File Explorer

1"""Miscellaneous WSGI-related Utilities"""2 3import posixpath4 5__all__ = [6    'FileWrapper', 'guess_scheme', 'application_uri', 'request_uri',7    'shift_path_info', 'setup_testing_defaults',8]9 10 11class FileWrapper:12    """Wrapper to convert file-like objects to iterables"""13 14    def __init__(self, filelike, blksize=8192):15        self.filelike = filelike16        self.blksize = blksize17        if hasattr(filelike,'close'):18            self.close = filelike.close19 20    def __getitem__(self,key):21        import warnings22        warnings.warn(23            "FileWrapper's __getitem__ method ignores 'key' parameter. "24            "Use iterator protocol instead.",25            DeprecationWarning,26            stacklevel=227        )28        data = self.filelike.read(self.blksize)29        if data:30            return data31        raise IndexError32 33    def __iter__(self):34        return self35 36    def __next__(self):37        data = self.filelike.read(self.blksize)38        if data:39            return data40        raise StopIteration41 42def guess_scheme(environ):43    """Return a guess for whether 'wsgi.url_scheme' should be 'http' or 'https'44    """45    if environ.get("HTTPS") in ('yes','on','1'):46        return 'https'47    else:48        return 'http'49 50def application_uri(environ):51    """Return the application's base URI (no PATH_INFO or QUERY_STRING)"""52    url = environ['wsgi.url_scheme']+'://'53    from urllib.parse import quote54 55    if environ.get('HTTP_HOST'):56        url += environ['HTTP_HOST']57    else:58        url += environ['SERVER_NAME']59 60        if environ['wsgi.url_scheme'] == 'https':61            if environ['SERVER_PORT'] != '443':62                url += ':' + environ['SERVER_PORT']63        else:64            if environ['SERVER_PORT'] != '80':65                url += ':' + environ['SERVER_PORT']66 67    url += quote(environ.get('SCRIPT_NAME') or '/', encoding='latin1')68    return url69 70def request_uri(environ, include_query=True):71    """Return the full request URI, optionally including the query string"""72    url = application_uri(environ)73    from urllib.parse import quote74    path_info = quote(environ.get('PATH_INFO',''), safe='/;=,', encoding='latin1')75    if not environ.get('SCRIPT_NAME'):76        url += path_info[1:]77    else:78        url += path_info79    if include_query and environ.get('QUERY_STRING'):80        url += '?' + environ['QUERY_STRING']81    return url82 83def shift_path_info(environ):84    """Shift a name from PATH_INFO to SCRIPT_NAME, returning it85 86    If there are no remaining path segments in PATH_INFO, return None.87    Note: 'environ' is modified in-place; use a copy if you need to keep88    the original PATH_INFO or SCRIPT_NAME.89 90    Note: when PATH_INFO is just a '/', this returns '' and appends a trailing91    '/' to SCRIPT_NAME, even though empty path segments are normally ignored,92    and SCRIPT_NAME doesn't normally end in a '/'.  This is intentional93    behavior, to ensure that an application can tell the difference between94    '/x' and '/x/' when traversing to objects.95    """96    path_info = environ.get('PATH_INFO','')97    if not path_info:98        return None99 100    path_parts = path_info.split('/')101    path_parts[1:-1] = [p for p in path_parts[1:-1] if p and p != '.']102    name = path_parts[1]103    del path_parts[1]104 105    script_name = environ.get('SCRIPT_NAME','')106    script_name = posixpath.normpath(script_name+'/'+name)107    if script_name.endswith('/'):108        script_name = script_name[:-1]109    if not name and not script_name.endswith('/'):110        script_name += '/'111 112    environ['SCRIPT_NAME'] = script_name113    environ['PATH_INFO']   = '/'.join(path_parts)114 115    # Special case: '/.' on PATH_INFO doesn't get stripped,116    # because we don't strip the last element of PATH_INFO117    # if there's only one path part left.  Instead of fixing this118    # above, we fix it here so that PATH_INFO gets normalized to119    # an empty string in the environ.120    if name=='.':121        name = None122    return name123 124def setup_testing_defaults(environ):125    """Update 'environ' with trivial defaults for testing purposes126 127    This adds various parameters required for WSGI, including HTTP_HOST,128    SERVER_NAME, SERVER_PORT, REQUEST_METHOD, SCRIPT_NAME, PATH_INFO,129    and all of the wsgi.* variables.  It only supplies default values,130    and does not replace any existing settings for these variables.131 132    This routine is intended to make it easier for unit tests of WSGI133    servers and applications to set up dummy environments.  It should *not*134    be used by actual WSGI servers or applications, since the data is fake!135    """136 137    environ.setdefault('SERVER_NAME','127.0.0.1')138    environ.setdefault('SERVER_PROTOCOL','HTTP/1.0')139 140    environ.setdefault('HTTP_HOST',environ['SERVER_NAME'])141    environ.setdefault('REQUEST_METHOD','GET')142 143    if 'SCRIPT_NAME' not in environ and 'PATH_INFO' not in environ:144        environ.setdefault('SCRIPT_NAME','')145        environ.setdefault('PATH_INFO','/')146 147    environ.setdefault('wsgi.version', (1,0))148    environ.setdefault('wsgi.run_once', 0)149    environ.setdefault('wsgi.multithread', 0)150    environ.setdefault('wsgi.multiprocess', 0)151 152    from io import StringIO, BytesIO153    environ.setdefault('wsgi.input', BytesIO())154    environ.setdefault('wsgi.errors', StringIO())155    environ.setdefault('wsgi.url_scheme',guess_scheme(environ))156 157    if environ['wsgi.url_scheme']=='http':158        environ.setdefault('SERVER_PORT', '80')159    elif environ['wsgi.url_scheme']=='https':160        environ.setdefault('SERVER_PORT', '443')161 162 163 164_hoppish = {165    'connection', 'keep-alive', 'proxy-authenticate',166    'proxy-authorization', 'te', 'trailers', 'transfer-encoding',167    'upgrade'168}.__contains__169 170def is_hop_by_hop(header_name):171    """Return true if 'header_name' is an HTTP/1.1 "Hop-by-Hop" header"""172    return _hoppish(header_name.lower())173