/*
* Copyright (C) 2008 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.spi.Dependency;
/** Resolves a single parameter, to be used in a constructor or method invocation. */
final class SingleParameterInjector<T> {
private static final Object[] NO_ARGUMENTS = {};
private final Dependency<T> dependency;
private final Object source;
private final InternalFactory<? extends T> factory;
SingleParameterInjector(Dependency<T> dependency, BindingImpl<? extends T> binding) {
this.dependency = dependency;
this.source = binding.getSource();
this.factory = binding.getInternalFactory();
}
T inject(Errors errors, InternalContext context) throws ErrorsException {
Dependency<T> localDependency = dependency;
Dependency previous = context.pushDependency(localDependency, source);
try {
return factory.get(errors.withSource(localDependency), context, localDependency, false);
} finally {
context.popStateAndSetDependency(previous);
}
}
/** Returns an array of parameter values. */
static Object[] getAll(
Errors errors, InternalContext context, SingleParameterInjector<?>[] parameterInjectors)
throws ErrorsException {
if (parameterInjectors == null) {
return NO_ARGUMENTS;
}
int numErrorsBefore = errors.size();
int size = parameterInjectors.length;
Object[] parameters = new Object[size];
// optimization: use manual for/each to save allocating an iterator here
for (int i = 0; i < size; i++) {
SingleParameterInjector<?> parameterInjector = parameterInjectors[i];
try {
parameters[i] = parameterInjector.inject(errors, context);
} catch (ErrorsException e) {
errors.merge(e.getErrors());
}
}
errors.throwIfNewErrors(numErrorsBefore);
return parameters;
}
}