from .transport import Transport
from .offchain import prepare_transaction, fulfill_transaction
from .utils import _normalize_nodes
[docs]class BigchainDB:
"""BigchainDB driver class.
A :class:`~bigchaindb_driver.BigchainDB` driver is able to create, sign,
and submit transactions to one or more nodes in a Federation.
If initialized with ``>1`` nodes, the driver will send successive requests
to different nodes in a round-robin fashion (this will be customizable in
the future).
"""
[docs] def __init__(self, *nodes, transport_class=Transport, headers=None):
"""Initialize a :class:`~bigchaindb_driver.BigchainDB` driver instance.
Args:
*nodes (str): BigchainDB nodes to connect to. Currently, the full
URL must be given. In the absence of any node, the default
(``'http://localhost:9984'``) will be used.
transport_class: Optional transport class to use.
Defaults to :class:`~bigchaindb_driver.transport.Transport`.
headers (dict): Optional headers that will be passed with
each request. To pass headers only on a per-request
basis, you can pass the headers to the method of choice
(e.g. :meth:`BigchainDB().transactions.send()
<.TransactionsEndpoint.send>`).
"""
self._nodes = _normalize_nodes(*nodes)
self._transport = transport_class(*self._nodes, headers=headers)
self._transactions = TransactionsEndpoint(self)
self._outputs = OutputsEndpoint(self)
self.api_prefix = '/api/v1'
@property
def nodes(self):
""":obj:`tuple` of :obj:`str`: URLs of connected nodes."""
return self._nodes
@property
def transport(self):
""":class:`~bigchaindb_driver.transport.Transport`: Object
responsible for forwarding requests to a
:class:`~bigchaindb_driver.connection.Connection` instance (node).
"""
return self._transport
@property
def transactions(self):
""":class:`~bigchaindb_driver.driver.TransactionsEndpoint`:
Exposes functionalities of the ``'/transactions'`` endpoint.
"""
return self._transactions
@property
def outputs(self):
""":class:`~bigchaindb_driver.driver.OutputsEndpoint`:
Exposes functionalities of the ``'/outputs'`` endpoint.
"""
return self._outputs
[docs] def info(self, headers=None):
"""Retrieves information of the node being connected to via the
root endpoint ``'/'``.
Args:
headers (dict): Optional headers to pass to the request.
Returns:
dict: Details of the node that this instance is connected
to. Some information that may be interesting:
* the server version,
* the public key of the node, and
* its key ring (list of public keys of the nodes this
node is connected to).
Note:
Currently limited to one node, and will be expanded to
return information for each node that this instance is
connected to.
"""
return self.transport.forward_request(
method='GET', path='/', headers=headers)
[docs] def api_info(self, headers=None):
"""Retrieves information provided by the API root endpoint
``'/api/v1'``.
Args:
headers (dict): Optional headers to pass to the request.
Returns:
dict: Details of the HTTP API provided by the BigchainDB
server.
"""
return self.transport.forward_request(
method='GET',
path=self.api_prefix,
headers=headers,
)
[docs]class NamespacedDriver:
"""Base class for creating endpoints (namespaced objects) that can be added
under the :class:`~bigchaindb_driver.driver.BigchainDB` driver.
"""
PATH = '/'
[docs] def __init__(self, driver):
"""Initializes an instance of
:class:`~bigchaindb_driver.driver.NamespacedDriver` with the given
driver instance.
Args:
driver (BigchainDB): Instance of
:class:`~bigchaindb_driver.driver.BigchainDB`.
"""
self.driver = driver
@property
def transport(self):
return self.driver.transport
@property
def api_prefix(self):
return self.driver.api_prefix
@property
def path(self):
return self.api_prefix + self.PATH
[docs]class TransactionsEndpoint(NamespacedDriver):
"""Exposes functionality of the ``'/transactions/'`` endpoint.
Attributes:
path (str): The path of the endpoint.
"""
PATH = '/transactions/'
@staticmethod
[docs] def prepare(*, operation='CREATE', signers=None,
recipients=None, asset=None, metadata=None, inputs=None):
"""
Prepares a transaction payload, ready to be fulfilled.
Args:
operation (str): The operation to perform. Must be ``'CREATE'``
or ``'TRANSFER'``. Case insensitive. Defaults to ``'CREATE'``.
signers (:obj:`list` | :obj:`tuple` | :obj:`str`, optional):
One or more public keys representing the issuer(s) of
the asset being created. Only applies for ``'CREATE'``
operations. Defaults to ``None``.
recipients (:obj:`list` | :obj:`tuple` | :obj:`str`, optional):
One or more public keys representing the new recipients(s)
of the asset being created or transferred.
Defaults to ``None``.
asset (:obj:`dict`, optional): The asset to be created or
transferred. MUST be supplied for ``'TRANSFER'`` operations.
Defaults to ``None``.
metadata (:obj:`dict`, optional): Metadata associated with the
transaction. Defaults to ``None``.
inputs (:obj:`dict` | :obj:`list` | :obj:`tuple`, optional):
One or more inputs holding the condition(s) that this
transaction intends to fulfill. Each input is expected to
be a :obj:`dict`. Only applies to, and MUST be supplied for,
``'TRANSFER'`` operations.
Returns:
dict: The prepared transaction.
Raises:
:class:`~.exceptions.BigchaindbException`: If ``operation`` is
not ``'CREATE'`` or ``'TRANSFER'``.
.. important::
**CREATE operations**
* ``signers`` MUST be set.
* ``recipients``, ``asset``, and ``metadata`` MAY be set.
* If ``asset`` is set, it MUST be in the form of::
{
'data': {
...
}
}
* The argument ``inputs`` is ignored.
* If ``recipients`` is not given, or evaluates to
``False``, it will be set equal to ``signers``::
if not recipients:
recipients = signers
**TRANSFER operations**
* ``recipients``, ``asset``, and ``inputs`` MUST be set.
* ``asset`` MUST be in the form of::
{
'id': '<Asset ID (i.e. TX ID of its CREATE transaction)>'
}
* ``metadata`` MAY be set.
* The argument ``signers`` is ignored.
"""
return prepare_transaction(
operation=operation,
signers=signers,
recipients=recipients,
asset=asset,
metadata=metadata,
inputs=inputs,
)
@staticmethod
[docs] def fulfill(transaction, private_keys):
"""
Fulfills the given transaction.
Args:
transaction (dict): The transaction to be fulfilled.
private_keys (:obj:`str` | :obj:`list` | :obj:`tuple`): One or
more private keys to be used for fulfilling the
transaction.
Returns:
dict: The fulfilled transaction payload, ready to be sent to a
BigchainDB federation.
Raises:
:exc:`~.exceptions.MissingPrivateKeyError`: If a private
key is missing.
"""
return fulfill_transaction(transaction, private_keys=private_keys)
[docs] def get(self, *, asset_id, operation=None, headers=None):
"""Given an asset id, get its list of transactions (and
optionally filter for only ``'CREATE'`` or ``'TRANSFER'``
transactions).
Args:
asset_id (str): Id of the asset.
operation (str): The type of operation the transaction
should be. Either ``'CREATE'`` or ``'TRANSFER'``.
Defaults to ``None``.
headers (dict): Optional headers to pass to the request.
Note:
Please note that the id of an asset in BigchainDB is
actually the id of the transaction which created the asset.
In other words, when querying for an asset id with the
operation set to ``'CREATE'``, only one transaction should
be expected. This transaction will be the transaction in
which the asset was created, and the transaction id will be
equal to the given asset id. Hence, the following calls to
:meth:`.retrieve` and :meth:`.get` should return the same
transaction.
>>> bdb = BigchainDB()
>>> bdb.transactions.retrieve('foo')
>>> bdb.transactions.get(asset_id='foo', operation='CREATE')
Since :meth:`.get` returns a list of transactions, it may
be more efficient to use :meth:`.retrieve` instead, if one
is only interested in the ``'CREATE'`` operation.
Returns:
list: List of transactions.
"""
return self.transport.forward_request(
method='GET',
path=self.path,
params={'asset_id': asset_id, 'operation': operation},
headers=headers,
)
[docs] def send(self, transaction, headers=None):
"""Submit a transaction to the Federation.
Args:
transaction (dict): the transaction to be sent
to the Federation node(s).
headers (dict): Optional headers to pass to the request.
Returns:
dict: The transaction sent to the Federation node(s).
"""
return self.transport.forward_request(
method='POST', path=self.path, json=transaction, headers=headers)
[docs] def retrieve(self, txid, headers=None):
"""Retrieves the transaction with the given id.
Args:
txid (str): Id of the transaction to retrieve.
headers (dict): Optional headers to pass to the request.
Returns:
dict: The transaction with the given id.
"""
path = self.path + txid
return self.transport.forward_request(
method='GET', path=path, headers=None)
[docs] def status(self, txid, headers=None):
"""Retrieves the status of the transaction with the given id.
Args:
txid (str): Id of the transaction to retrieve the status for.
headers (dict): Optional headers to pass to the request.
Returns:
dict: A dict containing a 'status' item for the transaction.
"""
# TODO Once the HTTP API has stabilized, especially with matters
# relating to the transaction status, this can be updated to match the
# HTTP API more thoroughly.
path = self.api_prefix + '/statuses'
return self.transport.forward_request(
method='GET', path=path, params={'tx_id': txid}, headers=headers)
[docs]class OutputsEndpoint(NamespacedDriver):
"""Exposes functionality of the ``'/outputs'`` endpoint.
Attributes:
path (str): The path of the endpoint.
"""
PATH = '/outputs/'
[docs] def get(self, public_key, unspent=False, headers=None):
"""
Args:
public_key (str): Public key for which unfulfilled
conditions are sought.
unspent (bool): Whether to get the unconsumed outputs
only. Defaults to ``False``, meaning that both consumed,
and unconsumed outputs will be returned.
headers (dict): Optional headers to pass to the request.
Returns:
:obj:`list` of :obj:`str`: List of unfulfilled conditions.
Example:
Given a transaction with `id` ``da1b64a907ba54`` having an
`ed25519` condition (at index ``0``) with alice's public
key::
>>> bdb = BigchainDB()
>>> bdb.outputs.get(alice_pubkey)
... ['../transactions/da1b64a907ba54/conditions/0']
"""
return self.transport.forward_request(
method='GET',
path=self.path,
params={'public_key': public_key, 'unspent': unspent},
headers=headers,
)