Hello Patrick, On 04.07.2013, at 12:01, Patrick Ohly <patrick.o...@intel.com> wrote:
> I just noticed one aspect of the example configs that I wasn't aware of: > syncclient_sample_config.xml: <field name="PHOTO" type="blob" > compare="never" merge="fillempty"/> > > [...] > > What was the rationale for using that mode for PHOTO? Is it for storages > which store photo data after re-encoding it? Exactly. For the mobile platforms I wrote clients, I never had an address book which did not somehow mangle (re-encode, resize, etc.) the data. > With such a storage, the > comparison would yield a false "field is different", causing unnecessary > writes. Yes. > But with a storage that stores the data as-is, comparing it is > better (IMHO), because modified data actually gets stored. The downside > is that comparisons become more expensive. That's another reason. Comparison causes the BLOB contents to be pulled from storage (server side), which can be quite expensive. > Speaking of comparisons, with EDS this is slightly tricky. Inlined data > gets replaced with a file reference, so what the comparison really needs > to do is not comparing > "file:///tmp/testing/temp-testpim/data/evolution/addressbook/pim-manager-testsync-testcontacts-foo/photos/pas_id_51D53D1800000001_photo-file1.image%252Fjpeg" > against the binary data in the incoming item, but rather the content of that > file. > > I probably need to write a <comparescript> for that, right? In that case > compare="never" may be the right thing to do again, but I am not sure. There's a compare="script" for that (might not be in the docs because that was added later, if I correctly remember somehow related to SyncEvolution...) > Won't it lead to the situation again where MERGEFIELDS() incorrectly not > marks an item as changed even though it was? I haven't verified in the code right now, but I think that's what the "script" mode was supposed to avoid. Best Regards, Lukas _______________________________________________ os-libsynthesis mailing list os-libsynthesis@synthesis.ch http://lists.synthesis.ch/mailman/listinfo/os-libsynthesis
