claudioc
commented
7 years ago Hi @TakahashiNZ,
and thanks for your kind words :)
Soooo... the locking problem is a very tricky one and a lot of people have tried fixing it and died trying (just half-joking :P)
The problem with an "hard lock", one which prevents someone to edit a page while someone else is editing the same page is the management of the "stale" lock. Consider this scenario:
- User A open a page for editing
- User B tries to edit the same page, Jingo doesn't allow
- User A doesn't do anything explicit to "unlock" the page (like save it and return to the view). She just closes the page and start watching a movie on Netflix
At this point the system is in a unstable situation and recovering from it is tricky. As far as Jingo is concerned the page is still "locked", and User B is still unable to access it.
Jingo could automatically remove locks than are older than... what? One hour? One day? So User B won't be able to edit that page for so long. At this point someone will come asking for a system to FORCE the clearing of locks "If I know what I am doing, I'd like Jingo to remove that lock because I say so"... and so on and so forth.
Not to mention that at the moment the locking mechanism is in memory, so when the server is restarted all the lock will be cleared and this will happen:
- User A opens the page XXX for editing
- The server is restarted
- User B opens the page XXX for editing (and she can, because Jingo locks are not there anymore)
- User A tries to save her changes... boom, Jingo won't allow to save because now User B has the lock
This means that the locking system needs to be moved out from memory to the file system, using a lock file. But I know that people runs Jingo in multiprocess which means that at that point I'd need to consider multiple processes trying to access the same file...
As you see, locking is easy to explain, hard to implement.
watashiarc
FranklinYu
Hi Claudioc,
Firstly can I say thanks for all the hard work you have put into this project, it looks really good.
Secondly, I have read through a number of the issues on here and I can see that you are not keen on gold-plating jingo as you are worried about it getting hard to maintain - I completely understand and support your position.
Bearing that in mind, I was wondering if you would consider including a config option that would prevent users from editing a page if another user was already editing it? I see that you currently get a warning, I just want a way to make that warning physically stop you from trying to edit the page.
Secondly, would you consider a config option that added a warning when a user opened multiple sessions, I've noticed if the same user starts editing a page in two different sessions then it is easy to overwrite work.
Thanks for your time and consideration,
cheers James