Re: Re-loading an XML file without memory leak

[Alberto Massari]

Hi Adelino,
when you parse a document and retrieve it from the XercesDOMParser via 
the getDocument method, the DOM tree is still owned by the parser, and 
kept in an internal pool. When the parser is deleted, all the documents 
it parsed are deleted. So, the fact that you still see the leak even 
when you delete the xmlParser object is a hint that the leak is 
somewhere else, maybe in the code that navigates the DOM tree. Are you 
sure you are not using methods like XMLString::transcode()? They 
allocates memory that you must release.
As for avoiding deleting the parser, you can also call 
xmlParser->resetDocumentPool() before the new call to parse()

Alberto

Il 10/06/14 00:16, Adelino Rocha ha scritto:
Hi,

        I'm implementing a program which reads and parses an XML file 
when starts and then I would need to read same XML file again cyclicly 
to load the same file again to load any possible change.

    Summarily what I'm doing is this based on this example 
<http://www.yolinux.com/TUTORIALS/XML-Xerces-C.html> (I skipped all 
error handling, etc):

        .....
        this->xmlParser = new XercesDOMParser();
        this->xmlErrHandler = (ErrorHandler*) new HandlerBase();
this->xmlParser->setErrorHandler(this->xmlErrHandler);
this->xmlParser->setValidationScheme(XercesDOMParser::Val_Auto);
        this->xmlParser->setDoNamespaces(true);
        this->xmlParser->setDoSchema(false);

*        this->xmlParser->resetDocument();*
*        this->xmlParser->parse(fileName);**
**        xmlDoc = xmlParser->getDocument();*

       .... read XML sections here


    if I repeat the part in bold cyclicly I'm able to re-load the xml 
file successfully but I get a memory leak. Memory keeps increasing on 
each cycle.

    I had even tried to completely destroy the xml objects like this;

    this->xmlParser->reset();
    delete this->xmlParser;
    delete this->xmlErrHandler;
    this->xmlParser = NULL;
    this->xmlErrHandler = NULL;

    and intialize them again but still have a leak

    So my question is how can I cyclicly read an xml file without 
having a memory increase on every read and without having to almost 
destroy all objects and recreate tham back again ?

     Thanks,

        Adelino.