[Tilesathome] t at h client tilesetfile creation

[spaetz]

Hi Matthias (and others).

I tested the creation of tilesetfiles by the client. They look good. I have implemented tileset file handling now.

the upload happens with
layer,z,x,y POST variables that are used to determine where to save the file.

So far so good. One problem is that this will again save "empty" tileset files. This needs solving before we can use that one a large scale.

 And we can't (or want) afford the storage space for 16 million tileset files * 4 layers if they just contain land/sea. What strategy should we use?

Any of the following is possible, we just need to decide which one is best:
1) The server needs to do a content analyis of the tileset file in question and discards it if it's empty. I would like to avoid that if possible as it would require examining all of the uploaded tileset by the server as part of the upload process.

2) We implement a HTTP API call that let's clients notify the server that a tileset is indeed empty and that the server should delete a file if it's there. Easiest for the server, no idea how difficult on the client side.

3) we save the tilesets and have a cron job that examines all existing tileset files and deletes empty ones regularly. Not that difficult but probably wasteful?

4) ? other ideas?

spaetz