// Copyright (c) 2021 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 <map>
#include <memory>
#include <mutex>
#include <unordered_map>

#include "paddle/fluid/framework/ir/graph.h"
#include "paddle/fluid/framework/lod_tensor.h"
#include "paddle/fluid/framework/paddle2cinn/cinn_cache_key.h"
#include "paddle/fluid/framework/paddle2cinn/cinn_compiled_object.h"
#include "paddle/fluid/framework/scope.h"

namespace paddle {
namespace framework {
namespace paddle2cinn {

// Entrance to run CINN.
//
// CINN cannot handle changable shape now, so CinnRunner keeps a cache mapping
// from CinnCacheKey to CinnCompiledObject. If cache hits, we will re-use cache
// stored CinnCompiledObject, otherwise we will compile again and put into
// cache.
class CinnRunner {
 public:
  ~CinnRunner() {}

  // Singleton
  static std::shared_ptr<CinnRunner> GetInstance();

  // Replace Paddle graph with some CINN subgraphs/ops
  void ReplaceWithCinn(ir::Graph* graph);

  // Feed LoDTensors to tun CINN compiled object and return fetched result
  std::map<std::string, FetchType*> Run(
      const ir::Graph& graph, Scope* scope,
      std::map<std::string, const LoDTensor*>* feed_targets);

 private:
  CinnRunner() {}

  static std::once_flag get_instance_once_flag_;
  static std::shared_ptr<CinnRunner> instance_;
  std::unordered_map<CinnCacheKey, std::shared_ptr<CinnCompiledObject>,
                     CinnCacheKey::Hash>
      cache_;
};

}  // namespace paddle2cinn
}  // namespace framework
}  // namespace paddle