text: //
  // Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2018
  //
  // Distributed under the Boost Software License, Version 1.0. (See accompanying
  // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  //
  #include "td/utils/GzipByteFlow.h"
  
  char disable_linker_warning_about_empty_file_gzipbyteflow_cpp TD_UNUSED;
  
  #if TD_HAVE_ZLIB
  #include "td/utils/logging.h"
  #include "td/utils/Status.h"
  
  namespace td {
  
  void GzipByteFlow::loop() {
    while (true) {
      if (gzip_.need_input()) {
        auto slice = input_->prepare_read();
        if (slice.empty()) {
          if (!is_input_active_) {
            gzip_.close_input();
          } else {
            break;
          }
        } else {
          gzip_.set_input(input_->prepare_read());
        }
      }
      if (gzip_.need_output()) {
        auto slice = output_.prepare_append();
        CHECK(!slice.empty());
        gzip_.set_output(slice);
      }
      auto r_state = gzip_.run();
      auto output_size = gzip_.flush_output();
      if (output_size) {
        uncommited_size_ += output_size;
        total_output_size_ += output_size;
        if (total_output_size_ > max_output_size_) {
          return finish(Status::Error("Max output size limit exceeded"));
        }
        output_.confirm_append(output_size);
      }
  
      auto input_size = gzip_.flush_input();
      if (input_size) {
        input_->confirm_read(input_size);
      }
      if (r_state.is_error()) {
        return finish(r_state.move_as_error());
      }
      auto state = r_state.ok();
      if (state == Gzip::Done) {
        on_output_updated();
        return consume_input();
      }
    }
    if (uncommited_size_ >= MIN_UPDATE_SIZE) {
      uncommited_size_ = 0;
      on_output_updated();
    }
  }
  
  constexpr size_t GzipByteFlow::MIN_UPDATE_SIZE;
  
  }  // namespace td
  
  #endif
  