Add metadata property for cirq_google devices. (quantumlib#4869)

Adds metadata properties to cirq_google devices. Part of  quantumlib#4743 .


Note for @dstrain115 and @verult : I don't expect these metadata properties to take this exact form forever and that we may end up changing things once we have a more firmed up plan for how DeviceSpec protos and serialization might change.

Author: MichaelBroughton

cirq-google/cirq_google/devices/known_devices_test.py

@@ -21,13 +21,14 @@
 
 
 def test_foxtail_qubits():
-    with cirq.testing.assert_deprecated('Foxtail', deadline='v0.15'):
+    with cirq.testing.assert_deprecated('Foxtail', deadline='v0.15', count=2):
         expected_qubits = []
         for i in range(0, 2):
             for j in range(0, 11):
                 expected_qubits.append(cirq.GridQubit(i, j))
 
         assert set(expected_qubits) == cirq_google.Foxtail.qubits
+        assert len(cirq_google.Foxtail.metadata.qubit_pairs) == 31
 
 
 def test_foxtail_device_proto():
@@ -490,6 +491,22 @@ def test_sycamore_devices(device):
     assert device.duration_of(sqrt_iswap) == cirq.Duration(nanos=32)
 
 
+def test_sycamore_metadata():
+    assert len(cirq_google.Sycamore.metadata.qubit_pairs) == 88
+    assert len(cirq_google.Sycamore23.metadata.qubit_pairs) == 32
+    assert cirq_google.Sycamore.metadata.gateset == cirq.Gateset(
+        cirq.FSimGate,
+        cirq.ISwapPowGate,
+        cirq.PhasedXPowGate,
+        cirq.XPowGate,
+        cirq.YPowGate,
+        cirq.ZPowGate,
+        cirq.PhasedXZGate,
+        cirq.MeasurementGate,
+        cirq.WaitGate,
+    )
+
+
 def test_sycamore_circuitop_device():
     circuitop_gateset = cirq_google.SerializableGateSet(
         gate_set_name='circuitop_gateset',

cirq-google/cirq_google/devices/serializable_device.py

@@ -108,6 +108,25 @@ def __init__(
         """
         self.qubits = qubits
         self.gate_definitions = gate_definitions
+        self._metadata = cirq.GridDeviceMetadata(
+            qubit_pairs=[
+                (pair[0], pair[1])
+                for gate_defs in gate_definitions.values()
+                for gate_def in gate_defs
+                if gate_def.number_of_qubits == 2
+                for pair in gate_def.target_set
+                if len(pair) == 2 and pair[0] < pair[1]
+            ],
+            supported_gates=cirq.Gateset(
+                *[g for g in gate_definitions.keys() if isinstance(g, (cirq.Gate, type(cirq.Gate)))]
+            ),
+            gate_durations=None,
+        )
+
+    @property
+    def metadata(self) -> cirq.GridDeviceMetadata:
+        """Get metadata information for device."""
+        return self._metadata
 
     def qubit_set(self) -> FrozenSet[cirq.Qid]:
         return frozenset(self.qubits)

cirq-google/cirq_google/devices/serializable_device_test.py

@@ -77,6 +77,35 @@ def test_repr_pretty(cycle, func):
     printer.text.assert_called_once_with(func(device))
 
 
+def test_metadata_correct():
+    qubits = cirq.GridQubit.rect(2, 3, left=1, top=1)
+    pairs = [
+        (qubits[0], qubits[1]),
+        (qubits[0], qubits[3]),
+        (qubits[1], qubits[4]),
+        (qubits[4], qubits[5]),
+    ]
+    device_proto = cgdk.create_device_proto_for_qubits(
+        qubits=qubits,
+        pairs=pairs,
+        gate_sets=[cg.FSIM_GATESET],
+    )
+    device = cgdk.SerializableDevice.from_proto(device_proto, gate_sets=[cg.FSIM_GATESET])
+    assert device.metadata.qubit_pairs == frozenset(pairs)
+    assert device.metadata.gateset == cirq.Gateset(
+        cirq.FSimGate,
+        cirq.ISwapPowGate,
+        cirq.CZPowGate,
+        cirq.PhasedXPowGate,
+        cirq.XPowGate,
+        cirq.YPowGate,
+        cirq.ZPowGate,
+        cirq.PhasedXZGate,
+        cirq.MeasurementGate,
+        cirq.WaitGate,
+    )
+
+
 def test_gate_definition_equality():
     def1 = cg.devices.serializable_device._GateDefinition(
         duration=cirq.Duration(picos=4),

cirq-google/cirq_google/devices/xmon_device.py

@@ -45,6 +45,23 @@ def __init__(
         self._exp_w_duration = cirq.Duration(exp_w_duration)
         self._exp_z_duration = cirq.Duration(exp_11_duration)
         self.qubits = frozenset(qubits)
+        self._metadata = cirq.GridDeviceMetadata(
+            [(q0, q1) for q0 in self.qubits for q1 in self.qubits if q0.is_adjacent(q1)],
+            cirq.Gateset(
+                cirq.CZPowGate,
+                cirq.XPowGate,
+                cirq.YPowGate,
+                cirq.PhasedXPowGate,
+                cirq.MeasurementGate,
+                cirq.ZPowGate,
+            ),
+            None,
+        )
+
+    @property
+    def metadata(self) -> cirq.GridDeviceMetadata:
+        """Return the metadata for this device"""
+        return self._metadata
 
     def qubit_set(self) -> FrozenSet[cirq.GridQubit]:
         return self.qubits

cirq-google/cirq_google/devices/xmon_device_test.py

@@ -44,6 +44,35 @@ def qubits(self):
         raise NotImplementedError()
 
 
+@mock.patch.dict(os.environ, clear='CIRQ_TESTING')
+def test_device_metadata():
+    d = square_device(3, 3)
+    assert d.metadata.gateset == cirq.Gateset(
+        cirq.CZPowGate,
+        cirq.XPowGate,
+        cirq.YPowGate,
+        cirq.PhasedXPowGate,
+        cirq.MeasurementGate,
+        cirq.ZPowGate,
+    )
+    assert d.metadata.qubit_pairs == frozenset(
+        {
+            (cirq.GridQubit(0, 0), cirq.GridQubit(0, 1)),
+            (cirq.GridQubit(0, 1), cirq.GridQubit(1, 1)),
+            (cirq.GridQubit(2, 0), cirq.GridQubit(2, 1)),
+            (cirq.GridQubit(0, 0), cirq.GridQubit(1, 0)),
+            (cirq.GridQubit(0, 2), cirq.GridQubit(1, 2)),
+            (cirq.GridQubit(1, 0), cirq.GridQubit(2, 0)),
+            (cirq.GridQubit(1, 0), cirq.GridQubit(1, 1)),
+            (cirq.GridQubit(1, 1), cirq.GridQubit(2, 1)),
+            (cirq.GridQubit(1, 1), cirq.GridQubit(1, 2)),
+            (cirq.GridQubit(0, 1), cirq.GridQubit(0, 2)),
+            (cirq.GridQubit(2, 1), cirq.GridQubit(2, 2)),
+            (cirq.GridQubit(1, 2), cirq.GridQubit(2, 2)),
+        }
+    )
+
+
 @mock.patch.dict(os.environ, clear='CIRQ_TESTING')
 def test_init():
     d = square_device(2, 2, holes=[cirq.GridQubit(1, 1)])

dev_tools/requirements/deps/pytest.txt

@@ -3,6 +3,7 @@
 pytest
 pytest-asyncio
 pytest-cov
+coverage<=6.2
 
 # for parallel testing notebooks
 pytest-xdist~=2.2.0