Re: GetBuffer Problem

From:
"Tom Serface" <tom.nospam@camaswood.com>
Newsgroups:
microsoft.public.vc.mfc
Date:
Wed, 28 Mar 2007 07:03:49 -0700
Message-ID:
<#iQxsHUcHHA.4656@TK2MSFTNGP06.phx.gbl>
Hi Marcos,

I'm not sure what DoReplaceStrings does (I can't even find it on Google),
but why not just assign the data to the string. If you want to replace part
of the string you could use CString::Replace() to change the string. It
also looks tome like you are replacing the string inside of CString s 'aux'
with a pointer to its same data so I'm not sure why you're even doing it at
all. I don't see anywhere in this code where you use the CStringList
parameters.

My guess is you're running into some sort of reference counting problem
confusing the class by adding back the same string, but creating a new copy
of it. Still, I'm wondering why you're even doing this since that same data
is already in the original CString.

Tom

"Marcos Aguiar" <marcos.listacs@gmail.com> wrote in message
news:1175087755.633469.172520@r56g2000hsd.googlegroups.com...

Hi Everyone,
Here it goes:

void CMyObj::ReplaceStringsInList(BOOL bIsExpression, CString& s,
CStringList&, CStringList&)
{
    LPTSTR aux;
               try{

                aux = s.GetBuffer(256 * 1024 + 1);

            }catch(CException *e){
                aux = NULL;
                TCHAR sz[255];
                _stprintf(sz, _T("%d"), errno);
                TRACE1("%s", sz);
        }
        if( aux != NULL ){
            ::DoReplaceStrings(bIsExpression, CString((LPCTSTR)s), aux );
            s.ReleaseBuffer();
    }

}

I didn't have the try catch before, and it was blewing up my
application. I do a lot of calls because I want to change a property
inside a object in a collection that may itself have another object
collection and so on. If the propertys have the same value, this value
is replaced by the new one. It's a pretty complex model. But the
recursion is fine, there is no circular dependency. Something weird
also happened when I was debbuging. When I did it step by step on the
interation that was not allocating memory, it didn't raise a exception
and allocated memory fine. That's why I started to get suspicious
about the frequency of allocation as the source of the problem, but I
couldn't find any documentation about it.

Thanks
 Marcos

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