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tdfec/td/fec/algebra/InactivationDecoding.h

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+/*
+    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 2017-2019 Telegram Systems LLP
+*/
+#pragma once
+
+#include "td/utils/common.h"
+#include "td/fec/algebra/SparseMatrixGF2.h"
+
+namespace td {
+struct InactivationDecodingResult {
+  uint32 size;
+  vector<uint32> p_rows;
+  vector<uint32> p_cols;
+};
+
+class InactivationDecoding {
+ public:
+  InactivationDecoding(const SparseMatrixGF2 &L, uint32 PI) : L_(L), PI_(PI) {
+  }
+  InactivationDecodingResult run();
+
+ private:
+  const SparseMatrixGF2 &L_;
+  uint32 PI_;
+
+  const SparseMatrixGF2 L_rows_{L_.transpose()};
+  const uint32 cols_ = L_.cols() - PI_;
+  const uint32 rows_ = L_.rows();
+  vector<bool> was_row_;
+  vector<bool> was_col_;
+
+  vector<uint32> col_cnt_;
+  vector<uint32> row_cnt_;
+  vector<uint32> row_xor_;
+
+  vector<uint32> sorted_rows_;
+  vector<uint32> row_cnt_offset_;
+  vector<uint32> row_pos_;
+
+  vector<uint32> p_rows_;
+  vector<uint32> p_cols_;
+  vector<uint32> inactive_cols_;
+
+  void init();
+
+  void loop();
+
+  void check_sorted();
+
+  uint32 choose_col(uint32 row);
+
+  void inactivate_col(uint32 col);
+
+  void sort_rows();
+
+  void check(uint32 side);
+};
+}  // namespace td