def serve_file(load, fnd):
    '''
    Return a chunk from a file based on the data received
    '''
    if 'env' in load:
        salt.utils.warn_until(
            'Oxygen',
            'Parameter \'env\' has been detected in the argument list.  This '
            'parameter is no longer used and has been replaced by \'saltenv\' '
            'as of Salt Carbon.  This warning will be removed in Salt Oxygen.'
            )
        load.pop('env')

    ret = {'data': '',
           'dest': ''}
    if not all(x in load for x in ('path', 'loc', 'saltenv')):
        return ret
    if not fnd['path']:
        return ret
    ret['dest'] = fnd['rel']
    gzip = load.get('gzip', None)
    with salt.utils.fopen(fnd['path'], 'rb') as fp_:
        fp_.seek(load['loc'])
        data = fp_.read(__opts__['file_buffer_size'])
        if gzip and data:
            data = salt.utils.gzip_util.compress(data, gzip)
            ret['gzip'] = gzip
        ret['data'] = data
    return ret
dataset/ETHPy150Open saltstack/salt/salt/fileserver/hgfs.py/serve_file/original