def handle_refundtransfer(
mediator_state: MediatorTransferState,
mediator_state_change: ReceiveTransferRefund,
channelidentifiers_to_channels: typing.ChannelMap,
pseudo_random_generator: random.Random,
block_number: typing.BlockNumber,
):
""" Validate and handle a ReceiveTransferRefund mediator_state change.
A node might participate in mediated transfer more than once because of
refund transfers, eg. A-B-C-B-D-T, B tried to mediate the transfer through
C, which didn't have an available route to proceed and refunds B, at this
point B is part of the path again and will try a new partner to proceed
with the mediation through D, D finally reaches the target T.
In the above scenario B has two pairs of payer and payee transfers:
payer:A payee:C from the first SendLockedTransfer
payer:C payee:D from the following SendRefundTransfer
Args:
mediator_state (MediatorTransferState): Current mediator_state.
mediator_state_change (ReceiveTransferRefund): The mediator_state change.
Returns:
TransitionResult: The resulting iteration.
"""
if mediator_state.secret is None:
# The last sent transfer is the only one that may be refunded, all the
# previous ones are refunded already.
transfer_pair = mediator_state.transfers_pair[-1]
payee_transfer = transfer_pair.payee_transfer
payer_transfer = mediator_state_change.transfer
channel_identifier = payer_transfer.balance_proof.channel_identifier
payer_channel = channelidentifiers_to_channels[channel_identifier]
is_valid, channel_events, _ = channel.handle_refundtransfer(
received_transfer=payee_transfer,
channel_state=payer_channel,
refund=mediator_state_change,
)
if not is_valid:
return TransitionResult(None, channel_events)
iteration = mediate_transfer(
mediator_state,
mediator_state_change.routes,
payer_channel,
channelidentifiers_to_channels,
pseudo_random_generator,
payer_transfer,
block_number,
)
events = list()
events.extend(channel_events)
events.extend(iteration.events)
else:
events = list()
iteration = TransitionResult(mediator_state, events)
return iteration
def handle_refundtransfer(
mediator_state: MediatorTransferState,
mediator_state_change: ReceiveTransferRefund,
channelidentifiers_to_channels: initiator.ChannelMap,
pseudo_random_generator: random.Random,
block_number: typing.BlockNumber,
):
""" Validate and handle a ReceiveTransferRefund mediator_state change.
A node might participate in mediated transfer more than once because of
refund transfers, eg. A-B-C-B-D-T, B tried to mediate the transfer through
C, which didn't have an available route to proceed and refunds B, at this
point B is part of the path again and will try a new partner to proceed
with the mediation through D, D finally reaches the target T.
In the above scenario B has two pairs of payer and payee transfers:
payer:A payee:C from the first SendLockedTransfer
payer:C payee:D from the following SendRefundTransfer
Args:
mediator_state (MediatorTransferState): Current mediator_state.
mediator_state_change (ReceiveTransferRefund): The mediator_state change.
Returns:
TransitionResult: The resulting iteration.
"""
iteration = TransitionResult(mediator_state, list())
if mediator_state.secret is None:
# The last sent transfer is the only one that may be refunded, all the
# previous ones are refunded already.
transfer_pair = mediator_state.transfers_pair[-1]
payee_transfer = transfer_pair.payee_transfer
payer_transfer = mediator_state_change.transfer
channel_address = payer_transfer.balance_proof.channel_address
payer_channel = channelidentifiers_to_channels[channel_address]
is_valid, events, _ = channel.handle_refundtransfer(
received_transfer=payee_transfer,
channel_state=payer_channel,
refund=mediator_state_change,
)
if not is_valid:
return TransitionResult(None, events)
iteration = mediate_transfer(
mediator_state,
mediator_state_change.routes,
payer_channel,
channelidentifiers_to_channels,
pseudo_random_generator,
payer_transfer,
block_number,
)
return iteration
