Jochen Topf kirjoitti: > On Mon, May 23, 2011 at 04:18:05AM -0500, Scott Crosby wrote: >> On Sat, May 21, 2011 at 9:52 AM, Jochen Topf <[email protected]> wrote: >> > >> > If we use unsigned ints we have some more time. Problematic would only >> be >> > a few cases where negative IDs are currently used (like in JOSM for >> data >> > thats not yet uploaded to the server). But it seems wasteful to me, to >> go >> > to 64bit a year or so earlier than needed to accommodate this case. >> >> The 64 bit transition is unavoidable. I think this would double the >> effort, because we'd all have to go through our software twice, once >> to fix signedness bugs, and a second time to go to 64 bits. In >> addition, the Java stack couldn't transition to unsigned ints anyways, >> as Java lacks unsigned types. An unsigned int transition would be a >> 64-bit transition. > > First: It has always been clear that sooner or later we will need the > 64bit > space for OSM IDs. > > The file formats used for exchanging OSM data already allow them. For XML > there is really no limit on the size of the ID and for PBF the IDs are > defined as sint64. So we are fine here. > > But in practice in their software people have often used 32bit IDs > instead, > because a) currently they are enough and b) they are often more efficient > in > space and/or time. > > I think it is up to the implementor of each software to decide what > internal > representation he uses for IDs. Implementors just have to be aware of all > the issue involved.
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