ProtocolLib/src/main/java/com/comphenix/protocol/injector/EntityUtilities.java

313 lines
13 KiB
Java

/*
* ProtocolLib - Bukkit server library that allows access to the Minecraft protocol.
* Copyright (C) 2012 Kristian S. Stangeland
*
* This program is free software; you can redistribute it and/or modify it under the terms of the
* GNU General Public License as published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along with this program;
* if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
* 02111-1307 USA
*/
package com.comphenix.protocol.injector;
import com.comphenix.protocol.reflect.FieldAccessException;
import com.comphenix.protocol.reflect.FuzzyReflection;
import com.comphenix.protocol.reflect.accessors.Accessors;
import com.comphenix.protocol.reflect.accessors.FieldAccessor;
import com.comphenix.protocol.reflect.accessors.MethodAccessor;
import com.comphenix.protocol.reflect.fuzzy.FuzzyFieldContract;
import com.comphenix.protocol.reflect.fuzzy.FuzzyMethodContract;
import com.comphenix.protocol.utility.MinecraftFields;
import com.comphenix.protocol.utility.MinecraftReflection;
import com.comphenix.protocol.utility.MinecraftVersion;
import com.comphenix.protocol.utility.Util;
import com.comphenix.protocol.wrappers.WrappedIntHashMap;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.commons.lang.Validate;
import org.bukkit.World;
import org.bukkit.entity.Entity;
import org.bukkit.entity.Player;
/**
* Used to perform certain operations on entities.
*
* @author Kristian
*/
class EntityUtilities {
private static final EntityUtilities INSTANCE = new EntityUtilities();
private static final boolean NEW_TRACKER = MinecraftVersion.VILLAGE_UPDATE.atOrAbove();
private final Map<Class<?>, MethodAccessor> scanPlayersMethods = new ConcurrentHashMap<>();
private final Map<Class<?>, FieldAccessor> trackedEntityFields = new ConcurrentHashMap<>();
private FieldAccessor chunkMapField;
private FieldAccessor entityTrackerField;
private FieldAccessor trackedPlayersField;
private FieldAccessor trackedEntitiesField;
private FieldAccessor foliaTrackerField;
private MethodAccessor getEntity;
private MethodAccessor getChunkProvider;
private EntityUtilities() {
}
public static EntityUtilities getInstance() {
return INSTANCE;
}
public void updateEntity(Entity entity, List<Player> observers) {
if (entity == null || !entity.isValid()) {
return;
}
Collection<?> trackedPlayers = this.getTrackedPlayers(entity);
List<Object> nmsPlayers = this.unwrapBukkit(observers);
List<Object> removingEntries =
MinecraftVersion.CAVES_CLIFFS_1.atOrAbove() ? this.getPlayerConnections(nmsPlayers) : nmsPlayers;
trackedPlayers.removeAll(removingEntries);
// there can be multiple different entity tracker entry impls, see GH-732....
Object trackerEntry = this.getEntityTrackerEntry(entity.getWorld(), entity.getEntityId());
this.scanPlayersMethods.computeIfAbsent(trackerEntry.getClass(), this::findScanPlayers)
.invoke(trackerEntry, nmsPlayers);
}
public Entity getEntity(World world, int id) {
// new tracker registers the entity before sending out any packets - we can use the supported getter method here
if (NEW_TRACKER) {
Object level = BukkitUnwrapper.getInstance().unwrapItem(world);
if (this.getEntity == null) {
Method entityGetter = FuzzyReflection.fromObject(level).getMethodByReturnTypeAndParameters(
"getEntity",
MinecraftReflection.getEntityClass(),
int.class);
this.getEntity = Accessors.getMethodAccessor(entityGetter);
}
Object entity = this.getEntity.invoke(level, id);
return (Entity) MinecraftReflection.getBukkitEntity(entity);
}
// old tracker - now the pain begins
Object trackerEntry = this.getEntityTrackerEntry(world, id);
if (trackerEntry == null) {
// not tracked
return null;
}
FieldAccessor trackedEntityAccessor = this.trackedEntityFields.computeIfAbsent(trackerEntry.getClass(), clz -> {
try {
// try to get the first entity field from the tracker class
Field entityField = FuzzyReflection.fromClass(clz, true).getField(FuzzyFieldContract.newBuilder()
.typeExact(MinecraftReflection.getEntityClass())
.build());
return Accessors.getFieldAccessor(entityField);
} catch (IllegalArgumentException exception) {
// no such field, try the base tracker class instead
Class<?> trackerClass = MinecraftReflection.getEntityTrackerClass();
Field entityField = FuzzyReflection.fromClass(trackerClass, true).getField(FuzzyFieldContract.newBuilder()
.typeExact(MinecraftReflection.getEntityClass())
.build());
return Accessors.getFieldAccessor(entityField);
}
});
Object entity = trackedEntityAccessor.get(trackerEntry);
return (Entity) MinecraftReflection.getBukkitEntity(entity);
}
private MethodAccessor findScanPlayers(Class<?> trackerClass) {
MethodAccessor candidate = Accessors.getMethodAccessorOrNull(trackerClass, "scanPlayers");
if (candidate != null) {
return candidate;
}
FuzzyReflection fuzzy = FuzzyReflection.fromClass(trackerClass, true);
return Accessors.getMethodAccessor(fuzzy.getMethod(FuzzyMethodContract.newBuilder()
.returnTypeVoid()
.parameterExactArray(List.class)
.build()));
}
/**
* Retrieve every client that is receiving information about a given entity.
*
* @param entity - the entity that is being tracked.
* @return Every client/player that is tracking the given entity.
* @throws FieldAccessException If reflection failed.
*/
public List<Player> getEntityTrackers(Entity entity) {
if (entity == null || !entity.isValid()) {
return new ArrayList<>();
}
List<Player> result = new ArrayList<>();
Collection<?> trackedPlayers = this.getTrackedPlayers(entity);
// Wrap every player - we also ensure that the underlying tracker list is immutable
for (Object tracker : trackedPlayers) {
if (MinecraftVersion.CAVES_CLIFFS_1.atOrAbove() && MinecraftReflection.isServerHandler(tracker)) {
result.add(MinecraftReflection.getBukkitPlayerFromConnection(tracker));
} else if (MinecraftReflection.isMinecraftPlayer(tracker)) {
result.add((Player) MinecraftReflection.getBukkitEntity(tracker));
}
}
return result;
}
private Collection<?> getTrackedPlayers(Entity entity) {
Validate.notNull(entity, "entity cannot be null");
Object trackerEntry = this.getEntityTrackerEntry(entity.getWorld(), entity.getEntityId());
if (trackerEntry == null) { //entity.toString() is too expensive to be called every time
throw new IllegalArgumentException("Could not find entity trackers for " + entity);
}
if (this.trackedPlayersField == null) {
this.trackedPlayersField = Accessors.getFieldAccessor(
FuzzyReflection.fromObject(trackerEntry).getFieldByType("java\\.util\\..*"));
}
Validate.notNull(this.trackedPlayersField, "Could not find trackedPlayers field");
Object value = this.trackedPlayersField.get(trackerEntry);
if (value instanceof Collection) {
return (Collection<?>) value;
} else if (value instanceof Map) {
return ((Map<?, ?>) value).keySet();
} else {
// Please. No more changes.
throw new IllegalStateException(
"trackedPlayers field was an unknown type: expected Collection or Map, but got " + value.getClass());
}
}
@SuppressWarnings("unchecked")
private Object getNewEntityTracker(Object worldServer, int entityId) {
if (Util.isUsingFolia()) {
if (this.getEntity == null) {
Method entityGetter = FuzzyReflection.fromObject(worldServer).getMethodByReturnTypeAndParameters(
"getEntity",
MinecraftReflection.getEntityClass(),
int.class);
this.getEntity = Accessors.getMethodAccessor(entityGetter);
}
Object entity = this.getEntity.invoke(worldServer, entityId);
if (this.foliaTrackerField == null) {
this.foliaTrackerField = Accessors.getFieldAccessor(FuzzyReflection.fromClass(entity.getClass(), false)
.getField(FuzzyFieldContract.newBuilder().typeExact(MinecraftReflection.getEntityTrackerClass()).build()));
}
return this.foliaTrackerField.get(entity);
}
if (this.getChunkProvider == null) {
Class<?> chunkProviderClass = MinecraftReflection.getChunkProviderServer();
this.getChunkProvider = Accessors.getMethodAccessor(FuzzyReflection.fromClass(worldServer.getClass(), false)
.getMethod(FuzzyMethodContract.newBuilder().parameterCount(0).returnTypeExact(chunkProviderClass).build()));
}
Object chunkProvider = this.getChunkProvider.invoke(worldServer);
if (this.chunkMapField == null) {
Class<?> chunkMapClass = MinecraftReflection.getPlayerChunkMap();
this.chunkMapField = Accessors.getFieldAccessor(FuzzyReflection.fromClass(chunkProvider.getClass(), false)
.getField(FuzzyFieldContract.newBuilder().typeExact(chunkMapClass).build()));
}
Object playerChunkMap = this.chunkMapField.get(chunkProvider);
if (this.trackedEntitiesField == null) {
if (MinecraftVersion.CAVES_CLIFFS_1.atOrAbove()) {
this.trackedEntitiesField = Accessors.getFieldAccessor(
FuzzyReflection.fromClass(playerChunkMap.getClass(), true)
.getField(FuzzyFieldContract.newBuilder()
.banModifier(Modifier.STATIC)
.requirePublic()
.typeExact(MinecraftReflection.getInt2ObjectMapClass())
.build()));
} else {
this.trackedEntitiesField = Accessors.getFieldAccessor(
FuzzyReflection.fromClass(playerChunkMap.getClass(), false).getField(
FuzzyFieldContract.newBuilder().typeDerivedOf(Map.class).nameExact("trackedEntities").build()));
}
}
Map<Integer, Object> trackedEntities = (Map<Integer, Object>) this.trackedEntitiesField.get(playerChunkMap);
return trackedEntities.get(entityId);
}
private Object getEntityTrackerEntry(World world, int entityID) {
BukkitUnwrapper unwrapper = new BukkitUnwrapper();
Object worldServer = unwrapper.unwrapItem(world);
if (NEW_TRACKER) {
return this.getNewEntityTracker(worldServer, entityID);
}
if (this.entityTrackerField == null) {
this.entityTrackerField = Accessors.getFieldAccessor(FuzzyReflection.fromObject(worldServer).
getFieldByType("tracker", MinecraftReflection.getEntityTrackerClass()));
}
// Get the tracker
Object tracker = this.entityTrackerField.get(worldServer);
// Looking for an IntHashMap in the tracker entry
if (this.trackedEntitiesField == null) {
this.trackedEntitiesField = Accessors.getFieldAccessor(FuzzyReflection.fromObject(tracker, false)
.getFieldByType("trackedEntities", MinecraftReflection.getIntHashMapClass()));
}
// Read the map
Object trackedEntities = this.trackedEntitiesField.get(tracker);
return WrappedIntHashMap.fromHandle(trackedEntities).get(entityID);
}
private List<Object> getPlayerConnections(List<Object> nmsPlayers) {
List<Object> connections = new ArrayList<>(nmsPlayers.size());
nmsPlayers.forEach(nmsPlayer -> connections.add(MinecraftFields.getPlayerConnection(nmsPlayer)));
return connections;
}
private List<Object> unwrapBukkit(List<Player> players) {
final List<Object> output = new ArrayList<>();
BukkitUnwrapper unwrapper = new BukkitUnwrapper();
// Get the NMS equivalent
for (Player player : players) {
Object result = unwrapper.unwrapItem(player);
if (result != null) {
output.add(result);
} else {
throw new IllegalArgumentException("Cannot unwrap item " + player);
}
}
return output;
}
}