def _handle_msg(self, req):
"""!
@brief Handle received u-RPC message.
@param req Request message stream.
@return Response message stream.
"""
# Message ID defaults to 0 (Unknown)
msg_id = 0
try:
# Response stream
res = None
# Parse magic string and version
magic_ver_byte = read_data(req, URPC_TYPE_U8)
if (magic_ver_byte >> 4) != URPC_MAGIC:
raise URPCError(URPC_ERR_BROKEN_MSG)
if (magic_ver_byte & 0xf) != URPC_VERSION:
raise URPCError(URPC_ERR_NO_SUPPORT)
# Parse message ID and type
msg_id = read_data(req, URPC_TYPE_U16)
msg_type = read_data(req, URPC_TYPE_U8)
# Call message handler
msg_handler = _urpc_msg_handlers[msg_type]
if not msg_handler:
raise URPCError(URPC_ERR_NO_SUPPORT)
return msg_handler(self, req, msg_id)
# URPC error occured
except URPCError as e:
res = self._build_header(URPC_MSG_ERROR, "recv")
# Write request message ID and error code
write_data(res, msg_id, URPC_TYPE_U16)
write_data(res, e.reason, URPC_TYPE_U8)
# Return stream
return res
def _handle_func_resp(self, res, msg_id):
"""!
@brief u-RPC function query response handler.
@param res Response message stream.
@param msg_id Response message ID.
"""
# Request message ID
req_msg_id = read_data(res, URPC_TYPE_U16)
# Function handle
handle = read_data(res, URPC_TYPE_U16)
# Invoke callback
self._invoke_callback(req_msg_id, handle)
def _handle_error(self, res, msg_id):
"""!
@brief u-RPC error result handler.
@param res Response message stream.
@param msg_id Response message ID.
"""
# Request message ID and error number
req_msg_id = read_data(res, URPC_TYPE_U16)
error_num = read_data(res, URPC_TYPE_U8)
# Invoke callback with error object
callback = self._oper_callbacks[req_msg_id]
callback(URPCError(error_num), None)
# Remove callback function
del self._oper_callbacks[req_msg_id]
def _handle_call(self, req, msg_id):
"""!
@brief u-RPC function call handler.
@param req Request message stream.
@param msg_id Request message ID.
@return A u-RPC response message.
"""
# Function handle
handle = read_data(req, URPC_TYPE_U16)
# Arguments and signature
sig_args = read_vary(req)
args = self._unmarshall(req, sig_args)
# Lookup for function in store
func = seq_get(self._funcs_store, handle)
if not func:
raise URPCError(URPC_ERR_NONEXIST)
# Call function
sig_rets, result = func(sig_args, args)
if len(result) != len(sig_rets):
raise URPCError(URPC_ERR_SIG_INCORRECT)
# Response message
res = self._build_header(URPC_MSG_CALL_RESULT, "recv")
write_data(res, msg_id, URPC_TYPE_U16)
# Return values and signature
write_vary(res, sig_rets)
self._marshall(res, sig_rets, result)
return res
def _handle_call_result(self, res, msg_id):
"""!
@brief u-RPC error result handler.
@param res Response message stream.
@param msg_id Response message ID.
"""
# Request message ID
req_msg_id = read_data(res, URPC_TYPE_U16)
# Result and signature
sig_rets = read_vary(res)
result = self._unmarshall(res, sig_rets)
# Invoke callback
self._invoke_callback(req_msg_id, result)
def _unmarshall(self, stream, sig):
"""!
@brief Unmarshall objects from data stream.
@param stream Data stream.
@param sig Signature of objects.
@return Objects in an array.
"""
objects = []
# Unmarshall arguments
for obj_type in sig:
obj = None
# Read argument
if obj_type == URPC_TYPE_VARY:
obj = read_vary(stream, "H")
else:
obj = read_data(stream, obj_type)
objects.append(obj)
return objects