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Update framers to ease message integration (only decode/encode) #2064

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Merged
janiversen merged 3 commits into from
Mar 1, 2024
Merged

Update framers to ease message integration (only decode/encode) #2064

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dfd6664
Update framers to ease message integration.
janiversen Feb 27, 2024
d65b810
transaction.
janiversen Feb 28, 2024
553c51a
binary.
janiversen Mar 1, 2024
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93 changes: 28 additions & 65 deletions pymodbus/framer/ascii_framer.py
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -42,12 +42,6 @@ def __init__(self, decoder, client=None):
self._start = b":"
self._end = b"\r\n"

# ----------------------------------------------------------------------- #
# Private Helper Functions
# ----------------------------------------------------------------------- #
def _process(self, callback, error=False):
"""Process incoming packets irrespective error condition."""

def decode_data(self, data):
"""Decode data."""
if len(data) > 1:
Expand All @@ -56,77 +50,46 @@ def decode_data(self, data):
return {"slave": uid, "fcode": fcode}
return {}

def checkFrame(self):
"""Check and decode the next frame.

:returns: True if we successful, False otherwise
"""
start = self._buffer.find(self._start)
if start == -1:
return False
if start > 0: # go ahead and skip old bad data
self._buffer = self._buffer[start:]
start = 0

if (end := self._buffer.find(self._end)) != -1:
self._header["len"] = end
self._header["uid"] = int(self._buffer[1:3], 16)
self._header["lrc"] = int(self._buffer[end - 2 : end], 16)
data = a2b_hex(self._buffer[start + 1 : end - 2])
return MessageAscii.check_LRC(data, self._header["lrc"])
return False

def advanceFrame(self):
"""Skip over the current framed message.

This allows us to skip over the current message after we have processed
it or determined that it contains an error. It also has to reset the
current frame header handle
"""
self._buffer = self._buffer[self._header["len"] + 2 :]
self._header = {"lrc": "0000", "len": 0, "uid": 0x00}

def isFrameReady(self):
"""Check if we should continue decode logic.

This is meant to be used in a while loop in the decoding phase to let
the decoder know that there is still data in the buffer.

:returns: True if ready, False otherwise
"""
return len(self._buffer) > 1

def getFrame(self):
"""Get the next frame from the buffer.

:returns: The frame data or ""
"""
start = self._hsize + 1
end = self._header["len"] - 2
buffer = self._buffer[start:end]
if end > 0:
return a2b_hex(buffer)
return b""

# ----------------------------------------------------------------------- #
# Public Member Functions
# ----------------------------------------------------------------------- #
def frameProcessIncomingPacket(self, single, callback, slave, _tid=None, **kwargs):
"""Process new packet pattern."""
while self.isFrameReady():
if not self.checkFrame():
def check_frame(self):
"""Check and decode the next frame."""
start = self._buffer.find(self._start)
if start == -1:
return False
if start > 0: # go ahead and skip old bad data
self._buffer = self._buffer[start:]
start = 0

if (end := self._buffer.find(self._end)) != -1:
self._header["len"] = end
self._header["uid"] = int(self._buffer[1:3], 16)
self._header["lrc"] = int(self._buffer[end - 2 : end], 16)
data = a2b_hex(self._buffer[start + 1 : end - 2])
return MessageAscii.check_LRC(data, self._header["lrc"])
return False

while len(self._buffer) > 1:
if not check_frame(self):
break
if not self._validate_slave_id(slave, single):
header_txt = self._header["uid"]
Log.error("Not a valid slave id - {}, ignoring!!", header_txt)
self.resetFrame()
continue

frame = self.getFrame()
start = self._hsize + 1
end = self._header["len"] - 2
buffer = self._buffer[start:end]
if end > 0:
frame = a2b_hex(buffer)
else:
frame = b""
if (result := self.decoder.decode(frame)) is None:
raise ModbusIOException("Unable to decode response")
self.populateResult(result)
self.advanceFrame()
self._buffer = self._buffer[self._header["len"] + 2 :]
self._header = {"lrc": "0000", "len": 0, "uid": 0x00}
callback(result) # defer this

def buildPacket(self, message):
Expand Down
93 changes: 28 additions & 65 deletions pymodbus/framer/binary_framer.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -53,12 +53,6 @@ def __init__(self, decoder, client=None):
self._end = b"\x7d" # }
self._repeat = [b"}"[0], b"{"[0]] # python3 hack

# ----------------------------------------------------------------------- #
# Private Helper Functions
# ----------------------------------------------------------------------- #
def _process(self, callback, error=False):
"""Process incoming packets irrespective error condition."""

def decode_data(self, data):
"""Decode data."""
if len(data) > self._hsize:
Expand All @@ -67,76 +61,45 @@ def decode_data(self, data):
return {"slave": uid, "fcode": fcode}
return {}

def checkFrame(self) -> bool:
"""Check and decode the next frame.

:returns: True if we are successful, False otherwise
"""
start = self._buffer.find(self._start)
if start == -1:
return False
if start > 0: # go ahead and skip old bad data
self._buffer = self._buffer[start:]

if (end := self._buffer.find(self._end)) != -1:
self._header["len"] = end
self._header["uid"] = struct.unpack(">B", self._buffer[1:2])[0]
self._header["crc"] = struct.unpack(">H", self._buffer[end - 2 : end])[0]
data = self._buffer[1 : end - 2]
return checkCRC(data, self._header["crc"])
return False

def advanceFrame(self) -> None:
"""Skip over the current framed message.

This allows us to skip over the current message after we have processed
it or determined that it contains an error. It also has to reset the
current frame header handle
"""
self._buffer = self._buffer[self._header["len"] + 2 :]
self._header = {"crc": 0x0000, "len": 0, "uid": 0x00}

def isFrameReady(self) -> bool:
"""Check if we should continue decode logic.

This is meant to be used in a while loop in the decoding phase to let
the decoder know that there is still data in the buffer.

:returns: True if ready, False otherwise
"""
return len(self._buffer) > 1

def getFrame(self):
"""Get the next frame from the buffer.

:returns: The frame data or ""
"""
start = self._hsize + 1
end = self._header["len"] - 2
buffer = self._buffer[start:end]
if end > 0:
return buffer
return b""

# ----------------------------------------------------------------------- #
# Public Member Functions
# ----------------------------------------------------------------------- #
def frameProcessIncomingPacket(self, single, callback, slave, _tid=None, **kwargs):
"""Process new packet pattern."""
while self.isFrameReady():
if not self.checkFrame():
def check_frame(self) -> bool:
"""Check and decode the next frame."""
start = self._buffer.find(self._start)
if start == -1:
return False
if start > 0: # go ahead and skip old bad data
self._buffer = self._buffer[start:]

if (end := self._buffer.find(self._end)) != -1:
self._header["len"] = end
self._header["uid"] = struct.unpack(">B", self._buffer[1:2])[0]
self._header["crc"] = struct.unpack(">H", self._buffer[end - 2 : end])[0]
data = self._buffer[1 : end - 2]
return checkCRC(data, self._header["crc"])
return False

while len(self._buffer) > 1:
if not check_frame(self):
Log.debug("Frame check failed, ignoring!!")
self.resetFrame()
break
if not self._validate_slave_id(slave, single):
header_txt = self._header["uid"]
Log.debug("Not a valid slave id - {}, ignoring!!", header_txt)
self.resetFrame()
break
if (result := self.decoder.decode(self.getFrame())) is None:
start = self._hsize + 1
end = self._header["len"] - 2
buffer = self._buffer[start:end]
if end > 0:
frame = buffer
else:
frame = b""
if (result := self.decoder.decode(frame)) is None:
raise ModbusIOException("Unable to decode response")
self.populateResult(result)
self.advanceFrame()
self._buffer = self._buffer[self._header["len"] + 2 :]
self._header = {"crc": 0x0000, "len": 0, "uid": 0x00}
callback(result) # defer or push to a thread?

def buildPacket(self, message):
Expand Down
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