Provide an offline engine API (#1567)

test/srt/run_suite.py

@@ -19,6 +19,7 @@ suites = {
         "test_pytorch_sampling_backend.py",
         "test_server_args.py",
         "test_skip_tokenizer_init.py",
+        "test_srt_engine.py",
         "test_srt_endpoint.py",
         "test_torch_compile.py",
         "test_torchao.py",

test/srt/test_srt_engine.py

@@ -0,0 +1,33 @@
+import json
+import unittest
+
+import sglang as sgl
+from sglang.test.test_utils import DEFAULT_MODEL_NAME_FOR_TEST
+
+
+class TestSRTBackend(unittest.TestCase):
+
+    def test_engine_runtime_consistency(self):
+        prompt = "Today is a sunny day and I like"
+        model_path = DEFAULT_MODEL_NAME_FOR_TEST
+
+        sampling_params = {"temperature": 0, "max_new_tokens": 8}
+
+        engine = sgl.Engine(model_path=model_path, random_seed=42)
+        out1 = engine.generate(prompt, sampling_params)["text"]
+        engine.shutdown()
+
+        runtime = sgl.Runtime(model_path=model_path, random_seed=42)
+        out2 = json.loads(runtime.generate(prompt, sampling_params))["text"]
+        runtime.shutdown()
+
+        print("==== Answer 1 ====")
+        print(out1)
+
+        print("==== Answer 2 ====")
+        print(out2)
+        assert out1 == out2, f"{out1} != {out2}"
+
+
+if __name__ == "__main__":
+    unittest.main()