from pycsdr.types import Format from csdr.module import ThreadModule import pickle import logging logger = logging.getLogger(__name__) FEND = 0xC0 FESC = 0xDB TFEND = 0xDC TFESC = 0xDD class KissDeframer(ThreadModule): def __init__(self): self.escaped = False self.buf = bytearray() super().__init__() def getInputFormat(self) -> Format: return Format.CHAR def getOutputFormat(self) -> Format: return Format.CHAR def run(self): while self.doRun: data = self.reader.read() if data is None: self.doRun = False else: for frame in self.parse(data): self.writer.write(pickle.dumps(frame)) def parse(self, input): for b in input: if b == FESC: self.escaped = True elif self.escaped: if b == TFEND: self.buf.append(FEND) elif b == TFESC: self.buf.append(FESC) else: logger.warning("invalid escape char: %s", str(input[0])) self.escaped = False elif b == FEND: # data frames start with 0x00 if len(self.buf) > 1 and self.buf[0] == 0x00: yield self.buf[1:] self.buf = bytearray() else: self.buf.append(b)