JVM bulk loads: search for a subnormal exponent, not any "e-3"

src/arcadedb/type_conversion.py

@@ -7,6 +7,7 @@
 
 import json
 import math
+import re
 import sys
 from datetime import date, datetime, time, timedelta, timezone
 from decimal import Decimal
@@ -746,18 +747,24 @@ def _has_subnormal(value: Any) -> bool:
     return False
 
 
+# the exponent json.dumps writes for a subnormal double (5e-324 up to 2.2250738585072009e-308): e-308 to e-329 after a digit
+_SUBNORMAL_EXPONENT = re.compile(r"[0-9]e-3(?:0[89]|[12][0-9])")
+
+
 def _dumps_checked(rows: Any, **kwargs: Any) -> str:
     """json.dumps for the bulk paths, refusing a subnormal double.
 
     The engine's JSON parser reads the text of a subnormal (``5e-324``) as a
     BigDecimal, so it was stored as a DECIMAL and read back as ``Decimal``
     where every other write path stores a double. ValueError sends the row down
     the per-row path, which stores the double. Every subnormal is written with
-    an exponent of -308 or below, so the text is searched first (C speed) and
-    only a hit pays for the walk over the rows.
+    an exponent of -308 or below, so the text is searched first (C speed) for
+    such an exponent after a digit, and only a hit pays for the walk over the
+    rows. A bare "e-3" would also hit ordinary text (hex ids, UUIDs, "name-3")
+    and send every such load through the walk.
     """
     text = json.dumps(rows, allow_nan=False, **kwargs)
-    if "e-3" in text and any(_has_subnormal(row) for row in rows):
+    if _SUBNORMAL_EXPONENT.search(text) and any(_has_subnormal(row) for row in rows):
         raise ValueError("a subnormal double cannot go through the JSON bulk path")
     return text
 

tests/test_bulk_json_paths.py

@@ -143,3 +143,20 @@ def test_ordinary_rows_stay_on_the_bulk_path(temp_db_path):
 )
 def test_json_bulk_scalar_ok(value, ok):
     assert type_conversion.json_bulk_scalar_ok(value) is ok
+
+
+def test_text_that_only_looks_like_an_exponent_skips_the_subnormal_walk(monkeypatch):
+    # "e-3" is common in ordinary text (hex ids, UUIDs, "name-3"): only an exponent a subnormal can have may send a chunk
+    # through the per-row Python walk, so a load of such text keeps the fast check
+    calls = []
+    real = type_conversion._has_subnormal
+    monkeypatch.setattr(
+        type_conversion, "_has_subnormal", lambda row: calls.append(row) or real(row)
+    )
+    rows = [{"id": f"4fe-3a{i}", "tag": "name-3", "x": 1e-30} for i in range(3)]
+    assert type_conversion.json_bulk_dumps(rows) == json.dumps(rows)
+    assert calls == []
+    with pytest.raises(ValueError):
+        type_conversion.json_bulk_dumps([{"x": 5e-324}])
+    with pytest.raises(ValueError):
+        type_conversion.json_bulk_dumps([{"x": 2.2250738585072009e-308}])