def _sendtxn(self, minfo):
"""
Build a transaction for the update, wrap it in a message with all
of the appropriate signatures and post it to the validator
"""
txn = XoTransaction(minfo=minfo)
# add the last transaction submitted to ensure that the ordering
# in the journal matches the order in which we generated them
if self.LastTransaction:
txn.Dependencies = [self.LastTransaction]
txn.sign_from_node(self.LocalNode)
txnid = txn.Identifier
txn.check_valid(self._current_state.State)
if not txn.is_valid(self._current_state.State):
raise XoClientException('transaction failed to apply')
msg = XoTransactionMessage()
msg.Transaction = txn
msg.SenderID = self.LocalNode.Identifier
msg.sign_from_node(self.LocalNode)
try:
LOGGER.debug('Posting transaction: %s', txnid)
result = self.postmsg(msg.MessageType, msg.dump())
except MessageException:
return None
except:
LOGGER.debug('message post failed for some unusual reason')
return None
# if there was no exception thrown then all transactions should return
# a value which is a dictionary with the message that was sent
assert result
# if the message was successfully posted, then save the transaction
# id for future dependencies this could be a problem if the transaction
# fails during application
self.LastTransaction = txnid
txn.apply(self._current_state.State)
return txnid
