On Fri, Jan 24, 2014 at 2:22 PM, Branko Čibej <br...@wandisco.com> wrote: > On 24.01.2014 14:09, Stefan Sperling wrote: > > On Thu, Jan 23, 2014 at 01:11:36PM +0000, Kuno Meyer wrote: > > Hi all, > > One of the repositories I am working with has a long list of "svn:external" > links. This has a major impact on working copy update performance, since > each external link needs an additional roundtrip to the (painfully slow) SVN > server. So it can easily be the case that the update of the main working > copy (several 10k files) is done in <10 seconds, but querying the 40-45 > external repository takes another 60-80 seconds. > > However, since the external links are all fixed to a specific revision > number, and since the working copy knows its current reference revision > number, why do you have to roundtrip to the SVN server anyway? Wouldn't it > be safe to omit the server roundtrip, under the assumption that a published > revision is immutable? > > Yes in principle, but the external working copy must have been tampered > with. E.g. it must not contain mixed revisions. > > And non-pinned externals inside of pinned externals need to be handled > properly. > > There may be more restrictions I'm not aware of right now. > Many retrictions can be determined cheaply by querying the external > working copy's database, but some may need a disk crawl. > > At least in my case, this would result in a speedup of "svn update" of > factor 5-15 in the case of no or only a only few changesets to download. > > Please file an ENHANCEMENT issue for this. I like the idea. > > > I think we'd get much better performance if we parallelized externals > handling. I'm not aware of any reason (apart from serializing notifications) > why this wouldn't work, as long as the externals have separate working > copies.
That would be a more general improvement, making all externals updates faster (not only the pinned ones). However, "doing no work" should still be faster than "doing N things in parallel" :-), so that would be an additional saving for externals I guess. -- Johan
