Revert "sort in place"

This reverts commit e1313eb.

Author: Rachel Chen

snuba/web/rpc/v1/endpoint_get_trace.py

@@ -473,15 +473,19 @@ def _process_results(
 ) -> ProcessedResults:
     """
     Used to process the results returned from clickhouse in two passes.
-    The first pass parses rows and builds attributes, and the second pass
-    sorts the attributes on each item.
+    The first pass adds attributes to each row, and the second pass sorts
+    the attributes and assembles the final items.
     """
-    items: list[GetTraceResponse.Item] = []
     last_seen_timestamp_precise = 0.0
     last_seen_id = ""
+    row_count = 0
+
+    # First pass: parse rows and build attribute dicts
+    parsed_rows: list[tuple[str, Timestamp, dict[str, GetTraceResponse.Item.Attribute]]] = []
 
     with sentry_sdk.start_span(op="function", description="add_attributes") as span:
         for row in data:
+            row_count += 1
             id = row.pop("id")
             ts = row.pop("timestamp")
             arrays = row.pop("attributes_array", "{}") or "{}"
@@ -523,19 +527,26 @@ def add_attribute(key: str, value: Any) -> None:
             for int_key, int_value in integers.items():
                 add_attribute(int_key, int_value)
 
-            items.append(
-                GetTraceResponse.Item(
-                    id=id,
-                    timestamp=timestamp,
-                    attributes=attributes.values(),
-                )
-            )
+            parsed_rows.append((id, timestamp, attributes))
+
+        span.set_data("rows_processed", row_count)
+
+    # Second pass: sort attributes and assemble items
+    items: list[GetTraceResponse.Item] = []
 
     with sentry_sdk.start_span(op="function", description="sort_attributes") as span:
-        for item in items:
-            item.attributes.sort(key=attrgetter("key.name"))
+        for id, timestamp, attributes in parsed_rows:
+            item = GetTraceResponse.Item(
+                id=id,
+                timestamp=timestamp,
+                attributes=sorted(
+                    attributes.values(),
+                    key=attrgetter("key.name"),
+                ),
+            )
+            items.append(item)
 
-    span.set_data("rows_processed", len(items))
+        span.set_data("rows_sorted", len(parsed_rows))
 
     return ProcessedResults(
         items=items,