| /* |
| * 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.tinkerpop.gremlin.server.handler; |
| |
| import org.apache.tinkerpop.gremlin.driver.MessageSerializer; |
| import org.apache.tinkerpop.gremlin.driver.message.RequestMessage; |
| import org.apache.tinkerpop.gremlin.driver.ser.SerializationException; |
| import io.netty.buffer.ByteBuf; |
| import io.netty.channel.ChannelHandler; |
| import io.netty.channel.ChannelHandlerContext; |
| import io.netty.handler.codec.MessageToMessageDecoder; |
| import io.netty.handler.codec.http.websocketx.BinaryWebSocketFrame; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import java.nio.charset.Charset; |
| import java.util.List; |
| import java.util.Map; |
| |
| /** |
| * Decodes the contents of a {@code BinaryWebSocketFrame}. Binary-based frames assume that the format is encoded |
| * in the first initial bytes of the message. From there the proper serializer can be chosen and the message |
| * can then be deserialized. |
| * |
| * @author Stephen Mallette (http://stephen.genoprime.com) |
| */ |
| @ChannelHandler.Sharable |
| public class WsGremlinBinaryRequestDecoder extends MessageToMessageDecoder<BinaryWebSocketFrame> { |
| private static final Logger logger = LoggerFactory.getLogger(WsGremlinBinaryRequestDecoder.class); |
| |
| private static final Charset UTF8 = Charset.forName("UTF-8"); |
| private final Map<String, MessageSerializer> serializers; |
| |
| public WsGremlinBinaryRequestDecoder(final Map<String, MessageSerializer> serializers) { |
| this.serializers = serializers; |
| } |
| |
| @Override |
| protected void decode(final ChannelHandlerContext channelHandlerContext, final BinaryWebSocketFrame frame, final List<Object> objects) throws Exception { |
| final ByteBuf messageBytes = frame.content(); |
| final byte len = messageBytes.readByte(); |
| if (len <= 0) { |
| objects.add(RequestMessage.INVALID); |
| return; |
| } |
| |
| final ByteBuf contentTypeBytes = channelHandlerContext.alloc().buffer(len); |
| try { |
| messageBytes.readBytes(contentTypeBytes); |
| final String contentType = contentTypeBytes.toString(UTF8); |
| final MessageSerializer serializer = select(contentType, ServerSerializers.DEFAULT_SERIALIZER); |
| |
| // it's important to re-initialize these channel attributes as they apply globally to the channel. in |
| // other words, the next request to this channel might not come with the same configuration and mixed |
| // state can carry through from one request to the next |
| channelHandlerContext.channel().attr(StateKey.SESSION).set(null); |
| channelHandlerContext.channel().attr(StateKey.SERIALIZER).set(serializer); |
| channelHandlerContext.channel().attr(StateKey.USE_BINARY).set(true); |
| |
| try { |
| objects.add(serializer.deserializeRequest(messageBytes.discardReadBytes())); |
| } catch (SerializationException se) { |
| objects.add(RequestMessage.INVALID); |
| } |
| } finally { |
| contentTypeBytes.release(); |
| } |
| } |
| |
| private MessageSerializer select(final String mimeType, final MessageSerializer defaultSerializer) { |
| if (logger.isWarnEnabled() && !serializers.containsKey(mimeType)) |
| logger.warn("Gremlin Server is not configured with a serializer for the requested mime type [{}] - using {} by default", |
| mimeType, defaultSerializer.getClass().getName()); |
| |
| return serializers.getOrDefault(mimeType, defaultSerializer); |
| } |
| } |