Concurrently get contents of a folder

[Akito_Kami]

I have an app which reads a folder structure containing files which are stored in the lowest level. I have a function that gets the contents of the path specified. I would like to concurrently run this function for every folder and generate a struct of each folder showing Name -> Date -> File List.

Struct FSModel {
    QString name;
    QMap<QString, QVector<QString>> datedContents;
}

QVector<QString> getContents(const QFlag &type, const QString &path, void(*process)(QVector<QString>), int count=0)
{
    QDir dir(path);
    QVector<QString> collection;
    QStringList temp = dir.entryList(QDir::NoDotAndDotDot, type);
    for (QString& str : temp)
    {
        collection << str;
        count += 1;
    }
    process(collection);
    return collection;
}

In the constructor,I have tried to call QtConcurrent::mappedReduced, to return a QPair<QString, QVector<QString> but receive an error for QFuture<QPair<...>> not being a scalar type. How should I load the folder structure into memory?

[jsulm]

@Akito_Kami Take a look at http://doc.qt.io/qt-5/qfilesystemwatcher.html

[Akito_Kami]

@jsulm I don't need to watch folders/files. I need to get a model of the folder contents.

[jsulm]

@Akito_Kami Then maybe http://doc.qt.io/qt-5.7/qfilesystemmodel.html ?

[VRonin]

@Akito_Kami said in Concurrently get contents of a folder:

in the constructor,I have tried to call QtConcurrent::mappedReduced

could you show us your code?

[Akito_Kami]

@VRonin It didn't work because of QFuture requiring a scalar type and not being able to convert to non scalar type. I initially tried to return a QPair<QString, QVector<QString>> since QMaps didn't work but to no avail.

On another note, how do you pass QDir::Filter which is either QDir::Files or QDir::Dirs to a function? I keep getting "error: no matching function for call to 'QDir::entryList(QDir::Filter&, QDir::Filter)'
QStringList temp = dir.entryList(type, QDir::NoDotAndDotDot);"

[jsulm]

@Akito_Kami

QStringList QDir::entryList(Filters filters = NoFilter, SortFlags sort = NoSort) const

so

QStringList temp = dir.entryList(QDir::Files | QDir::NoDotAndDotDot);
// or type if type holds QDir::Files or QDir::Dirs
QStringList temp = dir.entryList(type | QDir::NoDotAndDotDot);

[Akito_Kami]

@jsulm Fixed it with changing QDir::Filters to QDir::Filter which is what I had before I tried QFlags but works now?

[jsulm]

@Akito_Kami Is it a question? QDir::Filter is the enum yes.

[Akito_Kami]

@jsulm No it's not. Just wondering why it didn't work before.