shaded.com.google.inject.internal.ProvisionListenerCallbackStore Maven / Gradle / Ivy
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/*
* Copyright (C) 2011 Google Inc.
*
* 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 shaded.shaded.com.google.inject.internal;
import shaded.shaded.com.google.common.cache.CacheBuilder;
import shaded.shaded.com.google.common.cache.CacheLoader;
import shaded.shaded.com.google.common.cache.LoadingCache;
import shaded.shaded.com.google.common.collect.ImmutableList;
import shaded.shaded.com.google.common.collect.ImmutableSet;
import shaded.shaded.com.google.common.collect.Lists;
import shaded.shaded.com.google.inject.Binding;
import shaded.shaded.com.google.inject.Injector;
import shaded.shaded.com.google.inject.Key;
import shaded.shaded.com.google.inject.Stage;
import shaded.shaded.com.google.inject.spi.ProvisionListener;
import shaded.shaded.com.google.inject.spi.ProvisionListenerBinding;
import java.util.List;
import java.util.logging.Logger;
/**
* {@link ProvisionListenerStackCallback} for each key.
*
* @author [email protected] (Sam Berlin)
*/
final class ProvisionListenerCallbackStore {
// TODO(sameb): Consider exposing this in the API somehow? Maybe?
// Lots of code often want to skip over the internal stuffs.
private static final ImmutableSet> INTERNAL_BINDINGS =
ImmutableSet.of(Key.get(Injector.class), Key.get(Stage.class), Key.get(Logger.class));
private final ImmutableList listenerBindings;
private final LoadingCache> cache =
CacheBuilder.newBuilder()
.build(
new CacheLoader>() {
@Override
public ProvisionListenerStackCallback load(KeyBinding key) {
return create(key.binding);
}
});
ProvisionListenerCallbackStore(List listenerBindings) {
this.listenerBindings = ImmutableList.copyOf(listenerBindings);
}
/**
* Returns a new {@link ProvisionListenerStackCallback} for the key or {@code null} if there are
* no listeners
*/
@SuppressWarnings(
"unchecked") // the ProvisionListenerStackCallback type always agrees with the passed type
public ProvisionListenerStackCallback get(Binding binding) {
// Never notify any listeners for internal bindings.
if (!INTERNAL_BINDINGS.contains(binding.getKey())) {
ProvisionListenerStackCallback callback =
(ProvisionListenerStackCallback)
cache.getUnchecked(new KeyBinding(binding.getKey(), binding));
return callback.hasListeners() ? callback : null;
}
return null;
}
/**
* Purges a key from the cache. Use this only if the type is not actually valid for binding and
* needs to be purged. (See issue 319 and
* ImplicitBindingTest#testCircularJitBindingsLeaveNoResidue and
* #testInstancesRequestingProvidersForThemselvesWithChildInjectors for examples of when this is
* necessary.)
*
* Returns true if the type was stored in the cache, false otherwise.
*/
boolean remove(Binding type) {
return cache.asMap().remove(type) != null;
}
/**
* Creates a new {@link ProvisionListenerStackCallback} with the correct listeners for the key.
*/
private ProvisionListenerStackCallback create(Binding binding) {
List listeners = null;
for (ProvisionListenerBinding provisionBinding : listenerBindings) {
if (provisionBinding.getBindingMatcher().matches(binding)) {
if (listeners == null) {
listeners = Lists.newArrayList();
}
listeners.addAll(provisionBinding.getListeners());
}
}
if (listeners == null || listeners.isEmpty()) {
// Optimization: don't bother constructing the callback if there are
// no listeners.
return ProvisionListenerStackCallback.emptyListener();
}
return new ProvisionListenerStackCallback(binding, listeners);
}
/** A struct that holds key & binding but uses just key for equality/hashcode. */
private static class KeyBinding {
final Key key;
final Binding binding;
KeyBinding(Key key, Binding binding) {
this.key = key;
this.binding = binding;
}
@Override
public boolean equals(Object obj) {
return obj instanceof KeyBinding && key.equals(((KeyBinding) obj).key);
}
@Override
public int hashCode() {
return key.hashCode();
}
}
}