"""Miscellaneous utility functions useful for dealing with ESIS streams."""
import re
import string
import xml.dom.pulldom
import xml.sax
import xml.sax.handler
import xml.sax.xmlreader
_data_match = re.compile(r"[^\\][^\\]*").match
def decode(s):
r = ''
while s:
m = _data_match(s)
if m:
r = r + m.group()
s = s[m.end():]
elif s[1] == "\\":
r = r + "\\"
s = s[2:]
elif s[1] == "n":
r = r + "\n"
s = s[2:]
elif s[1] == "%":
s = s[2:]
n, s = s.split(";", 1)
r = r + unichr(int(n))
else:
raise ValueError, "can't handle " + `s`
return r
_charmap = {}
for c in map(chr, range(256)):
_charmap[c] = c
_charmap["\n"] = r"\n"
_charmap["\\"] = r"\\"
del c
_null_join = ''.join
def encode(s):
return _null_join(map(_charmap.get, s))
class ESISReader(xml.sax.xmlreader.XMLReader):
"""SAX Reader which reads from an ESIS stream.
No verification of the document structure is performed by the
reader; a general verifier could be used as the target
ContentHandler instance.
"""
_decl_handler = None
_lexical_handler = None
_public_id = None
_system_id = None
_buffer = ""
_is_empty = 0
_lineno = 0
_started = 0
def __init__(self, contentHandler=None, errorHandler=None):
xml.sax.xmlreader.XMLReader.__init__(self)
self._attrs = {}
self._attributes = Attributes(self._attrs)
self._locator = Locator()
self._empties = {}
if contentHandler:
self.setContentHandler(contentHandler)
if errorHandler:
self.setErrorHandler(errorHandler)
def get_empties(self):
return self._empties.keys()
def parse(self, source):
raise RuntimeError
self._locator._public_id = source.getPublicId()
self._locator._system_id = source.getSystemId()
fp = source.getByteStream()
handler = self.getContentHandler()
if handler:
handler.startDocument()
lineno = 0
while 1:
token, data = self._get_token(fp)
if token is None:
break
lineno = lineno + 1
self._locator._lineno = lineno
self._handle_token(token, data)
handler = self.getContentHandler()
if handler:
handler.startDocument()
def feed(self, data):
if not self._started:
handler = self.getContentHandler()
if handler:
handler.startDocument()
self._started = 1
data = self._buffer + data
self._buffer = None
lines = data.split("\n")
if lines:
for line in lines[:-1]:
self._lineno = self._lineno + 1
self._locator._lineno = self._lineno
if not line:
e = xml.sax.SAXParseException(
"ESIS input line contains no token type mark",
None, self._locator)
self.getErrorHandler().error(e)
else:
self._handle_token(line[0], line[1:])
self._buffer = lines[-1]
else:
self._buffer = ""
def close(self):
handler = self.getContentHandler()
if handler:
handler.endDocument()
self._buffer = ""
def _get_token(self, fp):
try:
line = fp.readline()
except IOError, e:
e = SAXException("I/O error reading input stream", e)
self.getErrorHandler().fatalError(e)
return
if not line:
return None, None
if line[-1] == "\n":
line = line[:-1]
if not line:
e = xml.sax.SAXParseException(
"ESIS input line contains no token type mark",
None, self._locator)
self.getErrorHandler().error(e)
return
return line[0], line[1:]
def _handle_token(self, token, data):
handler = self.getContentHandler()
if token == '-':
if data and handler:
handler.characters(decode(data))
elif token == ')':
if handler:
handler.endElement(decode(data))
elif token == '(':
if self._is_empty:
self._empties[data] = 1
if handler:
handler.startElement(data, self._attributes)
self._attrs.clear()
self._is_empty = 0
elif token == 'A':
name, value = data.split(' ', 1)
if value != "IMPLIED":
type, value = value.split(' ', 1)
self._attrs[name] = (decode(value), type)
elif token == '&':
pass
elif token == '?':
if handler:
if ' ' in data:
target, data = string.split(data, None, 1)
else:
target, data = data, ""
handler.processingInstruction(target, decode(data))
elif token == 'N':
handler = self.getDTDHandler()
if handler:
handler.notationDecl(data, self._public_id, self._system_id)
self._public_id = None
self._system_id = None
elif token == 'p':
self._public_id = decode(data)
elif token == 's':
self._system_id = decode(data)
elif token == 'e':
self._is_empty = 1
elif token == 'C':
pass
else:
e = SAXParseException("unknown ESIS token in event stream",
None, self._locator)
self.getErrorHandler().error(e)
def setContentHandler(self, handler):
old = self.getContentHandler()
if old:
old.setDocumentLocator(None)
if handler:
handler.setDocumentLocator(self._locator)
xml.sax.xmlreader.XMLReader.setContentHandler(self, handler)
def getProperty(self, property):
if property == xml.sax.handler.property_lexical_handler:
return self._lexical_handler
elif property == xml.sax.handler.property_declaration_handler:
return self._decl_handler
else:
raise xml.sax.SAXNotRecognizedException("unknown property %s"
% `property`)
def setProperty(self, property, value):
if property == xml.sax.handler.property_lexical_handler:
if self._lexical_handler:
self._lexical_handler.setDocumentLocator(None)
if value:
value.setDocumentLocator(self._locator)
self._lexical_handler = value
elif property == xml.sax.handler.property_declaration_handler:
if self._decl_handler:
self._decl_handler.setDocumentLocator(None)
if value:
value.setDocumentLocator(self._locator)
self._decl_handler = value
else:
raise xml.sax.SAXNotRecognizedException()
def getFeature(self, feature):
if feature == xml.sax.handler.feature_namespaces:
return 1
else:
return xml.sax.xmlreader.XMLReader.getFeature(self, feature)
def setFeature(self, feature, enabled):
if feature == xml.sax.handler.feature_namespaces:
pass
else:
xml.sax.xmlreader.XMLReader.setFeature(self, feature, enabled)
class Attributes(xml.sax.xmlreader.AttributesImpl):
def getType(self, name):
return self._attrs[name][1]
def getValue(self, name):
return self._attrs[name][0]
def getValueByQName(self, name):
return self._attrs[name][0]
def __getitem__(self, name):
return self._attrs[name][0]
def get(self, name, default=None):
if self._attrs.has_key(name):
return self._attrs[name][0]
return default
def items(self):
L = []
for name, (value, type) in self._attrs.items():
L.append((name, value))
return L
def values(self):
L = []
for value, type in self._attrs.values():
L.append(value)
return L
class Locator(xml.sax.xmlreader.Locator):
_lineno = -1
_public_id = None
_system_id = None
def getLineNumber(self):
return self._lineno
def getPublicId(self):
return self._public_id
def getSystemId(self):
return self._system_id
def parse(stream_or_string, parser=None):
if type(stream_or_string) in [type(""), type(u"")]:
stream = open(stream_or_string)
else:
stream = stream_or_string
if not parser:
parser = ESISReader()
return xml.dom.pulldom.DOMEventStream(stream, parser, (2 ** 14) - 20)