// Copyright (C) 2009 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.server.git;
import com.google.common.collect.Maps;
import com.google.gerrit.server.util.RequestContext;
import com.google.gerrit.server.util.ThreadLocalRequestContext;
import com.google.gerrit.server.util.ThreadLocalRequestScopePropagator;
import com.google.inject.Inject;
import com.google.inject.Key;
import com.google.inject.OutOfScopeException;
import com.google.inject.Provider;
import com.google.inject.Scope;
import java.util.Map;
import java.util.concurrent.Callable;
public class PerThreadRequestScope {
public interface Scoper {
<T> Callable<T> scope(Callable<T> callable);
}
private static class Context {
private final Map<Key<?>, Object> map;
private Context() {
map = Maps.newHashMap();
}
private <T> T get(Key<T> key, Provider<T> creator) {
@SuppressWarnings("unchecked")
T t = (T) map.get(key);
if (t == null) {
t = creator.get();
map.put(key, t);
}
return t;
}
}
public static class Propagator extends ThreadLocalRequestScopePropagator<Context> {
@Inject
Propagator(ThreadLocalRequestContext local) {
super(REQUEST, current, local);
}
@Override
protected Context continuingContext(Context ctx) {
return new Context();
}
public <T> Callable<T> scope(RequestContext requestContext, Callable<T> callable) {
final Context ctx = new Context();
final Callable<T> wrapped = context(requestContext, cleanup(callable));
return new Callable<T>() {
@Override
public T call() throws Exception {
Context old = current.get();
current.set(ctx);
try {
return wrapped.call();
} finally {
current.set(old);
}
}
};
}
}
private static final ThreadLocal<Context> current = new ThreadLocal<Context>();
private static Context requireContext() {
final Context ctx = current.get();
if (ctx == null) {
throw new OutOfScopeException("Not in command/request");
}
return ctx;
}
public static final Scope REQUEST = new Scope() {
@Override
public <T> Provider<T> scope(final Key<T> key, final Provider<T> creator) {
return new Provider<T>() {
@Override
public T get() {
return requireContext().get(key, creator);
}
@Override
public String toString() {
return String.format("%s[%s]", creator, REQUEST);
}
};
}
@Override
public String toString() {
return "PerThreadRequestScope.REQUEST";
}
};
}