I've been playing around with different sorting methods and have noticed that the naive way to sort a QStringList with localeAwareCompare is atrociously slow on my system (64bit Linux, German locale - up to a thousand times slower than using the lessThan-operator). While a locale aware sorting is obviously inherently slower than basically a memory compare I believe we can do a lot better.
As many desktop application need to sort lists of strings in a locale aware fashion, I think Qt should provide something to do this efficiently. In fact, there are already two places in Qt that would benefit from faster sorting (QDir and QSortFilterProxyModel are currently using the slow naive method). The most simple approach to speed this up is to generate the ICU sort keys for all the strings and sort the list with them. But this method can be pretty inefficient for longer strings and uses a lot of RAM. A more adaptive method would be to generate (and cache) on each string comparison only the sort key prefix necessary to distinguish the two strings. Or we could go all out - I have an idea for a parallelizable bucket/merge sort combination ;) So my questions: Is there interest in (or even plans for) something like this? Also, I can hardly believe I'm the first to do something about this. Does anyone know of a library that deals with the problem already? Anyway, if there is interest, I can upload my small benchmark to the Qt bug tracker. Best regards, Zeno Endemann _______________________________________________ Development mailing list Development@qt-project.org http://lists.qt-project.org/mailman/listinfo/development
