text: /* <!-- copyright */
  /*
   * aria2 - The high speed download utility
   *
   * Copyright (C) 2010 Tatsuhiro Tsujikawa
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program 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 General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   *
   * In addition, as a special exception, the copyright holders give
   * permission to link the code of portions of this program with the
   * OpenSSL library under certain conditions as described in each
   * individual source file, and distribute linked combinations
   * including the two.
   * You must obey the GNU General Public License in all respects
   * for all of the code used other than OpenSSL.  If you modify
   * file(s) with this exception, you may extend this exception to your
   * version of the file(s), but you are not obligated to do so.  If you
   * do not wish to do so, delete this exception statement from your
   * version.  If you delete this exception statement from all source
   * files in the program, then also delete it here.
   */
  /* copyright --> */
  #include "GZipDecodingStreamFilter.h"
  
  #include <cassert>
  
  #include "fmt.h"
  #include "DlAbortEx.h"
  
  namespace aria2 {
  
  const std::string GZipDecodingStreamFilter::NAME("GZipDecodingStreamFilter");
  
  GZipDecodingStreamFilter::GZipDecodingStreamFilter(
      std::unique_ptr<StreamFilter> delegate)
      : StreamFilter{std::move(delegate)},
        strm_{nullptr},
        finished_{false},
        bytesProcessed_{0}
  {
  }
  
  GZipDecodingStreamFilter::~GZipDecodingStreamFilter() { release(); }
  
  void GZipDecodingStreamFilter::init()
  {
    finished_ = false;
    release();
    strm_ = new z_stream();
    strm_->zalloc = Z_NULL;
    strm_->zfree = Z_NULL;
    strm_->opaque = Z_NULL;
    strm_->avail_in = 0;
    strm_->next_in = Z_NULL;
  
    // initialize z_stream with gzip/zlib format auto detection enabled.
    if (Z_OK != inflateInit2(strm_, 47)) {
      throw DL_ABORT_EX("Initializing z_stream failed.");
    }
  }
  
  void GZipDecodingStreamFilter::release()
  {
    if (strm_) {
      inflateEnd(strm_);
      delete strm_;
      strm_ = nullptr;
    }
  }
  
  ssize_t
  GZipDecodingStreamFilter::transform(const std::shared_ptr<BinaryStream>& out,
                                      const std::shared_ptr<Segment>& segment,
                                      const unsigned char* inbuf, size_t inlen)
  {
    bytesProcessed_ = 0;
    ssize_t outlen = 0;
    if (inlen == 0) {
      return outlen;
    }
  
    strm_->avail_in = inlen;
    strm_->next_in = const_cast<unsigned char*>(inbuf);
  
    unsigned char outbuf[OUTBUF_LENGTH];
    while (1) {
      strm_->avail_out = OUTBUF_LENGTH;
      strm_->next_out = outbuf;
  
      int ret = ::inflate(strm_, Z_NO_FLUSH);
  
      if (ret == Z_STREAM_END) {
        finished_ = true;
      }
      else if (ret != Z_OK && ret != Z_BUF_ERROR) {
        throw DL_ABORT_EX(fmt("libz::inflate() failed. cause:%s", strm_->msg));
      }
  
      size_t produced = OUTBUF_LENGTH - strm_->avail_out;
  
      outlen += getDelegate()->transform(out, segment, outbuf, produced);
      if (strm_->avail_out > 0) {
        break;
      }
    }
    assert(inlen >= strm_->avail_in);
    bytesProcessed_ = inlen - strm_->avail_in;
    return outlen;
  }
  
  bool GZipDecodingStreamFilter::finished()
  {
    return finished_ && getDelegate()->finished();
  }
  
  const std::string& GZipDecodingStreamFilter::getName() const { return NAME; }
  
  } // namespace aria2
  