Hi,
I managed to get rid of the buffer error.
But now im facing a unpack error.
See error and code which generate the error.
I managed to get rid of the buffer error.
But now im facing a unpack error.
See error and code which generate the error.
Python 3.8.6 (tags/v3.8.6:db45529, Sep 23 2020, 15:52:53) [MSC v.1927 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license()" for more information.
>>>
=============== RESTART: C:\Users\Makada\Desktop\cr1000 modbus.py ==============
Device is connected: True
2020-11-11 18:56:05
Traceback (most recent call last):
File "C:\Users\Makada\Desktop\cr1000 modbus.py", line 5, in <module>
print(device.list_tables())
File "C:\Python38\lib\site-packages\pycampbellcr1000\device.py", line 182, in list_tables
return [item['Header']['TableName'] for item in self.table_def]
File "C:\Python38\lib\site-packages\pycampbellcr1000\utils.py", line 65, in __get__
value = self.func(obj)
File "C:\Python38\lib\site-packages\pycampbellcr1000\device.py", line 177, in table_def
tabledef = self.pakbus.parse_tabledef(data)
File "C:\Python38\lib\site-packages\pycampbellcr1000\pakbus.py", line 700, in parse_tabledef
values, size = self.decode_bin(types, raw[offset:])
File "C:\Python38\lib\site-packages\pycampbellcr1000\pakbus.py", line 318, in decode_bin
value = struct.unpack(str(fmt), buff[offset:offset + size])
struct.error: unpack requires a buffer of 4 bytes
>>> # -*- coding: utf-8 -*-
'''
PyCampbellCR1000.pakbus
-----------------------
PakBus protocol Implementation.
Original Author: Dietrich Feist, Max Planck Institute for Biogeochemistry,
Jena Germany (PyPak)
:copyright: Copyright 2012 Salem Harrache and contributors, see AUTHORS.
:license: GNU GPL v3.
'''
from __future__ import division, unicode_literals
import struct
import time
from .compat import ord, chr, is_text, is_py3, bytes
from .logger import LOGGER
from .utils import Singleton
from .exceptions import DeliveryFailureException
from .utils import bytes_to_hex, nsec_to_time
class Transaction(Singleton):
id = 0
def next_id(self):
self.id += 1
self.id &= 0xFF
return self.id
class PakBus(object):
'''Interface for a pakbus client.
:param link: A `PyLink` connection.
:param dest_addr: Destination physical address (12-bit int) (default dest)
:param dest: Destination node ID (12-bit int) (default 0x001)
:param src_addr: Source physical address (12-bit int) (default src)
:param src: Source node ID (12-bit int) (default 0x802)
:param security_code: 16-bit security code (default 0x0000)
'''
DATATYPE = {
'Byte': {'code': 1, 'fmt': 'B', 'size': 1},
'UInt2': {'code': 2, 'fmt': '>H', 'size': 2},
'UInt4': {'code': 3, 'fmt': '>L', 'size': 4},
'Int1': {'code': 4, 'fmt': 'b', 'size': 1},
'Int2': {'code': 5, 'fmt': '>h', 'size': 2},
'Int4': {'code': 6, 'fmt': '>l', 'size': 4},
'FP2': {'code': 7, 'fmt': '>H', 'size': 2},
'FP3': {'code': 15, 'fmt': '3c', 'size': 3},
'FP4': {'code': 8, 'fmt': '4c', 'size': 4},
'IEEE4B': {'code': 9, 'fmt': '>f', 'size': 4},
'IEEE8B': {'code': 18, 'fmt': '>d', 'size': 8},
'Bool8': {'code': 17, 'fmt': 'B', 'size': 1},
'Bool': {'code': 10, 'fmt': 'B', 'size': 1},
'Bool2': {'code': 27, 'fmt': '>H', 'size': 2},
'Bool4': {'code': 28, 'fmt': '>L', 'size': 4},
'Sec': {'code': 12, 'fmt': '>l', 'size': 4},
'USec': {'code': 13, 'fmt': '6c', 'size': 6},
'NSec': {'code': 14, 'fmt': '>2l', 'size': 8},
'ASCII': {'code': 11, 'fmt': 's', 'size': None},
'ASCIIZ': {'code': 16, 'fmt': 's', 'size': None},
'Short': {'code': 19, 'fmt': '<h', 'size': 2},
'Long': {'code': 20, 'fmt': '<l', 'size': 4},
'UShort': {'code': 21, 'fmt': '<H', 'size': 2},
'ULong': {'code': 22, 'fmt': '<L', 'size': 4},
'IEEE4L': {'code': 24, 'fmt': '<f', 'size': 4},
'IEEE8L': {'code': 25, 'fmt': '<d', 'size': 8},
'SecNano': {'code': 23, 'fmt': '<2l', 'size': 8},
}
# link state
RING = 0x9
READY = 0xA
FINISHED = 0xB
def __init__(self, link, dest_addr=None, dest=0x001,
src_addr=None, src=0x802, security_code=0x0000):
self.link = link
self.src = src
if (src_addr != None):
self.src_addr = src_addr
else:
self.src_addr = src
self.dest = dest
if (dest_addr != None):
self.dest_addr = dest_addr
else:
self.dest_addr = dest
self.security_code = security_code
self.transaction = Transaction()
LOGGER.info('Get the node attention')
self.link.write(b'\xBD\xBD\xBD\xBD\xBD\xBD')
def write(self, packet):
'''Send packet over PakBus.'''
LOGGER.info('Packet data: %s' % bytes_to_hex(packet))
LOGGER.info('Calculate signature for packet')
sign = self.compute_signature(packet)
LOGGER.info('Calculate signature nullifier to create packet')
nullifier = self.compute_signature_nullifier(sign)
frame = self.quote(b''.join((packet, nullifier)))
packet = b''.join((b'\xBD', frame, b'\xBD'))
LOGGER.info('Write: %s' % bytes_to_hex(packet))
self.link.write(packet)
def read(self):
'''Receive packet over PakBus.'''
all_bytes = []
byte = None
begin = time.time()
while byte != b'\xBD':
if (byte != None):
LOGGER.info('Read byte: %s' % bytes_to_hex(byte))
if time.time() - begin > self.link.timeout:
return None
# Read until first \xBD frame character
byte = self._read_one_byte()
while byte == b'\xBD':
# Read unitl first character other than \xBD
byte = self._read_one_byte()
while byte != b'\xBD':
# Read until next occurence of \xBD character
all_bytes.append(byte)
byte = self._read_one_byte()
# Unquote quoted characters
packet = b''.join(all_bytes)
LOGGER.info('Read packet: %s' % bytes_to_hex(packet))
packet = self.unquote(packet)
# Calculate signature (should be zero)
if self.compute_signature(packet):
LOGGER.error('Check signature : Error')
return None
else:
LOGGER.info('Check signature : OK')
# Strip last 2 signature bytes and return packet
return packet[:-2]
def _read_one_byte(self):
'''Read only one byte.'''
data = self.link.read(1)
if is_text(data):
return bytes(data.encode('utf-8'))
else:
return data
def wait_packet(self, transac_id=None):
'''Wait for an incoming packet.
:param transac_id: Expected transaction number.
'''
LOGGER.info('Wait packet with transaction %s' % transac_id)
data = self.read()
if data is None or data == b'':
return {}, {}
hdr, msg = self.decode_packet(data)
if hdr == {} or msg == {}:
return hdr, msg
# ignore packets that are not for us
LOGGER.info('src, SrcNodeId = <%x, %x>' %
(self.src, hdr['SrcNodeId']))
LOGGER.info('dest, DstNodeId = <%x, %x>' %
(self.dest, hdr['DstNodeId']))
if (hdr['DstNodeId'] != self.src):
return {}, {}
# Handle 'please wait' packets
if msg['TranNbr'] == transac_id and msg['MsgType'] == 0xa1:
timewait = msg['WaitSec']
LOGGER.info('Please Wait Message packet <%s sec>' % timewait)
time.sleep(timewait)
return self.wait_packet(transac_id)
# Handle failure message packets and raise exception
if msg['MsgType'] == 0x81:
raise DeliveryFailureException()
# This should be the packet we are waiting for
if msg['TranNbr'] == transac_id:
return hdr, msg
def pack_header(self, hi_proto, exp_more=0x2, link_state=None,
hops=0x0):
'''Generate PakBus header.
:param hi_proto: Higher level protocol code (4 bits). 0x0: PakCtrl,
0x1: BMP5
:param exp_more: Whether client should expect another packet (2 bits)
:param link_state: Link state (4 bits)
:param hops: Number of hops to destination (4 bits)
'''
LOGGER.info('Create header')
priority = 0x1
link_state = link_state or self.READY
# bitwise encoding of header fields
hdr = struct.pack(str('>4H'),
(link_state & 0xF) << 12 | (self.dest_addr & 0xFFF),
(exp_more & 0x3) << 14 | (priority & 0x3) << 12
| (self.src_addr & 0xFFF),
(hi_proto & 0xF) << 12 | (self.dest & 0xFFF),
(hops & 0xF) << 12 | (self.src & 0xFFF))
return hdr
def compute_signature(self, buff, seed=0xAAAA):
'''Compute signature for PakBus packets.'''
sig = seed
for x in buff:
x = ord(x)
j = sig
sig = (sig << 1) & 0x1FF
if sig >= 0x100:
sig += 1
sig = ((((sig + (j >> 8) + x) & 0xFF) | (j << 8))) & 0xFFFF
return sig
def compute_signature_nullifier(self, sig):
'''Compute signature nullifier needed to create valid PakBus
packets.'''
nulb = nullif = b''
for i in (1, 2):
sig = self.compute_signature(nulb, sig)
sig2 = (sig << 1) & 0x1FF
if sig2 >= 0x100:
sig2 += 1
nulb = chr((0x100 - (sig2 + (sig >> 8))) & 0xFF)
nullif += nulb
return nullif
def quote(self, packet):
'''Quote the PakBus packet.'''
LOGGER.info('Quote packet')
packet = packet.replace(b'\xBC', b'\xBC\xDC')
packet = packet.replace(b'\xBD', b'\xBC\xDD')
return packet
def unquote(self, packet):
'''Unquote the PakBus packet.'''
LOGGER.info('Unquote packet')
packet = packet.replace(b'\xBC\xDD', b'\xBD')
packet = packet.replace(b'\xBC\xDC', b'\xBC')
return packet
def encode_bin(self, types, values):
'''Encode binary data according to data type.'''
buff = [] # buffer for binary data
for i, type_ in enumerate(types):
fmt = self.DATATYPE[type_]['fmt'] # get default format for type_
value = values[i]
if type_ == 'ASCIIZ':
# special handling: nul-terminated string
value += '\0'
# Add nul to end of string
fmt_ = str('%d%s' % (len(value), fmt))
if is_py3:
enc = struct.pack(fmt_, bytes(value, encoding='utf8'))
else:
enc = struct.pack(fmt_, str(value))
elif type_ == 'ASCII':
# special handling: fixed-length string
fmt_ = str('%d%s' % (len(value), fmt))
enc = struct.pack(fmt_, str(value))
elif type_ == 'NSec':
# special handling: NSec time
enc = struct.pack(str(fmt), value[0], value[1])
else:
# default encoding scheme
enc = struct.pack(str(fmt), value)
buff.append(enc)
return b''.join(buff)
def decode_bin(self, types, buff, length=1):
'''Decode binary data according to data type.'''
offset = 0 # offset into buffer
values = [] # list of values to return
for type_ in types:
# get default format and size for Type
fmt = self.DATATYPE[type_]['fmt']
size = self.DATATYPE[type_]['size']
if type_ == 'ASCIIZ':
# special handling: nul-terminated string
nul = buff.index(b'\0', offset)
# find first '\0' after offset
if nul == -1:
value = buff[offset:]
else:
value = buff[offset:nul]
# return string without trailing '\0'
size = len(value) + 1
elif type_ == 'ASCII':
# special handling: fixed-length string
size = length
value = buff[offset:offset + size]
# return fixed-length string
elif type_ == 'FP2':
# special handling: FP2 floating point number
fp2 = struct.unpack(str(fmt), buff[offset:offset + size])
mant = fp2[0] & 0x1FFF # mantissa is in bits 1-13
exp = fp2[0] >> 13 & 0x3 # exponent is in bits 14-15
sign = fp2[0] >> 15 # sign is in bit 16
value = ((-1) ** sign * float(mant) / 10 ** exp, )
else:
# default decoding scheme
if buff[offset:offset + size]:
value = struct.unpack(str(fmt), buff[offset:offset + size])
else:
value = ''
# un-tuple single values
if len(value) == 1:
value = value[0]
values.append(value)
offset += size
# Return decoded values and current offset into buffer (size)
return values, offset
def decode_packet(self, data):
'''Decode packet from raw data.'''
LOGGER.info('Decode packet')
# pkt: buffer containing unquoted packet, signature nullifier stripped
# Initialize output variables
hdr = {'LinkState': None, 'DstPhyAddr': None, 'ExpMoreCode': None,
'Priority': None, 'SrcPhyAddr': None, 'HiProtoCode': None,
'DstNodeId': None, 'HopCnt': None, 'SrcNodeId': None}
msg = {'MsgType': None, 'TranNbr': None, 'raw': None}
# decode PakBus header
rawhdr = struct.unpack(str('>4H'), data[0:8]) # raw header bits
hdr['LinkState'] = rawhdr[0] >> 12
hdr['DstPhyAddr'] = rawhdr[0] & 0x0FFF
hdr['ExpMoreCode'] = (rawhdr[1] & 0xC000) >> 14
hdr['Priority'] = (rawhdr[1] & 0x3000) >> 12
hdr['SrcPhyAddr'] = rawhdr[1] & 0x0FFF
hdr['HiProtoCode'] = rawhdr[2] >> 12
hdr['DstNodeId'] = rawhdr[2] & 0x0FFF
hdr['HopCnt'] = rawhdr[3] >> 12
hdr['SrcNodeId'] = rawhdr[3] & 0x0FFF
# decode default message fields:
# raw message, message type and transaction number
msg['raw'] = data[8:]
values, size = self.decode_bin(('Byte', 'Byte'), msg['raw'][:2])
msg['MsgType'], msg['TranNbr'] = values
LOGGER.info('HiProtoCode, MsgType = <%x, %x>' %
(hdr['HiProtoCode'], msg['MsgType']))
# PakBus Control Packets
if hdr['HiProtoCode'] == 0 and msg['MsgType'] in (0x09, 0x89, 0xe):
msg = self.unpack_hello_response(msg)
elif hdr['HiProtoCode'] == 0 and msg['MsgType'] == 0x81:
msg = self.unpack_failure_response(msg)
elif hdr['HiProtoCode'] == 0 and msg['MsgType'] == 0x8f:
msg = self.unpack_getsettings_response(msg)
# BMP5 Application Packets
elif hdr['HiProtoCode'] == 1 and msg['MsgType'] == 0x89:
msg = self.unpack_collectdata_response(msg)
elif hdr['HiProtoCode'] == 1 and msg['MsgType'] == 0x97:
msg = self.unpack_clock_response(msg)
elif hdr['HiProtoCode'] == 1 and msg['MsgType'] == 0x98:
msg = self.unpack_getprogstat_response(msg)
elif hdr['HiProtoCode'] == 1 and msg['MsgType'] == 0x9c:
msg = self.unpack_filedownload_response(msg)
elif hdr['HiProtoCode'] == 1 and msg['MsgType'] == 0x9d:
msg = self.unpack_fileupload_response(msg)
elif hdr['HiProtoCode'] == 1 and msg['MsgType'] == 0xa1:
msg = self.unpack_pleasewait_response(msg)
else:
LOGGER.error('No implementation for <(%r, %r)> packet type'
% (hdr['HiProtoCode'], msg['MsgType']))
return hdr, msg
def get_hello_cmd(self):
'''Create Hello Command packet.'''
transac_id = self.transaction.next_id()
hdr = self.pack_header(0x0, 0x1, self.RING)
msg = self.encode_bin(['Byte', 'Byte', 'Byte', 'Byte', 'UInt2'],
[0x09, transac_id, 0x00, 0x02, 1800])
return b''.join((hdr, msg)), transac_id
def get_hello_response(self, transac_id):
'''Create Hello Response packet.'''
hdr = self.pack_header(0x0)
msg = self.encode_bin(['Byte', 'Byte', 'Byte', 'Byte', 'UInt2'],
[0x89, transac_id, 0x00, 0x02, 1800])
return b''.join([hdr, msg])
def unpack_hello_response(self, msg):
'''Create Hello Response packet.'''
raw = msg['raw'][2:]
values, size = self.decode_bin(['Byte', 'Byte', 'UInt2'], raw)
msg['IsRouter'], msg['HopMetric'], msg['VerifyIntv'] = values
return msg
def unpack_failure_response(self, msg):
'''Unpack Failure Response packet.'''
(msg['ErrCode'],), size = self.decode_bin(['Byte'], msg['raw'][2:])
return msg
def get_getsettings_cmd(self):
'''Create Getsettings Command packet.'''
transac_id = self.transaction.next_id()
hdr = self.pack_header(0x0)
msg = self.encode_bin(['Byte', 'Byte'], [0x0f, transac_id])
return b''.join([hdr, msg]), transac_id
def unpack_getsettings_response(self, msg):
'''Unpack Getsettings Response packet.'''
(msg['Outcome'],), size = self.decode_bin(['Byte'], msg['raw'][2:])
offset = size + 2
# Generate dictionary of all settings
msg['Settings'] = []
if msg['Outcome'] == 0x01:
values, size = self.decode_bin(['UInt2', 'Byte', 'Byte', 'Byte'],
msg['raw'][offset:])
msg['DeviceType'] = values[0]
msg['MajorVersion'] = values[1]
msg['MinorVersion'] = values[2]
msg['MoreSettings'] = values[3]
offset += size
while offset < len(msg['raw']):
# Get setting ID
[SettingId], size = self.decode_bin(['UInt2'],
msg['raw'][offset:])
offset += size
if not msg['raw'][offset:]:
break
# Get flags and length
[bit16], size = self.decode_bin(['UInt2'], msg['raw'][offset:])
LargeValue = (bit16 & 0x8000) >> 15
ReadOnly = (bit16 & 0x4000) >> 14
SettingLen = bit16 & 0x3FFF
offset += size
# Get value
SettingValue = msg['raw'][offset:offset + SettingLen]
offset += SettingLen
item = {'SettingId': SettingId,
'SettingValue': SettingValue,
'LargeValue': LargeValue,
'ReadOnly': ReadOnly}
msg['Settings'].append(item)
return msg
def get_collectdata_cmd(self, tablenbr, tabledefsig, mode=0x04, p1=0,
p2=0):
'''Create Collect Data Command packet
:param tablenbr: Table number that contain data.
:param tabledefsig: Table definition signature.
:param mode: Collection mode code (p1 and p2 will be used depending on
value).
:param p1: 1st parameter used to specify what to collect (optional)
:param p2: 2nd parameter used to specify what to collect (optional)
'''
transac_id = self.transaction.next_id()
# BMP5 Application Packet
hdr = self.pack_header(0x1)
msg = self.encode_bin(['Byte', 'Byte', 'UInt2', 'Byte'],
[0x09, transac_id, self.security_code,
mode])
# encode table number and signature
msg += self.encode_bin(['UInt2', 'UInt2'], [tablenbr, tabledefsig])
# add p1 and p2 according to collect mode
if (mode == 0x04) | (mode == 0x05):
# only P1 used (type UInt4)
msg += self.encode_bin(['UInt4'], [p1])
elif (mode == 0x06) | (mode == 0x08):
# P1 and P2 used (type UInt4)
msg += self.encode_bin(['UInt4', 'UInt4'], [p1, p2])
elif mode == 0x07:
# P1 and P2 used (type NSec)
msg += self.encode_bin(['NSec', 'NSec'], [p1, p2])
# add field list = all fields
msg += self.encode_bin(['UInt2'], [0])
return b''.join((hdr, msg)), transac_id
def unpack_collectdata_response(self, msg):
'''Unpack Collect Data Response body.'''
(msg['RespCode'],), size = self.decode_bin(['Byte'], msg['raw'][2:])
# return raw record data for later parsing
msg['RecData'] = msg['raw'][size + 2:]
return msg
def get_clock_cmd(self, adjustment=(0, 0)):
'''Create Clock Command packet.
:param adjustment: Clock adjustment (seconds, nanoseconds).
'''
transac_id = self.transaction.next_id()
# BMP5 Application Packet
hdr = self.pack_header(0x1)
msg = self.encode_bin(['Byte', 'Byte', 'UInt2', 'NSec'],
[0x17, transac_id, self.security_code,
adjustment])
return b''.join((hdr, msg)), transac_id
def unpack_clock_response(self, msg):
'''Unpack Clock Response packet.'''
values, size = self.decode_bin(['Byte', 'NSec'], msg['raw'][2:])
msg['RespCode'], msg['Time'] = values
return msg
def get_getprogstat_cmd(self):
'''Create Get Programming Statistics Transaction packet.'''
transac_id = self.transaction.next_id()
# BMP5 Application Packet
hdr = self.pack_header(0x1)
msg = self.encode_bin(['Byte', 'Byte', 'UInt2'],
[0x18, transac_id, self.security_code])
return b''.join((hdr, msg)), transac_id
def unpack_getprogstat_response(self, msg):
'''Unpack Get Programming Statistics Response packet.'''
# Get response code
(msg['RespCode'], ), size = self.decode_bin(['Byte'], msg['raw'][2:])
# Get report data if RespCode == 0
if msg['RespCode'] == 0:
types = ['ASCIIZ', 'UInt2', 'ASCIIZ', 'ASCIIZ', 'Byte', 'ASCIIZ',
'UInt2', 'NSec', 'ASCIIZ']
values, size = self.decode_bin(types, msg['raw'][3:])
item = {'OSVer': values[0], 'OSSig': values[1],
'SerialNbr': values[2], 'PowUpProg': values[3],
'CompState': values[4], 'ProgName': values[5],
'ProgSig': values[6], 'CompTime': values[7],
'CompResult': values[8]}
msg['Stats'] = item
return msg
def get_filedownload_cmd(self, filename, data, offset=0x00000000,
closeflag=0x00, transac_id=None):
'''Create Filedownload Command packet.
:param filename: File name as string
:param offset: Byte offset into the file or fragment
:param closeflag: Flag if file should be closed after this transaction
:param transac_id: Transaction number for continuing partial reads
'''
raise NotImplementedError('Filedownload transaction is not implemented'
' yet')
def unpack_filedownload_response(self, msg):
'''Unpack Filedownload Response packet.'''
raise NotImplementedError('Filedownload transaction is not implemented'
' yet')
def get_fileupload_cmd(self, filename, offset=0x00000000, swath=0x0200,
closeflag=0x01, transac_id=None):
'''Create Fileupload Command packet.
:param filename: File name as string
:param offset: Byte offset into the file or fragment
:param swath: Number of bytes to read
:param closeflag: Flag if file should be closed after this transaction
:param transac_id: Transaction number for continuing partial reads
(required by OS>=17!)
'''
if transac_id is None:
transac_id = self.transaction.next_id()
# BMP5 Application Packet
hdr = self.pack_header(0x1)
types = ['Byte', 'Byte', 'UInt2', 'ASCIIZ', 'Byte', 'UInt4', 'UInt2']
values = [0x1d, transac_id, self.security_code, filename, closeflag,
offset, swath]
msg = self.encode_bin(types, values)
return b''.join((hdr, msg)), transac_id
def unpack_fileupload_response(self, msg):
'''Unpack Fileupload Response packet.'''
values, size = self.decode_bin(['Byte', 'UInt4'], msg['raw'][2:7])
msg['RespCode'], msg['FileOffset'] = values
msg['FileData'] = msg['raw'][7:]
return msg
def unpack_pleasewait_response(self, msg):
'''Unpack PeaseWait Response packet.'''
values, size = self.decode_bin(['Byte', 'UInt2'], msg['raw'][2:])
msg['CmdMsgType'], msg['WaitSec'] = values
return msg
def get_bye_cmd(self):
'''Create Bye Command packet.'''
transac_id = self.transaction.next_id()
# PakBus Control Packet
hdr = self.pack_header(0x0, 0x0, self.FINISHED)
msg = self.encode_bin(['Byte', 'Byte'], [0x0d, 0x0])
return b''.join((hdr, msg)), transac_id
def parse_filedir(self, data):
'''Parse file directory format.'''
offset = 0 # offset into raw buffer
fd = {'files': []} # initialize file directory structure
[fd['DirVersion']], size = self.decode_bin(['Byte'], data[offset:])
offset += size
# Extract file entries
while len(data) > offset:
file_ = {} # file description
[filename], size = self.decode_bin(['ASCIIZ'], data[offset:])
offset += size
# end loop when file attribute list terminator reached
if filename == '':
break
file_['FileName'] = filename
values, size = self.decode_bin(['UInt4', 'ASCIIZ'], data[offset:])
file_['FileSize'], file_['LastUpdate'] = values
offset += size
# Read file attribute list
file_['Attribute'] = []
# initialize file attribute list (up to 12)
for i in range(12):
[attribute], size = self.decode_bin(['Byte'], data[offset:])
offset += size
if attribute:
# append file attribute to list
file_['Attribute'].append(attribute)
else:
break # End of attribute list reached
fd['files'].append(file_) # add file entry to list
return fd
def parse_tabledef(self, raw):
'''Parse table definition.'''
tabledef = [] # List of table definitions
offset = 0 # offset into raw buffer
fslversion, size = self.decode_bin(['Byte'], raw[offset:])
offset += size
# Parse list of table definitions
while offset < len(raw):
tblhdr = {} # table header
tblfld = [] # table field definitions
start = offset # start of table definition
# Extract table header data
types = ['ASCIIZ', 'UInt4', 'Byte', 'NSec', 'NSec']
values, size = self.decode_bin(types, raw[offset:])
tblhdr['TableName'] = values[0]
tblhdr['TableSize'] = values[1]
tblhdr['TimeType'] = values[2]
tblhdr['TblTimeInto'] = values[3]
tblhdr['TblInterval'] = values[4]
offset += size
# Extract field definitions
(fieldtype,), size = self.decode_bin(['Byte'], raw[offset:])
offset += size
while fieldtype != 0:
fld = {}
# Extract bits from fieldtype
fld['ReadOnly'] = fieldtype >> 7 # only Bit 7
# Convert fieldtype to ASCII FieldType (e.g. 'FP4') if possible
# else return numerical value
fld['FieldType'] = fieldtype & 0x7F # only Bits 0..6
for Type in self.DATATYPE.keys():
if fld['FieldType'] == self.DATATYPE[Type]['code']:
fld['FieldType'] = Type
break
# Extract field name
values, size = self.decode_bin(['ASCIIZ'], raw[offset:])
fld['FieldName'] = values[0]
offset += size
# Extract AliasName list
fld['AliasName'] = []
aliasname = b'00'
# Alias names list terminator reached
while aliasname != b'':
values, size = self.decode_bin(['ASCIIZ'], raw[offset:])
aliasname = values[0]
offset += size
if aliasname != b'':
fld['AliasName'].append(aliasname)
# Extract other mandatory field definition items
types = ['ASCIIZ', 'ASCIIZ', 'ASCIIZ', 'UInt4', 'UInt4']
values, size = self.decode_bin(types, raw[offset:])
fld['Processing'] = values[0]
fld['Units'] = values[1]
fld['Description'] = values[2]
fld['BegIdx'] = values[3]
fld['Dimension'] = values[4]
offset += size
# Extract sub dimension (if any)
fld['SubDim'] = []
subdim = 1
# sub-dimension list terminator reached
while subdim != 0:
(subdim,), size = self.decode_bin(['UInt4'], raw[offset:])
offset += size
if subdim != 0:
fld['SubDim'].append(subdim)
# append current field definition to list
tblfld.append(fld)
(fieldtype,), size = self.decode_bin(['Byte'], raw[offset:])
offset += size
# calculate table signature
tblsig = self.compute_signature(raw[start:offset])
# Append header, field list and signature to table definition list
item = {'Header': tblhdr, 'Fields': tblfld, 'Signature': tblsig}
tabledef.append(item)
return tabledef
def parse_collectdata(self, raw, tabledef, fieldnbr=[]):
'''Parse data returned by Collectdata Response.'''
offset = 0
recdata = [] # output structure
while offset < len(raw) - 1:
frag = {} # record fragment
values, size = self.decode_bin(['UInt2', 'UInt4'], raw[offset:])
frag['TableNbr'], frag['BegRecNbr'] = values
offset += size
# Provide table name
t_frag = tabledef[frag['TableNbr'] - 1]
tablename = t_frag['Header']['TableName']
frag['TableName'] = tablename
# Decode number of records (16 bits) or ByteOffset (32 Bits)
(isoffset,), size = self.decode_bin(['Byte'], raw[offset:])
frag['IsOffset'] = isoffset >> 7
# Handle fragmented records
if frag['IsOffset']:
(byteoffset,), size = self.decode_bin(['UInt4'], raw[offset:])
offset += size
frag['ByteOffset'] = byteoffset & 0x7FFFFFFF
frag['NbrOfRecs'] = None
# Copy remaining raw data into RecFrag
frag['RecFrag'] = raw[offset:-1]
offset += len(frag['RecFrag'])
# Handle complete records (standard case)
else:
(nbrofrecs,), size = self.decode_bin(['UInt2'], raw[offset:])
offset += size
frag['NbrOfRecs'] = nbrofrecs & 0x7FFF
frag['ByteOffset'] = None
# Get time of first record and time interval information
interval = t_frag['Header']['TblInterval']
if interval == (0, 0): # event-driven table
timeofrec = None
else:
# interval data, read time of first record
[timeofrec], size = self.decode_bin(['NSec'], raw[offset:])
offset += size
# Loop over all records
frag['RecFrag'] = []
for n in range(frag['NbrOfRecs']):
record = {}
# Calculate current record number
record['RecNbr'] = frag['BegRecNbr'] + n
# Get TimeOfRec for interval data or event-driven tables
if timeofrec: # interval data
next_timeofrec = (timeofrec[0] + n * interval[0],
timeofrec[1] + n * interval[1])
record['TimeOfRec'] = nsec_to_time(next_timeofrec)
else:
# event-driven, time data precedes each record
values, size = self.decode_bin(['NSec'], raw[offset:])
record['TimeOfRec'] = values[0]
record['TimeOfRec'] = nsec_to_time(record['TimeOfRec'])
offset += size
# Loop over all field indices
record['Fields'] = {}
if fieldnbr:
# explicit field numbers provided
fields = fieldnbr
else:
# default: generate list of all fields in table
fields = t_frag['Fields']
fields = range(1, len(fields) + 1)
for field in fields:
fieldname = t_frag['Fields'][field - 1]['FieldName']
fieldtype = t_frag['Fields'][field - 1]['FieldType']
dimension = t_frag['Fields'][field - 1]['Dimension']
if fieldtype == 'ASCII':
values, size = self.decode_bin([fieldtype],
raw[offset:],
dimension)
record['Fields'][fieldname] = values[0]
else:
values, size = \
self.decode_bin(dimension * [fieldtype],
raw[offset:])
record['Fields'][fieldname] = values[0]
offset += size
frag['RecFrag'].append(record)
recdata.append(frag)
# Get flag if more records exist
(more_rec,), size = self.decode_bin(['Bool'], raw[offset:])
return recdata, more_rec
def __del__(self):
self.link.close()
def __str__(self):
name = self.__class__.__name__
return '<%s %s>' % (name, self.link)
def __repr__(self):
return '%s' % self.__str__()With kindest regards.