# Copyright (C) 2024 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 QiskitBackend Class
"""
from __future__ import annotations
from typing import TYPE_CHECKING, Optional, Union
from qiskit_ibm_runtime import QiskitRuntimeService
from qbraid.programs import load_program
from qbraid.runtime.device import QuantumDevice
from qbraid.runtime.enums import DeviceStatus
from .job import QiskitJob
if TYPE_CHECKING:
import qiskit
import qiskit_ibm_runtime
import qbraid.runtime.qiskit
[docs]
class QiskitBackend(QuantumDevice):
"""Wrapper class for IBM Qiskit ``Backend`` objects."""
[docs]
def __init__(
self,
profile: qbraid.runtime.TargetProfile,
service: Optional[qiskit_ibm_runtime.QiskitRuntimeService] = None,
):
"""Create a QiskitBackend."""
super().__init__(profile=profile)
self._service = service or QiskitRuntimeService()
self._backend = self._service.backend(
self.id, instance=getattr(self.profile, "instance", None)
)
def __str__(self):
"""Official string representation of QuantumDevice object."""
return f"{self.__class__.__name__}('{self.id}')"
def status(self):
"""Return the status of this Device.
Returns:
str: The status of this Device
"""
if getattr(self.profile, "local", False):
return DeviceStatus.ONLINE
status = self._backend.status()
if status.operational:
if status.status_msg == "active":
return DeviceStatus.ONLINE
return DeviceStatus.UNAVAILABLE
return DeviceStatus.OFFLINE
def queue_depth(self) -> int:
"""Return the number of jobs in the queue for the ibm backend"""
if getattr(self.profile, "local", False):
return 0
return self._backend.status().pending_jobs
def transform(self, run_input: qiskit.QuantumCircuit) -> qiskit.QuantumCircuit:
"""Transpile a circuit for the device."""
program = load_program(run_input)
program.transform(self)
return program.program
def submit(
self,
run_input: Union[qiskit.QuantumCircuit, list[qiskit.QuantumCircuit]],
*args,
**kwargs,
) -> qbraid.runtime.qiskit.QiskitJob:
"""Runs circuit(s) on qiskit backend via :meth:`~qiskit.execute`
Uses the :meth:`~qiskit.execute` method to create a :class:`~qiskit.providers.QuantumJob`
object, applies a :class:`~qbraid.runtime.qiskit.QiskitJob`, and return the result.
Args:
run_input: A circuit object to run on the IBM device.
Keyword Args:
shots (int): The number of times to run the task on the device. Default is 1024.
Returns:
qbraid.runtime.qiskit.QiskitJob: The job like object for the run.
"""
backend = self._backend
shots = kwargs.pop("shots", backend.options.get("shots"))
memory = kwargs.pop("memory", True) # Needed to get measurements
job = backend.run(run_input, *args, shots=shots, memory=memory, **kwargs)
return QiskitJob(job.job_id(), job=job, device=self)