def get_sdr_data_helper(reserve_fn, get_fn, record_id, reservation_id=None):
"""Helper function to retrieve the sdr data using the specified
functions.
This can be used for SDRs from the Sensor Device or form the SDR
repository.
"""
if reservation_id is None:
reservation_id = reserve_fn()
(next_id, data) = get_fn(reservation_id, record_id, 0, 5)
header = ByteBuffer(data)
record_id = header.pop_unsigned_int(2)
record_version = header.pop_unsigned_int(1)
record_type = header.pop_unsigned_int(1)
record_payload_length = header.pop_unsigned_int(1)
record_length = record_payload_length + 5
record_data = ByteBuffer(data)
offset = len(record_data)
max_req_len = 20
retry = 20
# now get the other record data
while True:
retry -= 1
if retry == 0:
raise RetryError()
length = max_req_len
if (offset + length) > record_length:
length = record_length - offset
try:
(next_id, data) = get_fn(reservation_id, record_id, offset, length)
except CompletionCodeError as e:
if e.cc == constants.CC_CANT_RET_NUM_REQ_BYTES:
# reduce max lenght
max_req_len -= 4
if max_req_len <= 0:
retry = 0
else:
raise CompletionCodeError(e.cc)
record_data.extend(data[:])
offset = len(record_data)
if len(record_data) >= record_length:
break
return (next_id, record_data)
def sel_entries(self):
"""Generator which returns all SEL entries."""
rsp = self.send_message_with_name('GetSelInfo')
if rsp.entries == 0:
return
reservation_id = self.get_sel_reservation_id()
next_record_id = 0
while True:
req = create_request_by_name('GetSelEntry')
req.reservation_id = reservation_id
req.record_id = next_record_id
req.offset = 0
self.max_req_len = 0xff # read entire record
record_data = ByteBuffer()
while True:
req.length = self.max_req_len
if (self.max_req_len != 0xff
and (req.offset + req.length) > 16):
req.length = 16 - req.offset
rsp = self.send_message(req)
if rsp.completion_code == constants.CC_CANT_RET_NUM_REQ_BYTES:
if self.max_req_len == 0xff:
self.max_req_len = 16
else:
self.max_req_len -= 1
continue
else:
check_completion_code(rsp.completion_code)
record_data.extend(rsp.record_data)
req.offset = len(record_data)
if len(record_data) >= 16:
break
next_record_id = rsp.next_record_id
yield SelEntry(record_data)
if next_record_id == 0xffff:
break
