class LocalBlockchainRPCReader(object):
"""Fetches blockchain data from bitcoind RPC interface."""
def __init__(self, username=None, password=None, host=None, port=None):
if None in (username, password, host, port):
username, password, host, port, _ = get_config_settings()
self.rpc_connection = AuthServiceProxy(
"http://%s:%s@%s:%s" % (username, password, host, port))
def get_block_hash_at_height(self, block_height):
"""Get the hash of the block at the specified height."""
return self.rpc_connection.getblockhash(block_height)
def get_json_for_block_hash(self, block_hash):
"""Get a JSON representation of all transactions at specified height."""
return self.rpc_connection.getblock(block_hash)
def _get_raw_tx(self, tx_id):
"""Returns tx in raw format.
If the requested transaction is the sole transaction of the genesis
block, bitcoind's RPC interface will throw an error 'No information
available about transaction (code -5)' so we preempt this by raising an
error. Iterating callers should just move on to the next tx or block.
"""
if tx_id == (
'4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7af'
'deda33b'):
raise NoDataAvailableForGenesisBlockError
else:
return self.rpc_connection.getrawtransaction(tx_id)
def get_decoded_tx(self, tx_id):
"""Returns a human-readable string of the transaction in JSON format."""
#print "DEBUG: get_decoded_tx %s" % tx_id
try:
return self.rpc_connection.decoderawtransaction(
self._get_raw_tx(tx_id))
except NoDataAvailableForGenesisBlockError:
#bitcoind won't generate this, but here's what it would look like
genesis_json = {
'txid': ('4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2'
'127b7afdeda33b'),
'version':
1,
'locktime':
0,
'vin': [{
"sequence":
4294967295,
'coinbase':
('04ffff001d0104455468652054696d65732030332f4a6'
'16e2f32303039204368616e63656c6c6f72206f6e2062'
'72696e6b206f66207365636f6e64206261696c6f75742'
'0666f722062616e6b73')
}],
'vout': [{
'value': 50.00000000,
'n': 0,
'scriptPubKey': {
'asm': ('04678afdb0fe5548271967f1a67130b7105cd6a828'
'e03909a67962e0ea1f61deb649f6bc3f4cef38c4f3'
'5504e51ec112de5c384df7ba0b8d578a4c702b6bf1'
'1d5f OP_CHECKSIG'),
'hex': ('4104678afdb0fe5548271967f1a67130b7105cd6a8'
'28e03909a67962e0ea1f61deb649f6bc3f4cef38c4'
'f35504e51ec112de5c384df7ba0b8d578a4c702b6b'
'f11d5fac'),
'reqSigs':
1,
'type':
'pubkey',
'addresses': ['1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa']
}
}]
}
return genesis_json
def get_decoded_script(self, asm):
"""Convert bitcoind's 'asm' value to decoded format."""
return self.rpc_connection.decodescript(asm)
