// 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 == database.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
}
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
}
// 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)
}
// 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 aid in the generation 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
}
// 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
}
// fetchAddrIndexTip returns the last block height and block sha to be indexed.
// Meta-data about the address tip is currently cached in memory, and will be
// updated accordingly by functions that modify the state. This function is
// used on start up to load the info into memory. Callers will use the public
// version of this function below, which returns our cached copy.
func (db *LevelDb) fetchAddrIndexTip() (*btcwire.ShaHash, int64, error) {
db.dbLock.Lock()
defer db.dbLock.Unlock()
data, err := db.lDb.Get(addrIndexMetaDataKey, db.ro)
if err != nil {
return &btcwire.ShaHash{}, -1, database.ErrAddrIndexDoesNotExist
}
var blkSha btcwire.ShaHash
blkSha.SetBytes(data[0:32])
blkHeight := binary.LittleEndian.Uint64(data[32:])
return &blkSha, int64(blkHeight), nil
}
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)
}
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
}
// UpdateAddrIndexForBlock updates the stored addrindex with passed
// index information for a particular block height. Additionally, it
// will update the stored meta-data related to the curent tip of the
// addr index. These two operations are performed in an atomic
// transaction which is commited before the function returns.
// Transactions indexed by address are stored with the following format:
// * prefix || hash160 || blockHeight || txoffset || txlen
// Indexes are stored purely in the key, with blank data for the actual value
// in order to facilitate ease of iteration by their shared prefix and
// also to allow limiting the number of returned transactions (RPC).
// Alternatively, indexes for each address could be stored as an
// append-only list for the stored value. However, this add unnecessary
// overhead when storing and retrieving since the entire list must
// be fetched each time.
func (db *LevelDb) UpdateAddrIndexForBlock(blkSha *btcwire.ShaHash, blkHeight int64, addrIndex database.BlockAddrIndex) error {
db.dbLock.Lock()
defer db.dbLock.Unlock()
var blankData []byte
batch := db.lBatch()
defer db.lbatch.Reset()
// Write all data for the new address indexes in a single batch
// transaction.
for addrKey, indexes := range addrIndex {
for _, txLoc := range indexes {
index := &txAddrIndex{
hash160: addrKey,
blkHeight: blkHeight,
txoffset: txLoc.TxStart,
txlen: txLoc.TxLen,
}
// The index is stored purely in the key.
packedIndex := addrIndexToKey(index)
batch.Put(packedIndex, blankData)
}
}
// Update tip of addrindex.
newIndexTip := make([]byte, 40, 40)
copy(newIndexTip[:32], blkSha.Bytes())
binary.LittleEndian.PutUint64(newIndexTip[32:], uint64(blkHeight))
batch.Put(addrIndexMetaDataKey, newIndexTip)
if err := db.lDb.Write(batch, db.wo); err != nil {
return err
}
db.lastAddrIndexBlkIdx = blkHeight
db.lastAddrIndexBlkSha = *blkSha
return nil
}
func shaSpentTxToKey(sha *btcwire.ShaHash) []byte {
shaB := sha.Bytes()
shaB = append(shaB, "sx"...)
return shaB
}
func shaBlkToKey(sha *btcwire.ShaHash) []byte {
shaB := sha.Bytes()
return shaB
}
// 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.netParams.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.netParams.GenesisHash)
return locator
}