fix: batch byte limit is properly checked on a new step

src/neptune_scale/core/components/aggregating_queue.py

@@ -93,11 +93,12 @@ def get(self) -> BatchedOperations:
             if element is None:
                 break
 
-            if not batch_operations or element.batch_key != last_batch_key:
+            if not batch_operations:
                 new_operation = RunOperation()
                 new_operation.ParseFromString(element.operation)
                 batch_operations.append(new_operation)
                 last_batch_key = element.batch_key
+                batch_bytes += len(element.operation)
             else:
                 if not element.is_batchable:
                     logger.debug("Batch closed due to next operation not being batchable")
@@ -111,21 +112,22 @@ def get(self) -> BatchedOperations:
 
                 new_operation = RunOperation()
                 new_operation.ParseFromString(element.operation)
-                merge_run_operation(batch_operations[-1], new_operation)
+                if element.batch_key != last_batch_key:
+                    batch_operations.append(new_operation)
+                    last_batch_key = element.batch_key
+                else:
+                    merge_run_operation(batch_operations[-1], new_operation)
+                batch_bytes += element.metadata_size
 
             batch_sequence_id = element.sequence_id
             batch_timestamp = element.timestamp
 
-            if element.metadata_size is not None:
-                batch_bytes += element.metadata_size
-            else:
-                batch_bytes += len(element.operation)
             elements_in_batch += 1
 
             self.commit()
 
             if not element.is_batchable:
-                logger.debug("Batch closed due to first not being batchable")
+                logger.debug("Batch closed due to the first element not being batchable")
                 break
 
             t1 = time.monotonic()

tests/unit/test_aggregating_queue.py

@@ -182,6 +182,42 @@ def test__batching():
     assert all(k in batch.update.assign for k in ["aa0", "aa1", "bb0", "bb1"])
 
 
+@freeze_time("2024-09-01")
+def test__queue_element_size_limit_with_different_steps():
+    # given
+    update1 = UpdateRunSnapshot(step=Step(whole=1), assign={f"aa{i}": Value(int64=(i * 97)) for i in range(2)})
+    update2 = UpdateRunSnapshot(step=Step(whole=2), assign={f"bb{i}": Value(int64=(i * 25)) for i in range(2)})
+    operation1 = RunOperation(update=update1)
+    operation2 = RunOperation(update=update2)
+    element1 = SingleOperation(
+        sequence_id=1,
+        timestamp=time.process_time(),
+        operation=operation1.SerializeToString(),
+        is_batchable=True,
+        metadata_size=update1.ByteSize(),
+        batch_key=1.0,
+    )
+    element2 = SingleOperation(
+        sequence_id=2,
+        timestamp=time.process_time(),
+        operation=operation2.SerializeToString(),
+        is_batchable=True,
+        metadata_size=update2.ByteSize(),
+        batch_key=2.0,
+    )
+
+    # and
+    queue = AggregatingQueue(max_queue_size=2, max_queue_element_size=update1.ByteSize())
+
+    # when
+    queue.put_nowait(element=element1)
+    queue.put_nowait(element=element2)
+
+    # then
+    assert queue.get() == BatchedOperations(sequence_id=1, timestamp=element1.timestamp, operation=element1.operation)
+    assert queue.get() == BatchedOperations(sequence_id=2, timestamp=element2.timestamp, operation=element2.operation)
+
+
 @freeze_time("2024-09-01")
 def test__not_merge_two_run_creation():
     # given