Ton

1
/*
2
    This file is part of TON Blockchain Library.
3

4
    TON Blockchain Library is free software: you can redistribute it and/or modify
5
    it under the terms of the GNU Lesser General Public License as published by
6
    the Free Software Foundation, either version 2 of the License, or
7
    (at your option) any later version.
8

9
    TON Blockchain Library is distributed in the hope that it will be useful,
10
    but WITHOUT ANY WARRANTY; without even the implied warranty of
11
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12
    GNU Lesser General Public License for more details.
13

14
    You should have received a copy of the GNU Lesser General Public License
15
    along with TON Blockchain Library.  If not, see <http://www.gnu.org/licenses/>.
16

17
    Copyright 2017-2020 Telegram Systems LLP
18
*/
19

20
#include "FecHelper.h"
21

22
#include "td/utils/check.h"
23

24
namespace ton {
25
namespace rldp2 {
26
td::uint32 FecHelper::get_fec_symbols_count() const {
27
  constexpr td::uint32 x = 5;
28
  constexpr td::uint32 y = 5;
29
  // smallest (symbols_count + x + y * i) >  received_symbols_count
30
  if (symbols_count + x > received_symbols_count) {
31
    return symbols_count + x;
32
  }
33
  td::uint32 i = (received_symbols_count - (symbols_count + x)) / y + 1;
34
  return symbols_count + x + i * y;
35
}
36

37
td::uint32 FecHelper::get_left_fec_symbols_count() const {
38
  auto fec_symbols_count = get_fec_symbols_count();
39
  CHECK(fec_symbols_count > received_symbols_count);
40
  return fec_symbols_count - received_symbols_count;
41
}
42
}  // namespace rldp2
43
}  // namespace ton
44