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// Copyright (C) 2013 The Android Open Source Project
//
// 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.gerrit.util.cli;
import com.google.common.collect.ImmutableMap;
import com.google.gerrit.common.Nullable;
import com.google.inject.Binding;
import com.google.inject.Inject;
import com.google.inject.Injector;
import com.google.inject.Key;
import com.google.inject.Provider;
import com.google.inject.Singleton;
import com.google.inject.TypeLiteral;
import java.lang.reflect.ParameterizedType;
import java.util.Map.Entry;
@Singleton
public class OptionHandlers {
public static OptionHandlers empty() {
ImmutableMap<Class<?>, Provider<OptionHandlerFactory<?>>> m =
ImmutableMap.of();
return new OptionHandlers(m);
}
private final ImmutableMap<Class<?>, Provider<OptionHandlerFactory<?>>> map;
@Inject
OptionHandlers(Injector parent) {
this(build(parent));
}
OptionHandlers(ImmutableMap<Class<?>, Provider<OptionHandlerFactory<?>>> m) {
this.map = m;
}
@Nullable
OptionHandlerFactory<?> get(Class<?> type) {
Provider<OptionHandlerFactory<?>> b = map.get(type);
return b != null ? b.get() : null;
}
private static ImmutableMap<Class<?>, Provider<OptionHandlerFactory<?>>> build(Injector i) {
ImmutableMap.Builder<Class<?>, Provider<OptionHandlerFactory<?>>> map =
ImmutableMap.builder();
for (; i != null; i = i.getParent()) {
for (Entry<Key<?>, Binding<?>> e : i.getBindings().entrySet()) {
TypeLiteral<?> type = e.getKey().getTypeLiteral();
if (type.getRawType() == OptionHandlerFactory.class
&& e.getKey().getAnnotation() == null
&& type.getType() instanceof ParameterizedType) {
map.put(getType(type), cast(e.getValue()).getProvider());
}
}
}
return map.build();
}
private static Class<?> getType(TypeLiteral<?> t) {
ParameterizedType p = (ParameterizedType) t.getType();
return (Class<?>) p.getActualTypeArguments()[0];
}
@SuppressWarnings("unchecked")
private static Binding<OptionHandlerFactory<?>> cast(Binding<?> e) {
return (Binding<OptionHandlerFactory<?>>) e;
}
}