hasher.hpp

//--------------------------------------------------------------------------------------------------
// Copyright (c) 2018 Marcus Geelnard
//
// This software is provided 'as-is', without any express or implied warranty. In no event will the
// authors be held liable for any damages arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose, including commercial
// applications, and to alter it and redistribute it freely, subject to the following restrictions:
//
//  1. The origin of this software must not be misrepresented; you must not claim that you wrote
//     the original software. If you use this software in a product, an acknowledgment in the
//     product documentation would be appreciated but is not required.
//
//  2. Altered source versions must be plainly marked as such, and must not be misrepresented as
//     being the original software.
//
//  3. This notice may not be removed or altered from any source distribution.
//--------------------------------------------------------------------------------------------------
 
#ifndef BUILDCACHE_HASHER_HPP_
#define BUILDCACHE_HASHER_HPP_
 
#include <base/string_list.hpp>
 
#include <cstdint>
 
#include <map>
#include <string>
 
namespace bcache {
 
class hasher_t {
public:
  class hash_t {
  public:
    uint8_t* data() {
      return &m_data[0];
    }
 
    const uint8_t* data() const {
      return &m_data[0];
    }
 
    std::string as_string() const;
 
    // The hash size is 128 bits.
    static const size_t SIZE = 16U;
 
  private:
    uint8_t m_data[SIZE]{};
  };
 
  hasher_t();
  ~hasher_t();
 
  hasher_t(const hasher_t& other);
 
  hasher_t& operator=(const hasher_t& other);
 
  void update(const void* data, const size_t size);
 
  void update(const std::string& text) {
    update(text.data(), text.size());
  }
 
  void update(const string_list_t& data);
 
  void update(const std::map<std::string, std::string>& data);
 
  void update_from_file(const std::string& path);
 
  void update_from_file_deterministic(const std::string& path);
 
  void inject_separator();
 
  hash_t final();
 
private:
  void update_from_ar_data(const std::string& data);
 
  // This is in fact an XXH3_state_t pointer, but we don't want to include xxhash.h in this
  // header (to avoid leaking inlined code and to avoid namespace pollution).
  void* m_state = nullptr;
};
 
}  // namespace bcache
 
#endif  // BUILDCACHE_HASHER_HPP_