Tested all formats, did not happen for a reasonable complex CAS.
Am 02.09.2016 um 15:26 schrieb Marshall Schor: > Re: deserializing the same CAS twice shouldn't change the addresses; if you > have a case where it's doing that, I'll investigate (need a small test > case...). > > -Marshall > > On 9/2/2016 5:36 AM, Peter Klügl wrote: >> Same here. >> >> >> It looks like that we are now also starting to use the address, and I am >> also thinking of using it more in Ruta (internal indexing). >> >> >> Btw, I did some simple experiments lately concerning the stability of >> the addresses when using CasIOUtils. Can it happens that the addresses >> change if you just deserialize the same CAs twice without serializing it >> in between? >> >> >> Best, >> >> >> Peter >> >> >> >> Am 01.09.2016 um 19:29 schrieb Richard Eckart de Castilho: >>> FS IDs are IMHO a very useful thing. Providing out-of-band (i.e. >>> out-of-type-system) unique identifiers for feature structures facilitates >>> handling them in e.g. in editors. We use that quite a bit in WebAnno. >>> >>> In WebAnno, we do not rely on any heap arithmetics - an ID is just expected >>> to be a unique identifier. However, I could imagine cases where people >>> might rely on the ID to increment monotonically for new FSes. >>> >>> Most binary formats do not preserve the ID across a save/load cycle. >>> However, SERIALIZED and SERIALIZED_TSI *do* preserve the ID, and WebAnno >>> makes used of that. It allows to keep references to FSes without having to >>> keep the CAS in memory all the time. >>> >>> There should continue to be a V3 serialization format which preserves IDs >>> across a load/save cycle. >>> >>> I do presently not see a case where a strong similarity between V2 and V3 >>> IDs would be important. It would be nice if deserializing a V2 SERIALIZED >>> or SERIALIZED_TSI into V3 would restore the V2 IDs - I expect it to be an >>> easy thing to do. >>> >>> Cheers, >>> >>> -- Richard >>> >>>> On 01.09.2016, at 16:09, Marshall Schor <m...@schor.com> wrote: >>>> >>>> UIMA V3 implementation includes in many places extra code (takes time / >>>> space) >>>> whose goal is to make things look closer to version 2. Some of this is for >>>> interoperability with version 2 artifacts, like serialized forms. >>>> >>>> An example: in v2, many serialization forms include "references" to other >>>> Feature Structures (FSs), and for those, the encoding is the "address" in >>>> the >>>> heap of the FS. >>>> >>>> In v3, there is no heap, but the FSs have "ids", which are (at the moment) >>>> an >>>> int which increments by 1. This mis-matches the "address" in v2, so many >>>> parts >>>> of the serialization code builds a map at serialization time from the v3 >>>> id's to >>>> v2 "addresses", and uses the latter in the serialization form. >>>> >>>> Currently, this is done for various binary serializations, so that these >>>> can be >>>> read back in by v2 code. >>>> >>>> Currently, it's not done for JSON or XMI (and maybe XCAS - haven't >>>> checked). So >>>> the serialized forms for these differ between v2 and v3, in that the >>>> numbers >>>> used to represent references to other FSs are different. >>>> >>>> The deserialization code for XMI and JSON doesn't depend on these numbers >>>> being >>>> anything other than unique per FS, so there's no issue in deserializing. >>>> But >>>> the UIMA community may have built other things that depend on these >>>> identifiers >>>> not changing. >>>> >>>> What's your opinion: should the XMI and JSON etc serialization in V3 be >>>> changed >>>> to reproduce (approximately) the same reference numbers as v2? I say >>>> approximately, because other factors might affect these, such as the >>>> ordering >>>> for things not in "ordered" indexes, etc. between v2 and v3. >>>> >>>> -Marshall >>>>
