hash_digest build_merkle_tree(hash_list& merkle)
{
if (merkle.empty())
return null_hash;
else if (merkle.size() == 1)
return merkle[0];
while (merkle.size() > 1)
{
if (merkle.size() % 2 != 0)
merkle.push_back(merkle.back());
hash_list new_merkle;
for (auto it = merkle.begin(); it != merkle.end(); it += 2)
{
serializer concat;
concat.write_hash(*it);
concat.write_hash(*(it + 1));
hash_digest new_root = generate_sha256_hash(concat.data());
new_merkle.push_back(new_root);
}
merkle = new_merkle;
}
return merkle[0];
}
hash_digest build_merkle_tree(hash_list& merkle)
{
// Stop if hash list is empty.
if (merkle.empty())
return null_hash;
// While there is more than 1 hash in the list, keep looping...
while (merkle.size() > 1)
{
// If number of hashes is odd, duplicate last hash in the list.
if (merkle.size() % 2 != 0)
merkle.push_back(merkle.back());
// List size is now even.
BITCOIN_ASSERT(merkle.size() % 2 == 0);
// New hash list.
hash_list new_merkle;
// Loop through hashes 2 at a time.
for (auto it = merkle.begin(); it != merkle.end(); it += 2)
{
// Join both current hashes together (concatenate).
data_chunk concat_data;
data_sink concat_stream(concat_data);
ostream_writer concat_sink(concat_stream);
concat_sink.write_hash(*it);
concat_sink.write_hash(*(it + 1));
concat_stream.flush();
BITCOIN_ASSERT(concat_data.size() == (2 * hash_size));
// Hash both of the hashes.
const auto new_root = bitcoin_hash(concat_data);
// Add this to the new list.
new_merkle.push_back(new_root);
}
// This is the new list.
merkle = new_merkle;
}
// Finally we end up with a single item.
return merkle[0];
}
/*
void fetch_block_transaction_hashes_by_height(node_impl& node,
const incoming_message& request, queue_send_callback queue_send)
{
const data_chunk& data = request.data();
BITCOIN_ASSERT(data.size() == 4);
auto deserial = make_deserializer(data.begin(), data.end());
size_t height = deserial.read_4_bytes();
node.blockchain().fetch_block_transaction_hashes(height,
std::bind(block_transaction_hashes_fetched,
_1, _2, request, queue_send));
}
*/
void block_transaction_hashes_fetched(const std::error_code& ec,
const hash_list& hashes,
const incoming_message& request, queue_send_callback queue_send)
{
data_chunk result(4 + hash_size * hashes.size());
auto serial = make_serializer(result.begin());
write_error_code(serial, ec);
BITCOIN_ASSERT(serial.iterator() == result.begin() + 4);
for (const hash_digest& tx_hash: hashes)
serial.write_hash(tx_hash);
BITCOIN_ASSERT(serial.iterator() == result.end());
log_debug(LOG_REQUEST) << "blockchain.fetch_block_transaction_hashes()"
" finished. Sending response.";
outgoing_message response(request, result);
queue_send(response);
}