[LLM] First commit the llm deployment code

fastdeploy/model_executor/model_loader.py

@@ -0,0 +1,60 @@
+"""
+# Copyright (c) 2025  PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""
+
+from abc import ABC, abstractmethod
+
+import paddle
+from paddle import nn
+
+from fastdeploy.config import LLMConfig, LoadConfig, ModelConfig
+
+
+# TODO(gongshaotian): implement real interface to replace this
+def get_model(llm_config: LLMConfig) -> nn.Layer:
+    """ load or download model """
+    model_path = llm_config.load_config.model_path
+    model = paddle.load(model_path, return_numpy=True)
+    return model
+
+
+class BaseModelLoader(ABC):
+    """ Base class for model loaders. """
+
+    def __init__(self, load_config: LoadConfig):
+        self.load_config = load_config
+
+    @abstractmethod
+    def download_model(self, load_config: ModelConfig) -> None:
+        """ Download a model so that it can be immediately loaded."""
+        raise NotImplementedError
+
+    @abstractmethod
+    def load_model(self, llm_config: LLMConfig) -> nn.Layer:
+        """ Load a model with the given configurations."""
+        raise NotImplementedError
+
+
+class DefaultModelLoader(BaseModelLoader):
+    """ ModelLoader that can load registered models """
+
+    def __init__(self, load_config: LoadConfig):
+        super().__init__(load_config)
+
+    def download_model(self, model_config: ModelConfig) -> None:
+        pass
+
+    def load_model(self, llm_config: LLMConfig) -> nn.Layer:
+        pass