return attempt metric on new attempt

Author: daniel-sanche

google/cloud/bigtable/data/_metrics/__init__.py

@@ -17,9 +17,15 @@
 
 from google.cloud.bigtable.data._metrics.data_model import OperationType
 from google.cloud.bigtable.data._metrics.data_model import ActiveOperationMetric
+from google.cloud.bigtable.data._metrics.data_model import ActiveAttemptMetric
+from google.cloud.bigtable.data._metrics.data_model import CompletedOperationMetric
+from google.cloud.bigtable.data._metrics.data_model import CompletedAttemptMetric
 
 __all__ = (
     "BigtableClientSideMetricsController",
     "OperationType",
     "ActiveOperationMetric",
+    "ActiveAttemptMetric",
+    "CompletedOperationMetric",
+    "CompletedAttemptMetric",
 )

google/cloud/bigtable/data/_metrics/data_model.py

@@ -184,7 +184,7 @@ def start(self) -> None:
             return self._handle_error(INVALID_STATE_ERROR.format("start", self.state))
         self.start_time_ns = time.monotonic_ns()
 
-    def start_attempt(self) -> None:
+    def start_attempt(self) -> ActiveAttemptMetric:
         """
         Called to initiate a new attempt for the operation.
 
@@ -210,6 +210,7 @@ def start_attempt(self) -> None:
             backoff_ns = 0
 
         self.active_attempt = ActiveAttemptMetric(backoff_before_attempt_ns=backoff_ns)
+        return self.active_attempt
 
     def add_response_metadata(self, metadata: dict[str, bytes | str]) -> None:
         """