osd-contiki/tools/sky/serial/serialutil.py

66 lines
2 KiB
Python
Raw Normal View History

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