GenesisHash)
return locator
}
