| /** |
| * 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.storm.messaging.netty; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| import org.apache.storm.messaging.TaskMessage; |
| import org.apache.storm.serialization.KryoValuesDeserializer; |
| import org.apache.storm.shade.io.netty.buffer.ByteBuf; |
| import org.apache.storm.shade.io.netty.channel.ChannelHandlerContext; |
| import org.apache.storm.shade.io.netty.handler.codec.ByteToMessageDecoder; |
| |
| public class MessageDecoder extends ByteToMessageDecoder { |
| |
| private final KryoValuesDeserializer deser; |
| |
| public MessageDecoder(KryoValuesDeserializer deser) { |
| this.deser = deser; |
| } |
| |
| /* |
| * Each ControlMessage is encoded as: |
| * code (<0) ... short(2) |
| * Each TaskMessage is encoded as: |
| * task (>=0) ... short(2) |
| * len ... int(4) |
| * payload ... byte[] * |
| */ |
| @Override |
| protected void decode(ChannelHandlerContext ctx, ByteBuf buf, List<Object> out) throws Exception { |
| // Make sure that we have received at least a short |
| long available = buf.readableBytes(); |
| if (available < 2) { |
| //need more data |
| return; |
| } |
| |
| List<Object> ret = new ArrayList<>(); |
| |
| // Use while loop, try to decode as more messages as possible in single call |
| while (available >= 2) { |
| |
| // Mark the current buffer position before reading task/len field |
| // because the whole frame might not be in the buffer yet. |
| // We will reset the buffer position to the marked position if |
| // there's not enough bytes in the buffer. |
| buf.markReaderIndex(); |
| |
| // read the short field |
| short code = buf.readShort(); |
| available -= 2; |
| |
| // case 1: Control message |
| ControlMessage controlMessage = ControlMessage.mkMessage(code); |
| if (controlMessage != null) { |
| |
| if (controlMessage == ControlMessage.EOB_MESSAGE) { |
| continue; |
| } else { |
| out.add(controlMessage); |
| return; |
| } |
| } |
| |
| //case 2: SaslTokenMessageRequest |
| if (code == SaslMessageToken.IDENTIFIER) { |
| // Make sure that we have received at least an integer (length) |
| if (buf.readableBytes() < 4) { |
| //need more data |
| buf.resetReaderIndex(); |
| return; |
| } |
| |
| // Read the length field. |
| int length = buf.readInt(); |
| if (length <= 0) { |
| out.add(new SaslMessageToken(null)); |
| return; |
| } |
| |
| // Make sure if there's enough bytes in the buffer. |
| if (buf.readableBytes() < length) { |
| // The whole bytes were not received yet - return null. |
| buf.resetReaderIndex(); |
| return; |
| } |
| |
| // There's enough bytes in the buffer. Read it. |
| byte[] bytes = new byte[length]; |
| buf.readBytes(bytes); |
| // Successfully decoded a frame. |
| // Return a SaslTokenMessageRequest object |
| out.add(new SaslMessageToken(bytes)); |
| return; |
| } |
| |
| // case 3: BackPressureStatus |
| if (code == BackPressureStatus.IDENTIFIER) { |
| available = buf.readableBytes(); |
| if (available < 4) { |
| //Need more data |
| buf.resetReaderIndex(); |
| return; |
| } |
| int dataLen = buf.readInt(); |
| if (available < 4 + dataLen) { |
| // need more data |
| buf.resetReaderIndex(); |
| return; |
| } |
| byte[] bytes = new byte[dataLen]; |
| buf.readBytes(bytes); |
| out.add(BackPressureStatus.read(bytes, deser)); |
| return; |
| } |
| |
| // case 4: task Message |
| |
| // Make sure that we have received at least an integer (length) |
| if (available < 4) { |
| // need more data |
| buf.resetReaderIndex(); |
| break; |
| } |
| |
| // Read the length field. |
| int length = buf.readInt(); |
| |
| available -= 4; |
| |
| if (length <= 0) { |
| ret.add(new TaskMessage(code, null)); |
| break; |
| } |
| |
| // Make sure if there's enough bytes in the buffer. |
| if (available < length) { |
| // The whole bytes were not received yet - return null. |
| buf.resetReaderIndex(); |
| break; |
| } |
| available -= length; |
| |
| // There's enough bytes in the buffer. Read it. |
| byte[] bytes = new byte[length]; |
| buf.readBytes(bytes); |
| |
| // Successfully decoded a frame. |
| // Return a TaskMessage object |
| ret.add(new TaskMessage(code, bytes)); |
| } |
| |
| if (!ret.isEmpty()) { |
| out.add(ret); |
| } |
| } |
| } |