[mapguide-internals] RFC required for tile caching changes?

Jason Birch Jason.Birch at nanaimo.ca
Mon Jan 15 14:30:43 EST 2007


Paul wrote:

-------------------------------------

In ka-Map, the size of a tile is configurable and by default is 200x200
px.  There is a second concept that I've called a 'meta tile'.  A meta
tile is some number of tiles wide x high, typically 10 x 10.  When a
request for a tile comes to the tile server, it checks the cache.

If the tile exists, the tile (200x200px) is returned.  This happens
without invoking any map rendering ... the tile exists as an image on
disk.

If the tile does not exist, then a map render happens.  

-------------------------------------

That makes more sense :)

I like the idea of sharing a cache, but I would prefer to see it
implemented the way that Andy suggested, with a TileMap object that
could be shared by various maps.  This would have immediate benefit in
my situation, where I expect to have many different themes based on the
same basic area and core layers.  I wouldn't want the overhead of
storing the tile set multiple times just because it's used in different
maps.

... and directory symlinks (junctions - reparse points) aren't all that
well known in Windows, though rumour has it that Vista uses them ( to
link "c:\Documents and Settings" to "c:\users" ).

Jason


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