wownero-python/docs/source/daemon.rst
2018-02-14 16:26:21 +01:00

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Interacting with daemon
=======================
The module offers an interface to interact with Monero daemon. For the time being, like with
wallet, the only available backend is JSON RPC.
.. code-block:: python
In [1]: from monero.daemon import Daemon
In [2]: from monero.backends.jsonrpc import JSONRPCDaemon
In [3]: daemon = Daemon(JSONRPCDaemon(port=28081))
In [4]: daemon.height()
Out[4]: 1099108
Also, the ``info()`` method will return a dictionary with details about the current daemon status.
Sending prepared transactions
-----------------------------
The daemon connection may be used for two-step sending of transactions. For example, you may want
to check the fee before broadcasting the transaction to the network.
To prepare a transaction, use ``transfer()`` or ``transfer_multiple()`` method of the wallet or
account, as described in :ref:`the section about sending payments <sending-payments>`.
The only difference is that now you want to add the ``relay=False`` argument.
.. code-block:: python
In [5]: from monero.wallet import Wallet
In [6]: from monero.backends.jsonrpc import JSONRPCWallet
In [7]: wallet = Wallet(JSONRPCWallet(port=28088))
In [8]: wallet.balance()
Out[8]: Decimal('17.642325205670')
In [9]: txs = wallet.transfer('Bg1nUjsEx6UUByxr68o6gXcQRF58BpQyKauoZSo2HwubGErEnz9x6AS9o5ybmk3QmgeUpX3Msgm74QkwZKx2CeVWFrrZZqt', 10, relay=False)
Now the return value is a list of resulting transactions (usually just one) which may be inspected
and validated.
.. code-block:: python
In [10]: txs
Out[10]: [38964a0c8c3be041051464b413996ad8d696223dc34925d98156848ed76a3ae3]
In [11]: txs[0].fee
Out[11]: Decimal('0.003766080000')
If anything is not OK, just discard the transaction and create a new one. There's no need to clean
up anything in the wallet.
Once you have the transaction accepted, it's time to post it to the daemon:
.. code-block:: python
In [12]: result = daemon.send_transaction(txs[0])
In [13]: result
Out[13]:
{'double_spend': False,
'fee_too_low': False,
'invalid_input': False,
'invalid_output': False,
'low_mixin': False,
'not_rct': False,
'not_relayed': False,
'overspend': False,
'reason': '',
'status': 'OK',
'too_big': False}
No batching due to double spends
--------------------------------
.. warning:: The workflow described above should not be used for preparing a batch of transactions
to be sent later. The wallet doesn't remember which inputs have been spent and will very likely
use the same in the next transaction, resulting in a double spend and broadcast failure.
The following example shows such behavior:
.. code-block:: python
In [14]: txs1 = wallet.transfer('BYSXsmmK44xdjNVMGprUW5Yau9tsc9SAMJrQsANjGgpk2RB83cvVhWjZAgYNwLgmhdPawATh5q1CTEoLGKZSeZqtThefV7D', 1, relay=False)
In [15]: txs2 = wallet.transfer('Bd5m5wTjWdYSaLBKe4i2avJjuFLYMEUKpiiE86F83NFiDXKE7QseSRvS7efTtJu5xHiHm5XmxgB2mfLu7NFrG7e3UTYRzEf', 2, relay=False)
In [16]: txs1, txs2
Out[16]:
([315901f250a1018e89e1fc2b3953bd5acfdfa759f843cf5a38306a2255de6d54],
[2bd978172226b486badc8a9dcbafb04acb4760c3f2a5794c694fee8575739c6e])
In [17]: daemon.send_transaction(txs1[0])
Out[17]:
{'double_spend': False,
'fee_too_low': False,
'invalid_input': False,
'invalid_output': False,
'low_mixin': False,
'not_rct': False,
'not_relayed': False,
'overspend': False,
'reason': '',
'status': 'OK',
'too_big': False}
In [18]: daemon.send_transaction(txs2[0])
---------------------------------------------------------------------------
TransactionBroadcastError Traceback (most recent call last)
<ipython-input-22-f24dc5d51c78> in <module>()
----> 1 daemon.send_transaction(txs2[0])
~/devel/monero-python/monero/daemon.py in send_transaction(self, tx, relay)
10
11 def send_transaction(self, tx, relay=True):
---> 12 return self._backend.send_transaction(tx.blob, relay=relay)
13
14 def mempool(self):
~/devel/monero-python/monero/backends/jsonrpc.py in send_transaction(self, blob, relay)
36 raise exceptions.TransactionBroadcastError(
37 "{status}: {reason}".format(**res),
---> 38 details=res)
39
40 def mempool(self):
TransactionBroadcastError: Failed: double spend
The second transaction failed because it used the same inputs as the previous one. The daemon
checks all incoming transactions for possible double-spends and rejects them if such conflict
is discovered.
API reference
-------------
.. automodule:: monero.daemon
:members: