Deprecate QuantumEngineSampler (#5432)

* Deprecate QuantumEngineSampler - Deprecates this class in favor of ProcessorSampler - Moves get_engine_sampler into engine with the other utility functions - Change engine.get_sampler to only support a single processor and have it point to the processor's sampler. - Fix calibration workflow to use ProcessorSampler Fixes: #5371
quantumlib · Jun 3, 2022 · fdb1527 · fdb1527
1 parent 74e6c7a
commit fdb1527
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diff --git a/cirq-google/cirq_google/calibration/workflow.py b/cirq-google/cirq_google/calibration/workflow.py
@@ -36,7 +36,7 @@
     LocalXEBPhasedFSimCalibrationRequest,
 )
 from cirq_google.calibration.xeb_wrapper import run_local_xeb_calibration
-from cirq_google.engine import Engine, QuantumEngineSampler, util
+from cirq_google.engine import AbstractProcessor, AbstractEngine, ProcessorSampler, util
 from cirq_google.serialization.serializer import Serializer
 
 _CALIBRATION_IRRELEVANT_GATES = cirq.MeasurementGate, cirq.WaitGate
@@ -730,8 +730,7 @@ def _merge_into_calibrations(
 
 def _run_calibrations_via_engine(
     calibration_requests: Sequence[PhasedFSimCalibrationRequest],
-    engine: Engine,
-    processor_id: str,
+    processor: AbstractProcessor,
     max_layers_per_request: int = 1,
     progress_func: Optional[Callable[[int, int], None]] = None,
 ):
@@ -750,7 +749,7 @@ def _run_calibrations_via_engine(
     ]
 
     for cal_layers in nested_calibration_layers:
-        job = engine.run_calibration(cal_layers, processor_id=processor_id)
+        job = processor.run_calibration(cal_layers)
         request_results = job.calibration_results()
         results += [
             calibration.parse_result(result, job)
@@ -776,7 +775,7 @@ def _run_local_calibrations_via_sampler(
 @util.deprecated_gate_set_parameter
 def run_calibrations(
     calibrations: Sequence[PhasedFSimCalibrationRequest],
-    sampler: Union[Engine, cirq.Sampler],
+    sampler: Union[AbstractEngine, cirq.Sampler],
     processor_id: Optional[str] = None,
     gate_set: Optional[Serializer] = None,
     max_layers_per_request: int = 1,
@@ -787,7 +786,7 @@ def run_calibrations(
     Args:
         calibrations: List of calibrations to perform described in a request object.
         sampler: cirq_google.Engine or cirq.Sampler object used for running the calibrations. When
-            sampler is cirq_google.Engine or cirq_google.QuantumEngineSampler object then the
+            sampler is cirq_google.Engine or cirq_google.ProcessorSampler object then the
             calibrations are issued against a Google's quantum device. The only other sampler
             supported for simulation purposes is cirq_google.PhasedFSimEngineSimulator.
         processor_id: Used when sampler is cirq_google.Engine object and passed to
@@ -824,24 +823,23 @@ def run_calibrations(
         )
     (calibration_request_type,) = calibration_request_types
 
-    if isinstance(sampler, Engine):
-        engine: Optional[Engine] = sampler
-    elif isinstance(sampler, QuantumEngineSampler):
-        engine = sampler.engine
-        (processor_id,) = sampler._processor_ids
-    else:
-        engine = None
-
-    if engine is not None:
+    if isinstance(sampler, AbstractEngine):
         if processor_id is None:
             raise ValueError('processor_id must be provided.')  # coverage: ignore
+        processor: Optional[AbstractProcessor] = sampler.get_processor(processor_id=processor_id)
+    elif isinstance(sampler, ProcessorSampler):
+        processor = sampler.processor
+    else:
+        processor = None
+
+    if processor is not None:
 
         if calibration_request_type == LocalXEBPhasedFSimCalibrationRequest:
-            engine_sampler = engine.get_sampler(processor_id=processor_id)
+            engine_sampler = processor.get_sampler()
             return _run_local_calibrations_via_sampler(calibrations, engine_sampler)
 
         return _run_calibrations_via_engine(
-            calibrations, engine, processor_id, max_layers_per_request, progress_func
+            calibrations, processor, max_layers_per_request, progress_func
         )
 
     if calibration_request_type == LocalXEBPhasedFSimCalibrationRequest:
@@ -1165,7 +1163,7 @@ def as_circuit(self) -> cirq.Circuit:
 @util.deprecated_gate_set_parameter
 def run_floquet_characterization_for_moments(
     circuit: cirq.Circuit,
-    sampler: Union[Engine, cirq.Sampler],
+    sampler: Union[AbstractEngine, cirq.Sampler],
     processor_id: Optional[str] = None,
     gate_set: Optional[Serializer] = None,
     options: FloquetPhasedFSimCalibrationOptions = WITHOUT_CHI_FLOQUET_PHASED_FSIM_CHARACTERIZATION,
@@ -1185,7 +1183,7 @@ def run_floquet_characterization_for_moments(
     Args:
         circuit: Circuit to characterize.
         sampler: cirq_google.Engine or cirq.Sampler object used for running the calibrations. When
-            sampler is cirq_google.Engine or cirq_google.QuantumEngineSampler object then the
+            sampler is cirq_google.Engine or cirq_google.ProcessorSampler object then the
             calibrations are issued against a Google's quantum device. The only other sampler
             supported for simulation purposes is cirq_google.PhasedFSimEngineSimulator.
         processor_id: Used when sampler is cirq_google.Engine object and passed to
@@ -1236,7 +1234,7 @@ def run_floquet_characterization_for_moments(
 @util.deprecated_gate_set_parameter
 def run_zeta_chi_gamma_compensation_for_moments(
     circuit: cirq.Circuit,
-    sampler: Union[Engine, cirq.Sampler],
+    sampler: Union[AbstractEngine, cirq.Sampler],
     processor_id: Optional[str] = None,
     gate_set: Optional[Serializer] = None,
     options: FloquetPhasedFSimCalibrationOptions = (
@@ -1261,7 +1259,7 @@ def run_zeta_chi_gamma_compensation_for_moments(
     Args:
         circuit: Circuit to characterize and calibrate.
         sampler: cirq_google.Engine or cirq.Sampler object used for running the calibrations. When
-            sampler is cirq_google.Engine or cirq_google.QuantumEngineSampler object then the
+            sampler is cirq_google.Engine or cirq_google.ProcessorSampler object then the
             calibrations are issued against a Google's quantum device. The only other sampler
             supported for simulation purposes is cirq_google.PhasedFSimEngineSimulator.
         processor_id: Used when sampler is cirq_google.Engine object and passed to

diff --git a/cirq-google/cirq_google/calibration/workflow_test.py b/cirq-google/cirq_google/calibration/workflow_test.py
@@ -1006,10 +1006,14 @@ def test_run_calibrations():
     job = cirq_google.engine.EngineJob('project_id', 'program_id', 'job_id', None)
     job._calibration_results = [result]
 
-    engine = mock.MagicMock(spec=cirq_google.Engine)
-    engine.run_calibration.return_value = job
+    processor = mock.MagicMock(spec=cirq_google.engine.SimulatedLocalProcessor)
+    processor.processor_id = 'qproc'
+    engine = cirq_google.engine.SimulatedLocalEngine([processor])
+    processor.engine.return_value = engine
+    processor.run_calibration.return_value = job
+    progress_calls = []
 
-    sampler = cirq_google.QuantumEngineSampler(engine=engine, processor_id='qproc')
+    sampler = cirq_google.ProcessorSampler(processor=processor)
 
     progress_calls = []
 
@@ -1105,9 +1109,11 @@ def test_run_characterization_with_engine():
     job = cirq_google.engine.EngineJob('project_id', 'program_id', 'job_id', None)
     job._calibration_results = [result]
 
-    engine = mock.MagicMock(spec=cirq_google.Engine)
-    engine.run_calibration.return_value = job
-
+    processor = mock.MagicMock(spec=cirq_google.engine.SimulatedLocalProcessor)
+    processor.processor_id = 'qproc'
+    engine = cirq_google.engine.SimulatedLocalEngine([processor])
+    processor.engine.return_value = engine
+    processor.run_calibration.return_value = job
     progress_calls = []
 
     def progress(step: int, steps: int) -> None:
@@ -1267,8 +1273,11 @@ def test_run_floquet_characterization_for_moments():
         )
     ]
 
-    engine = mock.MagicMock(spec=cirq_google.Engine)
-    engine.run_calibration.return_value = job
+    processor = mock.MagicMock(spec=cirq_google.engine.SimulatedLocalProcessor)
+    processor.processor_id = 'qproc'
+    engine = cirq_google.engine.SimulatedLocalEngine([processor])
+    processor.engine.return_value = engine
+    processor.run_calibration.return_value = job
 
     circuit_with_calibration, requests = workflow.run_floquet_characterization_for_moments(
         circuit, engine, 'qproc', options=options
@@ -1657,9 +1666,7 @@ def test_run_zeta_chi_gamma_calibration_for_moments_no_chi() -> None:
     )
 
 
-_MOCK_ENGINE_SAMPLER = mock.MagicMock(
-    spec=cirq_google.QuantumEngineSampler, _processor_ids=['my_fancy_processor'], _gate_set='test'
-)
+_MOCK_ENGINE_SAMPLER = mock.MagicMock(spec=cirq_google.ProcessorSampler)
 
 
 @pytest.mark.parametrize('sampler_engine', [cirq.Simulator, _MOCK_ENGINE_SAMPLER])

diff --git a/cirq-google/cirq_google/engine/__init__.py b/cirq-google/cirq_google/engine/__init__.py
@@ -49,6 +49,7 @@
     get_engine,
     get_engine_calibration,
     get_engine_device,
+    get_engine_sampler,
     ProtoVersion,
 )
 
@@ -66,7 +67,7 @@
     estimate_run_sweep_time,
 )
 
-from cirq_google.engine.engine_sampler import get_engine_sampler, QuantumEngineSampler
+from cirq_google.engine.engine_sampler import QuantumEngineSampler
 
 from cirq_google.engine.validating_sampler import ValidatingSampler
 

diff --git a/cirq-google/cirq_google/engine/engine.py b/cirq-google/cirq_google/engine/engine.py
@@ -42,7 +42,6 @@
     engine_job,
     engine_processor,
     engine_program,
-    engine_sampler,
     util,
 )
 from cirq_google.cloud import quantum
@@ -782,7 +781,7 @@ def get_processor(self, processor_id: str) -> engine_processor.EngineProcessor:
     @util.deprecated_gate_set_parameter
     def sampler(
         self, processor_id: Union[str, List[str]], gate_set: Optional[Serializer] = None
-    ) -> engine_sampler.QuantumEngineSampler:
+    ) -> 'cirq_google.ProcessorSampler':
         """Returns a sampler backed by the engine.
 
         Args:
@@ -801,21 +800,29 @@ def sampler(
     @util.deprecated_gate_set_parameter
     def get_sampler(
         self, processor_id: Union[str, List[str]], gate_set: Optional[Serializer] = None
-    ) -> engine_sampler.QuantumEngineSampler:
+    ) -> 'cirq_google.ProcessorSampler':
         """Returns a sampler backed by the engine.
 
         Args:
-            processor_id: String identifier, or list of string identifiers,
-                determining which processors may be used when sampling.
+            processor_id: String identifier of which processor should be used to sample.
             gate_set: A `Serializer` that determines how to serialize
                  circuits when requesting samples.
 
         Returns:
             A `cirq.Sampler` instance (specifically a `engine_sampler.QuantumEngineSampler`
             that will send circuits to the Quantum Computing Service
             when sampled.
+
+        Raises:
+            ValueError: if a list of processors is provided.  This is no longer supported.
         """
-        return engine_sampler.QuantumEngineSampler(engine=self, processor_id=processor_id)
+        if not isinstance(processor_id, str):
+            raise ValueError(
+                f'Passing a list of processors ({processor_id}) '
+                'to get_sampler() no longer supported. Use Engine.run() instead if '
+                'you need to specify a list.'
+            )
+        return self.get_processor(processor_id).get_sampler()
 
 
 def get_engine(project_id: Optional[str] = None) -> Engine:
@@ -877,3 +884,26 @@ def get_engine_calibration(
     May return None if no calibration metrics exist for the device.
     """
     return get_engine(project_id).get_processor(processor_id).get_current_calibration()
+
+
+def get_engine_sampler(
+    processor_id: str, project_id: Optional[str] = None
+) -> 'cirq_google.ProcessorSampler':
+    """Get an EngineSampler assuming some sensible defaults.
+
+    This uses the environment variable GOOGLE_CLOUD_PROJECT for the Engine
+    project_id, unless set explicitly.
+
+    Args:
+        processor_id: Engine processor ID (from Cloud console or
+            ``Engine.list_processors``).
+        project_id: Optional explicit Google Cloud project id. Otherwise,
+            this defaults to the environment variable GOOGLE_CLOUD_PROJECT.
+            By using an environment variable, you can avoid hard-coding
+            personal project IDs in shared code.
+
+    Raises:
+         EnvironmentError: If no project_id is specified and the environment
+            variable GOOGLE_CLOUD_PROJECT is not set.
+    """
+    return get_engine(project_id).get_processor(processor_id).get_sampler()
diff --git a/cirq-google/cirq_google/engine/engine_sampler.py b/cirq-google/cirq_google/engine/engine_sampler.py
@@ -22,6 +22,7 @@
     import cirq_google
 
 
+@cirq._compat.deprecated_class(deadline='v0.16', fix='Use cirq_google.ProcessorSampler instead.')
 class QuantumEngineSampler(cirq.Sampler):
     """A sampler that samples from processors managed by the Quantum Engine.
 
@@ -106,15 +107,10 @@ def engine(self) -> 'cirq_google.Engine':
         return self._engine
 
 
-@cirq._compat.deprecated_parameter(
-    deadline='v0.15',
-    fix='Remove the "gate_set_name" parameter.',
-    parameter_desc='gate_set_name',
-    match=lambda args, kwargs: 'gate_set_name' in kwargs or len(args) > 1,
-)
+@cirq._compat.deprecated(deadline='v0.16', fix='Use cirq_google.get_engine_sampler()')
 def get_engine_sampler(
     processor_id: str, gate_set_name: str = '', project_id: Optional[str] = None
-) -> 'cirq_google.QuantumEngineSampler':
+) -> cirq.Sampler:
     """Get an EngineSampler assuming some sensible defaults.
 
     This uses the environment variable GOOGLE_CLOUD_PROJECT for the Engine

diff --git a/cirq-google/cirq_google/engine/engine_sampler_test.py b/cirq-google/cirq_google/engine/engine_sampler_test.py
@@ -24,7 +24,10 @@
 @pytest.mark.parametrize('circuit', [cirq.Circuit(), cirq.FrozenCircuit()])
 def test_run_circuit(circuit):
     engine = mock.Mock()
-    sampler = cg.QuantumEngineSampler(engine=engine, processor_id='tmp')
+    with cirq.testing.assert_deprecated(
+        'Use cirq_google.ProcessorSampler instead.', deadline='v0.16'
+    ):
+        sampler = cg.QuantumEngineSampler(engine=engine, processor_id='tmp')
     params = [cirq.ParamResolver({'a': 1})]
     sampler.run_sweep(circuit, params, 5)
     engine.run_sweep.assert_called_with(
@@ -34,7 +37,10 @@ def test_run_circuit(circuit):
 
 def test_run_engine_program():
     engine = mock.Mock()
-    sampler = cg.QuantumEngineSampler(engine=engine, processor_id='tmp')
+    with cirq.testing.assert_deprecated(
+        'Use cirq_google.ProcessorSampler instead.', deadline='v0.16'
+    ):
+        sampler = cg.QuantumEngineSampler(engine=engine, processor_id='tmp')
     program = mock.Mock(spec=cg.EngineProgram)
     params = [cirq.ParamResolver({'a': 1})]
     sampler.run_sweep(program, params, 5)
@@ -44,7 +50,10 @@ def test_run_engine_program():
 
 def test_run_batch():
     engine = mock.Mock()
-    sampler = cg.QuantumEngineSampler(engine=engine, processor_id='tmp')
+    with cirq.testing.assert_deprecated(
+        'Use cirq_google.ProcessorSampler instead.', deadline='v0.16'
+    ):
+        sampler = cg.QuantumEngineSampler(engine=engine, processor_id='tmp')
     a = cirq.LineQubit(0)
     circuit1 = cirq.Circuit(cirq.X(a))
     circuit2 = cirq.Circuit(cirq.Y(a))
@@ -60,7 +69,10 @@ def test_run_batch():
 
 def test_run_batch_identical_repetitions():
     engine = mock.Mock()
-    sampler = cg.QuantumEngineSampler(engine=engine, processor_id='tmp')
+    with cirq.testing.assert_deprecated(
+        'Use cirq_google.ProcessorSampler instead.', deadline='v0.16'
+    ):
+        sampler = cg.QuantumEngineSampler(engine=engine, processor_id='tmp')
     a = cirq.LineQubit(0)
     circuit1 = cirq.Circuit(cirq.X(a))
     circuit2 = cirq.Circuit(cirq.Y(a))
@@ -76,7 +88,10 @@ def test_run_batch_identical_repetitions():
 
 def test_run_batch_bad_number_of_repetitions():
     engine = mock.Mock()
-    sampler = cg.QuantumEngineSampler(engine=engine, processor_id='tmp')
+    with cirq.testing.assert_deprecated(
+        'Use cirq_google.ProcessorSampler instead.', deadline='v0.16'
+    ):
+        sampler = cg.QuantumEngineSampler(engine=engine, processor_id='tmp')
     a = cirq.LineQubit(0)
     circuit1 = cirq.Circuit(cirq.X(a))
     circuit2 = cirq.Circuit(cirq.Y(a))
@@ -93,7 +108,10 @@ def test_run_batch_differing_repetitions():
     job = mock.Mock()
     job.results.return_value = []
     engine.run_sweep.return_value = job
-    sampler = cg.QuantumEngineSampler(engine=engine, processor_id='tmp')
+    with cirq.testing.assert_deprecated(
+        'Use cirq_google.ProcessorSampler instead.', deadline='v0.16'
+    ):
+        sampler = cg.QuantumEngineSampler(engine=engine, processor_id='tmp')
     a = cirq.LineQubit(0)
     circuit1 = cirq.Circuit(cirq.X(a))
     circuit2 = cirq.Circuit(cirq.Y(a))
@@ -111,7 +129,10 @@ def test_run_batch_differing_repetitions():
 
 def test_engine_sampler_engine_property():
     engine = mock.Mock()
-    sampler = cg.QuantumEngineSampler(engine=engine, processor_id='tmp')
+    with cirq.testing.assert_deprecated(
+        'Use cirq_google.ProcessorSampler instead.', deadline='v0.16'
+    ):
+        sampler = cg.QuantumEngineSampler(engine=engine, processor_id='tmp')
     assert sampler.engine is engine
 
 

diff --git a/cirq-google/cirq_google/engine/engine_test.py b/cirq-google/cirq_google/engine/engine_test.py
@@ -832,6 +832,9 @@ def test_sampler(client):
     with cirq.testing.assert_deprecated('sampler', deadline='1.0'):
         _ = engine.sampler(processor_id='tmp')
 
+    with pytest.raises(ValueError, match='list of processors'):
+        _ = engine.get_sampler(['test1', 'test2'])
+
 
 @mock.patch('cirq_google.cloud.quantum.QuantumEngineServiceClient')
 def test_get_engine(build):