Re: [geowebcache-users] GeoWebCache directory/file name structure

[Arne K. <ar...@ti...>]

1) "zoom level". For the default EPSG:900913 grid z=0 means the whole 
world in 4 tiles

2) Hm,,, good point. I dont think I went back and updated that wiki 
page, it was not more than a scratchpad for sharing ideas. The actual 
code is here[1], the difference is that the bit shifting starts with 2, 
effectively making it  2^( 1 +  ( z / 2 )). And there's some zero-padding.

3) The catch is that you need to know a little bit of Java, but if you 
do then it's potentially straightforward. It depends what the OpenSpace 
structure is based on, and whether we have similar tokens in GWC.

blobstore/file contains an implementation of BlobStore. You can copy the 
whole thing to a new package, and then make the FilePathGenerator output 
the structure you want. It is linked into the application using Spring, 
WEB-INF/geowebcache-core-context.xml , if you are working off trunk. I 
would guess that you also want a particular GridSet to go with that, to 
match the resolutions and origin used by OpenSpace.

It's possible someone has already done it, but so far I have not heard 
about it.

-Arne

1: 
http://geowebcache.org/trac/browser/trunk/geowebcache/core/src/main/java/org/geowebcache/storage/blobstore/file/FilePathGenerator.java


On 06/08/2010 05:33 PM, samclemmens wrote:
> Hi,
>
> I'm relatively new to GeoWebCache...and I'm a bit puzzled by the
> directory/file name structure that is produced.  I have a few questions,
> namely:
>
> 1.  The documentation states that the naming convention is:
> layername/projection_z/[x/(2^(z/2))]_[y/(2^(z/2))]/x_y.extension    What is
> the z value?
>
> 2.  Given the sample output
> .\gwc\roads\EPSG_900913_12\006_019\000848_002540.png, I assume that z=12,
> x=848, and y=2540.  Obviously the above formula won't produce 006_019 based
> on these numbers.  What conversion is required?
>
> 3.  Is it possible to change the directory/file name format?  I'd like to
> create a data set that can be used by Ordnance Survey OpenSpace, which uses
> a different structure based on the British National Grid.
>
> Cheers,
>
> Peter
>