src/util/MemoryMap.hpp

   1 // Copyright (C) 2024 ccache contributors
   2 //
   3 // See doc/AUTHORS.adoc for a complete list of contributors.
   4 //
   5 // This program is free software; you can redistribute it and/or modify it
   6 // under the terms of the GNU General Public License as published by the Free
   7 // Software Foundation; either version 3 of the License, or (at your option)
   8 // any later version.
   9 //
  10 // This program is distributed in the hope that it will be useful, but WITHOUT
  11 // ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12 // FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  13 // more details.
  14 //
  15 // You should have received a copy of the GNU General Public License along with
  16 // this program; if not, write to the Free Software Foundation, Inc., 51
  17 // Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  18
  19 #pragma once
  20
  21 #include <util/NonCopyable.hpp>
  22
  23 #include <third_party/tl/expected.hpp>
  24
  25 #include <string>
  26
  27 namespace util {
  28
  29 class MemoryMap : util::NonCopyable
  30 {
  31 public:
  32   MemoryMap() = default;
  33   ~MemoryMap();
  34
  35   MemoryMap(MemoryMap&& other) noexcept;
  36   MemoryMap& operator=(MemoryMap&& other) noexcept;
  37
  38   void unmap();
  39
  40   void* ptr();
  41
  42   static tl::expected<MemoryMap, std::string> map(int fd, size_t size);
  43
  44 private:
  45   void* m_ptr = nullptr;
  46 #ifndef _WIN32
  47   size_t m_size = 0; // munmap needs the size, not needed on Windows
  48 #else
  49   void* m_file_mapping_handle =
  50     nullptr; // On Windows a handle on a file mapping is needed
  51 #endif
  52 };
  53
  54 } // namespace util