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tdfec/td/fec/raptorq/Encoder.cpp

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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
+*/
+#include "td/fec/raptorq/Encoder.h"
+
+#include "td/fec/raptorq/Solver.h"
+
+namespace td {
+namespace raptorq {
+
+Result<std::unique_ptr<Encoder>> Encoder::create(size_t symbol_size, BufferSlice data) {
+  TRY_RESULT(p, Rfc::get_parameters((data.size() + symbol_size - 1) / symbol_size));
+  return std::make_unique<Encoder>(p, symbol_size, std::move(data));
+}
+
+Encoder::Encoder(Rfc::Parameters p, size_t symbol_size, BufferSlice data, optional<RawEncoder> raw_encoder)
+    : p_(p)
+    , symbol_size_(symbol_size)
+    , data_(std::move(data))
+    , raw_encoder_{std::move(raw_encoder)}
+    , has_encoder_{bool(raw_encoder_)} {
+}
+
+Encoder::Parameters Encoder::get_parameters() const {
+  Parameters res;
+  res.symbol_size = symbol_size_;
+  res.data_size = data_.size();
+  res.symbols_count = p_.K;
+  return res;
+}
+
+Encoder::Info Encoder::get_info() const {
+  Info res;
+  res.symbol_count = 1 << 24;
+  res.ready_symbol_count = has_precalc() ? res.symbol_count : p_.K;
+  return res;
+}
+
+Status Encoder::gen_symbol(uint32 id, MutableSlice slice) {
+  if (id < p_.K) {
+    slice.copy_from(first_symbols_.symbols()[id].data);
+    return Status::OK();
+  }
+  if (!has_precalc()) {
+    return Status::Error("Precalc is not finished");
+  }
+  (*raw_encoder_).gen_symbol(id + p_.K_padded - p_.K, slice);
+  return Status::OK();
+}
+
+bool Encoder::has_precalc() const {
+  return has_encoder_.load(std::memory_order_acquire);
+}
+
+void Encoder::precalc() {
+  if (has_precalc()) {
+    return;
+  }
+  auto r_C = Solver::run(p_, first_symbols_.symbols());
+  LOG_IF(FATAL, r_C.is_error()) << r_C.error();
+  raw_encoder_ = RawEncoder(p_, r_C.move_as_ok());
+  has_encoder_ = true;
+}
+
+}  // namespace raptorq
+}  // namespace td