Files
python-teos/pisa/appointment.py
Sergi Delgado Segura f287bdf073 Fixes returns
2019-12-10 12:02:25 +01:00

104 lines
4.1 KiB
Python

import json
from pisa.encrypted_blob import EncryptedBlob
class Appointment:
"""
The ``Appointment`` contains the information regarding an appointment between a client and the Watchtower.
Args:
locator (str): A 16-byte hex-encoded value used by the tower to detect channel breaches. It serves as a trigger
for the tower to decrypt and broadcast the penalty transaction.
start_time (int): The block height at which the tower is hired to start watching for breaches.
end_time (int): The block height at which the tower will stop watching for breaches.
dispute_delta (int): The ``to_self_delay`` encoded in the ``csv`` of the ``htlc`` that this appointment is
covering.
encrypted_blob (EncryptedBlob): An :mod:`EncryptedBlob <pisa.encrypted_blob>` object containing an encrypted
penalty transaction. The tower will decrypt it and broadcast the penalty transaction upon seeing a breach on
the blockchain.
"""
# DISCUSS: 35-appointment-checks
def __init__(self, locator, start_time, end_time, dispute_delta, encrypted_blob):
self.locator = locator
self.start_time = start_time # ToDo: #4-standardize-appointment-fields
self.end_time = end_time # ToDo: #4-standardize-appointment-fields
self.dispute_delta = dispute_delta
self.encrypted_blob = EncryptedBlob(encrypted_blob)
@classmethod
def from_dict(cls, appointment_data):
"""
Builds an appointment from a dictionary.
This method is useful to load data from a database.
Args:
appointment_data (dict): a dictionary containing the following keys:
``{locator, start_time, end_time, dispute_delta, encrypted_blob}``
Returns:
``Appointment``: An appointment initialized using the provided data.
Raises:
ValueError: If one of the mandatory keys is missing in ``appointment_data``.
"""
locator = appointment_data.get("locator")
start_time = appointment_data.get("start_time") # ToDo: #4-standardize-appointment-fields
end_time = appointment_data.get("end_time") # ToDo: #4-standardize-appointment-fields
dispute_delta = appointment_data.get("dispute_delta")
encrypted_blob_data = appointment_data.get("encrypted_blob")
if any(v is None for v in [locator, start_time, end_time, dispute_delta, encrypted_blob_data]):
raise ValueError("Wrong appointment data, some fields are missing")
else:
appointment = cls(locator, start_time, end_time, dispute_delta, encrypted_blob_data)
return appointment
def to_dict(self):
"""
Exports an appointment as a dictionary.
Returns:
``dict``: A dictionary containing the appointment attributes.
"""
# ToDO: #3-improve-appointment-structure
appointment = {
"locator": self.locator,
"start_time": self.start_time,
"end_time": self.end_time,
"dispute_delta": self.dispute_delta,
"encrypted_blob": self.encrypted_blob.data,
}
return appointment
def to_json(self, triggered=False):
"""
Exports an appointment as a deterministic json encoded string.
This method ensures that multiple invocations with the same data yield the same value. This is the format used
to store appointments in the database.
Args:
triggered (bool): Whether the dispute has been triggered or not. When an appointment passes from the
:mod:`Watcher <pisa.watcher>` to the :mod:`Responder <pisa.responder>` it is not deleted straightaway.
Instead, the appointment is stored in the DB flagged as ``triggered``. This aims to ease handling block
reorgs in the future.
Returns:
``str``: A json-encoded str representing the appointment.
"""
appointment = self.to_dict()
appointment["triggered"] = triggered
return json.dumps(appointment, sort_keys=True, separators=(",", ":"))