def copystream_progress(request, chunk_size=10 ** 5):
    """
    Copies request.env.wsgi_input into request.body
    and stores progress upload status in cache_ram
    X-Progress-ID:length and X-Progress-ID:uploaded
    """
    env = request.env
    if not env.get('CONTENT_LENGTH', None):
        return cStringIO.StringIO()
    source = env['wsgi.input']
    try:
        size = int(env['CONTENT_LENGTH'])
    except ValueError:
        raise HTTP(400, "Invalid Content-Length header")
    try: # Android requires this
        dest = tempfile.NamedTemporaryFile()
    except NotImplementedError: # and GAE this
        dest = tempfile.TemporaryFile()
    if not 'X-Progress-ID' in request.get_vars:
        copystream(source, dest, size, chunk_size)
        return dest
    cache_key = 'X-Progress-ID:' + request.get_vars['X-Progress-ID']
    cache_ram = CacheInRam(request)  # same as cache.ram because meta_storage
    cache_ram(cache_key + ':length', lambda: size, 0)
    cache_ram(cache_key + ':uploaded', lambda: 0, 0)
    while size > 0:
        if size < chunk_size:
            data = source.read(size)
            cache_ram.increment(cache_key + ':uploaded', size)
        else:
            data = source.read(chunk_size)
            cache_ram.increment(cache_key + ':uploaded', chunk_size)
        length = len(data)
        if length > size:
            (data, length) = (data[:size], size)
        size -= length
        if length == 0:
            break
        dest.write(data)
        if chunk_size < length:
            break
    dest.seek(0)
    cache_ram(cache_key + ':length', None)
    cache_ram(cache_key + ':uploaded', None)
    return dest
dataset/ETHPy150Open uwdata/termite-data-server/web2py/gluon/globals.py/copystream_progress/swapped operands of `<`