these types of chains would never normally occur, but they've been seen in the wild. Attempting to resolve such chains has exponentially increasing complexity.
every time a chunk passed through Level->generateChunkCallback(), it fired onChunkChanged() for chunk listeners, which in turn caused players to rerun chunk orders even though the target chunk had not been sent yet anyway.
this caused some performance issues and silent bugs with the generator, notably that the generator would always think all chunks had been changed, causing them to be re-set back into the world 9 times.
previously a file with a 4-letter name ending in 'mca' in the region folder of a PMAnvil world would cause the world format to be unrecognized. This happens because strrpos() returns false when the substring isn't found, which gets coerced to 0 when used in addition.
this has a couple of side effects which need to be explored.
- first of all, this bug prevented generateLevel() from filling in the preset from server.properties. With this fix, worlds which don't have any extra generator settings will start to be generated using server.properties settings, which is almost certainly not expected behaviour.
- preset can now be specified separately from generator in pocketmine.yml, which is nicer for users.
this allows plugins (and maybe later on the core) to detect async worker overload and warn the user about potential performance issues.
I planned to implement such detection in the core directly, but it turned out to be a bit more complex than I anticipated. At the least, this API might be useful to someone else.
Previously, upwards movement wouldn't be considered, but downwards would, so if an entity bobbed up and down in the air for a while (e.g. while being comboed in PvP), the downwards distance would accumulate and deal a large amount of fall damage on touchdown.
This commit changes fall distance measurement to correctly account for upwards movement.
A better way of measuring fall distance would simply be to record the highest Y coordinate reached while in the air, and then measure the distance between that and the point of contact when landing. This would also remove the need to constantly update the fallDistance field. However, this would involve a BC break and will therefore have to wait until PM4.
it's not clear what this was actually supposed to represent, but it actually reports VmSize, which is already reported by "Total virtual memory". This line confuses users and is misleading.
On larger packets, this worsens compression ratio by 1-2%, but reduces CPU load due to compression by 15-20%. Higher levels than 6 are far more expensive for diminishing returns.
Level 5 produces a further 25-30% CPU reduction, but increases bandwidth usage by 20-25%, so 6 is the sweet spot.
