Make "Checking" a Priority Over Downloading?

[Hossy]

I'm new to SABnzbd (and I love it btw)... I was wondering about the check before download option. I definitely have it enabled, but I noticed it only checks the currently active queue item. If there a way to have SABnzbd prioritize "checking" over downloading? This would allow me to quickly filter out queue items with missing articles so I can find/choose alternate NZBs to get (as can sonarr).

[jcfp]

For some people, minimizing bandwidth use is crucial (satellite or similar pay-per-gb connectivity) which is where the pre-check comes in. Unfortunately, running the pre-check long before starting the actual download would defeat its very purpose, as articles could be removed from the server in the meantime. First checking all queued jobs before starting any downloading could very well have that effect, especially since many server are rather slow to respond to the type of inquiry the pre-check uses.

For almost all other cases - unless your internet connection has some kind of medieval traffic volume caps - you're probably be better off with the 'abort jobs that cannot complete' approach that checks job health in real time while downloading. Added advantage is that it can look at the actual downloaded data rather than having to rely on whether a server claims to have a certain article, which may still be damaged or otherwise unusable.

[Hossy]

running the pre-check long before starting the actual download would defeat its very purpose, as articles could be removed from the server in the meantime.

I don't agree here. The odds are much less of the article being removed between the time you check and the time you download versus never checking. For young articles, your argument holds more merit, but I feel the benefit gained (i.e. the time saved) checking before downloading is much more valuable. This might simply come down to user preference, which is what I'm requesting here. I have heard people in the IRC channel say they prefer straight download too, so just as check before download is a preference, this could be too (or enabling one enables both).

The other problem this would solve is that "Checking" status queue items are not included in the total count or the timer. The argument was made on this that unchecked items are validated yet and aren't marked as pending download and are therefore not counted in the "to be downloaded" total. Prioritizing (or reserving one or a few connections) the checking for articles would also resolve this.

[safihre]

The precheck is not a feature we actively promote because its not reliable. We kind of wish we could remove it, but then again many users like it.
There are too many servers out there where a check lasts almost as long as real download would. And we have an unidentified bug that causes the precheck to hang the download, which we have not been able to reliablly reproduce (or fix) for more than a year now.

So to summarize, we don't want to make extra work of this feature..
But if you are a python programmer, we welcome contributions

[Hossy]

There are too many servers out there where a check lasts almost as long as real download would.

Maybe add a server-level setting that disallows precheck?

And we have an unidentified bug that causes the precheck to hang the download, which we have not been able to reliablly reproduce (or fix) for more than a year now.

So to summarize, we don't want to make extra work of this feature..
But if you are a python programmer, we welcome contributions

I don't spend forever digging into the code like you guys, but I'm willing to take a look and help if possible if you can provide more detail on the bug or point me to web link.