initial commit

tdfec/td/fec/online/Encoder.cpp

@@ -0,0 +1,63 @@
+/*
+    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
+*/
+#include "td/fec/online/Encoder.h"
+
+#include "td/fec/common/SymbolsView.h"
+
+namespace td {
+namespace online_code {
+Result<std::unique_ptr<Encoder>> Encoder::create(size_t symbol_size, BufferSlice data) {
+  return std::make_unique<Encoder>(symbol_size, data.as_slice());
+}
+
+Encoder::Encoder(size_t symbol_size, Slice data)
+    : parameters_(Rfc::get_parameters((data.size() + symbol_size - 1) / symbol_size).move_as_ok())
+    , C_(parameters_.source_blocks_count() + parameters_.outer_encoding_blocks_count(), symbol_size)
+    , d_(1, symbol_size)
+    , data_size_(data.size()) {
+  raptorq::SymbolsView view(parameters_.source_blocks_count() + parameters_.outer_encoding_blocks_count(), symbol_size,
+                            data);
+  for (auto &symbol : view.symbols()) {
+    C_.row_set(symbol.id, symbol.data);
+  }
+  parameters_.outer_encoding_for_each([&](uint32 i, uint32 j) {
+    if (j < parameters_.source_blocks_count()) {
+      C_.row_add(i + parameters_.source_blocks_count(), C_.row(j));
+    }
+  });
+}
+
+Encoder::Parameters Encoder::get_parameters() const {
+  Parameters p;
+  p.symbols_count = parameters_.source_blocks_count();
+  p.symbol_size = C_.cols();
+  p.data_size = data_size_;
+  return p;
+}
+
+Status Encoder::gen_symbol(uint32 symbol_id, MutableSlice slice) {
+  d_.set_zero();
+  for (auto id : parameters_.get_inner_encoding_row(symbol_id)) {
+    d_.row_add(0, C_.row(id));
+  }
+  slice.copy_from(d_.row(0));
+  return Status::OK();
+}
+}  // namespace online_code
+}  // namespace td