Buffer handling is now completely moved to the worker. Instead of moving data around all the time, the worker is responsible for buffer handling. When reads happen, the data that is read is used directly from the worker and its buffer is updated. With the previous approach it was possible, that transfers never completed. It was possible, that new data was read between calls of bytesAvailable and read and the availability of that data was never communicated to the user. If a read that does not read all the data happens, we signal, that there is still data available, so that the user is notified about that fact. At the same time we avoid unnecessary readyRead calls by blocking them until a read happens. To make future debugging sessions easier, categorized logging (including verbose) was added to the socket engine. Task-number: QTBUG-65556 Change-Id: I12020ffcccf8eb3efec9c36dc5b0e6c0ebef7eb5 Reviewed-by: Andre de la Rocha <andre.rocha@qt.io> Reviewed-by: Maurice Kalinowski <maurice.kalinowski@qt.io>