On Tue, Jun 26, 2012 at 3:17 PM, Hyrum K Wright <hyrum.wri...@wandisco.com> wrote: > On Sun, Jun 24, 2012 at 6:09 PM, Vladimir Berezniker <v...@hitechman.com> > wrote: >> Hi All, >> >> I have been taking a peek at ev2 code to see what it would take for JavaHL >> implementation and I have following questions that do not seem do be covered >> by the docs: >> >> * svn_ra__get_commit_ev2() takes svn_cancel_func_t as a parameter, however >> session already has a cancellation callback specified in the >> svn_ra_callbacks2_t structure. What is the relationship between the two? >> Is one of these going away? > > I've not looked at the session struct, but can explain a bit about the > reason get_commit_ev2() takes a cancellation func/baton. > Historically, we've had a number of places where we'd wrap an editor > with a cancellation editor, which was just a pain. Ev2 folds the > (optional) cancellation editor into the editor itself. Understood > > My guess is that in most places, the session cancellation callback and > the one provided to get_commit_ev2() will be the same, though they > will be invoked in different places.
But how come other ra functions grab the cancellation callback from the ra session, but ev2 editor wants to get one passed directly to it rather than taking one from the ra session? > >> * svn_editor_add_directory() function requires that >> "const apr_array_header_t *children" and "apr_hash_t *props" parameters >> cannot be NULL, instead an empty structure should be passed. However, >> svn_editor_alter_directory() permits the same parameters to be NULL. >> What is the reason for this difference? > > In the case of add_directory(), callers MUST provide the list of > children and properties, since they are not known a priori. However, > in the case of alter_directory(), if there are no changes, a NULL > parameter may be used to indicate that. (It would be rather pointless > to require clients to fetch the list of children and then replay them > back to the server if there are no changes.) > I think I was not very clear in asking the question. Lets take following use cases. 1) Add new directory without any children, with 1 property 2) Alter a directory, by adding 1 property In both cases caller needs to indicate that there are 0 children at play. In call to add_directory() 0 size array means no affected children. In call to alter_directory() NULL means no affected children. Or another way, what is the behavior of alter_directory() if passed a 0 size children array rather than NULL? Thank you for your time, as I might just being dense here. Vladimir
