Add _ViewInstrumentMatch

Fixes open-telemetry#2296

opentelemetry-sdk/src/opentelemetry/sdk/_metrics/_view_instrument_match.py

@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from threading import Lock
 from typing import Callable, Dict, List
 
 from opentelemetry.sdk._metrics.aggregation import Aggregation
@@ -31,7 +32,38 @@ def __init__(
         exemplar_reservoir: Callable,
         resource: Resource,
     ):
-        pass
+        self._name = name
+        self._unit = unit
+        self._description = description
+
+        if attribute_keys is None:
+            self._attribute_keys = set()
+        else:
+            self._attribute_keys = set(attribute_keys.items())
+
+        self._extra_dimensions = extra_dimensions
+        self._aggregation = aggregation
+        self._exemplar_reservoir = exemplar_reservoir
+        self._attributes_aggregation = {}
+        self._lock = Lock()
 
     def _process(self, measurement: Measurement) -> None:
-        pass
+
+        if measurement.attributes is None:
+            attributes = {}
+
+        else:
+            attributes = measurement.attributes
+
+        attributes = frozenset(
+            set(attributes).difference(self._attribute_keys)
+        )
+
+        if attributes not in self._attributes_aggregation.keys():
+            # FIXME how to handle aggregations that support config?
+            with self._lock:
+                self._attributes_aggregation[attributes] = self._aggregation[
+                    attributes
+                ]
+
+        self._attributes_aggregation[attributes].aggregate(measurement.amount)