# Copyright (C) 2023 qBraid
#
# This file is part of the qBraid-SDK
#
# The qBraid-SDK is free software released under the GNU General Public License v3
# or later. You can redistribute and/or modify it under the terms of the GPL v3.
# See the LICENSE file in the project root or <https://www.gnu.org/licenses/gpl-3.0.html>.
#
# THERE IS NO WARRANTY for the qBraid-SDK, as per Section 15 of the GPL v3.
"""
Module defining BraketQuantumTask Class
"""
import logging
from typing import Optional
from braket.aws import AwsQuantumTask
from qbraid.providers.enums import JOB_FINAL
from qbraid.providers.exceptions import JobStateError
from qbraid.providers.job import QuantumJob
from .result import BraketGateModelResult
from .tracker import get_quantum_task_cost
logger = logging.getLogger(__name__)
class AmazonBraketVersionError(Exception):
"""Exception raised for Amazon Braket SDK errors due to versioning."""
[docs]
class BraketQuantumTask(QuantumJob):
"""Wrapper class for Amazon Braket ``QuantumTask`` objects."""
[docs]
def __init__(self, job_id: str, **kwargs):
"""Create a BraketQuantumTask."""
super().__init__(job_id, **kwargs)
def _get_job(self):
"""Return the job like object that is being wrapped."""
return AwsQuantumTask(self.vendor_job_id)
def _get_status(self):
"""Returns status from Braket QuantumTask object metadata."""
return self._job.state()
def queue_position(self) -> Optional[int]:
"""Returns queue position from Braket QuantumTask.
'>2000' returns as 2000 for typing consistency."""
try:
position = self._job.queue_position().queue_position
if isinstance(position, str):
if position.startswith(">"):
position = position[1:]
return int(position)
return position
except AttributeError as err:
raise AmazonBraketVersionError(
"Queue visibility is only available for amazon-braket-sdk>=1.56.0"
) from err
def result(self) -> BraketGateModelResult:
"""Return the results of the job."""
if self.status() not in JOB_FINAL:
logger.info("Result will be available when job has reached final state.")
return BraketGateModelResult(self._job.result())
def cancel(self) -> None:
"""Cancel the quantum task."""
task = self._job
status = self.status()
if status in JOB_FINAL:
raise JobStateError(f"Cannot cancel quantum job in the {status} state.")
try:
task.cancel()
except RuntimeError:
task._aws_session.cancel_quantum_task(task.arn)
def get_cost(self) -> float:
"""Return the cost of the job."""
decimal_cost = get_quantum_task_cost(self.vendor_job_id)
return float(decimal_cost)