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tdutils/td/utils/Gzip.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"
+
+#if TD_HAVE_ZLIB
+#include "td/utils/buffer.h"
+#include "td/utils/Slice.h"
+#include "td/utils/Status.h"
+
+namespace td {
+
+class Gzip {
+ public:
+  Gzip();
+  Gzip(const Gzip &) = delete;
+  Gzip &operator=(const Gzip &) = delete;
+  Gzip(Gzip &&other);
+  Gzip &operator=(Gzip &&other);
+  ~Gzip();
+
+  enum Mode { Empty, Encode, Decode };
+  Status init(Mode mode) TD_WARN_UNUSED_RESULT {
+    if (mode == Encode) {
+      return init_encode();
+    } else if (mode == Decode) {
+      return init_decode();
+    }
+    clear();
+    return Status::OK();
+  }
+
+  Status init_encode() TD_WARN_UNUSED_RESULT;
+
+  Status init_decode() TD_WARN_UNUSED_RESULT;
+
+  void set_input(Slice input);
+
+  void set_output(MutableSlice output);
+
+  void close_input() {
+    close_input_flag_ = true;
+  }
+
+  bool need_input() const {
+    return left_input() == 0;
+  }
+
+  bool need_output() const {
+    return left_output() == 0;
+  }
+
+  size_t left_input() const;
+
+  size_t left_output() const;
+
+  size_t used_input() const {
+    return input_size_ - left_input();
+  }
+
+  size_t used_output() const {
+    return output_size_ - left_output();
+  }
+
+  size_t flush_input() {
+    auto res = used_input();
+    input_size_ = left_input();
+    return res;
+  }
+
+  size_t flush_output() {
+    auto res = used_output();
+    output_size_ = left_output();
+    return res;
+  }
+
+  enum State { Running, Done };
+  Result<State> run() TD_WARN_UNUSED_RESULT;
+
+ private:
+  class Impl;
+  unique_ptr<Impl> impl_;
+
+  size_t input_size_ = 0;
+  size_t output_size_ = 0;
+  bool close_input_flag_ = false;
+  Mode mode_ = Empty;
+
+  void init_common();
+  void clear();
+
+  void swap(Gzip &other);
+};
+
+BufferSlice gzdecode(Slice s);
+
+BufferSlice gzencode(Slice s, double k = 0.9);
+
+}  // namespace td
+
+#endif