Incompatible data file changes.

[James Hollingshead]

I've been doing some work on the qtile rendering today. There are a couple
of things that are going to need changing in the database file:
- Current files are limited in size to 4GB as the index offets are only
stored in 4 bytes. (in fact some client code limits them to 2GB by
using signed long, but this could be fixed)
- Files this size (eg. the whole of Europe is c.6GB) might be problematic
on some systems, so it would be good to allow the DB split across several
smaller files.
- The index wastes 8bytes/index entry in redundant information
- There is no place in the format for adding streetnames

This is going to need a change to an incompatible fileformat. Can I just make
the change and bin the old code (forcing everyone to update their map files),
or do you want legacy code left in for a changover period?

James

[Christoph Eckert]

Hi James,

nice to meet you :) .

> This is going to need a change to an incompatible fileformat. Can I just
> make the change and bin the old code (forcing everyone to update their map
> files), or do you want legacy code left in for a changover period?

I've just created a branch for my UI changes. We can then decide whether and
when to merge them into tip/head.

--
Beste Grüße,
Best regards,

ce

[Christian Vetter]

Hi,

On Sun, May 22, 2011 at 7:21 PM, James Hollingshead <ja...@hollo.org> wrote:
> This is going to need a change to an incompatible fileformat. Can I just make
> the change and bin the old code (forcing everyone to update their map files),
> or do you want legacy code left in for a changover period?

I think we can break the file format for 0.4. When somebody wants to
generate an older map he should use 0.3.x to do so.

Regards,

Christian

[Christoph Eckert]

Hi,

> I think we can break the file format for 0.4. When somebody wants to
> generate an older map he should use 0.3.x to do so.

"as we are at it": How often do you think that we should update the map
material? OSMers want their map material in realtime, that's out of the
question. However, the german OSM server often is at its limits, and so I
think we should be "lazy" unless people really request up-to-date map
material.