com.google.inject.internal.InternalContext Maven / Gradle / Ivy
/*
* Copyright (C) 2006 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 com.google.inject.internal;
import com.google.inject.internal.InjectorImpl.InjectorOptions;
import com.google.inject.spi.Dependency;
import java.util.IdentityHashMap;
/**
* Internal context. Used to coordinate injections and support circular dependencies.
*
* @author [email protected] (Bob Lee)
*/
final class InternalContext implements AutoCloseable {
private final InjectorOptions options;
private final IdentityHashMap> constructionContexts =
new IdentityHashMap<>();
/** Keeps track of the type that is currently being requested for injection. */
private Dependency dependency;
/**
* The number of times {@link #enter()} has been called + 1 for initial construction. This value
* is decremented when {@link #exit()} is called.
*/
private int enterCount;
/**
* A single element array to clear when the {@link #enterCount} hits {@code 0}.
*
* This is the value stored in the {@code InjectorImpl.localContext} thread local.
*/
private final Object[] toClear;
InternalContext(InjectorOptions options, Object[] toClear) {
this.options = options;
this.toClear = toClear;
this.enterCount = 1;
}
/** Should only be called by InjectorImpl.enterContext(). */
void enter() {
enterCount++;
}
/** Should be called any any method that received an instance via InjectorImpl.enterContext(). */
@Override
public void close() {
int newCount = --enterCount;
if (newCount < 0) {
throw new IllegalStateException("Called close() too many times");
}
if (newCount == 0) {
toClear[0] = null;
}
}
InjectorOptions getInjectorOptions() {
return options;
}
@SuppressWarnings("unchecked")
ConstructionContext getConstructionContext(Object key) {
ConstructionContext constructionContext =
(ConstructionContext) constructionContexts.get(key);
if (constructionContext == null) {
constructionContext = new ConstructionContext<>();
constructionContexts.put(key, constructionContext);
}
return constructionContext;
}
Dependency getDependency() {
return dependency;
}
/**
* Used to set the current dependency.
*
* The currentDependency field is only used by InternalFactoryToProviderAdapter to propagate
* information to singleton scope. See comments in that class about alternatives.
*/
void setDependency(Dependency dependency) {
this.dependency = dependency;
}
}