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. > > and > > $ 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 > either. > > BillK >
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. BillK _______________________________________________ Openmoko community mailing list [email protected] http://lists.openmoko.org/mailman/listinfo/community
