Java tutorial
/* * Copyright (c) 2015 Uber Technologies, Inc. * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ package com.uber.tchannel.handlers; import com.uber.tchannel.checksum.ChecksumType; import com.uber.tchannel.codecs.MessageCodec; import com.uber.tchannel.frames.CallFrame; import com.uber.tchannel.frames.CallRequestContinueFrame; import com.uber.tchannel.frames.CallRequestFrame; import com.uber.tchannel.frames.CallResponseContinueFrame; import com.uber.tchannel.frames.CallResponseFrame; import com.uber.tchannel.frames.FrameType; import com.uber.tchannel.messages.Response; import com.uber.tchannel.messages.RawMessage; import com.uber.tchannel.messages.Request; import com.uber.tchannel.tracing.Trace; import com.uber.tchannel.utils.TChannelUtilities; import io.netty.buffer.ByteBuf; import io.netty.channel.ChannelHandlerContext; import io.netty.handler.codec.MessageToMessageEncoder; import java.util.ArrayList; import java.util.List; public class MessageFragmenter extends MessageToMessageEncoder<RawMessage> { @Override protected void encode(ChannelHandlerContext ctx, RawMessage msg, List<Object> out) throws Exception { writeFrames(ctx, msg, out); if (msg instanceof Response) { ((Response) msg).release(); } } protected void writeFrames(ChannelHandlerContext ctx, RawMessage msg, List<Object> frames) throws Exception { List<ByteBuf> args = new ArrayList<>(); args.add(msg.getArg1()); args.add(msg.getArg2()); args.add(msg.getArg3()); CallFrame frame = null; while (!args.isEmpty()) { if (frame == null || frame.isPayloadFull()) { frame = createFrame(msg, args.size()); } frame.encodePayload(ctx.alloc(), args); frames.add(MessageCodec.encode(ctx.alloc(), MessageCodec.encode(ctx.alloc(), frame))); } } protected CallFrame createFrame(RawMessage msg, int argCount) { if (msg.getType() == FrameType.CallRequest) { Request request = (Request) msg; if (argCount == 3) { return new CallRequestFrame(request.getId(), (byte) 0, request.getTTL(), new Trace(0, 0, 0, (byte) 0x00), request.getService(), request.getTransportHeaders(), ChecksumType.NoChecksum, 0, TChannelUtilities.emptyByteBuf); } else { return new CallRequestContinueFrame(request.getId(), (byte) 0, ChecksumType.NoChecksum, 0, TChannelUtilities.emptyByteBuf); } } else { Response response = (Response) msg; if (argCount == 3) { return new CallResponseFrame(response.getId(), (byte) 0, response.getResponseCode(), new Trace(0, 0, 0, (byte) 0x00), response.getTransportHeaders(), ChecksumType.NoChecksum, 0, TChannelUtilities.emptyByteBuf); } else { return new CallResponseContinueFrame(response.getId(), (byte) 0, ChecksumType.NoChecksum, 0, TChannelUtilities.emptyByteBuf); } } } }