C / C++ / MFC

CPallini5-Jun-07 23:07

CPallini

5-Jun-07 23:07

Anurag Gandhi wrote:
It seems that CString doesn't work beyond 30,000 characters of length.

Actually the following code snippet:

CString sTest="";
for (int i=0; i<50000; i++)
{
  sTest+="*";
}
int iLen = sTest.GetLength();

works fine on my system.

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

Matthew Faithfull5-Jun-07 23:09

Matthew Faithfull

5-Jun-07 23:09

At those sort of links I'd be tempted to say just use several CStrings Big Grin | :-D

Seriously though CString is going to be horribly inefficient with this amount of data as it's constantly reallocating and moving stuff around. You're either writing some serious text processing here in which case I would do my own text buffer with the required functionality or you're in need of breaking up that CString. Have a look at CStringArray if MFC is your thing.
If things get difficult when they shouldn't be then often you just need to do more of the easy stuff. It's one of the reasons I love programming. Laugh | :laugh:

Nothing is exactly what it seems but everything with seems can be unpicked.

Anurag Gandhi5-Jun-07 23:50

Anurag Gandhi

5-Jun-07 23:50

Thanks to both.

The problem was not with CString, it was something else. Well, thanks a lot.

Anurag Gandhi.

David Crow6-Jun-07 2:59

Huge increase in memory usage with Debug binary [modified]

6-Jun-07 2:59

Anurag Gandhi wrote:
It seems that CString doesn't work beyond 30,000 characters of length.

CString has no such limitation.

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

mandanani5-Jun-07 22:34

Re: Huge increase in memory usage with Debug binary

5-Jun-07 22:34

Hi All,

I added virtual copy constructor for quite a few classes. I see a drastic difference in memory usage before and after the change, that too only with debug binary. When I ran release binary the memory usage is almost the same.

Here below are the memory statistics

Before Change
-------------
Peak Mem Usage & VM Size for Debug binary is: 15 MB & 10.5 MB
Peak Mem Usage & VM Size for Release binary is: 11.5 MB & 8 MB

After Change
-------------
Peak Mem Usage & VM Size for Debug binary is: 29 MB & 26 MB
Peak Mem Usage & VM Size for Release binary is: 12 MB & 8.5 MB

Is it the case virtual copy constructor makes debug binary use more space?

Thanks and Regards,
Nani

-- modified at 4:39 Wednesday 6th June, 2007

David Crow6-Jun-07 3:03

Re: Huge increase in memory usage with Debug binary

6-Jun-07 3:03

mandanani wrote:
I added virtual copy constructor...

How?

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

mandanani6-Jun-07 18:14

Re: Huge increase in memory usage with Debug binary

6-Jun-07 18:14

You mean in what way I added virtual copy constructor?

Here below is the code:

CValueObjectBase* CashflowVO::clone() const
{
return new CashflowVO(*this);
}

Here CValueObjectBase is base class and clone method is pure virtual method. The clone method of derived class copies the object and return base class pointer.

Hope I have provided the right information.

Cyrilix6-Jun-07 4:24

Cyrilix

6-Jun-07 4:24

I thought constructors couldn't be virtual, since they require complete information to create the object.

Re: Huge increase in memory usage with Debug binary

David Crow6-Jun-07 4:57

Re: Huge increase in memory usage with Debug binary

6-Jun-07 4:57

Cyrilix wrote:
I thought constructors couldn't be virtual, since they require complete information to create the object.

You are correct, hence my question to him as to how he managed to pull this off.

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

mandanani6-Jun-07 18:29

Re: Huge increase in memory usage with Debug binary

6-Jun-07 18:29

Actually, this is a method which does the job of constructor.

Here below is the code snippet:

class CashflowVO derived from CValueObjectBase
>>>>>>>>>>>>>>>>>>>>
CValueObjectBase* CashflowVO::clone() const
{
return new CashflowVO(*this);
}
>>>>>>>>>>>>>>>>>>>>

Clone methos is pure virtual method in CValueObjectBase. The below code calls the respective clone method of derived object. Here pValueObjectBaseOrg can be any of the derived class, but respective object is getting copied and pointer is returned to pValueObjectBase.

>>>>>>>>>>>>>>>>>>>>
CValueObjectBase * m_pValueObjectBase = m_pValueObjectBaseOrg->clone();
>>>>>>>>>>>>>>>>>>>>

Hope I make sense here.

Mark Salsbery6-Jun-07 5:39

Mark Salsbery

6-Jun-07 5:39

Besides the question that needs an answer (what the heck is a virtual copy constructor???)
the memory usage increase was hardly "drastic". Is there a reason you're worried about how
much memory (even if you could get an accurate measurement of it) your app is using in a
debug configuration?

Mark

"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder

Re: Huge increase in memory usage with Debug binary

mandanani6-Jun-07 18:21

Set the values of a field

6-Jun-07 18:21

Yes. The statistics I provided here are for sample data. When I ran my applicaiton with full production data the debug binary consumes 1.5 GB of virtual memory. Before the change the debug binary used to consume around 700 MB memory. There is not much difference in memory usage with release binary before and after the change.

I want to know whether virtual copy constructor adds more symbols to debug binary.

Thanks, Nani

villaa5-Jun-07 22:20

villaa

5-Jun-07 22:20

how to programmatically add the values of a apecific field in a .mdb file.(only that field is blank, the other fields are filled)
thanks

Re: Set the values of a field

Paresh Chitte6-Jun-07 0:58

Paresh Chitte

6-Jun-07 0:58

Which is the programming language are you using ?

You can use ADO to serve your purpose.

Regards,

Paresh.

Re: Set the values of a field

Hamid_RT6-Jun-07 7:55

Hamid_RT

6-Jun-07 7:55

Does Retrieving, Writing, and Creating Data in a Microsoft Access File (CDaoDatabase and CDaoRecordset)[^] helpful?

WhiteSky

Linking to ODBC.dll

Programm3r5-Jun-07 22:19

Programm3r

5-Jun-07 22:19

Hi all,

First of all I'm sorry about asking this type of question here but, after searching for 2 hours without no success and asking people on Tek Tips and DevX, I'm frustrated as hell.

How do you link to a dll (odbc32.dll) in Borland C++, I know how to do it in VS2005, but borland is another story.

Can anyone please help me??

Many Thanks
Regards,

The only programmers that are better than C programmers are those who code in 1's and 0's..... Smile | :)

Programm3r
My Blog: ^_^

Optimus Chaos5-Jun-07 22:36

Optimus Chaos

5-Jun-07 22:36

I don't know right now if there is any option dialog for this (currently working with VC++ Builder 6.0) but you can also include the #pragma preprocessor directive, assuming you have set the additional library (something like: "<installpath>\lib\psdk") path in a way, that odbc32.lib can be found:
#pragma comment ( lib, "odbc32.lib" )

Programm3r5-Jun-07 22:43

Programm3r

5-Jun-07 22:43

Thank you for the help.
Is this the way to do it? #pragma comment ( lib, "odbc32.lib" )
or is there other ways?

Thanks again Smile | :)

.
Regards,

The only programmers that are better than C programmers are those who code in 1's and 0's..... Smile | :)

Programm3r
My Blog: ^_^

Optimus Chaos5-Jun-07 22:54

Optimus Chaos

5-Jun-07 22:54

I just tried a project which links with other libs that are shipped with the source code:

It seems that you can simply add the *.lib file to your project. However I don't know if this will work with Platform SDK libraries.

Yes, this is a way that worked in my project when linking against shell32.lib. I just placed it in the source code where I needed the API call.

Programm3r5-Jun-07 23:16

Programm3r

5-Jun-07 23:16

Thanks you for the help.

Regards,

The only programmers that are better than C programmers are those who code in 1's and 0's..... Smile | :)

Programm3r
My Blog: ^_^

David Crow6-Jun-07 3:50