perf(cosmos): add __slots__ to Range and skip redundant .upper()

- Add __slots__ to Range class: eliminates per-instance __dict__,
  reducing from ~250 bytes to 64 bytes per Range object.
- Skip .upper() when string is already uppercase: avoids creating
  unnecessary string copies since service returns uppercase hex.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: tvaron3

sdk/cosmos/azure-cosmos/azure/cosmos/_routing/routing_range.py

@@ -39,6 +39,8 @@ class PartitionKeyRange(object):
 class Range(object):
     """description of class"""
 
+    __slots__ = ('min', 'max', 'isMinInclusive', 'isMaxInclusive')
+
     MinPath = "min"
     MaxPath = "max"
     IsMinInclusivePath = "isMinInclusive"
@@ -50,8 +52,8 @@ def __init__(self, range_min, range_max, isMinInclusive, isMaxInclusive):
         if range_max is None:
             raise ValueError("max is missing")
 
-        self.min = range_min.upper()
-        self.max = range_max.upper()
+        self.min = range_min if range_min == range_min.upper() else range_min.upper()
+        self.max = range_max if range_max == range_max.upper() else range_max.upper()
         self.isMinInclusive = isMinInclusive
         self.isMaxInclusive = isMaxInclusive
 

sdk/cosmos/azure-cosmos/tests/routing/test_shared_pk_range_cache.py

@@ -4,6 +4,7 @@
 import unittest
 import pytest
 
+import sys
 from azure.cosmos._routing.routing_range import Range
 from azure.cosmos._routing.collection_routing_map import CollectionRoutingMap
 from azure.cosmos._routing.routing_map_provider import (
@@ -98,5 +99,30 @@ def test_clear_cache_does_not_affect_other_endpoints(self):
         self.assertIn("coll2", cache2._collection_routing_map_by_item)
 
 
+
+    def test_range_has_slots(self):
+        """Range class uses __slots__ to reduce per-instance memory."""
+        r = Range("00", "FF", True, False)
+        self.assertFalse(hasattr(r, "__dict__"))
+        self.assertTrue(hasattr(Range, "__slots__"))
+
+    def test_range_slots_memory_savings(self):
+        """Range with __slots__ should be smaller than 100 bytes."""
+        r = Range("00", "FF", True, False)
+        self.assertLess(sys.getsizeof(r), 100)
+
+    def test_range_skips_upper_when_already_uppercase(self):
+        """Range reuses the same string object when input is already uppercase."""
+        original = "05C1C9CD673398"
+        r = Range(original, original, True, False)
+        self.assertIs(r.min, original)
+        self.assertIs(r.max, original)
+
+    def test_range_applies_upper_when_lowercase(self):
+        """Range uppercases lowercase input."""
+        r = Range("05c1c9cd", "05c1d9cd", True, False)
+        self.assertEqual(r.min, "05C1C9CD")
+        self.assertEqual(r.max, "05C1D9CD")
+
 if __name__ == "__main__":
     unittest.main()