Avoid creating circular references between the ExpatParser and the
ContentHandler. While GC will eventually clean up, it can take longer than
normal for applications that create a lot of strings (or other immutables)
rather without creating many containers.
This closes SF bug #535474.
diff --git a/Lib/xml/sax/expatreader.py b/Lib/xml/sax/expatreader.py
index 5473b36..2732ab0 100644
--- a/Lib/xml/sax/expatreader.py
+++ b/Lib/xml/sax/expatreader.py
@@ -26,6 +26,43 @@
AttributesNSImpl = xmlreader.AttributesNSImpl
import string
+import weakref
+
+# --- ExpatLocator
+
+class ExpatLocator(xmlreader.Locator):
+ """Locator for use with the ExpatParser class.
+
+ This uses a weak reference to the parser object to avoid creating
+ a circular reference between the parser and the content handler.
+ """
+ def __init__(self, parser):
+ self._ref = weakref.ref(parser)
+
+ def getColumnNumber(self):
+ parser = self._ref()
+ if parser is None or parser._parser is None:
+ return None
+ return parser._parser.ErrorColumnNumber
+
+ def getLineNumber(self):
+ parser = self._ref()
+ if parser is None or parser._parser is None:
+ return 1
+ return self._parser.ErrorLineNumber
+
+ def getPublicId(self):
+ parser = self._ref()
+ if parser is None:
+ return None
+ return parser._source.getPublicId()
+
+ def getSystemId(self):
+ parser = self._ref()
+ if parser is None:
+ return None
+ return parser._source.getSystemId()
+
# --- ExpatParser
@@ -49,7 +86,7 @@
self._source = source
self.reset()
- self._cont_handler.setDocumentLocator(self)
+ self._cont_handler.setDocumentLocator(ExpatLocator(self))
xmlreader.IncrementalParser.parse(self, source)
def prepareParser(self, source):