Make netplay's "same game" check more robust #8861
Conversation
|
This is really nice actually. Huge thumbs up. |
| // 2. Different for discs with differences that affect netplay/TAS sync | ||
| // 3. Much faster than hashing the entire disc | ||
| // The way the hash is calculated may change with updates to Dolphin. | ||
| std::array<u8, 20> sync_hash; |
There was a problem hiding this comment.
Perhaps an alias like:
using SyncHash = std::array<u8, 20>;should be made (or encapsulate it in its own struct if forward declaring matters), given how often this is repeated throughout the code to make it more self-documenting?
There was a problem hiding this comment.
Done. However, I haven't made use of this alias in DiscIO, since it feels a bit silly to include SyncIdentifier.h only for the alias. Do you think I should use it in DiscIO anyway?
There was a problem hiding this comment.
I was mainly suggesting it assuming it would be used consistently, so if it isn't going to be used like that, then there's no real point of using the alias.
There was a problem hiding this comment.
I'll revert the change, then.
JosJuice
force-pushed
the
netplay-hash
branch
2 times, most recently
from
005ab68
to
48bbc8a
Compare
JosJuice
force-pushed
the
netplay-hash
branch
5 times, most recently
from
191a4d7
to
4a1fae7
Compare
JosJuice
force-pushed
the
netplay-hash
branch
4 times, most recently
from
942a110
to
bce6a20
Compare
|
Something went wrong with your rebase here. |
Instead of comparing the game ID, revision, disc number and name, we can compare a hash of important parts of the disc including all the aforementioned data but also additional data such as the FST. The primary reason why I'm making this change is to let us catch more desyncs before they happen, but this should also fix https://bugs.dolphin-emu.org/issues/12115. As a bonus, the UI can now distinguish the case where a client doesn't have the game at all from the case where a client has the wrong version of the game.
There is no longer any major reason for why this function would need to return the same result for all players.
The new hash check catches essentially all desync problems that VolumeVerifier can catch, so from the user's perspective, such problems will result in Dolphin refusing to start the game on netplay rather than actually getting a desync.
Instead of comparing the game ID, revision, disc number and name, we can compare a hash of important parts of the disc including all the aforementioned data but also additional data such as the FST. The primary reason why I'm making this change is to let us catch more desyncs before they happen, but this should also fix https://bugs.dolphin-emu.org/issues/12115. As a UX bonus, the UI can now distinguish the case where a client doesn't have the game at all from the case where a client has the wrong version of the game, and we can show translated/custom names in the netplay game list.