[Tilecache] RV: Internal organisation

[Christopher Schmidt]

On Wed, Oct 07, 2009 at 01:14:48PM +0200, Vidal, Antoni wrote:
> Hi Steven,
> 
> Thank's for your answer, but I think that is not exactly my case. Maybe because We use an old version of Tilecache, it seems 2.8.



> My tilecache.cfg has the following entries. Pay attention to bbox in UTM (meters):
> 
> bbox=258000,4485000,536000,4752000
> srs=EPSG:23031
> resolutions=1100,550,275,100,50,25,10,5,2,1,0.5
> 
> And the structure I get running tilecache in example, level 7:
> 
> Topo/07/000/000/000 untill 215/000/000/number.jpg


This is exactly what Steven described? I'm not sure why you're confused.

Again, the layout is (in the default Disk Cache):

 layer/z/x/x/x/y/y/y.ext

Which is what you have.

Your X goes from 0-215, your Y from 0-number.

    0,number             215,number
    
                 .
    
    
    0,0                  215,0

> Only that 5th directory changes her name and contains, always, 2 directories more and the last contains images.
> 
> If I supose that there are 216 columns (5th. Directory) 216 columns multiplyed by 256 px = 55269 multiplyed by 5 meters/px = 276480 meters. This is good because east minus west = 536000 - 258000 = 278000, almost the same.
> 
> Best Regards,
> 
> Antoni Vidal
> Unitat d'Aplicacions SIG-WEB
> Institut Cartogràfic de Catalunya
> Parc de Montjuïc, E-08038 Barcelona
> Tel. (+34) 93 567 15 00 (ext. 3228)
> www.icc.cat
>  
> 
> 
> -----Missatge original-----
> De: Steven M. Ottens [mailto:steven at minst.net] 
> Enviat: miércoles, 07 de octubre de 2009 10:22
> Per a: Vidal, Antoni
> A/c: tilecache at openlayers.org
> Tema: Re: [Tilecache] Internal organisation
> 
> Hi Antoni,
> 
> The default structure is defined by this:
> 
>    components = ( self.basedir,
>                         tile.layer.name,
>                         "%02d" % tile.z,
>                         "%03d" % int(tile.x / 1000000),
>                         "%03d" % (int(tile.x / 1000) % 1000),
>                         "%03d" % (int(tile.x) % 1000),
>                         "%03d" % int(tile.y / 1000000),
>                         "%03d" % (int(tile.y / 1000) % 1000),
>                         "%03d.%s" % (int(tile.y) % 1000,  
> tile.layer.extension)
>                      )
> 
> Meaning:
> 1st directory: layername
> 2nd directory: zoomlevel (in 2 digits eg. 01)
> the 3rd-5th directory are the columnnumber (x), split into thousands:
> -if you have x = 018782353 you get
>    3rd: directory 018
>    4th directory: 782
>    5th directory: 353
> the 6th and 7th and the filename are the row numbers (y) split into  
> thousands:
> -if you have y = 786 347 862 you get
>    6rd: directory 786
>    7th directory: 347
>    filename: 862
> and you end with the filetype
> 
> So you end up with:
> layername/01/018/782/353/786/347/862.filetype
> 
> The actual number of rows, columns and zoomlevels depend on the  
> tileschema you are using. The reason for splitting the rows and  
> columns in a three deep directory structure is because certain  
> filesystems cannot handle large amounts of files in a directory. Also  
> there are different caching-backends, including a more simple  
> approach like layer/z/x/y.filetype
> 
> Regardds,
> Steven
> 
> 
> 
> On Oct 7, 2009, at 9:38 AM, Vidal, Antoni wrote:
> 
> > Hello,
> >
> >
> >
> > I'm new on tilecahe and I would like to understand the internal  
> > organisation of tiles. My porpouse is to study the possibility of  
> > change WMS request to an application that cut the original map  
> > image in the litle tiles.
> >
> >
> >
> > Our organisation is going to increase the number of actualizations  
> > of tilecache and requests to WMS server are too slow.
> >
> >
> >
> > Any help will be appreciate.
> >
> >
> >
> > Antoni Vidal
> >
> > Unitat d'Aplicacions SIG-WEB
> > Institut Cartogràfic de Catalunya
> > Parc de Montjuïc, E-08038 Barcelona
> > Tel. (+34) 93 567 15 00 (ext. 3228)
> > www.icc.cat
> >
> >
> >
> >
> >
> >
> >
> > _______________________________________________
> > Tilecache mailing list
> > Tilecache at openlayers.org
> > http://openlayers.org/mailman/listinfo/tilecache
> 
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-- 
Christopher Schmidt
MetaCarta