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