Initial contextual data work

src/main/java/org/spongepowered/common/bridge/data/VanishableBridge.java

@@ -24,6 +24,7 @@
  */
 package org.spongepowered.common.bridge.data;
 
+import org.spongepowered.api.data.DataPerspective;
 import org.spongepowered.api.effect.VanishState;
 
 public interface VanishableBridge {
@@ -32,6 +33,8 @@ public interface VanishableBridge {
 
     void bridge$vanishState(VanishState state);
 
+    void bridge$vanishState(VanishState state, DataPerspective perspective);
+
     boolean bridge$isInvisible();
 
     void bridge$setInvisible(boolean invisible);

src/main/java/org/spongepowered/common/data/ContextualDataHolder.java

@@ -0,0 +1,246 @@
+/*
+ * This file is part of Sponge, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) SpongePowered <https://www.spongepowered.org>
+ * Copyright (c) contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package org.spongepowered.common.data;
+
+import com.google.common.collect.Maps;
+import org.checkerframework.checker.nullness.qual.Nullable;
+import org.spongepowered.api.data.DataHolder;
+import org.spongepowered.api.data.DataPerspective;
+import org.spongepowered.api.data.DataPerspectiveResolver;
+import org.spongepowered.api.data.DataTransactionResult;
+import org.spongepowered.api.data.Key;
+import org.spongepowered.api.data.value.Value;
+import org.spongepowered.api.data.value.ValueContainer;
+import org.spongepowered.api.entity.Entity;
+import org.spongepowered.api.scoreboard.Team;
+import org.spongepowered.api.world.World;
+import org.spongepowered.common.util.CopyHelper;
+import org.spongepowered.plugin.PluginContainer;
+
+import java.util.EnumMap;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Optional;
+import java.util.Set;
+
+@SuppressWarnings("unchecked")
+public final class ContextualDataHolder {
+
+    private final DataHolder dataHolder;
+    private final Map<DataPerspective, PerspectiveContainer<?>> perspectives;
+
+    public ContextualDataHolder(final DataHolder dataHolder) {
+        this.dataHolder = dataHolder;
+
+        this.perspectives = Maps.newHashMap();
+    }
+
+    private PerspectiveContainer<?> createDataPerception(final DataPerspective perspective) {
+        return this.perspectives.computeIfAbsent(perspective, p -> {
+            if (p instanceof final Entity entity) {
+                return new EntityPerspectiveContainer(entity);
+            } else if (p instanceof final Team team) {
+                return new TeamPerspectiveContainer(team);
+            } else if (p instanceof final World<?, ?> world) {
+                return new WorldPerspectiveContainer(world);
+            }
+            throw new UnsupportedOperationException();
+        });
+    }
+
+    public DataHolder.Mutable createDataPerception(final PluginContainer plugin, final DataPerspective perspective) {
+        return new ContextualDataHolderProvider(plugin, this.createDataPerception(perspective));
+    }
+
+    public @Nullable ValueContainer get(final DataPerspective perspective) {
+        return this.perspectives.get(perspective);
+    }
+
+    abstract class PerspectiveContainer<T extends DataPerspective> implements ValueContainer {
+
+        protected final T perspective;
+
+        private final Map<Key<?>, Map<PluginContainer, Object>> pluginValues;
+        protected final Map<Key<?>, Object> activeValues;
+
+        protected PerspectiveContainer(final T perspective) {
+            this.perspective = perspective;
+
+            this.pluginValues = Maps.newHashMap();
+            this.activeValues = Maps.newHashMap();
+        }
+
+        <E> DataTransactionResult offer(final PluginContainer pluginContainer, final Key<? extends Value<E>> key, final E value) {
+            final @Nullable DataPerspectiveResolver<Value<E>, E> resolver = SpongeDataManager.getDataPerspectiveResolverRegistry().get(key);
+            if (resolver == null) {
+                return DataTransactionResult.failResult(Value.immutableOf(key, value));
+            }
+
+            final Map<PluginContainer, E> map = (Map<PluginContainer, E>) this.pluginValues.computeIfAbsent(key, k -> Maps.newLinkedHashMap());
+            if (Objects.equals(value, map.put(pluginContainer, value))) {
+                return DataTransactionResult.successResult(Value.immutableOf(key, value));
+            }
+
+            final E mergedValue = resolver.merge(map.values());
+            this.offer(key, resolver, mergedValue);
+            return DataTransactionResult.successResult(Value.immutableOf(key, mergedValue));
+        }
+
+        protected abstract <E> void offer(final Key<? extends Value<E>> key, final DataPerspectiveResolver<Value<E>, E> resolver, final E value);
+
+        @Override
+        public <E> Optional<E> get(final Key<? extends Value<E>> key) {
+            Objects.requireNonNull(key, "key");
+            final @Nullable E value = (E) this.activeValues.get(key);
+            if (value == null) {
+                return ContextualDataHolder.this.dataHolder.get(key);
+            }
+            return Optional.of(CopyHelper.copy(value));
+        }
+
+        @Override
+        public <E, V extends Value<E>> Optional<V> getValue(final Key<V> key) {
+            Objects.requireNonNull(key, "key");
+            final @Nullable E value = (E) this.activeValues.get(key);
+            if (value == null) {
+                return ContextualDataHolder.this.dataHolder.getValue(key);
+            }
+            return Optional.of(Value.genericMutableOf(key, CopyHelper.copy(value)));
+        }
+
+        @Override
+        public boolean supports(Key<?> key) {
+            return ContextualDataHolder.this.dataHolder.supports(key);
+        }
+
+        @Override
+        public Set<Key<?>> getKeys() {
+            return ContextualDataHolder.this.dataHolder.getKeys();
+        }
+
+        @Override
+        public Set<Value.Immutable<?>> getValues() {
+            return ContextualDataHolder.this.dataHolder.getValues();
+        }
+    }
+
+    private abstract class NonEntityContainer<T extends DataPerspective> extends PerspectiveContainer<T> {
+
+        protected NonEntityContainer(T perspective) {
+            super(perspective);
+        }
+
+        protected abstract PerspectiveType type();
+
+        protected <E> void offer(final Key<? extends Value<E>> key, final DataPerspectiveResolver<Value<E>, E> resolver, final E value) {
+            if (Objects.equals(this.activeValues.put(key, value), value)) {
+                return;
+            }
+
+            for (final DataPerspective perspective : this.perspective.perceives()) {
+                if (!(perspective instanceof Entity entity)) {
+                    continue;
+                }
+
+                final EntityPerspectiveContainer entityContainer = (EntityPerspectiveContainer) ContextualDataHolder.this.createDataPerception(entity);
+                entityContainer.offer(this.type(), key, resolver, value);
+            }
+        }
+    }
+
+    private final class TeamPerspectiveContainer extends NonEntityContainer<Team> {
+
+        public TeamPerspectiveContainer(final Team team) {
+            super(team);
+        }
+
+        @Override
+        protected PerspectiveType type() {
+            return PerspectiveType.TEAM;
+        }
+    }
+
+    private final class WorldPerspectiveContainer extends NonEntityContainer<World<?, ?>> {
+
+        public WorldPerspectiveContainer(final World<?, ?> world) {
+            super(world);
+        }
+
+        @Override
+        protected PerspectiveType type() {
+            return PerspectiveType.WORLD;
+        }
+    }
+
+    private final class EntityPerspectiveContainer extends PerspectiveContainer<Entity> {
+
+        private final Map<Key<?>, EnumMap<PerspectiveType, Object>> perspectiveValues;
+
+        public EntityPerspectiveContainer(final Entity entity) {
+            super(entity);
+
+            this.perspectiveValues = Maps.newHashMap();
+        }
+
+        private <E> EnumMap<PerspectiveType, E> getValues(final Key<? extends Value<E>> key) {
+            return (EnumMap<PerspectiveType, E>) this.perspectiveValues.computeIfAbsent(key, k -> Maps.newEnumMap(PerspectiveType.class));
+        }
+
+        @Override
+        protected <E> void offer(final Key<? extends Value<E>> key, final DataPerspectiveResolver<Value<E>, E> resolver, final E value) {
+            this.getValues(key).put(PerspectiveType.ENTITY, value);
+            if (!Objects.equals(value, this.activeValues.put(key, value))) {
+                resolver.apply(ContextualDataHolder.this.dataHolder, this.perspective, value);
+            }
+        }
+
+        <E> void offer(final PerspectiveType type, final Key<? extends Value<E>> key, final DataPerspectiveResolver<Value<E>, E> resolver, final E value) {
+            final EnumMap<PerspectiveType, E> values = this.getValues(key);
+            values.put(type, value);
+            this.updatePerspective(key, values, resolver);
+        }
+
+        private <E> void updatePerspective(final Key<? extends Value<E>> key, final EnumMap<PerspectiveType, E> values, final DataPerspectiveResolver<Value<E>, E> resolver) {
+            for (final PerspectiveType type : PerspectiveType.values()) {
+                final @Nullable E value = values.get(type);
+                if (value == null) {
+                    continue;
+                }
+
+                if (!Objects.equals(this.activeValues.put(key, value), value)) {
+                    resolver.apply(ContextualDataHolder.this.dataHolder, this.perspective, value);
+                }
+
+                return;
+            }
+        }
+    }
+
+    private enum PerspectiveType {
+        ENTITY,
+        TEAM,
+        WORLD
+    }
+}