| /* |
| * 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.nifi.processors.standard.relp.frame; |
| |
| import io.netty.buffer.ByteBuf; |
| import io.netty.buffer.Unpooled; |
| import io.netty.channel.ChannelHandlerContext; |
| import io.netty.handler.codec.ByteToMessageDecoder; |
| import org.apache.nifi.logging.ComponentLog; |
| import org.apache.nifi.processor.util.listen.event.EventFactoryUtil; |
| import org.apache.nifi.processor.util.listen.response.ChannelResponse; |
| import org.apache.nifi.processors.standard.relp.event.RELPMessageFactory; |
| import org.apache.nifi.processors.standard.relp.event.RELPMetadata; |
| import org.apache.nifi.processors.standard.relp.response.RELPChannelResponse; |
| import org.apache.nifi.processors.standard.relp.response.RELPResponse; |
| |
| import java.nio.charset.Charset; |
| import java.util.List; |
| import java.util.Map; |
| |
| /** |
| * Decode RELP message bytes into a RELPMessage |
| */ |
| public class RELPFrameDecoder extends ByteToMessageDecoder { |
| |
| private Charset charset; |
| private RELPDecoder decoder; |
| private final ComponentLog logger; |
| private final RELPEncoder encoder; |
| private final RELPMessageFactory eventFactory; |
| |
| static final String CMD_OPEN = "open"; |
| static final String CMD_CLOSE = "close"; |
| |
| public RELPFrameDecoder(final ComponentLog logger, final Charset charset) { |
| this.charset = charset; |
| this.logger = logger; |
| this.encoder = new RELPEncoder(charset); |
| this.eventFactory = new RELPMessageFactory(); |
| } |
| |
| @Override |
| protected void decode(final ChannelHandlerContext ctx, final ByteBuf in, final List<Object> out) throws Exception { |
| final int total = in.readableBytes(); |
| final String senderSocket = ctx.channel().remoteAddress().toString(); |
| this.decoder = new RELPDecoder(charset, total); |
| |
| // go through the buffer parsing the RELP command |
| for (int i = 0; i < total; i++) { |
| byte currByte = in.readByte(); |
| // if we found the end of a frame, handle the frame and mark the buffer |
| if (decoder.process(currByte)) { |
| final RELPFrame frame = decoder.getFrame(); |
| |
| logger.debug("Received RELP frame with transaction {} and command {}", |
| frame.getTxnr(), frame.getCommand()); |
| handle(frame, ctx, senderSocket, out); |
| in.markReaderIndex(); |
| } |
| } |
| } |
| |
| private void handle(final RELPFrame frame, final ChannelHandlerContext ctx, final String sender, final List<Object> out) { |
| // respond to open and close commands immediately, create and queue an event for everything else |
| if (CMD_OPEN.equals(frame.getCommand())) { |
| Map<String,String> offers = RELPResponse.parseOffers(frame.getData(), charset); |
| ChannelResponse response = new RELPChannelResponse(encoder, RELPResponse.open(frame.getTxnr(), offers)); |
| ctx.writeAndFlush(Unpooled.wrappedBuffer(response.toByteArray())); |
| } else if (CMD_CLOSE.equals(frame.getCommand())) { |
| ChannelResponse response = new RELPChannelResponse(encoder, RELPResponse.ok(frame.getTxnr())); |
| ctx.writeAndFlush(Unpooled.wrappedBuffer(response.toByteArray())); |
| ctx.close(); |
| } else { |
| final Map<String, String> metadata = EventFactoryUtil.createMapWithSender(sender); |
| metadata.put(RELPMetadata.TXNR_KEY, String.valueOf(frame.getTxnr())); |
| metadata.put(RELPMetadata.COMMAND_KEY, frame.getCommand()); |
| metadata.put(RELPMetadata.SENDER_KEY, sender); |
| out.add(eventFactory.create(frame.getData(), metadata)); |
| } |
| } |
| } |