[Interest] Deleting the QNetworkAccessManager post(req, iodev) QIODevice?

[Elvis Stansvik]

2016-03-02 18:56 GMT+01:00 Jason H <jhihn at gmx.com>:
> Indeed it is, there's a couple ways to skin this cat.

Another idea, after looking at the API: You could perhaps transport
your QFile* pointer in a user attribute of the request, e.g. something
like (untested):

int CoolFileAttribute = QNetworkRequest::User;

// Sending the request, attaching the QFile* pointer to it.
QFile *f = new QFile(filename);
f->open(QIODevice::ReadOnly)
...
req.setAttribute(CoolFileAttribute, QVariant::fromValue(f));
nam.post(req, f);

// And in your slot handling the reply, get the attribute from the
corresponding request.
QFile *f = reply->request().attribute(CoolFileAttribute).value<QFile*>();
f->remove();
f->close();
delete f;

With obviously some improved naming / error handling.

Elvis

> What I settled on (so far) is since I'm using setParent(), isto iterate over
> the children and just QFile::remove() anything that can be cast as a QFile*.
> It eliminates maintaining an additional mapping. it seems that this idea of
> having a file that is to be deleted on request does not exist, except for
> QTemporaryFile which you can't explitily state the filename.
>
>> Let me expand on this, I can f->setParent(reply), but I also need to
>> delete the file from disk. If I rely on the parent/child object deletion, I
>> can't get a change to delete the file.
>>
>> > QFile *f = new QFile(filename);
>> > f->open(QIODevice::ReadOnly)
>> > ...
>> > nam.post(req, f);
>> > ...
>> >
>> > // sometime later in the finished slot:
>> > finished(QNetworkReply *reply) {
>> >
>> >  // how to close and delete f ? (The QFile object)
>
> Save the pointer somewhere when you create it, then use the saved pointer to
> close/delete it?
>
> I guess you would need to store it indexed by the request, so that you know
> which file to close/delete in your slot.
>
> Take my advice with some grain of salt, as I haven't used QNAM before. But
> it sounds like a general resource management problem.
>
> Cheers,
> Elvis
>
>