initial commit

tdfec/td/fec/fec.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/buffer.h"
+
+namespace td {
+namespace raptorq {
+class Encoder;
+class Decoder;
+}  // namespace raptorq
+namespace online_code {
+class Encoder;
+class Decoder;
+}  // namespace online_code
+}  // namespace td
+
+namespace td {
+
+namespace fec {
+
+struct Symbol {
+  uint32 id;
+  BufferSlice data;
+};
+
+class Encoder;
+
+struct DataWithEncoder {
+  BufferSlice data;
+  std::unique_ptr<Encoder> encoder;
+};
+
+class Encoder {
+ public:
+  virtual Symbol gen_symbol(uint32 id) = 0;
+
+  struct Info {
+    uint32 symbol_count;
+    uint32 ready_symbol_count;
+  };
+
+  virtual Info get_info() const {
+    return Info{static_cast<uint32>(-1), static_cast<uint32>(-1)};
+  }
+
+  // Concurrent calls are forbidden
+  virtual void prepare_more_symbols() {
+  }
+
+  // struct Parameters;
+  // Parameters get_parameters();
+  virtual ~Encoder() {
+  }
+};
+
+class Decoder {
+ public:
+  virtual ~Decoder() {
+  }
+  virtual bool may_try_decode() const = 0;
+  virtual Result<DataWithEncoder> try_decode(bool need_encoder) = 0;
+  virtual Status add_symbol(Symbol symbol) = 0;
+};
+
+class RoundRobinEncoder : public Encoder {
+ public:
+  static std::unique_ptr<RoundRobinEncoder> create(BufferSlice data, size_t max_symbol_size);
+
+  Symbol gen_symbol(uint32 id) override;
+
+  struct Parameters {
+    size_t data_size;
+    size_t symbol_size;
+    size_t symbols_count;
+  };
+
+  Parameters get_parameters() const;
+
+  RoundRobinEncoder(BufferSlice data, size_t max_symbol_size);
+
+ private:
+  BufferSlice data_;
+  size_t symbol_size_;
+  size_t symbols_count_;
+  size_t rounded_data_size_;
+};
+
+class RoundRobinDecoder : public Decoder {
+ public:
+  static std::unique_ptr<RoundRobinDecoder> create(RoundRobinEncoder::Parameters parameters);
+  bool may_try_decode() const override;
+  Result<DataWithEncoder> try_decode(bool need_encoder) override;
+  Status add_symbol(Symbol symbol) override;
+  RoundRobinDecoder(RoundRobinEncoder::Parameters parameters);
+
+ private:
+  BufferSlice data_;
+  vector<bool> data_mask_;
+  size_t left_symbols_;
+  size_t symbol_size_;
+  size_t symbols_count_;
+};
+
+class RaptorQEncoder : public Encoder {
+ public:
+  static std::unique_ptr<RaptorQEncoder> create(BufferSlice data, size_t max_symbol_size);
+
+  Symbol gen_symbol(uint32 id) override;
+
+  Info get_info() const override;
+  void prepare_more_symbols() override;
+
+  struct Parameters {
+    size_t data_size;
+    size_t symbol_size;
+    size_t symbols_count;
+  };
+
+  Parameters get_parameters() const;
+
+  RaptorQEncoder(std::unique_ptr<raptorq::Encoder> encoder);
+  ~RaptorQEncoder();
+
+ private:
+  std::unique_ptr<raptorq::Encoder> encoder_;
+};
+
+class RaptorQDecoder : public Decoder {
+ public:
+  static std::unique_ptr<RaptorQDecoder> create(RaptorQEncoder::Parameters parameters);
+  bool may_try_decode() const override;
+  Result<DataWithEncoder> try_decode(bool need_encoder) override;
+  Status add_symbol(Symbol symbol) override;
+  RaptorQDecoder(std::unique_ptr<raptorq::Decoder> decoder);
+  ~RaptorQDecoder();
+
+ private:
+  std::unique_ptr<raptorq::Decoder> decoder_;
+  BufferSlice res_;
+};
+
+class OnlineEncoder : public Encoder {
+ public:
+  static std::unique_ptr<OnlineEncoder> create(BufferSlice data, size_t max_symbol_size);
+
+  Symbol gen_symbol(uint32 id) override;
+
+  struct Parameters {
+    size_t data_size;
+    size_t symbol_size;
+    size_t symbols_count;
+  };
+
+  Parameters get_parameters() const;
+
+  OnlineEncoder(std::unique_ptr<online_code::Encoder> encoder);
+  ~OnlineEncoder();
+
+ private:
+  std::unique_ptr<online_code::Encoder> encoder_;
+};
+
+class OnlineDecoder : public Decoder {
+ public:
+  static std::unique_ptr<OnlineDecoder> create(OnlineEncoder::Parameters parameters);
+  bool may_try_decode() const override;
+  Result<DataWithEncoder> try_decode(bool need_encoder) override;
+  Status add_symbol(Symbol symbol) override;
+  OnlineDecoder(std::unique_ptr<online_code::Decoder> decoder, size_t symbol_size);
+  ~OnlineDecoder();
+
+ private:
+  std::unique_ptr<online_code::Decoder> decoder_;
+  size_t symbol_size_;
+  BufferSlice res_;
+};
+}  // namespace fec
+
+}  // namespace td