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geforkt von Mirrors/Paper
Paper/patches/server/1005-Optimize-Pathfinder-Remove-Streams-Optimized-collect.patch
Bjarne Koll c5a10665b8
Remove wall-time / unused skip tick protection (#11412)
Spigot still maintains some partial implementation of "tick skipping", a
practice in which the MinecraftServer.currentTick field is updated not
by an increment of one per actual tick, but instead set to
System.currentTimeMillis() / 50. This behaviour means that the tracked
tick may "skip" a tick value in case a previous tick took more than the
expected 50ms.

To compensate for this in important paths, spigot/craftbukkit
implements "wall-time". Instead of incrementing/decrementing ticks on
block entities/entities by one for each call to their tick() method,
they instead increment/decrement important values, like
an ItemEntity's age or pickupDelay, by the difference of
`currentTick - lastTick`, where `lastTick` is the value of
`currentTick` during the last tick() call.

These "fixes" however do not play nicely with minecraft's simulation
distance as entities/block entities implementing the above behaviour
would "catch up" their values when moving from a non-ticking chunk to a
ticking one as their `lastTick` value remains stuck on the last tick in
a ticking chunk and hence lead to a large "catch up" once ticked again.

Paper completely removes the "tick skipping" behaviour (See patch
"Further-improve-server-tick-loop"), making the above precautions
completely unnecessary, which also rids paper of the previous described
incompatibility with non-ticking chunks.
2024-09-19 16:36:07 +02:00

134 Zeilen
7.0 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Tue, 4 Aug 2020 22:24:15 +0200
Subject: [PATCH] Optimize Pathfinder - Remove Streams / Optimized collections
I utilized the IDE to convert streams to non streams code, so shouldn't
be any risk of behavior change. Only did minor optimization of the
generated code set to remove unnecessary things.
I expect us to just drop this patch on next major update and re-apply
it with the IDE again and re-apply the collections optimization.
Optimize collection by creating a list instead of a set of the key and value.
This lets us get faster foreach iteration, as well as avoids map lookups on
the values when needed.
diff --git a/src/main/java/net/minecraft/world/level/pathfinder/PathFinder.java b/src/main/java/net/minecraft/world/level/pathfinder/PathFinder.java
index 8a483c8d2a54617d78af19de32fa0ded71b3223a..18bbb3f8f99849333ff4bc020c8ce758a69312a5 100644
--- a/src/main/java/net/minecraft/world/level/pathfinder/PathFinder.java
+++ b/src/main/java/net/minecraft/world/level/pathfinder/PathFinder.java
@@ -38,8 +38,12 @@ public class PathFinder {
if (node == null) {
return null;
} else {
- Map<Target, BlockPos> map = positions.stream()
- .collect(Collectors.toMap(pos -> this.nodeEvaluator.getTarget((double)pos.getX(), (double)pos.getY(), (double)pos.getZ()), Function.identity()));
+ // Paper start - Perf: remove streams and optimize collection
+ List<Map.Entry<Target, BlockPos>> map = Lists.newArrayList();
+ for (final BlockPos pos : positions) {
+ map.add(new java.util.AbstractMap.SimpleEntry<>(this.nodeEvaluator.getTarget(pos.getX(), pos.getY(), pos.getZ()), pos));
+ }
+ // Paper end - Perf: remove streams and optimize collection
Path path = this.findPath(world.getProfiler(), node, map, followRange, distance, rangeMultiplier);
this.nodeEvaluator.done();
return path;
@@ -47,18 +51,19 @@ public class PathFinder {
}
@Nullable
- private Path findPath(ProfilerFiller profiler, Node startNode, Map<Target, BlockPos> positions, float followRange, int distance, float rangeMultiplier) {
+ // Paper start - Perf: remove streams and optimize collection
+ private Path findPath(ProfilerFiller profiler, Node startNode, List<Map.Entry<Target, BlockPos>> positions, float followRange, int distance, float rangeMultiplier) {
profiler.push("find_path");
profiler.markForCharting(MetricCategory.PATH_FINDING);
- Set<Target> set = positions.keySet();
+ // Set<Target> set = positions.keySet();
startNode.g = 0.0F;
- startNode.h = this.getBestH(startNode, set);
+ startNode.h = this.getBestH(startNode, positions); // Paper - optimize collection
startNode.f = startNode.h;
this.openSet.clear();
this.openSet.insert(startNode);
- Set<Node> set2 = ImmutableSet.of();
+ // Set<Node> set2 = ImmutableSet.of(); // Paper - unused - diff on change
int i = 0;
- Set<Target> set3 = Sets.newHashSetWithExpectedSize(set.size());
+ List<Map.Entry<Target, BlockPos>> entryList = Lists.newArrayListWithExpectedSize(positions.size()); // Paper - optimize collection
int j = (int)((float)this.maxVisitedNodes * rangeMultiplier);
while (!this.openSet.isEmpty()) {
@@ -69,14 +74,18 @@ public class PathFinder {
Node node = this.openSet.pop();
node.closed = true;
- for (Target target : set) {
+ // Paper start - optimize collection
+ for (int i1 = 0; i1 < positions.size(); i1++) {
+ final Map.Entry<Target, BlockPos> entry = positions.get(i1);
+ Target target = entry.getKey();
if (node.distanceManhattan(target) <= (float)distance) {
target.setReached();
- set3.add(target);
+ entryList.add(entry);
+ // Paper end - Perf: remove streams and optimize collection
}
}
- if (!set3.isEmpty()) {
+ if (!entryList.isEmpty()) { // Paper - Perf: remove streams and optimize collection; rename
break;
}
@@ -91,7 +100,7 @@ public class PathFinder {
if (node2.walkedDistance < followRange && (!node2.inOpenSet() || g < node2.g)) {
node2.cameFrom = node;
node2.g = g;
- node2.h = this.getBestH(node2, set) * 1.5F;
+ node2.h = this.getBestH(node2, positions) * 1.5F; // Paper - Perf: remove streams and optimize collection
if (node2.inOpenSet()) {
this.openSet.changeCost(node2, node2.g + node2.h);
} else {
@@ -103,23 +112,32 @@ public class PathFinder {
}
}
- Optional<Path> optional = !set3.isEmpty()
- ? set3.stream().map(node -> this.reconstructPath(node.getBestNode(), positions.get(node), true)).min(Comparator.comparingInt(Path::getNodeCount))
- : set.stream()
- .map(targetx -> this.reconstructPath(targetx.getBestNode(), positions.get(targetx), false))
- .min(Comparator.comparingDouble(Path::getDistToTarget).thenComparingInt(Path::getNodeCount));
+ // Paper start - Perf: remove streams and optimize collection
+ Path best = null;
+ boolean entryListIsEmpty = entryList.isEmpty();
+ Comparator<Path> comparator = entryListIsEmpty ? Comparator.comparingInt(Path::getNodeCount)
+ : Comparator.comparingDouble(Path::getDistToTarget).thenComparingInt(Path::getNodeCount);
+ for (Map.Entry<Target, BlockPos> entry : entryListIsEmpty ? positions : entryList) {
+ Path path = this.reconstructPath(entry.getKey().getBestNode(), entry.getValue(), !entryListIsEmpty);
+ if (best == null || comparator.compare(path, best) < 0)
+ best = path;
+ }
profiler.pop();
- return optional.isEmpty() ? null : optional.get();
+ return best;
+ // Paper end - Perf: remove streams and optimize collection
}
protected float distance(Node a, Node b) {
return a.distanceTo(b);
}
- private float getBestH(Node node, Set<Target> targets) {
+ private float getBestH(Node node, List<Map.Entry<Target, BlockPos>> targets) { // Paper - Perf: remove streams and optimize collection; Set<Target> -> List<Map.Entry<Target, BlockPos>>
float f = Float.MAX_VALUE;
- for (Target target : targets) {
+ // Paper start - Perf: remove streams and optimize collection
+ for (int i = 0, targetsSize = targets.size(); i < targetsSize; i++) {
+ final Target target = targets.get(i).getKey();
+ // Paper end - Perf: remove streams and optimize collection
float g = node.distanceTo(target);
target.updateBest(g, node);
f = Math.min(g, f);