66 lines
2 KiB
Python
66 lines
2 KiB
Python
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class SerialException(Exception):
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pass
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class FileLike:
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"""An abstract file like class.
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This class implements readline and readlines based on read and
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writelines based on write.
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This class is used to provide the above functions for to Serial
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port objects.
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Note that when the serial port was opened with _NO_ timeout that
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readline blocks until it sees a newline (or the specified size is
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reached) and that readlines would never return and therefore
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refuses to work (it raises an exception in this case)!
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"""
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def read(self, size): raise NotImplementedError
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def write(self, s): raise NotImplementedError
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def readline(self, size=None, eol='\n'):
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"""read a line which is terminated with end-of-line (eol) character
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('\n' by default) or until timeout"""
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line = ''
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while 1:
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c = self.read(1)
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if c:
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line += c #not very efficient but lines are usually not that long
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if c == eol:
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break
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if size is not None and len(line) >= size:
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break
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else:
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break
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return line
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def readlines(self, sizehint=None, eol='\n'):
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"""read a list of lines, until timeout
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sizehint is ignored"""
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if self.timeout is None:
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raise ValueError, "Serial port MUST have enabled timeout for this function!"
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lines = []
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while 1:
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line = self.readline(eol=eol)
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if line:
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lines.append(line)
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if line[-1] != eol: #was the line received with a timeout?
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break
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else:
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break
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return lines
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def xreadlines(self, sizehint=None):
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"""just call readlines - here for compatibility"""
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return self.readlines()
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def writelines(self, sequence):
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for line in sequence:
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self.write(line)
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def flush(self):
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"""flush of file like objects"""
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pass
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