tdlib-fork/tdutils/td/utils/GzipByteFlow.cpp

//
// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2019
//
// 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/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