# GT 24Mai2003 
import xml.sax
import warnings
from zlib import crc32

#
# class XmlHandler ############################################
#

class XmlHandler(xml.sax.ContentHandler):
	def __init__(self):
		xml.sax.ContentHandler.__init__(self)

	def startElement(self, name, attrs):
		self.myData = ""
		if name in ("outer", "inner", "crc"):
			pass
		else:
			warning.warn("Unexpected tag "+name, RuntimeWarning)

	def endElement(self, name):
		if name == "outer":
			pass
			
		elif name == "inner":
			self.myInner = self.myData
			
		elif name == "crc":
			if int(self.myData) != crc32(self.myInner):
				warnings.warn("checksum error "+self.myInner)
		else:
			warning.warn("Unexpected tag "+name, RuntimeWarning)

	def characters(self, data):
		self.myData += data # remember for later processing

#
# main #############################################################
#

def main(filename):
	xh = XmlHandler()
	xml.sax.parse(filename, xh)

#
# __main__ #########################################################
#
if __name__ == "__main__":
	import sys
	if len(sys.argv) == 2:
		main(sys.argv[1])
	else:
		print "usage: readTest filename"