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Merged
MrMicky-FR merged 5 commits into from
Jun 20, 2026
+116 −106
Merged

Move away from final field mutations #85

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d4db970
Move away from final field mutations
syldium Jun 7, 2026
b3b6ef3
Remove PacketConstructor
syldium Jun 7, 2026
93a6d3d
Remove unused code
MrMicky-FR Jun 12, 2026
22284a7
Remove unused code (and minor formatting)
MrMicky-FR Jun 12, 2026
e26936a
Fix final field mutation when sending a team packet
syldium Jun 15, 2026
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189 changes: 116 additions & 73 deletions src/main/java/fr/mrmicky/fastboard/FastBoardBase.java
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Original file line number Diff line number Diff line change
Expand Up @@ -29,6 +29,7 @@
import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.MethodType;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
Expand All @@ -54,33 +55,31 @@ public abstract class FastBoardBase<T> {
private static final VersionType VERSION_TYPE;
// Packets and components
private static final Class<?> CHAT_COMPONENT_CLASS;
private static final Class<?> CHAT_FORMAT_ENUM;
private static final Object RESET_FORMATTING;
private static final MethodHandle PLAYER_CONNECTION;
private static final MethodHandle SEND_PACKET;
private static final MethodHandle PLAYER_GET_HANDLE;
private static final MethodHandle FIXED_NUMBER_FORMAT;
// Scoreboard teams
private static final MethodHandle OBJECTIVE;
private static final MethodHandle PLAYER_TEAM;
// Scoreboard packets
private static final FastReflection.PacketConstructor PACKET_SB_OBJ;
private static final FastReflection.PacketConstructor PACKET_SB_DISPLAY_OBJ;
private static final FastReflection.PacketConstructor PACKET_SB_TEAM;
private static final FastReflection.PacketConstructor PACKET_SB_SERIALIZABLE_TEAM;
private static final MethodHandle PACKET_SB_OBJ;
private static final MethodHandle PACKET_SB_DISPLAY_OBJ;
private static final MethodHandle PACKET_SB_TEAM;
private static final MethodHandle PACKET_SB_SERIALIZABLE_TEAM;
private static final MethodHandle PACKET_SB_SET_SCORE;
private static final MethodHandle PACKET_SB_RESET_SCORE;
private static final boolean SCORE_OPTIONAL_COMPONENTS;
// Scoreboard enums
private static final Class<?> DISPLAY_SLOT_TYPE;
private static final Class<?> ENUM_SB_HEALTH_DISPLAY;
private static final Class<?> ENUM_SB_ACTION;
private static final Class<?> ENUM_VISIBILITY;
private static final Class<?> ENUM_COLLISION_RULE;
private static final Object BLANK_NUMBER_FORMAT;
private static final Object SIDEBAR_DISPLAY_SLOT;
private static final Object ENUM_SB_HEALTH_DISPLAY_INTEGER;
private static final Object ENUM_SB_ACTION_CHANGE;
private static final Object ENUM_SB_ACTION_REMOVE;
private static final Object ENUM_VISIBILITY_ALWAYS;
private static final Object ENUM_COLLISION_RULE_ALWAYS;
private static final Object DUMMY_SCOREBOARD_CRITERIA;

static {
try {
Expand Down Expand Up @@ -119,16 +118,20 @@ public abstract class FastBoardBase<T> {
.filter(m -> m.getParameterCount() == 1 && m.getParameterTypes()[0] == packetClass)
.findFirst().orElseThrow(NoSuchMethodException::new);
Optional<Class<?>> displaySlotEnum = FastReflection.nmsOptionalClass("world.scores", "DisplaySlot");
CHAT_COMPONENT_CLASS = FastReflection.nmsClass("network.chat", "IChatBaseComponent","Component");
CHAT_FORMAT_ENUM = FastReflection.nmsClass(null, "EnumChatFormat", "ChatFormatting");
CHAT_COMPONENT_CLASS = FastReflection.nmsClass("network.chat", "IChatBaseComponent", "Component");
DISPLAY_SLOT_TYPE = displaySlotEnum.orElse(int.class);
RESET_FORMATTING = FastReflection.enumValueOf(CHAT_FORMAT_ENUM, "RESET", 21);
SIDEBAR_DISPLAY_SLOT = displaySlotEnum.isPresent() ? FastReflection.enumValueOf(DISPLAY_SLOT_TYPE, "SIDEBAR", 1) : 1;
PLAYER_GET_HANDLE = lookup.findVirtual(craftPlayerClass, "getHandle", MethodType.methodType(entityPlayerClass));
PLAYER_CONNECTION = lookup.unreflectGetter(playerConnectionField);
SEND_PACKET = lookup.unreflect(sendPacketMethod);
PACKET_SB_OBJ = FastReflection.findPacketConstructor(packetSbObjClass, lookup);
PACKET_SB_DISPLAY_OBJ = FastReflection.findPacketConstructor(packetSbDisplayObjClass, lookup);

Class<?> scoreboardClass = FastReflection.nmsClass("world.scores", "Scoreboard");
Class<?> playerTeamClass = FastReflection.nmsClass("world.scores", "ScoreboardTeam", "PlayerTeam");
Class<?> objectiveClass = FastReflection.nmsClass("world.scores", "ScoreboardObjective", "Objective");
Class<?> objectiveCriteriaClass = FastReflection.nmsClass("world.scores.criteria", "IScoreboardCriteria", "ObjectiveCriteria");
PLAYER_TEAM = lookup.unreflectConstructor(playerTeamClass.getConstructor(scoreboardClass, String.class));

Class<?> objectiveRenderTypeClass = FastReflection.nmsOptionalClass("world.scores.criteria", "IScoreboardCriteria$EnumScoreboardHealthDisplay", "ObjectiveCriteria$RenderType").orElse(null);

Optional<Class<?>> numberFormat = FastReflection.nmsOptionalClass("network.chat.numbers", "NumberFormat");
MethodHandle packetSbSetScore;
Expand All @@ -138,6 +141,10 @@ public abstract class FastBoardBase<T> {
boolean scoreOptionalComponents = false;

if (numberFormat.isPresent()) { // 1.20.3
OBJECTIVE = lookup.unreflectConstructor(objectiveClass.getConstructor(scoreboardClass, String.class, objectiveCriteriaClass, CHAT_COMPONENT_CLASS, objectiveRenderTypeClass, boolean.class, numberFormat.get()));
PACKET_SB_OBJ = lookup.unreflectConstructor(packetSbObjClass.getConstructor(objectiveClass, int.class));
PACKET_SB_DISPLAY_OBJ = lookup.unreflectConstructor(packetSbDisplayObjClass.getConstructor(DISPLAY_SLOT_TYPE, objectiveClass));

Class<?> blankFormatClass = FastReflection.nmsClass("network.chat.numbers", "BlankFormat");
Class<?> fixedFormatClass = FastReflection.nmsClass("network.chat.numbers", "FixedFormat");
Class<?> resetScoreClass = FastReflection.nmsClass(gameProtocolPackage, "ClientboundResetScorePacket");
Expand All @@ -158,31 +165,31 @@ public abstract class FastBoardBase<T> {
Class<?> enumSbAction = FastReflection.nmsClass("server", "ScoreboardServer$Action", "ServerScoreboard$Method");
MethodType scoreType = MethodType.methodType(void.class, enumSbAction, String.class, String.class, int.class);
packetSbSetScore = lookup.findConstructor(packetSbScoreClass, scoreType);
OBJECTIVE = lookup.unreflectConstructor(objectiveClass.getConstructor(scoreboardClass, String.class, objectiveCriteriaClass, CHAT_COMPONENT_CLASS, objectiveRenderTypeClass));
PACKET_SB_OBJ = lookup.unreflectConstructor(packetSbObjClass.getConstructor(objectiveClass, int.class));
PACKET_SB_DISPLAY_OBJ = lookup.unreflectConstructor(packetSbDisplayObjClass.getConstructor(int.class, objectiveClass));
} else {
packetSbSetScore = lookup.findConstructor(packetSbScoreClass, MethodType.methodType(void.class));
if (VersionType.V1_13.isHigherOrEqual()) {
OBJECTIVE = lookup.unreflectConstructor(objectiveClass.getConstructor(scoreboardClass, String.class, objectiveCriteriaClass, CHAT_COMPONENT_CLASS, objectiveRenderTypeClass));
} else {
OBJECTIVE = lookup.unreflectConstructor(objectiveClass.getConstructor(scoreboardClass, String.class, objectiveCriteriaClass));
}
PACKET_SB_OBJ = lookup.unreflectConstructor(packetSbObjClass.getConstructor(objectiveClass, int.class));
PACKET_SB_DISPLAY_OBJ = lookup.unreflectConstructor(packetSbDisplayObjClass.getConstructor(int.class, objectiveClass));
}

PACKET_SB_SET_SCORE = packetSbSetScore;
PACKET_SB_RESET_SCORE = packetSbResetScore;
PACKET_SB_TEAM = FastReflection.findPacketConstructor(packetSbTeamClass, lookup);
PACKET_SB_SERIALIZABLE_TEAM = sbTeamClass != null ? FastReflection.findPacketConstructor(sbTeamClass, lookup) : null;
Constructor<?> packetSbTeamConstructor = sbTeamClass != null ? packetSbTeamClass.getDeclaredConstructor(String.class, int.class, Optional.class, Collection.class) : packetSbTeamClass.getDeclaredConstructor();
packetSbTeamConstructor.setAccessible(true);
PACKET_SB_TEAM = lookup.unreflectConstructor(packetSbTeamConstructor);
PACKET_SB_SERIALIZABLE_TEAM = sbTeamClass != null ? lookup.unreflectConstructor(sbTeamClass.getConstructor(playerTeamClass)) : null;
FIXED_NUMBER_FORMAT = fixedFormatConstructor;
BLANK_NUMBER_FORMAT = blankNumberFormat;
SCORE_OPTIONAL_COMPONENTS = scoreOptionalComponents;

if (VersionType.V1_17.isHigherOrEqual()) {
ENUM_VISIBILITY = FastReflection.nmsClass("world.scores", "ScoreboardTeamBase$EnumNameTagVisibility", "Team$Visibility");
ENUM_COLLISION_RULE = FastReflection.nmsClass("world.scores", "ScoreboardTeamBase$EnumTeamPush", "Team$CollisionRule");
ENUM_VISIBILITY_ALWAYS = FastReflection.enumValueOf(ENUM_VISIBILITY, "ALWAYS", 0);
ENUM_COLLISION_RULE_ALWAYS = FastReflection.enumValueOf(ENUM_COLLISION_RULE, "ALWAYS", 0);
} else {
ENUM_VISIBILITY = null;
ENUM_COLLISION_RULE = null;
ENUM_VISIBILITY_ALWAYS = null;
ENUM_COLLISION_RULE_ALWAYS = null;
}

for (Class<?> clazz : Arrays.asList(packetSbObjClass, packetSbDisplayObjClass, packetSbScoreClass, packetSbTeamClass, sbTeamClass)) {
for (Class<?> clazz : Arrays.asList(packetSbScoreClass, packetSbTeamClass, sbTeamClass, playerTeamClass, objectiveClass)) {
if (clazz == null) {
continue;
}
Expand Down Expand Up @@ -211,6 +218,11 @@ public abstract class FastBoardBase<T> {
ENUM_SB_ACTION_CHANGE = null;
ENUM_SB_ACTION_REMOVE = null;
}
if (VersionType.V1_13.isHigherOrEqual()) {
DUMMY_SCOREBOARD_CRITERIA = null;
} else {
DUMMY_SCOREBOARD_CRITERIA = FastReflection.nmsClass("world.scores.criteria", "ScoreboardBaseCriteria").getConstructor(String.class).newInstance("dummy");
}
} catch (Throwable t) {
throw new ExceptionInInitializerError(t);
}
Expand All @@ -235,8 +247,8 @@ protected FastBoardBase(Player player) {
this.id = "fb-" + Integer.toHexString(ThreadLocalRandom.current().nextInt());

try {
sendObjectivePacket(ObjectiveMode.CREATE);
sendDisplayObjectivePacket();
Object objective = sendObjectivePacket(ObjectiveMode.CREATE);
sendDisplayObjectivePacket(objective);
} catch (Throwable t) {
throw new RuntimeException("Unable to create scoreboard", t);
}
Expand Down Expand Up @@ -641,32 +653,53 @@ protected T getLineByScore(List<T> lines, int score) {
return score < lines.size() ? lines.get(lines.size() - score - 1) : null;
}

protected void sendObjectivePacket(ObjectiveMode mode) throws Throwable {
Object packet = PACKET_SB_OBJ.invoke();

setField(packet, String.class, this.id);
setField(packet, int.class, mode.ordinal());

if (mode != ObjectiveMode.REMOVE) {
setComponentField(packet, this.title, 1);
setField(packet, Optional.class, Optional.empty()); // Number format for 1.20.5+, previously nullable

if (VersionType.V1_8.isHigherOrEqual()) {
setField(packet, ENUM_SB_HEALTH_DISPLAY, ENUM_SB_HEALTH_DISPLAY_INTEGER);
}
} else if (VERSION_TYPE == VersionType.V1_7) {
setField(packet, String.class, "", 1);
protected Object sendObjectivePacket(ObjectiveMode mode) throws Throwable {
Object objective;
if (BLANK_NUMBER_FORMAT != null) {
objective = OBJECTIVE.invoke(
null, // Scoreboard, unused
this.id, // Objective name
null, // Criteria, unused
toMinecraftComponent(this.title), // Display name
ENUM_SB_HEALTH_DISPLAY_INTEGER, // Render type
false, // Auto-update, unused
null // Number format
);
} else if (VersionType.V1_17.isHigherOrEqual()) {
objective = OBJECTIVE.invoke(
null, // Scoreboard, unused
this.id, // Objective name
null, // Criteria, unused
toMinecraftComponent(this.title), // Display name
ENUM_SB_HEALTH_DISPLAY_INTEGER // Render type
);
} else if (VersionType.V1_13.isHigherOrEqual()) {
objective = OBJECTIVE.invoke(
null, // Scoreboard, unused
this.id, // Objective name
null, // Criteria, unused
toMinecraftComponent(this.title), // Display name
ENUM_SB_HEALTH_DISPLAY_INTEGER // Render type
);
} else {
objective = OBJECTIVE.invoke(
null, // Scoreboard, unused
this.id, // Objective name
DUMMY_SCOREBOARD_CRITERIA // Criteria
);
setComponentField(objective, this.title, 1);
}

Object packet = PACKET_SB_OBJ.invoke(objective, mode.ordinal());
sendPacket(packet);
return objective;
}

protected void sendDisplayObjectivePacket() throws Throwable {
Object packet = PACKET_SB_DISPLAY_OBJ.invoke();

setField(packet, DISPLAY_SLOT_TYPE, SIDEBAR_DISPLAY_SLOT); // Position
setField(packet, String.class, this.id); // Score Name

protected void sendDisplayObjectivePacket(Object objective) throws Throwable {
Object packet = PACKET_SB_DISPLAY_OBJ.invoke(
SIDEBAR_DISPLAY_SLOT, // Position
objective // Score Name
);
sendPacket(packet);
}

Expand Down Expand Up @@ -732,37 +765,47 @@ protected void sendTeamPacket(int score, TeamMode mode, T prefix, T suffix)
throw new UnsupportedOperationException();
}

Object packet = PACKET_SB_TEAM.invoke();

setField(packet, String.class, this.id + ':' + score); // Team name
setField(packet, int.class, mode.ordinal(), VERSION_TYPE == VersionType.V1_8 ? 1 : 0); // Update mode

Object packet;
if (mode == TeamMode.REMOVE) {
if (VersionType.V1_17.isHigherOrEqual()) {
packet = PACKET_SB_TEAM.invoke(
this.id + ':' + score, // Team name
mode.ordinal(), // Update mode
Optional.empty(), // Serializable team, unused
Collections.emptyList() // Players
);
} else {
packet = PACKET_SB_TEAM.invoke();
setField(packet, String.class, this.id + ':' + score); // Team name
setField(packet, int.class, mode.ordinal(), VERSION_TYPE == VersionType.V1_8 ? 1 : 0); // Update mode
}
sendPacket(packet);
return;
}

if (VersionType.V1_17.isHigherOrEqual()) {
Object team = PACKET_SB_SERIALIZABLE_TEAM.invoke();
// Since the packet is initialized with null values, we need to change more things.
setComponentField(team, null, 0); // Display name
setField(team, CHAT_FORMAT_ENUM, RESET_FORMATTING); // Color
setComponentField(team, prefix, 1); // Prefix
setComponentField(team, suffix, 2); // Suffix
setField(team, String.class, "always", 0); // Visibility before 1.21.5
setField(team, String.class, "always", 1); // Collisions before 1.21.5
setField(team, ENUM_VISIBILITY, ENUM_VISIBILITY_ALWAYS, 0); // 1.21.5+
setField(team, ENUM_COLLISION_RULE, ENUM_COLLISION_RULE_ALWAYS, 0); // 1.21.5+
setField(packet, Optional.class, Optional.of(team));
Object team = PLAYER_TEAM.invoke(null, this.id + ':' + score);
setComponentField(team, null, 1); // Display name
setComponentField(team, prefix, 2); // Prefix
setComponentField(team, suffix, 3); // Suffix
Object serializableTeam = PACKET_SB_SERIALIZABLE_TEAM.invoke(team);
packet = PACKET_SB_TEAM.invoke(
this.id + ':' + score, // Team name
mode.ordinal(), // Update mode
Optional.of(serializableTeam), // Serializable team
mode == TeamMode.CREATE ? Collections.singletonList(COLOR_CODES[score]) : Collections.emptyList() // Players
);
} else {
packet = PACKET_SB_TEAM.invoke();
setField(packet, String.class, this.id + ':' + score); // Team name
setField(packet, int.class, mode.ordinal(), VERSION_TYPE == VersionType.V1_8 ? 1 : 0); // Update mode
setComponentField(packet, prefix, 2); // Prefix
setComponentField(packet, suffix, 3); // Suffix
setField(packet, String.class, "always", 4); // Visibility for 1.8+
setField(packet, String.class, "always", 5); // Collisions for 1.9+
}

if (mode == TeamMode.CREATE) {
setField(packet, Collection.class, Collections.singletonList(COLOR_CODES[score])); // Players in the team
if (mode == TeamMode.CREATE) {
setField(packet, Collection.class, Collections.singletonList(COLOR_CODES[score])); // Players in the team
}
}

sendPacket(packet);
Expand Down
33 changes: 0 additions & 33 deletions src/main/java/fr/mrmicky/fastboard/FastReflection.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -28,7 +28,6 @@
import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.MethodType;
import java.lang.reflect.Field;
import java.util.Optional;
import java.util.function.Predicate;

Expand All @@ -43,12 +42,9 @@ public final class FastReflection {
private static final String OBC_PACKAGE = Bukkit.getServer().getClass().getPackage().getName();
private static final String NMS_PACKAGE = OBC_PACKAGE.replace("org.bukkit.craftbukkit", NM_PACKAGE + ".server");

private static final MethodType VOID_METHOD_TYPE = MethodType.methodType(void.class);
private static final boolean NMS_REPACKAGED = optionalClass(NM_PACKAGE + ".network.protocol.Packet").isPresent();
private static final boolean MOJANG_MAPPINGS = optionalClass(NM_PACKAGE + ".network.chat.Component").isPresent();

private static volatile Object theUnsafe;

private FastReflection() {
throw new UnsupportedOperationException();
}
Expand Down Expand Up @@ -135,33 +131,4 @@ static Optional<MethodHandle> optionalConstructor(Class<?> declaringClass, Metho
return Optional.empty();
}
}

public static PacketConstructor findPacketConstructor(Class<?> packetClass, MethodHandles.Lookup lookup) throws Exception {
try {
MethodHandle constructor = lookup.findConstructor(packetClass, VOID_METHOD_TYPE);
return constructor::invoke;
} catch (NoSuchMethodException | IllegalAccessException e) {
// try below with Unsafe
}

if (theUnsafe == null) {
synchronized (FastReflection.class) {
if (theUnsafe == null) {
Class<?> unsafeClass = Class.forName("sun.misc.Unsafe");
Field theUnsafeField = unsafeClass.getDeclaredField("theUnsafe");
theUnsafeField.setAccessible(true);
theUnsafe = theUnsafeField.get(null);
}
}
}

MethodType allocateMethodType = MethodType.methodType(Object.class, Class.class);
MethodHandle allocateMethod = lookup.findVirtual(theUnsafe.getClass(), "allocateInstance", allocateMethodType);
return () -> allocateMethod.invoke(theUnsafe, packetClass);
}

@FunctionalInterface
interface PacketConstructor {
Object invoke() throws Throwable;
}
}
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