| /* |
| * * |
| * * Licensed to the Apache Software Foundation (ASF) under one |
| * * or more contributor license agreements. See the NOTICE file |
| * * distributed with this work for additional information |
| * * regarding copyright ownership. The ASF licenses this file |
| * * to you 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 |
| * * <p> |
| * * http://www.apache.org/licenses/LICENSE-2.0 |
| * * <p> |
| * * 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 org.apache.storm.sql.runtime; |
| |
| import backtype.storm.tuple.Values; |
| |
| public class Channels { |
| private static final ChannelContext VOID_CTX = new ChannelContext() { |
| @Override |
| public void emit(Values data) {} |
| |
| @Override |
| public void fireChannelInactive() {} |
| }; |
| |
| private static class ChannelContextAdapter implements ChannelContext { |
| private final ChannelHandler handler; |
| private final ChannelContext next; |
| |
| public ChannelContextAdapter( |
| ChannelContext next, ChannelHandler handler) { |
| this.handler = handler; |
| this.next = next; |
| } |
| |
| @Override |
| public void emit(Values data) { |
| handler.dataReceived(next, data); |
| } |
| |
| @Override |
| public void fireChannelInactive() { |
| handler.channelInactive(next); |
| } |
| } |
| |
| private static class ForwardingChannelContext implements ChannelContext { |
| private final ChannelContext next; |
| |
| public ForwardingChannelContext(ChannelContext next) { |
| this.next = next; |
| } |
| |
| @Override |
| public void emit(Values data) { |
| next.emit(data); |
| } |
| |
| @Override |
| public void fireChannelInactive() { |
| next.fireChannelInactive(); |
| } |
| } |
| |
| public static ChannelContext chain( |
| ChannelContext next, ChannelHandler handler) { |
| return new ChannelContextAdapter(next, handler); |
| } |
| |
| public static ChannelContext voidContext() { |
| return VOID_CTX; |
| } |
| } |