On Fri, Nov 25, 2005 at 03:51:28PM +0100, Jean-Marc Lasgouttes wrote: > > I think the change of container from list to vector for ParagraphList > is putting us in a bad situation. Remember the weird bug I had to > solve with DEPM a few weeks ago: everytime you insert a paragraph in a > document, all subsequent paragraphs are cloned and deleted because > they have to move. > > But the situation seems to be worse. Launch LyX and load > Help>Introduction. See how the first paragraph has id 262. This > probably means that the whole document has been > allocated/deallocated/reallocated just be loading it. Strange.
std::vector<>::push_back copies its items when resizing is necessary. We could faily simple work around coping actual paragraph contents by either using some std::vector<some_ref_counted_ptr<Paragraph> > instead of std::vector<Paragraph>, or by implementing some container on top of std::vector<Paragraph> that forwards most functions but uses a custom push_back that uses 'swap' on the contents instead of copying it when resizing. > Now, in Document>Settings, change the textclass to article. This gives > 3 errors, since the chapter headings have been changed to Standard. > But the error list does not work: it searches for id 994 (which was > 266 before switching class: document allocated three more time), but > 994 does not exist anymore, it is 1258 already :) I think paragraph ids are an anachrnism. We have stable(!) doc iterators nowadays, so positions could be indicated by those. > My problem is that I do not know where and why this happens... But > this cannot be good for performance or memory fragmentation anyway. > > So, would it still be time to go back to std::list or something else? This woul require reworking the doc iterator stuff as this relies on fast access using integer offsets. > Can we have a vector of share_ptr<Paragraph> or some other wicked > construct? This would be the first option mention above. I'd personally prefer the second. Andre'
