def encode(payload):
''' Encoding RCMP Frame
Args:
payload: payload('str' or 'utf-8 bytes' format)
Returns:
RCMP Frame
Raises:
EXP.VRException: An error occurred when encoding.
'''
if isinstance(payload, str):
raw_bytes = bytes(payload, 'utf-8')
elif isinstance(payload, bytes):
raw_bytes = payload
elif not payload:
raw_bytes = bytes()
else:
raise EXP.RCException(errno=ERR.ERROR,
errmsg='invalid payload type: {}'.format(
type(payload)))
payloadSize = len(raw_bytes)
if payloadSize > CONST.RCMP_MAXPAYLOAD:
raise EXP.RCException(ERR.ERROR_INVALID, 'payload too large')
frame_head = FRAME_HEAD_FMT.pack(CONST.RCMP_STARTFLAG,
CONST.RCMP_VERSION, payloadSize)
return frame_head + raw_bytes
def parse(rawbuf):
''' parse signaling from raw data
Args:
rawbuf: buffer
Returns:
(sig, frame_length)
Raises:
EXP.RCException: An error occurred when parse raw data.
EXP.RCException_More_Data: Need more data
'''
# parse frame payload from raw data
frame_payload, frame_length = RCMPFrame.parse(rawbuf)
# parse frame payload
try:
if isinstance(frame_payload, bytes):
# decode buffer as 'utf-8'
frame_payload = frame_payload.decode('utf-8')
sig = json.loads(frame_payload)
cmd = sig['cmd']
if cmd not in CONST.SIG_CMD_LIST:
raise EXP.RCException(ERR.ERROR_UNSUPPORT,
'unsupport cmd: {}'.format(cmd))
except Exception as e:
raise EXP.RCException(ERR.ERROR_INVALID,
'parse frame paload fail: {}'.format(e))
return (sig, frame_length)
def parse(rawbuf):
''' Parse RCMP Frame
Args:
param rawbuf: raw buffer
Returns:
(raw_payload, frame_length)
Raises:
EXP.VRException: An error occurred when parse raw data.
EXP.RCException_More_Data: Need more data
'''
bufsize = len(rawbuf)
if bufsize < CONST.RCMP_FRAMEHEADSIZE:
# Need more data
raise EXP.RCException_More_Data(ERR.ERROR, 'need more data')
# check start flag
if rawbuf[0] != CONST.RCMP_STARTFLAG:
raise EXP.RCException(ERR.ERROR_INVALID, 'invalid Start Flag')
# parse buffer
[_, version, payloadSize
] = FRAME_HEAD_FMT.unpack(rawbuf[:CONST.RCMP_FRAMEHEADSIZE])
# check version
if version != CONST.RCMP_VERSION:
raise EXP.RCException(ERR.ERROR_UNSUPPORT,
'unsupport version: {}'.format(version))
# check payload size
if payloadSize > CONST.RCMP_MAXPAYLOAD:
raise EXP.RCException(ERR.ERROR_INVALID, 'payload too large')
# check buffer size
if CONST.RCMP_FRAMEHEADSIZE + payloadSize > bufsize:
# need more data
raise EXP.RCException_More_Data(ERR.ERROR, 'need more data')
frame_length = CONST.RCMP_FRAMEHEADSIZE + payloadSize
if payloadSize > 0:
raw_payload = rawbuf[CONST.RCMP_FRAMEHEADSIZE:frame_length]
else:
raw_payload = None
return (raw_payload, frame_length)
def req(req_cmd, seq, payload=None):
if req_cmd not in CONST.SIG_REQ_CMD_LIST:
raise EXP.RCException(ERR.ERROR_INVALID,
'invalid req cmd id: {}'.format(req_cmd))
return {
'cmd': req_cmd,
'seq': seq,
'payload': payload
}
def resp(resp_cmd, seq, errno, errmsg, payload=None):
if resp_cmd not in CONST.SIG_RESP_CMD_LIST:
raise EXP.RCException(ERR.ERROR_INVALID,
'invalid resp cmd id: {}'.format(resp_cmd))
return {
'cmd': resp_cmd,
'seq': seq,
'errno': errno,
'errmsg': errmsg,
'payload': payload
}