TorrentHeader.h

/*
    This file is part of TON Blockchain Library.

    TON Blockchain Library is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation, either version 2 of the License, or
    (at your option) any later version.

    TON Blockchain Library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with TON Blockchain Library.  If not, see <http://www.gnu.org/licenses/>.

    Copyright 2017-2020 Telegram Systems LLP
*/

#pragma once

#include "td/utils/Slice.h"
#include "td/utils/buffer.h"
#include "td/utils/Status.h"

namespace ton {
// fec_info_none#c82a1964 = FecInfo;
//
// torrent_header#9128aab7
//   files_count:uint32
//   tot_name_size:uint64
//   tot_data_size:uint64
//   fec:FecInfo
//   dir_name_size:uint32
//   dir_name:(dir_name_size * [uint8])
//   name_index:(files_count * [uint64])
//   data_index:(files_count * [uint64])
//   names:(file_names_size * [uint8])
//   data:(tot_data_size * [uint8])
//     = TorrentHeader;
//
// Filename rules:
// 1) Name can't be empty
// 2) Names in a torrent should be unique
// 3) Name can't start or end with '/' or contain two consequitive '/'
// 4) Components of name can't be equal to "." or ".."
// 5) If there's a name aaa/bbb/ccc, no other name can start with aaa/bbb/ccc/

struct TorrentHeader {
  td::uint32 files_count{0};
  td::uint64 tot_names_size{0};
  td::uint64 tot_data_size{0};
  //fec_none
  std::string dir_name;
  std::vector<td::uint64> name_index;
  std::vector<td::uint64> data_index;
  std::string names;

  td::uint64 get_data_begin(td::uint64 file_i) const;
  td::uint64 get_data_end(td::uint64 file_i) const;
  td::uint64 get_data_offset(td::uint64 offset_i) const;
  td::uint64 get_data_size(td::uint64 file_i) const;
  td::Slice get_name(td::uint64 file_i) const;
  td::CSlice get_dir_name() const;
  td::uint32 get_files_count() const;

  td::uint64 serialization_size() const;
  td::BufferSlice serialize() const;

  static constexpr td::uint32 type = 0x9128aab7;
  template <class StorerT>
  void store(StorerT &storer) const;
  template <class ParserT>
  void parse(ParserT &parser);

  td::Status validate(td::uint64 total_size, td::uint64 header_size) const;
};
}  // namespace ton