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c5a10665b8
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.
52 lines
2.1 KiB
Diff
52 lines
2.1 KiB
Diff
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
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From: astei <andrew@steinborn.me>
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Date: Sat, 28 Oct 2023 19:46:21 -0400
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Subject: [PATCH] Optimize VarInts
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https://github.com/PaperMC/Paper/pull/6957#issuecomment-985250854
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diff --git a/src/main/java/net/minecraft/network/VarInt.java b/src/main/java/net/minecraft/network/VarInt.java
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index 49a8ddc269d53458cfbd639b7de838c2e5765748..74ed47659d3e615c2dae7da98d5a8cf1559625bf 100644
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--- a/src/main/java/net/minecraft/network/VarInt.java
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+++ b/src/main/java/net/minecraft/network/VarInt.java
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@@ -9,6 +9,18 @@ public class VarInt {
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private static final int DATA_BITS_PER_BYTE = 7;
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public static int getByteSize(int i) {
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+ // Paper start - Optimize VarInts
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+ return VARINT_EXACT_BYTE_LENGTHS[Integer.numberOfLeadingZeros(i)];
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+ }
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+ private static final int[] VARINT_EXACT_BYTE_LENGTHS = new int[33];
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+ static {
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+ for (int i = 0; i <= 32; ++i) {
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+ VARINT_EXACT_BYTE_LENGTHS[i] = (int) Math.ceil((31d - (i - 1)) / 7d);
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+ }
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+ VARINT_EXACT_BYTE_LENGTHS[32] = 1; // Special case for the number 0.
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+ }
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+ public static int getByteSizeOld(int i) {
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+ // Paper end - Optimize VarInts
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for (int j = 1; j < 5; j++) {
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if ((i & -1 << j * 7) == 0) {
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return j;
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@@ -39,6 +51,21 @@ public class VarInt {
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}
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public static ByteBuf write(ByteBuf buf, int i) {
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+ // Paper start - Optimize VarInts
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+ // Peel the one and two byte count cases explicitly as they are the most common VarInt sizes
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+ // that the proxy will write, to improve inlining.
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+ if ((i & (0xFFFFFFFF << 7)) == 0) {
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+ buf.writeByte(i);
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+ } else if ((i & (0xFFFFFFFF << 14)) == 0) {
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+ int w = (i & 0x7F | 0x80) << 8 | (i >>> 7);
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+ buf.writeShort(w);
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+ } else {
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+ writeOld(buf, i);
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+ }
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+ return buf;
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+ }
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+ public static ByteBuf writeOld(ByteBuf buf, int i) {
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+ // Paper end - Optimize VarInts
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while ((i & -128) != 0) {
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buf.writeByte(i & 127 | 128);
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i >>>= 7;
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