[Speculative Decoding] Add native UNO serving support (#37667)

Co-authored-by: drproduck <drproduck@MacBook-Air-2.local>
Co-authored-by: BBuf <1182563586@qq.com>

test/registered/unit/mem_cache/test_uno_allocation_sizing.py

@@ -0,0 +1,36 @@
+"""Unit tests for UNO allocation sizing."""
+
+import unittest
+
+from sglang.srt.mem_cache.allocation_sizing import (
+    get_alloc_len_per_decode,
+    get_alloc_reserve_per_decode,
+    get_req_to_token_extra_context_len,
+)
+from sglang.srt.runtime_context import get_context, get_parallel
+from sglang.test.ci.ci_register import register_cpu_ci
+from sglang.test.test_utils import CustomTestCase
+
+register_cpu_ci(est_time=1, suite="base-a-test-cpu")
+
+
+class TestUnoAllocationSizing(CustomTestCase):
+    def test_page_size_one_row_covers_decode_reserve(self):
+        with (
+            get_context().override_server_args(
+                speculative_algorithm="UNO",
+                speculative_num_draft_tokens=8,
+                page_size=1,
+            ),
+            get_parallel().override(attn_dcp_size=1),
+        ):
+            self.assertEqual(get_alloc_len_per_decode(), 9)
+            self.assertEqual(get_alloc_reserve_per_decode(), 18)
+            self.assertGreaterEqual(
+                get_req_to_token_extra_context_len(),
+                get_alloc_reserve_per_decode(),
+            )
+
+
+if __name__ == "__main__":
+    unittest.main()