/**
* PermissionsEx
* Copyright (C) zml and PermissionsEx contributors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package ninja.leaping.permissionsex.data;
import com.github.benmanes.caffeine.cache.AsyncLoadingCache;
import com.github.benmanes.caffeine.cache.Caffeine;
import com.google.common.collect.Maps;
import ninja.leaping.permissionsex.PermissionsEx;
import ninja.leaping.permissionsex.backend.DataStore;
import javax.annotation.Nullable;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.atomic.AtomicReference;
import java.util.function.Function;
public class SubjectCache {
private final String type;
private DataStore dataStore;
private final AtomicReference<AsyncLoadingCache<String, ImmutableSubjectData>> cache = new AtomicReference<>();
private final Map<String, Caching<ImmutableSubjectData>> cacheHolders = new ConcurrentHashMap<>();
private final CacheListenerHolder<String, ImmutableSubjectData> listeners;
private final Map.Entry<String, String> defaultIdentifier;
public SubjectCache(final String type, final DataStore dataStore) {
this.type = type;
update(dataStore);
this.defaultIdentifier = Maps.immutableEntry(PermissionsEx.SUBJECTS_DEFAULTS, type);
this.listeners = new CacheListenerHolder<>();
}
public void update(DataStore newDataStore) {
this.dataStore = newDataStore;
AsyncLoadingCache<String, ImmutableSubjectData> oldCache = this.cache.getAndSet(Caffeine.newBuilder()
.maximumSize(512)
.buildAsync(((key, executor) -> dataStore.getData(type, key, clearListener(key)))));
if (oldCache != null) {
oldCache.synchronous().asMap().forEach((k, v) -> {
getData(k, null).thenAccept(data -> listeners.call(k, data));
// TODO: Not ignore this somehow? Add a listener in to the backend?
});
}
}
public CompletableFuture<ImmutableSubjectData> getData(String identifier, Caching<ImmutableSubjectData> listener) {
Objects.requireNonNull(identifier, "identifier");
CompletableFuture<ImmutableSubjectData> ret = cache.get().get(identifier);
ret.thenRun(() -> {
if (listener != null) {
listeners.addListener(identifier, listener);
}
});
return ret;
}
public CompletableFuture<SubjectDataReference> getReference(String identifier) {
return getReference(identifier, true);
}
public CompletableFuture<SubjectDataReference> getReference(String identifier, boolean strongListeners) {
final SubjectDataReference ref = new SubjectDataReference(identifier, this, strongListeners);
return getData(identifier, ref).thenApply(data -> {
ref.data.set(data);
return ref;
});
}
public CompletableFuture<ImmutableSubjectData> update(String identifier, Function<ImmutableSubjectData, ImmutableSubjectData> action) {
return getData(identifier, null)
.thenCompose(data -> {
ImmutableSubjectData newData = action.apply(data);
if (data != newData) {
return set(identifier, newData);
} else {
return CompletableFuture.completedFuture(data);
}
});
}
public void load(String identifier) throws ExecutionException {
Objects.requireNonNull(identifier, "identifier");
cache.get().get(identifier);
}
public void invalidate(String identifier) {
Objects.requireNonNull(identifier, "identifier");
cache.get().synchronous().invalidate(identifier);
cacheHolders.remove(identifier);
listeners.removeAll(identifier);
}
public void cacheAll() {
for (String ident : dataStore.getAllIdentifiers(type)) {
cache.get().synchronous().refresh(ident);
}
}
public CompletableFuture<Boolean> isRegistered(String identifier) {
Objects.requireNonNull(identifier, "identifier");
return dataStore.isRegistered(type, identifier);
}
public CompletableFuture<ImmutableSubjectData> remove(String identifier) {
return set(identifier, null);
}
CompletableFuture<ImmutableSubjectData> set(String identifier, @Nullable ImmutableSubjectData newData) {
Objects.requireNonNull(identifier, "identifier");
return dataStore.setData(type, identifier, newData);
}
private Caching<ImmutableSubjectData> clearListener(final String name) {
Caching<ImmutableSubjectData> ret = newData -> {
cache.get().put(name, CompletableFuture.completedFuture(newData));
listeners.call(name, newData);
};
cacheHolders.put(name, ret);
return ret;
}
public void addListener(String identifier, Caching<ImmutableSubjectData> listener) {
Objects.requireNonNull(identifier, "identifier");
Objects.requireNonNull(listener, "listener");
listeners.addListener(identifier, listener);
}
public String getType() {
return type;
}
public Set<String> getAllIdentifiers() {
return dataStore.getAllIdentifiers(type);
}
/**
* Get the identifier for the subject holding default data for subjects of this type
* @return The id for the default subject of this type
*/
public Map.Entry<String, String> getDefaultIdentifier() {
return defaultIdentifier;
}
}