> Yes, if the same object is changed then I get the callback. But this makes > the stat calculation difficult and dependent on the number of messages in the > mailbox.
I'm still unsure to understand your problem. Do you have a small reproducible code which exposes your problem? I'm keen to either fix the documentation or the bug if it happens to be a a problem in Irmin. Thomas > > Gregory > >> On Aug 7, 2015, at 10:59 AM, Thomas Gazagnaire <[email protected]> wrote: >> >>> You are right. In this scenario there is nothing to update. But if we both >>> make changes then there is. >> >> In that case the merge will not be a fast-forward and the merge callback >> should be called. >> >> Thoma >> >>> Even if we both just add files then the stats needs to be updated, for >>> instance the message count. So if I add m1, m2 and Bob adds m3,m4 then the >>> count in each database is 2 and 2 but the merged count is 4. This is an >>> easy case and the count can be derived from the updated objects, >>> specifically from the index, which is a list of UID to the message hash >>> map. But I have to search through all of the index to figure out what was >>> deleted/added so the time will increase as the number of messages >>> increases. But then there is other statistics like recent and unseen >>> messages, the first unseen message, and the next message UID. Some of them >>> are not easy to figure out. But if I get the changes in the custom merge >>> then figuring out this statistics is straightforward and the performance >>> doesn’t depend on the number of messages in the mailbox. >>> >>> Gregory >>> >>>> On Aug 6, 2015, at 11:52 PM, Thomas Gazagnaire <[email protected]> >>>> wrote: >>>> >>>>> I think it might be useful for setting different mailbox's merge >>>>> profiles. But it is definitely very helpful and easier in updating >>>>> mailbox’s overall statistics like message count, recent messages, etc. >>>>> I’m actually not sure if I can use the changed objects only to derive >>>>> this statistics. The change to the API seems fairly small - it could be >>>>> an optional argument to the merge that indicates whether to use >>>>> ‘fast-forward’ or not and set to true by default. >>>> >>>> But I'm not sure to understand why a non fast-foward merge means. >>>> >>>> ie, let's say your database is in state x. The Bob forks it. Then you do >>>> some operation, and you are in a state y. Then Bob wants to merge. The >>>> merge callback will be called with old=x, x and y. As Bob didn't do any >>>> operation, the merge result is simply y. There is no stats to update as >>>> Bob didn't do anything (otherwise it wouldn't have stayed in state x). Do >>>> you have a concrete scenario where you still have to update some stats >>>> even if Bob didn't do anything? >>>> >>>> Thomas >>>> >>>> >>>>> >>>>> Gregory >>>>> >>>>>> On Aug 6, 2015, at 5:09 PM, Thomas Gazagnaire <[email protected]> >>>>>> wrote: >>>>>> >>>>>>> As far as I can tell from the code, cases when lca=t1 or lca=t2 are >>>>>>> handled by the ‘default' method so the custom defined merge is not >>>>>>> called. >>>>>>> But this was not always the case - in some revisions of ir_merge.ml the >>>>>>> ‘default’ ( in method biject’ ) was not called first : >>>>>>> Commits on Mar 4,Feb 6, Feb 2 2015 - call ‘default’ first >>>>>>> Commits on Jan 27, Jan 26, Jan 12 2015 - don’t call ‘default’ first >>>>>>> Commits on Jan 11 2015, and older - call ‘default’ first >>>>>> >>>>>> if the lca is the same as one of the 2 values then yes, we are now doing >>>>>> a "fast-forward" merge ie. we pick the most recent version (basically, >>>>>> that means that the other versions is late). Are you sure that you want >>>>>> to do a merge in that case? >>>>>> >>>>>> Thomas >>>>>> >>>>>> >>>>>> >>>>>>> >>>>>>> So it changed back and forth. I am not sure what the intention was but >>>>>>> I think having the ability to custom-handle all cases is preferred? >>>>>>> >>>>>>> Thanks, >>>>>>> Gregory >>>>>>> >>>>>>>> On Aug 5, 2015, at 11:45 PM, Thomas Gazagnaire <[email protected]> >>>>>>>> wrote: >>>>>>>> >>>>>>>>> I have a question about Irmin merge call back for user-defined >>>>>>>>> contents. It appears that merge is only called for the content that >>>>>>>>> was changed but not added or deleted. Is it possible to have it >>>>>>>>> called for all actions? >>>>>>>> >>>>>>>> It's supposed to be called even when one of the version is added or >>>>>>>> deleted. In that case one of the values will be a None. That's why the >>>>>>>> merge callback [1] takes an option type. Notice that you should not >>>>>>>> normally have None for all the 3 elements of the 3-way merge. >>>>>>>> >>>>>>>> Best, >>>>>>>> Thomas >>>>>>>> >>>>>>>> [1] http://mirage.github.io/irmin/Irmin.Contents.S.html#VALmerge >>>>>>>> >>>>>>> >>>>>> >>>>> >>>> >>> >> > _______________________________________________ MirageOS-devel mailing list [email protected] http://lists.xenproject.org/cgi-bin/mailman/listinfo/mirageos-devel
