Add support for dynamic backends for IonQ (#428)

* Add support for dynamic backends for IonQ

Using the backends endpoint, add available backends to the list.

* Review comments

* Formatting fixes

* changelog

* Remove unnecessary element in docstring

Co-authored-by: Nguyen Damien <ngn.damien@gmail.com>

CHANGELOG.md

@@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+- Added IonQ dynamic backends fetch.
+
 ### Repository
 
 -   Fix issues with building on CentOS 7 & 8

projectq/backends/_ionq/_ionq_http_client.py

@@ -47,6 +47,11 @@ def __init__(self, verbose=False):
 
     def update_devices_list(self):
         """Update the list of devices this backend can support."""
+        self.authenticate(self.token)
+        req = super().get(urljoin(_API_URL, 'backends'))
+        req.raise_for_status()
+        r_json = req.json()
+        # Legacy backends, kept for backward compatibility.
         self.backends = {
             'ionq_simulator': {
                 'nq': 29,
@@ -57,6 +62,8 @@ def update_devices_list(self):
                 'target': 'qpu',
             },
         }
+        for backend in r_json:
+            self.backends[backend["backend"]] = {"nq": backend["qubits"], "target": backend["backend"]}
         if self._verbose:  # pragma: no cover
             print('- List of IonQ devices available:')
             print(self.backends)
@@ -240,19 +247,14 @@ def _handle_sigint_during_get_result(*_):  # pragma: no cover
 
         raise RequestTimeoutError("Timeout. The ID of your submitted job is {}.".format(execution_id))
 
+    def show_devices(self):
+        """Show the currently available device list for the IonQ provider.
 
-def show_devices(verbose=False):
-    """Show the currently available device list for the IonQ provider.
-
-    Args:
-        verbose (bool): If True, additional information is printed
-
-    Returns:
-        list: list of available devices and their properties.
-    """
-    ionq_session = IonQ(verbose=verbose)
-    ionq_session.update_devices_list()
-    return ionq_session.backends
+        Returns:
+            list: list of available devices and their properties.
+        """
+        self.update_devices_list()
+        return self.backends
 
 
 def retrieve(
@@ -398,6 +400,5 @@ def send(
 __all__ = [
     'send',
     'retrieve',
-    'show_devices',
     'IonQ',
 ]

projectq/backends/_ionq/_ionq_http_client_test.py

@@ -53,18 +53,74 @@ def user_password_input(prompt):
     assert str(excinfo.value) == 'An authentication token is required!'
 
 
-def test_is_online():
+def test_is_online(monkeypatch):
+    def mock_get(_self, path, *args, **kwargs):
+        assert urljoin(_api_url, 'backends') == path
+        mock_response = mock.MagicMock()
+        mock_response.json = mock.MagicMock(
+            return_value=[
+                {
+                    "backend": "qpu.s11",
+                    "status": "available",
+                    "qubits": 11,
+                    "average_queue_time": 3253287,
+                    "last_updated": 1647863473555,
+                    "characterization_url": "/characterizations/48ccd423-2913-45e0-a669-e0f676abeb82",
+                },
+                {
+                    "backend": "simulator",
+                    "status": "available",
+                    "qubits": 19,
+                    "average_queue_time": 1499,
+                    "last_updated": 1627065490042,
+                },
+            ],
+        )
+        return mock_response
+
+    monkeypatch.setattr('requests.sessions.Session.get', mock_get)
+
     ionq_session = _ionq_http_client.IonQ()
     ionq_session.authenticate('not none')
     ionq_session.update_devices_list()
     assert ionq_session.is_online('ionq_simulator')
     assert ionq_session.is_online('ionq_qpu')
+    assert ionq_session.is_online('qpu.s11')
     assert not ionq_session.is_online('ionq_unknown')
 
 
-def test_show_devices():
-    device_list = _ionq_http_client.show_devices()
+def test_show_devices(monkeypatch):
+    def mock_get(_self, path, *args, **kwargs):
+        assert urljoin(_api_url, 'backends') == path
+        mock_response = mock.MagicMock()
+        mock_response.json = mock.MagicMock(
+            return_value=[
+                {
+                    "backend": "qpu.s11",
+                    "status": "available",
+                    "qubits": 11,
+                    "average_queue_time": 3253287,
+                    "last_updated": 1647863473555,
+                    "characterization_url": "/characterizations/48ccd423-2913-45e0-a669-e0f676abeb82",
+                },
+                {
+                    "backend": "simulator",
+                    "status": "available",
+                    "qubits": 19,
+                    "average_queue_time": 1499,
+                    "last_updated": 1627065490042,
+                },
+            ],
+        )
+        return mock_response
+
+    monkeypatch.setattr('requests.sessions.Session.get', mock_get)
+
+    ionq_session = _ionq_http_client.IonQ()
+    ionq_session.authenticate('not none')
+    device_list = ionq_session.show_devices()
     assert isinstance(device_list, dict)
+    assert len(device_list) == 4
     for info in device_list.values():
         assert 'nq' in info
         assert 'target' in info

projectq/setups/ionq.py

@@ -21,7 +21,7 @@
 ->The 29 qubits simulator
 """
 from projectq.backends._exceptions import DeviceOfflineError
-from projectq.backends._ionq._ionq_http_client import show_devices
+from projectq.backends._ionq._ionq_http_client import IonQ
 from projectq.backends._ionq._ionq_mapper import BoundedQubitMapper
 from projectq.ops import (
     Barrier,
@@ -47,7 +47,10 @@
 
 def get_engine_list(token=None, device=None):
     """Return the default list of compiler engine for the IonQ platform."""
-    devices = show_devices(token)
+    service = IonQ()
+    if token is not None:
+        service.authenticate(token=token)
+    devices = service.show_devices()
     if not device or device not in devices:
         raise DeviceOfflineError("Error checking engine list: no '{}' devices available".format(device))
 

projectq/setups/ionq_test.py

@@ -17,6 +17,7 @@
 import pytest
 
 from projectq.backends._exceptions import DeviceOfflineError
+from projectq.backends._ionq._ionq_http_client import IonQ
 from projectq.backends._ionq._ionq_mapper import BoundedQubitMapper
 
 
@@ -26,7 +27,11 @@ def test_basic_ionq_mapper(monkeypatch):
     def mock_show_devices(*args, **kwargs):
         return {'dummy': {'nq': 3, 'target': 'dummy'}}
 
-    monkeypatch.setattr(projectq.setups.ionq, 'show_devices', mock_show_devices)
+    monkeypatch.setattr(
+        IonQ,
+        'show_devices',
+        mock_show_devices,
+    )
     engine_list = projectq.setups.ionq.get_engine_list(device='dummy')
     assert len(engine_list) > 1
     mapper = engine_list[-1]
@@ -41,7 +46,11 @@ def test_ionq_errors(monkeypatch):
     def mock_show_devices(*args, **kwargs):
         return {'dummy': {'nq': 3, 'target': 'dummy'}}
 
-    monkeypatch.setattr(projectq.setups.ionq, 'show_devices', mock_show_devices)
+    monkeypatch.setattr(
+        IonQ,
+        'show_devices',
+        mock_show_devices,
+    )
 
     with pytest.raises(DeviceOfflineError):
         projectq.setups.ionq.get_engine_list(device='simulator')