Release 4.18.0-ALPHA1

changelogs/4.18-alpha.md

@@ -0,0 +1,45 @@
+**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.
+
+### Alpha release warning
+Alpha releases are **experimental**. Features introduced in these releases are subject to change or removal.
+
+APIs which existed **prior** to this version will continue to work as normal, so plugins which use them will continue to work.
+
+### Highlights
+This version makes changes to the internal network system to improve server performance and reduce memory usage.
+
+While these changes don't affect non-internal API, they are still significant enough to warrant a new minor version, as they may break plugins which use the internal network API (not recommended).
+
+# 4.18.0-ALPHA1
+Released 16th March 2023.
+
+## General
+- Improved server performance in congested areas of the world (lots of players and/or entities in the same area).
+
+## API
+### `pocketmine\event\server`
+- The following new classes have been added:
+  - `DataPacketDecodeEvent` - called before a packet is decoded by a `NetworkSession`; useful to mitigate DoS attacks if PocketMine-MP hasn't been patched against new bugs yet
+
+## Internals
+- Introduced new system for broadcasting entity events to network sessions.
+  - This change improves performance when lots of players and/or entities are in the same area.
+  - New interface `EntityEventBroadcaster` and class `StandardEntityEventBroadcaster` have been added to implement this.
+  - All entity-specific `on*()` and `sync*()` methods have been removed from `NetworkSession` (BC break).
+  - `NetworkSession` now accepts an `EntityEventBroadcaster` instance in its constructor.
+  - `NetworkBroadcastUtils::broadcastEntityEvent()` can be used to efficiently broadcast events to unique broadcasters shared by several network sessions.
+- All network sessions now share the same `PacketSerializerContext` and `PacketBroadcaster` by default.
+  - Previously, every session had its own context, meaning that broadcast optimisations were not used, causing significant performance losses compared to 3.x.
+  - This change improves performance in congested areas by allowing reuse of previously encoded packet buffers for all sessions sharing the same context.
+  - Packet broadcasts are automatically encoded separately per unique `PacketSerializerContext` instance. This allows, for example, a multi-version fork to have a separate context for each protocol version, to ensure maximum broadcast efficiency while encoding different packets for different versions.
+  - `PacketSerializerContext` is now passed in `NetworkSession::__construct()`, instead of being created by the session.
+- `StandardPacketBroadcaster` is now locked to a single `PacketSerializer` context, reducing complexity.
+- Introduced `NetworkBroadcastUtils::broadcastPackets()`, replacing `Server->broadcastPackets()`.
+- `Server->broadcastPackets()` has been deprecated. It will be removed in a future version.

src/VersionInfo.php

@@ -31,9 +31,9 @@ use function str_repeat;
 
 final class VersionInfo{
 	public const NAME = "PocketMine-MP";
-	public const BASE_VERSION = "4.17.1";
-	public const IS_DEVELOPMENT_BUILD = true;
-	public const BUILD_CHANNEL = "stable";
+	public const BASE_VERSION = "4.18.0-ALPHA1";
+	public const IS_DEVELOPMENT_BUILD = false;
+	public const BUILD_CHANNEL = "alpha";
 
 	private function __construct(){
 		//NOOP