TelescopeControl log files don't get contents until closed

[10110111]

I was debugging an Lx200 server, using Stellarium as a client, and it was very puzzling to have an empty log_TelescopeServer1.txt all the way until I finally closed Stellarium.

It appears that the log system is based on QFile that's opened with QFile::Unbuffered, on top of which a QTextStream is layered, and this one is always buffered. Previously the log output was done with endl at the end, which, according to the docs, writes \r\n on Windows and \n on other platforms (provided the file is opened with QFile::Text, which it is), after which it flushes the stream. But since e8d67bc these endl were replaced by a kludge of StelUtils::getEndLineChar(), which of course only writes the line ending but doesn't flush.

Now, what problem was this replacement meant to solve? The endl should've been doing its job well enough, no?

[gzotti]

I have always wondered about these separate logfiles which look like legacy from the early 2000s. Why is logfile category not enough? There is really much legacy in the Telescope plugin, and we could really use help from another user with developer skills who cares about optimizing telescope support for the late 2020s: AltAz goto scopes, DIY pointing gizmos on USB powered Arduinos/RPiZeros, ...

[10110111]

Why is logfile category not enough?

I wondered about the same. One reason might be that there's a separate file for each telescope, which makes the static categories unsuitable for this.

[gzotti]

Yes, in theory. How many users operate more than 1 telescope? Or more concrete, track down software bugs or technical hardware issues (broken cables?) with more than one at a time? (I can imagine running a few scopes simultaneously for imaging, when all are working well.) We could extend the log categories to the separate subtypes, but of course not by configurable names. The categorized log messages could be enhanced to prepend telescope name for easier filtering. (And often by clearer messages what the actual problem is. In the Arm64 branch I separated warnings from debug noise as first step, but did not even look into the separate logs.)

[10110111]

Yeah, I think simply prepending telescope number (what's called "slot" now) to the log output is sufficient. All this custom logging machinery is really confusing and generally not very useful.

[gzotti]

Please wait for the win/arm64 branch being merged before further changes.