Unnecessary shader cache invalidation with new layout

[HerrHulaHoop]

After #5453, all cache has been moved to a separate folder. While this is neat, it did create a new problem. Previously, every time a game update was installed, the current PPU and SPU cache would be invalidated and recompiled afresh. But the shader cache was not invalidated and could be used irrespective of game version. With the new layout, the shader cache sits within the PPU specific folder and gets invalidated along with the PPU and SPU cache and starts generating afresh.

Old layout:

Shaders cache: data > GAMEID > xxxxxx-EBOOT.BIN > shaders_cache
PPU cache:     data > GAMEID > xxxxxx-EBOOT.BIN
SPU cache:     data > GAMEID > ppu-xxxxxx-EBOOT.BIN

Every time a game update is installed, a new ppu-xxxxxx-EBOOT.BIN folder is created, forcing a new SPU cache. The PPU modules were present in the same folder but were recompiled once again. The shader cache remained in the same folder and was still used independent of any game updates.

New layout:

Shaders cache: cache > GAMEID > ppu-xxxxxx-EBOOT.BIN > shaders_cache
PPU cache:     cache > GAMEID > ppu-xxxxxx-EBOOT.BIN
SPU cache:     cache > GAMEID > ppu-xxxxxx-EBOOT.BIN

As mentioned above, every time a game update is installed a new ppu-xxxxxx-EBOOT.BIN folder is created. As before, the PPU and SPU cache is invalidated and compiled afresh. New PPU cache goes into the new folder as well which is nice. But the shader cache from the original folder is also ignored and we need to unnecessarily cache it all over again.

I don't think the shader cache needs to be invalidated in this scenario. The easiest way to fix this would be to move the shader cache alone back into a PPU independent folder (cache > GAMEID > xxxxxx-EBOOT.BIN > shaders_cache). Even better would be to let the shader_cache folder sit independently like cache > GAMEID > shaders_cache.

[kd-11]

Not every executable has a GameID. In fact if you boot via the Boot ELF menu option (e.g for collections) the only way to differentiate which 'game' you're running is the PPU hash. This is why it was done that way.

[HerrHulaHoop]

So you're saying the new implementation of invalidating the shader cache every time a game update is installed is the right way to go? and the previous method was actually the incorrect one?

[kd-11]

My comment only addresses the suggestion in your last paragraph.

I don't think the shader cache needs to be invalidated in this scenario. The easiest way to fix this would be to move the shader cache alone back into a PPU independent folder (cache > GAMEID > xxxxxx-EBOOT.BIN > shaders_cache). Even better would be to let the shader_cache folder sit independently like cache > GAMEID > shaders_cache.

GAMEID may not exist at all, making a GAMEID/shader_cache solution impossible. The only known constant location is the PPU-xxxxx folder which uniquely identifies the executable so thats what is used right now. If anyone has a better suggestion then we can use it, maybe a hash of the full executable path instead attached to a gameid, which would be GAMEID-xxxxxx for games with GAMEID and just the path hash for the others, xxxxx/shader_cache. Another alternative is to have shader_cache folder as part of cache and the game subdirectories under it, something I'm not a huge fan of since there would be no way to quickly find the shader dump from a Game. With the current setup, Just use the UI to open the PPu cache folder (if the functionality has been updated that is, i think we used the config directory path before) and you can easily find the shaders cache. The alt path would require a user to remember the GAMEID or somehow guess the correct hash. All of these are minor inconveniences really, if anyone wants to put in the time, all of this can be managed properly and separate from the PPU/SPU caches.

[Psycho-A]

If anyone has a better suggestion then we can use it, maybe a hash of the full executable path instead attached to a gameid, which would be GAMEID-xxxxxx for games with GAMEID and just the path hash for the others, xxxxx/shader_cache.

I would suggest to use game executable's byte hash (better CRC32 for readability) instead of path. This would also solve problem of moving the same games or the whole emulator to different folders without needing to recompile all stuff again and keep old unused garbage inside of cache folders.