Program Listing for File first_fit_allocator_base.hpp

            

            
/*
* SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
* SPDX-License-Identifier: Apache-2.0
*
* 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.
*/
#ifndef HOLOSCAN_CORE_RESOURCES_GXF_FIRST_FIT_ALLOCATOR_BASE_HPP
#define HOLOSCAN_CORE_RESOURCES_GXF_FIRST_FIT_ALLOCATOR_BASE_HPP

#include <cstdint>
#include <memory>
#include <new>
#include <utility>

#include "holoscan/core/expected.hpp"

namespace holoscan {

class FirstFitAllocatorBase {
 public:
  enum class Error {
    kAlreadyInUse,
    kInvalidSize,
    kOutOfMemory,
    kBlockNotAllocated,
    kLogicError,
  };

  template <typename T>
  using expected_t = expected<T, Error>;
  using unexpected_t = unexpected<Error>;

  FirstFitAllocatorBase();

  expected_t<void> allocate(int32_t size);

  expected_t<int32_t> acquire(int32_t size);

  expected_t<void> release(int32_t index);

 private:
  struct Memory {
    void update(const Memory& left_child, const Memory& right_child);

    void set(int32_t free);

    int32_t left;
    int32_t right;
    int32_t max;
    int32_t size;
  };

  void propagate_to_root(int32_t idx);

  void update(int32_t left, int32_t right, int32_t free);

  std::unique_ptr<Memory[]> tree_;
  int32_t size_;
  int32_t last_layer_first_index_;
};

}  // namespace holoscan

#endif// HOLOSCAN_CORE_RESOURCES_GXF_FIRST_FIT_ALLOCATOR_BASE_HPP