/*
 * Copyright © 2021 The Fuchsia Authors
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 */

#ifndef SIMPLE_ALLOCATOR_H
#define SIMPLE_ALLOCATOR_H

#include <list>

#include "address_space_allocator.h"

class SimpleAllocator final : public AddressSpaceAllocator {
 public:
  static std::unique_ptr<SimpleAllocator> Create(uint64_t base, size_t size);

  bool Alloc(size_t size, uint8_t align_pow2, uint64_t* addr_out) override;
  bool Free(uint64_t addr) override;
  bool GetSize(uint64_t addr, size_t* size_out) override;

 private:
  SimpleAllocator(uint64_t base, size_t size);

  struct Region {
    Region(uint64_t base, size_t size);
    uint64_t base;
    size_t size;
  };

  bool CheckGap(SimpleAllocator::Region* prev, SimpleAllocator::Region* next, uint64_t align,
                size_t size, uint64_t* addr_out, bool* continue_search_out);

 private:
  std::list<SimpleAllocator::Region>::iterator FindRegion(uint64_t addr);

  std::list<SimpleAllocator::Region> regions_;
};

#endif  // SIMPLE_ALLOCATOR_H