release initial code

Co-authored-by: Ying Sheng <sqy1415@gmail.com>
Co-authored-by: Liangsheng Yin <hnyls2002@gmail.com>
Co-authored-by: Zhiqiang Xie <xiezhq@stanford.edu>
Co-authored-by: parasol-aser <3848358+parasol-aser@users.noreply.github.com>
Co-authored-by: LiviaSun <33578456+ChuyueSun@users.noreply.github.com>
Co-authored-by: Cody Yu <hao.yu.cody@gmail.com>

python/sglang/backend/base_backend.py

@@ -0,0 +1,74 @@
+from typing import Callable, List, Optional, Union
+
+from sglang.lang.chat_template import get_chat_template
+from sglang.lang.interpreter import StreamExecutor
+from sglang.lang.ir import SamplingParams
+
+
+class BaseBackend:
+    def __init__(self) -> None:
+        self.support_concate_and_append = False
+        self.chat_template = get_chat_template("default")
+
+    def get_model_name(self):
+        raise NotImplementedError()
+
+    def get_chat_template(self):
+        return self.chat_template
+
+    def cache_prefix(self, prefix_str: str):
+        pass
+
+    def uncache_prefix(self, rid: str):
+        pass
+
+    def end_request(self, rid: Union[str, List[str]]):
+        pass
+
+    def begin_program(self, s: StreamExecutor):
+        pass
+
+    def end_program(self, s: Union[StreamExecutor, List[StreamExecutor]]):
+        pass
+
+    def commit_lazy_operations(self, s: StreamExecutor):
+        pass
+
+    def fork_program(
+        self,
+        src: StreamExecutor,
+        dst: List[StreamExecutor],
+        position_ids_offset: Optional[List[int]] = None,
+    ):
+        pass
+
+    def fill_image(self, s: StreamExecutor):
+        pass
+
+    def generate(
+        self,
+        s: StreamExecutor,
+        sampling_params: SamplingParams,
+    ):
+        raise NotImplementedError()
+
+    def generate_stream(
+        self,
+        s: StreamExecutor,
+        sampling_params: SamplingParams,
+    ):
+        raise NotImplementedError()
+
+    def select(
+        self,
+        s: StreamExecutor,
+        choices: List[str],
+        temperature: float,
+    ):
+        raise NotImplementedError()
+
+    def concatenate_and_append(self, src_rids: List[str], dst_rid: str):
+        raise NotImplementedError()
+
+    def shutdown(self):
+        pass