PocketMine-MP/changelogs/4.19.md

**For Minecraft: Bedrock Edition 1.19.70**

### Note about API versions
Plugins which don't touch the `pocketmine\network\mcpe` namespace are compatible with any previous 4.x.y version will also run on these releases and do not need API bumps.
Plugin developers should **only** update their required API to this version if you need the changes in this build.

**WARNING: If your plugin uses the `pocketmine\network\mcpe` namespace, you're not shielded by API change constraints.**
Consider using the `mcpe-protocol` directive in `plugin.yml` as a constraint if you're using packets directly.

### Highlights
This version introduces support for a new, more advanced version of Timings.
This improved system provides more detail than the old system, and supports being displayed in a tree view, making it much easier to see which timers contribute to which other timers.

In addition, some minor performance improvements have been made, along with a couple of minor API additions.

# 4.19.0
Released 11th April 2023.

## General
- Updated the Timings system.
  - Timings records now include parent information, allowing them to be displayed in a tree view (e.g. https://timings.pmmp.io/?id=303556).
  - Timings records now include additional information, such as Peak (max time spent on any single tick), and Ticks (number of ticks the timer was active on).
  - New timings have been added for every event.
  - A new timer `Player Network Send - Pre-Spawn Game Data` has been added, and covers most of the time spent handling `ResourcePackClientResponsePacket`, giving a clearer picture of what's happening.
- Improved performance of the plugin event system.
  - By introducing some caching, the event system now has 90% less overhead than in previous versions.
- Improved performance of the random chunk ticking system.
  - The selection of ticked random chunks, and their validation for ticking, is now cached. This significantly reduces the overhead of chunk selection.
  - Factions servers and other game modes with big maps and sparsely populated areas will see the most benefit from this change.
  - Real-world performance benefit of this change is anywhere from 0-20%, depending on server type and configuration.
- The `timings paste` command now logs a debug message with the server response on failure to paste a timings report.

## API
### `pocketmine\entity\object`
- The following API constants have been added:
  - `ExperienceOrb::DEFAULT_DESPAWN_DELAY` - the default delay in ticks before an experience orb despawns
  - `ExperienceOrb::NEVER_DESPAWN` - magic value for `setDespawnDelay()` to make an experience orb never despawn
  - `ExperienceOrb::MAX_DESPAWN_DELAY` - the maximum delay in ticks before an experience orb despawns
- The following API methods have been added:
  - `public ExperienceOrb->getDespawnDelay() : int` - returns the delay in ticks before this experience orb despawns
  - `public ExperienceOrb->setDespawnDelay(int $despawnDelay) : void` - sets the delay in ticks before this experience orb despawns
- The following properties have been deprecated
  - `ExperienceOrb->age` - superseded by despawn delay methods

### `pocketmine\event`
- The following API methods have been added:
  - `public HandlerList->getListenerList() : list<RegisteredListener>` - returns an ordered list of handlers to be called for the event

### `pocketmine\player`
- The following API methods have behavioural changes:
  - `ChunkSelector->selectChunks()` now yields the distance in chunks from the center as the key, instead of an incrementing integer.
- The following classes have been deprecated:
  - `PlayerChunkLoader` (this was technically internal, but never marked as such)

### `pocketmine\timings`
- The following API constants have been deprecated:
  - `Timings::INCLUDED_BY_OTHER_TIMINGS_PREFIX` - this is superseded by timings group support (see `Timings::GROUP_BREAKDOWN`)
- The following API constants have been added:
  - `Timings::GROUP_BREAKDOWN` - this group makes a timer appear in the `Minecraft - Breakdown` section of a timings report
- The following API methods have been added:
  - `public TimingsHandler->getGroup() : string` - returns the name of the table in which this timer will appear in a timings report
- The following API methods have changed signatures:
  - `TimingsHandler->__construct()` now accepts an additional, optional `string $group` parameter, which defaults to `Minecraft`.

### `pocketmine\world`
#### Highlights
Ticking chunks is now done using the `ChunkTicker` system, which has a much more fine-grained API than the old `TickingChunkLoader` system, as well as better performance.
It works similarly to the `ChunkLoader` system, in that chunks will be ticked as long as at least one `ChunkTicker` is registered for them.

#### API changes
- The following classes have been deprecated:
  - `TickingChunkLoader` - this has been superseded by the more powerful and performant `ChunkTicker` APIs
- The following classes have been added:
  - `ChunkTicker` - an opaque object used for `registerTickingChunk()` to instruct the `World` that we want a chunk to be ticked
- The following API methods have been added:
  - `public World->registerTickingChunk(ChunkTicker $ticker, int $chunkX, int $chunkZ) : void` - registers a chunk to be ticked by the given `ChunkTicker`
  - `public World->unregisterTickingChunk(ChunkTicker $ticker, int $chunkX, int $chunkZ) : void` - unregisters a chunk from being ticked by the given `ChunkTicker`

# 4.19.1
Released 14th April 2023.

## Fixes
- Fixed inventory rollbacks when spreading items in ender chests.
- Fixed inventory rollbacks when shift-clicking to craft and the outputs would have been split across multiple inventory slots.
- Fixed incorrect spawn terrain generation for newly created worlds.
- Fixed `chunk-ticking.tick-radius` not disabling chunk ticking when set to `0`.
- Fixed chunks not being ticked if they previously left a player's simulation distance without leaving their view distance.
- Fixed height of collision boxes for Grass Path and Farmland blocks.

# 4.19.2
Released 14th April 2023.

## Fixes
- Fixed player timings duplication leading to extremely large timings reports when timings runs for a long time with many players.
- Packet timings are now indexed by class FQN instead of packet ID. This prevents erroneous timer reuse on packet ID reuse (e.g. multi version servers).
- Fixed entity timings being shared by different classes with the same short name. This led to incorrect timings being reported for some entities when custom entities were used.

# 4.19.3
Released 21st April 2023.

## General
- Error IDs for `Packet processing error` disconnects are now split into 4-character chunks to make them easier to type (since they can't be copied from the disconnection screen of a client).

## Fixes
- Fixed entity-block intersections being checked twice per tick. Besides wasting CPU time, this may have caused unexpected behaviour during entity-block interactions with blocks like water or cacti.
- Fixed performance issue in network inventory synchronization due item NBT being prepared twice.
- Fixed `tools/simulate-chunk-selector.php` argument parsing being completely broken (weird behaviour of PHP `getopt()`).

## Internals
- `TimingsHandler->stopTiming()` now logs an error message if a subtimer wasn't stopped, rather than throwing an exception.
  - Due to interactions between `try...finally` and unexpected errors, throwing exceptions made it difficult for plugin developers to debug errors in their plugins, since it obscured the original error.