com.google.gerrit.server.git.PerThreadRequestScope Maven / Gradle / Ivy
// 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.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.HashMap;
import java.util.Map;
import java.util.concurrent.Callable;
public class PerThreadRequestScope {
public interface Scoper {
Callable scope(Callable callable);
}
private static class Context {
private final Map, Object> map;
private Context() {
map = new HashMap<>();
}
private T get(Key key, Provider 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 {
@Inject
Propagator(ThreadLocalRequestContext local) {
super(REQUEST, current, local);
}
@Override
protected Context continuingContext(Context ctx) {
return new Context();
}
public Callable scope(RequestContext requestContext, Callable callable) {
Context ctx = new Context();
Callable wrapped = context(requestContext, cleanup(callable));
return () -> {
Context old = current.get();
current.set(ctx);
try {
return wrapped.call();
} finally {
current.set(old);
}
};
}
}
private static final ThreadLocal current = new ThreadLocal<>();
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 Provider scope(Key key, Provider creator) {
return new Provider<>() {
@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";
}
};
}