On Fri, Feb 22, 2008 at 04:46:44PM -0500, rgheck wrote: > Andre Poenitz wrote: >> Does anybody remember why we use a shared pointer and not an index into >> the global list of textclasses? > > Yes, that was my doing.
So this is a recent change? > It used to be a list of textclasses, when these were static objects. > But now the textclasses that are in use are dynamic objects: They get > changed as modules are loaded and unloaded. The shared pointer is > there because of the following situation: You cut some text, and then > close the document. The textclass needs to stay with the cut text, so > it can't just live with the document. > > Now we could have some global list of dynamic text classes, and Abdel > suggested this possibility after I'd already implemented it the other > way. The only downside to this is that it might waste memory. > You don't have to keep the textclasses around forever; only so long as > something's using them. So if you had the global list and opened a > document, and then loaded a module, you'd have two entries in the > global list, since you can't tell (or, at least, it's very hard to > tell) whether some bit of cut text has a reference to the old one. And > if you do this a few times, you can end up with several of these lying > around. So basically we use the shared pointer to potentially save a few kBytes for users opening/closing lots of different documents in a single session? > Now they're probably not all that huge, so maybe that doesn't matter > so much. But that was my thinking at the time. Hm, ok... I see your point, but I think I consider the 'worst case scenario' described a really rare case and rather have the index based solution. [Apart from that, if need arises there could be some 'garbage collection' of unused classes without much effort...] Andre'
