Add paddlelite backend support (#260)

* Add paddlelite backend support

* Update CMakeLists.txt

* Update __init__.py

fastdeploy/backends/lite/lite_backend.h

@@ -0,0 +1,61 @@
+// Copyright (c) 2022 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.
+
+#pragma once
+
+#include <iostream>
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "fastdeploy/backends/backend.h"
+#include "paddle_api.h"  // NOLINT
+
+namespace fastdeploy {
+
+struct LiteBackendOption {
+};
+
+// Convert data type from paddle lite to fastdeploy
+FDDataType LiteDataTypeToFD(const paddle::lite_api::PrecisionType& dtype);
+
+class LiteBackend : public BaseBackend {
+ public:
+  LiteBackend() {}
+  virtual ~LiteBackend() = default;
+  void BuildOption(const LiteBackendOption& option);
+
+  bool InitFromPaddle(const std::string& model_file,
+                      const std::string& params_file,
+                      const LiteBackendOption& option = LiteBackendOption());
+
+  bool Infer(std::vector<FDTensor>& inputs, std::vector<FDTensor>* outputs);
+
+  int NumInputs() const { return inputs_desc_.size(); }
+
+  int NumOutputs() const { return outputs_desc_.size(); }
+
+  TensorInfo GetInputInfo(int index);
+  TensorInfo GetOutputInfo(int index);
+  std::vector<TensorInfo> GetInputInfos() override;
+  std::vector<TensorInfo> GetOutputInfos() override;
+
+ private:
+  paddle::lite_api::CxxConfig config_;
+  std::shared_ptr<paddle::lite_api::PaddlePredictor> predictor_;
+  std::vector<TensorInfo> inputs_desc_;
+  std::vector<TensorInfo> outputs_desc_;
+  std::map<std::string, int> inputs_order_;
+};
+}  // namespace fastdeploy