// 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 <memory>
#include "dnnl.hpp"  // NOLINT

namespace phi {
namespace funcs {
///
/// @brief      Helper class for AXPY execution using oneDNN library.
///
/// @tparam     T     Data type.
///
template <typename T>
class OneDNNAXPYHandler {
 public:
  OneDNNAXPYHandler(OneDNNAXPYHandler&) = delete;
  OneDNNAXPYHandler(OneDNNAXPYHandler&&) = delete;
  OneDNNAXPYHandler& operator=(OneDNNAXPYHandler&) = delete;
  OneDNNAXPYHandler& operator=(OneDNNAXPYHandler&&) = delete;
  ///
  /// @brief      Constructor.
  ///
  /// @param[in]  n              The number of elements in tensor (assumed 1D
  /// tensor)
  /// @param[in]  alpha          The alpha coefficient.
  /// @param[in]  onednn_engine  The oneDNN engine.
  ///
  OneDNNAXPYHandler(int64_t n, T alpha, dnnl::engine onednn_engine);
  ///
  /// @brief      Executes AXPY.
  ///
  /// @param[in]  x     The pointer to input X tensor data.
  /// @param[out] y     The pointer to output Y tensor data.
  ///
  void operator()(const T* x, T* y);

 private:
  OneDNNAXPYHandler() = delete;
  // (arogowie-intel) Private implementation idiom to hide dependency
  // on OneDNN headers.
  class Impl;
  // We need custom deleter, since the compiler is unable to parameterize
  // an allocator's default deleter due to incomple type.
  std::unique_ptr<Impl, void (*)(Impl*)> pimpl_;
};
}  // namespace funcs
}  // namespace phi