Yaouh! out (update for tangogps maps)
billk at iinet.net.au
Tue Jan 20 11:52:57 CET 2009
On Tue, 2009-01-20 at 19:44 +0900, William Kenworthy wrote:
> On Tue, 2009-01-20 at 11:00 +0100, Helge Hafting wrote:
> > William Kenworthy wrote:
> > > ...
> > > Where I live (Perth, Western Australia) there are large areas of
> > > surrounding sea/land/forestry/desert etc that use a single colour tile -
> > > each of only 103 bytes. I symlinked all identical files (based on
> > > md5sum) such that only one copy of each is kept. This has the advantage
> > > that as ext2/3 uses fast-symlinks, the actual symlink (provided the path
> > > is < 60 characters) is stored in the inode and doesnt take any block
> > > space on the FS. This shrinks the size as given by du -sh from 3.3Gb
> > > down to ~550Mb.
> > >
> > Interesting idea. Half of my tiles are blank too.
> > But what happens when tangogps (or yaouh or whatever)
> > re-downloads some previously blank tile that now has a new road on it?
> > Will the link break for that tile? Or will the sole blank tile be
> > replaced, so that every blank area now has the same road on it?
> > I don't keep a tile repositiory on my desktop, I download
> > directly to the freerunner.
> > Helge Hafting
> Check if you have run out of inodes - there are only so many to go
> around! - this was a problem foe until I realised it as it looks like
> there is plenty of room, but strange crashes and the like occur as there
> are no free inodes.
> $ echo aa > aa
> $ ln -s aa bb
> $ echo cc > bb
> $ cat aa
> $ cc
> So it will overwrite. Not a problem for me as I dont use gprs (too
> expensive in Oz for casual use, and coverage is miserable outside the
> central capitals and large towns.) and the desktop system is always the
> master. Started out this way as kept losing the partition in the early
> days and ext2/3 is not a very good filesystem for devices like this
> anyway, corruption occurs quite readily so I dont trust it :)
> Alternatively, identify the symlined master and make it read only - wont
> update, but wont overwrite all similar tiles either.
> Also, I didnt think tangogps overwrote files already downloaded - it
> uses them from the cache instead - will have to test the download
> dialog, but I seem to remember that didnt download existing tiles
A little thought - if a tile is to be replaced, delete it first (and
therefore if its a symlink, problem solved. Scripts like yaouh could be
easily adapted - tangogps, may not be necessary - need to prove that.
More information about the community