Read JSON WITHOUT readAll()

[fem_dev]

Until now, I'm reading my JSON files using:

QFile file(file_path);
if(!file.open(QIODevice::ReadOnly)){
    qDebug() << "Failed to open " << file_path;
    exit(1);
}

QTextStream file_text(&file);
QString json_string = file_text.readAll();
file.close();

QByteArray json_bytes = json_string.toLocal8Bit();

auto json_doc = QJsonDocument::fromJson(json_bytes);

if (json_doc.isNull()) {
    qDebug()<<"Failed to create JSON doc.";
    exit(2);
}

if (!json_doc.isObject()) {
    qDebug()<<"JSON is not an object.";
    exit(3);
}

QJsonObject json_obj = json_doc.object();

if (json_obj.isEmpty()) {
    qDebug()<<"JSON object is empty.";
    exit(4);
}

// do some stuff

It works great, but I would like to know if is possible to replace the readAll() method and read just a single JSON node/object/array from the JSON file.
I was thinking about it because my JSON files are very big.

Maybe, something like:

QJsonObject my_node = file.magic_read().value("root").toObject().value("node_a").toObject();

Is this possible?

[Kent-Dorfman]

doubtful...the json is a document format. so, to be parsed correctly it needs to be cached somewhere. The readall() pulls the whole document into memory so that it can be parsed.