[train] KTransformers SFT as backend engine for LLaMA-Factory (#9400)

Co-authored-by: jimmy128 <jimmy128@noreply.gitcode.com>
Co-authored-by: Yaowei Zheng <hiyouga@buaa.edu.cn>

src/llamafactory/extras/constants.py

@@ -120,6 +120,7 @@ class EngineName(str, Enum):
     HF = "huggingface"
     VLLM = "vllm"
     SGLANG = "sglang"
+    KT = "ktransformers"
 
 
 class DownloadSource(str, Enum):

src/llamafactory/extras/misc.py

@@ -312,6 +312,8 @@ def use_openmind() -> bool:
 def use_ray() -> bool:
     return is_env_enabled("USE_RAY")
 
+def use_kt() -> bool:
+    return is_env_enabled("USE_KT")
 
 def find_available_port() -> int:
     r"""Find an available port on the local machine."""

src/llamafactory/extras/packages.py

@@ -82,6 +82,10 @@ def is_ray_available():
     return _is_package_available("ray")
 
 
+def is_kt_available():
+    return _is_package_available("ktransformers")
+
+
 def is_requests_available():
     return _is_package_available("requests")