| /* |
| * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package jdk.incubator.http; |
| |
| import java.util.Optional; |
| import java.util.concurrent.Flow; |
| import java.util.function.Consumer; |
| |
| /** |
| * A single threaded Publisher which runs in same thread as subscriber. |
| */ |
| class PushPublisher<T> extends AbstractPushPublisher<T> { |
| Subscription subscription; |
| Flow.Subscriber<? super T> subscriber; |
| SubscriptionState state; |
| long demand; |
| |
| /** |
| * Pushes/consumes the incoming objects. |
| * The consumer blocks until subscriber ready to receive. |
| */ |
| @Override |
| public void acceptData(Optional<T> item) { |
| SubscriptionState s = this.state; |
| |
| if (s == SubscriptionState.CANCELLED) return; |
| if (s == SubscriptionState.DONE) { |
| throw new IllegalStateException("subscription complete"); |
| } |
| |
| if (!item.isPresent()) { |
| subscriber.onComplete(); |
| this.state = SubscriptionState.DONE; |
| return; |
| } |
| if (demand == 0) { |
| throw new IllegalStateException("demand == 0"); |
| } |
| demand--; |
| subscriber.onNext(item.get()); |
| } |
| |
| @Override |
| public Consumer<Optional<T>> asDataConsumer() { |
| return this::acceptData; |
| } |
| |
| @Override |
| public void subscribe(Flow.Subscriber<? super T> subscriber) { |
| subscription = new Subscription(subscriber); |
| subscriber.onSubscribe(subscription); |
| } |
| |
| private class Subscription implements Flow.Subscription { |
| |
| Subscription(Flow.Subscriber<? super T> subscriber) { |
| PushPublisher.this.subscriber = subscriber; |
| } |
| |
| @Override |
| public void request(long n) { |
| demand += n; |
| } |
| |
| @Override |
| public void cancel() { |
| state = SubscriptionState.CANCELLED; |
| } |
| } |
| |
| @Override |
| public void acceptError(Throwable t) { |
| if (this.state == SubscriptionState.DONE) { |
| throw new IllegalStateException("subscription complete"); |
| } |
| this.state = SubscriptionState.CANCELLED; |
| subscriber.onError(t); |
| } |
| } |