/**
* Process a block against the given state of the chain.
* @param BlockHeaderInterface $header
* @return bool
*/
public function process(BlockHeaderInterface $header)
{
// Ignore the genesis block
$hash = $header->getBlockHash();
if ($hash === $this->genesis->getBlockHash()) {
return true;
}
if ($this->index()->height()->contains($hash)) {
return true;
}
try {
// Attempt to add it to the chain
$this->add($header);
$this->pow->checkHeader($header);
$result = true;
} catch (BlockPrevNotFound $e) {
// If it fails because it doesn't elongate the chain, process it as an orphan.
// Result will be determined
$result = $this->processOrphan($header);
} catch (BlockPowError $e) {
$result = false;
// Invalid block.
}
return $result;
}
/**
* @param BlockHeaderInterface $header
* @return $this
* @throws \Exception
*/
public function save(BlockHeaderInterface $header)
{
$height = $this->height();
$this->index->save('height', ++$height);
$key = $this->cacheIndex($height);
$this->index->save($key, $header->getBlockHash());
return $this;
}
/**
* @param BlockHeaderInterface $header
* @return bool
* @throws \Exception
*/
public function checkHeader(BlockHeaderInterface $header)
{
$math = $this->math;
$target = $this->difficulty->getTarget($header->getBits());
if ($math->cmp($target, 0) == 0 || $math->cmp($target, $this->limit()) > 0) {
throw new \Exception('nBits below minimum work');
}
$hashInt = $math->hexDec($header->getBlockHash());
if ($math->cmp($hashInt, $target) > 0) {
throw new \Exception("Hash doesn't match nBits");
}
return true;
}
/**
* @param TransactionInterface|null $coinbaseTx
* @return Block
* @throws \BitWasp\Bitcoin\Exceptions\MerkleTreeEmpty
*/
public function run(TransactionInterface $coinbaseTx = null)
{
$nonce = '0';
$maxNonce = $this->math->pow(2, 32);
// Allow user supplied transactions
if ($coinbaseTx == null) {
$coinbaseTx = new Transaction();
$coinbaseTx->getInputs()->addInput(new TransactionInput('0000000000000000000000000000000000000000000000000000000000000000', 4294967295.0));
$coinbaseTx->getOutputs()->addOutput(new TransactionOutput(5000000000.0, $this->script));
}
$inputs = $coinbaseTx->getInputs();
$found = false;
$usingDiff = $this->lastBlockHeader->getBits();
$diff = new Difficulty($this->math);
$target = $diff->getTarget($usingDiff);
while (false === $found) {
// Set coinbase script, and build Merkle tree & block header.
$inputs->getInput(0)->setScript($this->getCoinbaseScriptBuf());
$transactions = new TransactionCollection(array_merge(array($coinbaseTx), $this->transactions->getTransactions()));
$merkleRoot = new MerkleRoot($this->math, $transactions);
$merkleHash = $merkleRoot->calculateHash();
$header = new BlockHeader($this->version, $this->lastBlockHeader->getBlockHash(), $merkleHash, $this->timestamp, $usingDiff, '0');
$t = microtime(true);
// Loop through all nonces (up to 2^32). Restart after modifying extranonce.
while ($this->math->cmp($header->getNonce(), $maxNonce) <= 0) {
$header->setNonce($this->math->add($header->getNonce(), '1'));
$hash = (new Parser())->writeBytes(32, Hash::sha256d($header->getBuffer()), true)->getBuffer();
if ($this->math->cmp($hash->getInt(), $target) <= 0) {
$block = new Block($this->math, $header, $transactions);
return $block;
}
if ($this->report && $this->math->cmp($this->math->mod($header->getNonce(), 100000), '0') == 0) {
$time = microtime(true) - $t;
$khash = $nonce / $time / 1000;
echo "extraNonce[{$this->extraNonce}] nonce[{$nonce}] time[{$time}] khash/s[{$khash}] \n";
}
}
// Whenever we exceed 2^32, increment extraNonce and reset $nonce
$this->extraNonce++;
$nonce = '0';
}
}
/**
* @param BlockHeaderInterface $blk
* @return string
*/
private function cacheIndexBlk(BlockHeaderInterface $blk)
{
return $this->cacheIndex($blk->getBlockHash());
}
/**
* @param BlockHeaderInterface $header
* @return $this
*/
public function delete(BlockHeaderInterface $header)
{
$hash = $header->getBlockHash();
$this->hash()->delete($this->height()->fetch($hash));
$this->height()->delete($hash);
return $this;
}
/**
* @param BlockHeaderInterface $header
* @return string
*/
private function cacheIndexHeader(BlockHeaderInterface $header)
{
return "blkheight_" . $header->getBlockHash();
}
