| /** |
| * 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 |
| * |
| * 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 org.apache.hadoop.hdfs.ipc; |
| |
| import io.netty.channel.ChannelDuplexHandler; |
| import io.netty.channel.ChannelHandlerContext; |
| import io.netty.channel.ChannelPromise; |
| import java.io.IOException; |
| import java.util.HashMap; |
| import java.util.Map; |
| import org.apache.hadoop.classification.InterfaceAudience; |
| |
| @InterfaceAudience.Private |
| public class BufferCallBeforeInitHandler extends ChannelDuplexHandler { |
| |
| private enum BufferCallAction { |
| FLUSH, FAIL |
| } |
| |
| public static final class BufferCallEvent { |
| |
| public final BufferCallAction action; |
| |
| public final IOException error; |
| |
| private BufferCallEvent(BufferCallBeforeInitHandler.BufferCallAction action, |
| IOException error) { |
| this.action = action; |
| this.error = error; |
| } |
| |
| public static BufferCallBeforeInitHandler.BufferCallEvent success() { |
| return SUCCESS_EVENT; |
| } |
| |
| public static BufferCallBeforeInitHandler.BufferCallEvent fail( |
| IOException error) { |
| return new BufferCallEvent(BufferCallAction.FAIL, error); |
| } |
| } |
| |
| private static final BufferCallEvent SUCCESS_EVENT = |
| new BufferCallEvent(BufferCallAction.FLUSH, null); |
| |
| private final Map<Integer, Call> id2Call = new HashMap<>(); |
| |
| @Override |
| public void write(ChannelHandlerContext ctx, Object msg, |
| ChannelPromise promise) { |
| if (msg instanceof Call) { |
| Call call = (Call) msg; |
| id2Call.put(call.getId(), call); |
| // The call is already in track so here we set the write operation as |
| // success. |
| // We will fail the call directly if we can not write it out. |
| promise.trySuccess(); |
| } else { |
| ctx.write(msg, promise); |
| } |
| } |
| |
| @Override |
| public void userEventTriggered(ChannelHandlerContext ctx, Object evt) |
| throws Exception { |
| if (evt instanceof BufferCallEvent) { |
| BufferCallEvent bcEvt = (BufferCallBeforeInitHandler.BufferCallEvent) evt; |
| switch (bcEvt.action) { |
| case FLUSH: |
| for (Call call : id2Call.values()) { |
| ctx.write(call); |
| } |
| break; |
| case FAIL: |
| for (Call call : id2Call.values()) { |
| call.setException(bcEvt.error); |
| } |
| break; |
| } |
| ctx.flush(); |
| ctx.pipeline().remove(this); |
| } else { |
| ctx.fireUserEventTriggered(evt); |
| } |
| } |
| } |