def do_extra_handshake(self, request):
"""Do extra checking in WebSocket handshake.
Select a handler based on request.uri and call its
web_socket_do_extra_handshake function.
Args:
request: mod_python request.
Raises:
DispatchException: when handler was not found
AbortedByUserException: when user handler abort connection
HandshakeException: when opening handshake failed
"""
handler_suite = self.get_handler_suite(request.ws_resource)
if handler_suite is None:
raise DispatchException('No handler for: %r' % request.ws_resource)
do_extra_handshake_ = handler_suite.do_extra_handshake
try:
do_extra_handshake_(request)
except handshake.AbortedByUserException as e:
# Re-raise to tell the caller of this function to finish this
# connection without sending any error.
self._logger.debug('%s', util.get_stack_trace())
raise
except Exception as e:
util.prepend_message_to_exception(
'%s raised exception for %s: ' % (
_DO_EXTRA_HANDSHAKE_HANDLER_NAME,
request.ws_resource),
e)
raise handshake.HandshakeException(e, common.HTTP_STATUS_FORBIDDEN)
class Dispatcher(object):
"""Dispatches WebSocket requests.
This class maintains a map from resource name to handlers.
"""
def __init__(self,
root_dir,
scan_dir=None,
allow_handlers_outside_root_dir=True):
"""Construct an instance.
Args:
root_dir: The directory where handler definition files are
placed.
scan_dir: The directory where handler definition files are
searched. scan_dir must be a directory under root_dir,
including root_dir itself. If scan_dir is None,
root_dir is used as scan_dir. scan_dir can be useful
in saving scan time when root_dir contains many
subdirectories.
allow_handlers_outside_root_dir: Scans handler files even if their
canonical path is not under root_dir.
"""
self._logger = util.get_class_logger(self)
self._handler_suite_map = {}
self._source_warnings = []
if scan_dir is None:
scan_dir = root_dir
if not os.path.realpath(scan_dir).startswith(
os.path.realpath(root_dir)):
raise DispatchException('scan_dir:%s must be a directory under '
'root_dir:%s.' % (scan_dir, root_dir))
self._source_handler_files_in_dir(root_dir, scan_dir,
allow_handlers_outside_root_dir)
def add_resource_path_alias(self, alias_resource_path,
existing_resource_path):
"""Add resource path alias.
Once added, request to alias_resource_path would be handled by
handler registered for existing_resource_path.
Args:
alias_resource_path: alias resource path
existing_resource_path: existing resource path
"""
try:
handler_suite = self._handler_suite_map[existing_resource_path]
self._handler_suite_map[alias_resource_path] = handler_suite
except KeyError:
raise DispatchException('No handler for: %r' %
existing_resource_path)
def source_warnings(self):
"""Return warnings in sourcing handlers."""
return self._source_warnings
def do_extra_handshake(self, request):
"""Do extra checking in WebSocket handshake.
Select a handler based on request.uri and call its
web_socket_do_extra_handshake function.
Args:
request: mod_python request.
Raises:
DispatchException: when handler was not found
AbortedByUserException: when user handler abort connection
HandshakeException: when opening handshake failed
"""
handler_suite = self.get_handler_suite(request.ws_resource)
if handler_suite is None:
raise DispatchException('No handler for: %r' % request.ws_resource)
do_extra_handshake_ = handler_suite.do_extra_handshake
try:
do_extra_handshake_(request)
except handshake.AbortedByUserException, e:
raise
except Exception, e:
util.prepend_message_to_exception(
'%s raised exception for %s: ' %
(_DO_EXTRA_HANDSHAKE_HANDLER_NAME, request.ws_resource), e)
raise handshake.HandshakeException(e, common.HTTP_STATUS_FORBIDDEN)