World handling
Functional
- Modern Minecraft Bedrock world formats are now supported.
- Automatic conversion of deprecated world formats is now implemented.
- All formats except leveldb have been deprecated. The following world formats will be automatically converted on load to a new format:
- 256 build-height is now supported in all worlds (facilitated by automatic conversion).
- Extended blocks are now supported (facilitated by automatic conversion).
- Unsupported world formats no longer causes a crash, but a graceful shutdown instead.
- World corruption no longer causes a crash, but a graceful shutdown instead.
Performance
- leveldb is now the primary supported world format. It is inherently faster than region-based formats thanks to better design.
- Partial chunk saves (only saving modified subcomponents of chunks) has been implemented. This drastically reduces the amount of data that is usually necessary to write on chunk save, which in turn drastically reduces the time to complete world saves. This is possible thanks to the modular design of the leveldb world format - this enhancement is not possible with region-based formats.
Network
This version features substantial changes to the network system, improving coherency, reliability and modularity.
A lot more of the boring stuff can be found on
https://github.com/pmmp/PocketMine-MP/blob/master/changelogs/4.0-snapshot.md. But that is apparently just the Tip of the iceberg.