STDMETHODIMP CHandler::Extract(const UInt32 *indices, UInt32 numItems,
    Int32 testMode, IArchiveExtractCallback *extractCallback)
{
  COM_TRY_BEGIN
  if (numItems == 0)
    return S_OK;
  if (numItems != (UInt32)-1 && (numItems != 1 || indices[0] != 0))
    return E_INVALIDARG;

  extractCallback->SetTotal(_packSize);
  UInt64 currentTotalPacked = 0;
  RINOK(extractCallback->SetCompleted(¤tTotalPacked));
  CMyComPtr<ISequentialOutStream> realOutStream;
  Int32 askMode = testMode ?
      NExtract::NAskMode::kTest :
      NExtract::NAskMode::kExtract;
  
  RINOK(extractCallback->GetStream(0, &realOutStream, askMode));
  
  if (!testMode && !realOutStream)
    return S_OK;

  extractCallback->PrepareOperation(askMode);

  if (_stream)
  {
    RINOK(_stream->Seek(_startPosition, STREAM_SEEK_SET, NULL));
  }

  CLocalProgress *lps = new CLocalProgress;
  CMyComPtr<ICompressProgressInfo> progress = lps;
  lps->Init(extractCallback, true);

  CCompressProgressWrap progressWrap(progress);

  SRes res;

  const UInt32 kInBufSize = 1 << 15;
  const UInt32 kOutBufSize = 1 << 21;

  UInt32 inPos = 0;
  UInt32 inSize = 0;
  UInt32 outPos = 0;
  CXzUnpackerCPP xzu;
  res = XzUnpacker_Create(&xzu.p, &g_Alloc);
  if (res == SZ_OK)
  {
    xzu.InBuf = (Byte *)MyAlloc(kInBufSize);
    xzu.OutBuf = (Byte *)MyAlloc(kOutBufSize);
    if (xzu.InBuf == 0 || xzu.OutBuf == 0)
      res = SZ_ERROR_MEM;
  }
  if (res == SZ_OK)
  for (;;)
  {
    if (inPos == inSize)
    {
      inPos = inSize = 0;
      RINOK(_seqStream->Read(xzu.InBuf, kInBufSize, &inSize));
    }

    SizeT inLen = inSize - inPos;
    SizeT outLen = kOutBufSize - outPos;
    ECoderStatus status;
    res = XzUnpacker_Code(&xzu.p,
        xzu.OutBuf + outPos, &outLen,
        xzu.InBuf + inPos, &inLen,
        (inSize == 0 ? CODER_FINISH_END : CODER_FINISH_ANY), &status);

    // printf("\n_inPos = %6d  inLen = %5d, outLen = %5d", inPos, inLen, outLen);

    inPos += (UInt32)inLen;
    outPos += (UInt32)outLen;
    lps->InSize += inLen;
    lps->OutSize += outLen;

    bool finished = (((inLen == 0) && (outLen == 0)) || res != SZ_OK);

    if (outPos == kOutBufSize || finished)
    {
      if (realOutStream && outPos > 0)
      {
        RINOK(WriteStream(realOutStream, xzu.OutBuf, outPos));
      }
      outPos = 0;
    }
    if (finished)
    {
      _packSize = lps->InSize;
      _unpackSize = lps->OutSize;
      _packSizeDefined = _unpackSizeDefined = true;
      if (res == SZ_OK)
      {
        if (status == CODER_STATUS_NEEDS_MORE_INPUT)
        {
          if (XzUnpacker_IsStreamWasFinished(&xzu.p))
            _packSize -= xzu.p.padSize;
          else
            res = SZ_ERROR_DATA;
        }
        else
          res = SZ_ERROR_DATA;
      }
      break;
    }
    RINOK(lps->SetCur());
  }

  Int32 opRes;
  switch(res)
  {
    case SZ_OK:
      opRes = NExtract::NOperationResult::kOK; break;
    case SZ_ERROR_UNSUPPORTED:
      opRes = NExtract::NOperationResult::kUnSupportedMethod; break;
    case SZ_ERROR_CRC:
      opRes = NExtract::NOperationResult::kCRCError; break;
    case SZ_ERROR_DATA:
    case SZ_ERROR_ARCHIVE:
    case SZ_ERROR_NO_ARCHIVE:
      opRes = NExtract::NOperationResult::kDataError; break;
    default:
      return SResToHRESULT(res);
  }
  realOutStream.Release();
  RINOK(extractCallback->SetOperationResult(opRes));
  return S_OK;
  COM_TRY_END
}