perf(serializer): Skip cycle-detection memo for atomic values

sentry_sdk/serializer.py

@@ -46,6 +46,7 @@
 MAX_DATABAG_DEPTH: int = 5
 MAX_DATABAG_BREADTH: int = 10
 CYCLE_MARKER = "<cyclic>"
+_ATOMIC_TYPES = frozenset((str, int, float, bool, type(None)))
 
 
 global_repr_processors: "List[ReprProcessor]" = []
@@ -199,6 +200,16 @@ def _serialize_node(
             self.path.append(segment)
 
         try:
+            if type(obj) in _ATOMIC_TYPES:
+                return self._serialize_node_impl(
+                    obj,
+                    is_databag=is_databag,
+                    is_request_body=is_request_body,
+                    should_repr_strings=should_repr_strings,
+                    remaining_depth=remaining_depth,
+                    remaining_breadth=remaining_breadth,
+                )
+
             with self.memo.memoize(obj) as result:
                 if result:
                     return CYCLE_MARKER

tests/test_serializer.py

@@ -3,7 +3,12 @@
 
 import pytest
 
-from sentry_sdk.serializer import MAX_DATABAG_BREADTH, MAX_DATABAG_DEPTH, serialize
+from sentry_sdk.serializer import (
+    MAX_DATABAG_BREADTH,
+    MAX_DATABAG_DEPTH,
+    Memo,
+    serialize,
+)
 
 try:
     import hypothesis.strategies as st
@@ -115,6 +120,44 @@ def test_custom_mapping_doesnt_mess_with_mock(extra_normalizer):
     assert len(m.mock_calls) == 0
 
 
+def test_atomic_values_serialization_output():
+    result = serialize(
+        {
+            "nested": {
+                "values": [
+                    "string",
+                    42,
+                    3.14,
+                    True,
+                    False,
+                    None,
+                    float("inf"),
+                    float("nan"),
+                ]
+            }
+        }
+    )
+
+    assert result == {
+        "nested": {"values": ["string", 42, 3.14, True, False, None, "inf", "nan"]}
+    }
+
+
+def test_atomic_values_are_not_memoized(monkeypatch):
+    memoized_objects = []
+    original_memoize = Memo.memoize
+
+    def counting_memoize(self, obj):
+        memoized_objects.append(obj)
+        return original_memoize(self, obj)
+
+    monkeypatch.setattr(Memo, "memoize", counting_memoize)
+    event = {"one": "1", "two": "2", "three": "3"}
+
+    assert serialize(event) == event
+    assert memoized_objects == [event]
+
+
 def test_custom_repr(extra_normalizer):
     class Foo:
         pass