QDataStream memory overflow [solved]

Francknos

Hi everybody,

I have a problem in my database when I import some data.
After checking my writting function which use datastream I found something that makes me think the problem is about memory overflow of my datastream.
Here is my code:
@QDataStream out(&file);
out.setVersion(QDataStream::Qt_5_2);
out << _missionsEx.size();
for(int i=0; i<_missionsEx.size() ;i++)
{
out << _missionsEx[i];

for(int j=0; j< _missionsEx[i]._porte[0]._cylindre.size() ;j++)
for(int k=0; k< _missionsEx[i]._porte[0]._cylindre[j]._axe.first()._aquisition.size() ;k++)
{
    if(_missionsEx[i]._porte[0]._cylindre[j]._axe.first()._aquisition[k]._bscan.isNull())
            qDebug()<< "NULL" <<_missionsEx[i]._porte[0]._cylindre[j]._axe.first()._aquisition[k]._id;
}

}@

My class MissionBDD is pretty big it contains several classes and the class Aquisition contains several images (_bscan) (about 2,5 Mo).
If I try to write mission which contains 150 images.
I have 53 images which are really written the others are "White".

Someone can help me to fix this problem ?
Thanks

Francknos

Someone can help me ?

SGaist

Hi,

Pretty strange… You could try flushing the QDataStream in between two _missionsEx.

Also, are you sure that everything is generated correctly ?

Francknos

Everything is generated correctly i'm sure because I work with this data.
I'd like try a "flush" between missions but there is no function flush or something like that in QDataStream.

thk for your reply.

SGaist

Sorry, it's in QTextStream.

One thing you could do is check the status of the stream between two writes

Francknos

The status is everytime ok.
All "missions" are done in the loop but I think the size of data is to big.
about 1,6 Go in RAM.
There is no error in writing, it's when I want import these data that the reader write first data (about 50 -55 missions).

SGaist

32bit application ?

Francknos

Yes I would like to do in 64 but i used a library in 32.

SGaist

I wonder if you're not hitting the 2GB memory limit somehow, but that should rather kill your application AFAIK.

giesbert

But writing or reading files with more then 2 GB should not hurt unless you allocate everything in memory, shouldn't it?

SGaist

AFAIK, it should not.

However I wonder what might happen if you are reaching the limit of available memory without allocating enough to make the OS decide to kill your application.

giesbert

What about: try it out? :D

Francknos

Hi Thanks for your reply,

For information, I think the OS block the use of memory at about 2Go.
I have a lot of memory (64Go). But my application use 1.6Go at maximum.

SGaist

It's because your application is 32bit, the max memory size it can use is 2GB even if you computer had terabytes available

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QDataStream memory overflow [solved]