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tdfec/td/fec/algebra/MatrixGF256.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/fec/algebra/Octet.h"
+#include "td/fec/algebra/Simd.h"
+
+#include "td/utils/Span.h"
+#include "td/utils/format.h"
+
+namespace td {
+class MatrixGF256 {
+ public:
+  MatrixGF256(size_t rows, size_t cols) : rows_(rows), cols_(cols) {
+    stride_ = (cols_ + Simd::alignment() - 1) / Simd::alignment() * Simd::alignment();
+    storage_ = std::make_unique<uint8[]>(stride_ * rows + Simd::alignment() - 1);
+    matrix_ = storage_.get();
+    while (!Simd::is_aligned_pointer(matrix_)) {
+      matrix_++;
+    }
+    CHECK(Simd::is_aligned_pointer(matrix_));
+    CHECK(Simd::is_aligned_pointer(matrix_ + stride_));
+    CHECK(static_cast<size_t>(matrix_ - storage_.get()) < Simd::alignment());
+  }
+  void set_zero() {
+    std::fill(matrix_, matrix_ + stride_ * rows_, 0);
+  }
+  size_t rows() const {
+    return rows_;
+  }
+  size_t cols() const {
+    return cols_;
+  }
+
+  MatrixGF256 apply_row_permutation(Span<uint32> permutation) {
+    MatrixGF256 res(rows_, cols_);
+    for (size_t row = 0; row < rows_; row++) {
+      res.row(row).copy_from(this->row(permutation[row]));
+    }
+    return res;
+  }
+
+  Octet get(size_t row, size_t col) const {
+    DCHECK(row < rows_ && col < cols_);
+    return Octet(matrix_[row * stride_ + col]);
+  }
+
+  void set(size_t row, size_t col, Octet o) {
+    DCHECK(row < rows_ && col < cols_);
+    matrix_[row * stride_ + col] = o.value();
+  }
+
+  void row_multiply(size_t row, Octet o) {
+    uint8* p = row_ptr(row);
+    Simd::gf256_mul(p, o.value(), stride_);
+  }
+
+  Slice row(size_t row) const {
+    return Slice(row_ptr(row), cols());
+  }
+  MutableSlice row(size_t row) {
+    return MutableSlice(row_ptr(row), cols());
+  }
+
+  template <class M>
+  void set_from(const M& m, size_t row_offset, size_t col_offset) {
+    auto to = block_view(row_offset, col_offset, rows() - row_offset, cols() - col_offset);
+    for (size_t i = 0; i < m.rows(); i++) {
+      to.row(i).copy_from(m.row(i));
+    }
+  }
+
+  MatrixGF256 copy() {
+    MatrixGF256 res(rows(), cols());
+    res.set_from(*this, 0, 0);
+    return res;
+  }
+
+  void add(const MatrixGF256& m) {
+    CHECK(m.rows() == rows());
+    CHECK(m.cols() == cols());
+    for (size_t i = 0; i < m.rows(); i++) {
+      auto* to = row_ptr(i);
+      auto* from = m.row_ptr(i);
+      row_add(to, from);
+    }
+  }
+
+  // row(a) += row(b) * m
+  void row_add_mul(size_t a, size_t b, Octet m) {
+    row_add_mul(row_ptr(a), row_ptr(b), m);
+  }
+  void row_add_mul(size_t a, Slice b, Octet m) {
+    row_add_mul(row_ptr(a), b.ubegin(), m);
+  }
+
+  // row(a) += row(b)
+  void row_add(size_t a, size_t b) {
+    row_add(row_ptr(a), row_ptr(b));
+  }
+
+  void row_add(size_t a, Slice b) {
+    row_add(row_ptr(a), b.ubegin());
+  }
+
+  void row_set(size_t a, Slice b) {
+    row(a).copy_from(b);
+  }
+
+  class BlockView {
+   public:
+    BlockView(size_t row_offset, size_t col_offset, size_t row_size, size_t col_size, MatrixGF256& m)
+        : row_offset_(row_offset), col_offset_(col_offset), row_size_(row_size), col_size_(col_size), m_(m) {
+    }
+    size_t cols() const {
+      return col_size_;
+    }
+    size_t rows() const {
+      return row_size_;
+    }
+    Slice row(size_t row) const {
+      return m_.row(row_offset_ + row).remove_prefix(col_offset_);
+    }
+    MutableSlice row(size_t row) {
+      return m_.row(row_offset_ + row).remove_prefix(col_offset_);
+    }
+
+   private:
+    size_t row_offset_;
+    size_t col_offset_;
+    size_t row_size_;
+    size_t col_size_;
+    MatrixGF256& m_;
+  };
+
+  BlockView block_view(size_t row_offset, size_t col_offset, size_t row_size, size_t col_size) {
+    return BlockView(row_offset, col_offset, row_size, col_size, *this);
+  }
+
+ private:
+  uint8* matrix_;
+  size_t rows_;
+  size_t cols_;
+  size_t stride_;
+  std::unique_ptr<uint8[]> storage_;
+
+  uint8* row_ptr(size_t row) {
+    return matrix_ + stride_ * row;
+  }
+  const uint8* row_ptr(size_t row) const {
+    return matrix_ + stride_ * row;
+  }
+
+  void row_add_mul(uint8* ap, const uint8* bp, Octet m) {
+    uint8 u = m.value();
+    if (u == 0) {
+      return;
+    }
+
+    if (u == 1) {
+      return row_add(ap, bp);
+    }
+
+    Simd::gf256_add_mul(ap, bp, u, stride_);
+  }
+
+  void row_add(uint8* ap, const uint8* bp) {
+    Simd::gf256_add(ap, bp, stride_);
+  }
+};
+
+inline StringBuilder& operator<<(StringBuilder& sb, const MatrixGF256& m) {
+  sb << "\n";
+  for (uint32 i = 0; i < m.rows(); i++) {
+    auto row = m.row(i);
+    for (uint32 j = 0; j < m.cols(); j++) {
+      uint8 x = row[j];
+      sb << " " << format::hex_digit(x / 16) << format::hex_digit(x % 16);
+    }
+    sb << "\n";
+  }
+  return sb;
+}
+}  // namespace td