Java tutorial
/* * 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.driver.ser; import io.netty.buffer.ByteBuf; import io.netty.buffer.ByteBufAllocator; import io.netty.util.ReferenceCountUtil; import org.apache.tinkerpop.gremlin.driver.message.RequestMessage; import org.apache.tinkerpop.gremlin.driver.message.ResponseMessage; import org.apache.tinkerpop.gremlin.driver.message.ResponseStatusCode; import org.apache.tinkerpop.gremlin.structure.Graph; import org.apache.tinkerpop.gremlin.structure.io.gryo.GryoIo; import org.apache.tinkerpop.gremlin.structure.io.gryo.GryoMapper; import org.apache.tinkerpop.shaded.kryo.ClassResolver; import org.apache.tinkerpop.shaded.kryo.Kryo; import org.apache.tinkerpop.shaded.kryo.Serializer; import org.apache.tinkerpop.shaded.kryo.io.Input; import org.apache.tinkerpop.shaded.kryo.io.Output; import java.io.ByteArrayOutputStream; import java.lang.reflect.Method; import java.nio.charset.Charset; import java.util.Collection; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Optional; import java.util.UUID; import java.util.function.Supplier; import java.util.stream.Collectors; /** * @author Stephen Mallette (http://stephen.genoprime.com) */ public abstract class AbstractGryoMessageSerializerV1d0 extends AbstractMessageSerializer { private GryoMapper gryoMapper; private ThreadLocal<Kryo> kryoThreadLocal = new ThreadLocal<Kryo>() { @Override protected Kryo initialValue() { return gryoMapper.createMapper(); } }; private static final Charset UTF8 = Charset.forName("UTF-8"); public static final String TOKEN_CUSTOM = "custom"; public static final String TOKEN_SERIALIZE_RESULT_TO_STRING = "serializeResultToString"; public static final String TOKEN_USE_MAPPER_FROM_GRAPH = "useMapperFromGraph"; public static final String TOKEN_BUFFER_SIZE = "bufferSize"; public static final String TOKEN_CLASS_RESOLVER_SUPPLIER = "classResolverSupplier"; protected boolean serializeToString = false; private int bufferSize = 4096; /** * Creates an instance with a provided mapper configured {@link GryoMapper} instance. Note that this instance * will be overridden by {@link #configure} is called. */ public AbstractGryoMessageSerializerV1d0(final GryoMapper kryo) { this.gryoMapper = kryo; } /** * Called from the {@link #configure(Map, Map)} method right before the call to create the builder. Sub-classes * can choose to alter the builder or completely replace it. */ GryoMapper.Builder configureBuilder(final GryoMapper.Builder builder, final Map<String, Object> config, final Map<String, Graph> graphs) { return builder; } @Override public final void configure(final Map<String, Object> config, final Map<String, Graph> graphs) { final GryoMapper.Builder builder; final Object graphToUseForMapper = config.get(TOKEN_USE_MAPPER_FROM_GRAPH); if (graphToUseForMapper != null) { if (null == graphs) throw new IllegalStateException(String.format( "No graphs have been provided to the serializer and therefore %s is not a valid configuration", TOKEN_USE_MAPPER_FROM_GRAPH)); final Graph g = graphs.get(graphToUseForMapper.toString()); if (null == g) throw new IllegalStateException( String.format("There is no graph named [%s] configured to be used in the %s setting", graphToUseForMapper, TOKEN_USE_MAPPER_FROM_GRAPH)); // a graph was found so use the mapper it constructs. this allows gryo to be auto-configured with any // custom classes that the implementation allows for builder = g.io(GryoIo.build()).mapper(); } else { // no graph was supplied so just use the default - this will likely be the case when using a graph // with no custom classes or a situation where the user needs complete control like when using two // distinct implementations each with their own custom classes. builder = GryoMapper.build(); } addIoRegistries(config, builder); addClassResolverSupplier(config, builder); addCustomClasses(config, builder); this.serializeToString = Boolean .parseBoolean(config.getOrDefault(TOKEN_SERIALIZE_RESULT_TO_STRING, "false").toString()); this.bufferSize = Integer.parseInt(config.getOrDefault(TOKEN_BUFFER_SIZE, "4096").toString()); this.gryoMapper = configureBuilder(builder, config, graphs).create(); } private void addClassResolverSupplier(final Map<String, Object> config, final GryoMapper.Builder builder) { final String className = (String) config.getOrDefault(TOKEN_CLASS_RESOLVER_SUPPLIER, null); if (className != null && !className.isEmpty()) { try { final Class<?> clazz = Class.forName(className); try { final Method instanceMethod = tryInstanceMethod(clazz); builder.classResolver((Supplier<ClassResolver>) instanceMethod.invoke(null)); } catch (Exception methodex) { // tried instance() and that failed so try newInstance() no-arg constructor builder.classResolver((Supplier<ClassResolver>) clazz.newInstance()); } } catch (Exception ex) { throw new IllegalStateException(ex); } } } private void addCustomClasses(final Map<String, Object> config, final GryoMapper.Builder builder) { final List<String> classNameList = getListStringFromConfig(TOKEN_CUSTOM, config); classNameList.stream().forEach(serializerDefinition -> { String className; Optional<String> serializerName; if (serializerDefinition.contains(";")) { final String[] split = serializerDefinition.split(";"); if (split.length != 2) throw new IllegalStateException(String.format( "Invalid format for serializer definition [%s] - expected <class>;<serializer-class>", serializerDefinition)); className = split[0]; serializerName = Optional.of(split[1]); } else { serializerName = Optional.empty(); className = serializerDefinition; } try { final Class clazz = Class.forName(className); final Serializer serializer; if (serializerName.isPresent()) { final Class serializerClazz = Class.forName(serializerName.get()); serializer = (Serializer) serializerClazz.newInstance(); builder.addCustom(clazz, kryo -> serializer); } else builder.addCustom(clazz); } catch (Exception ex) { throw new IllegalStateException("Class could not be found", ex); } }); } @Override public ResponseMessage deserializeResponse(final ByteBuf msg) throws SerializationException { try { final Kryo kryo = kryoThreadLocal.get(); final byte[] payload = new byte[msg.capacity()]; msg.readBytes(payload); try (final Input input = new Input(payload)) { final UUID requestId = kryo.readObjectOrNull(input, UUID.class); final int status = input.readShort(); final String statusMsg = input.readString(); final Map<String, Object> statusAttributes = (Map<String, Object>) kryo.readClassAndObject(input); final Object result = kryo.readClassAndObject(input); final Map<String, Object> metaAttributes = (Map<String, Object>) kryo.readClassAndObject(input); return ResponseMessage.build(requestId).code(ResponseStatusCode.getFromValue(status)) .statusMessage(statusMsg).statusAttributes(statusAttributes).result(result) .responseMetaData(metaAttributes).create(); } } catch (Exception ex) { logger.warn("Response [{}] could not be deserialized by {}.", msg, GryoMessageSerializerV1d0.class.getName()); throw new SerializationException(ex); } } @Override public ByteBuf serializeResponseAsBinary(final ResponseMessage responseMessage, final ByteBufAllocator allocator) throws SerializationException { ByteBuf encodedMessage = null; try { final Kryo kryo = kryoThreadLocal.get(); try (final ByteArrayOutputStream baos = new ByteArrayOutputStream()) { final Output output = new Output(baos, bufferSize); // request id - if present kryo.writeObjectOrNull(output, responseMessage.getRequestId() != null ? responseMessage.getRequestId() : null, UUID.class); // status output.writeShort(responseMessage.getStatus().getCode().getValue()); output.writeString(responseMessage.getStatus().getMessage()); kryo.writeClassAndObject(output, responseMessage.getStatus().getAttributes()); // result kryo.writeClassAndObject(output, serializeToString ? serializeResultToString(responseMessage) : responseMessage.getResult().getData()); kryo.writeClassAndObject(output, responseMessage.getResult().getMeta()); final long size = output.total(); if (size > Integer.MAX_VALUE) throw new SerializationException( String.format("Message size of %s exceeds allocatable space", size)); output.flush(); encodedMessage = allocator.buffer((int) size); encodedMessage.writeBytes(baos.toByteArray()); } return encodedMessage; } catch (Exception ex) { if (encodedMessage != null) ReferenceCountUtil.release(encodedMessage); logger.warn("Response [{}] could not be serialized by {}.", responseMessage.toString(), GryoMessageSerializerV1d0.class.getName()); throw new SerializationException(ex); } } @Override public RequestMessage deserializeRequest(final ByteBuf msg) throws SerializationException { try { final Kryo kryo = kryoThreadLocal.get(); final byte[] payload = new byte[msg.readableBytes()]; msg.readBytes(payload); try (final Input input = new Input(payload)) { // by the time the message gets here, the mime length/type have been already read, so this part just // needs to process the payload. final UUID id = kryo.readObject(input, UUID.class); final String processor = input.readString(); final String op = input.readString(); final RequestMessage.Builder builder = RequestMessage.build(op).overrideRequestId(id) .processor(processor); final Map<String, Object> args = kryo.readObject(input, HashMap.class); args.forEach(builder::addArg); return builder.create(); } } catch (Exception ex) { logger.warn("Request [{}] could not be deserialized by {}.", msg, GryoMessageSerializerV1d0.class.getName()); throw new SerializationException(ex); } } @Override public ByteBuf serializeRequestAsBinary(final RequestMessage requestMessage, final ByteBufAllocator allocator) throws SerializationException { ByteBuf encodedMessage = null; try { final Kryo kryo = kryoThreadLocal.get(); try (final ByteArrayOutputStream baos = new ByteArrayOutputStream()) { final Output output = new Output(baos, bufferSize); final String mimeType = mimeTypesSupported()[0]; output.writeByte(mimeType.length()); output.write(mimeType.getBytes(UTF8)); kryo.writeObject(output, requestMessage.getRequestId()); output.writeString(requestMessage.getProcessor()); output.writeString(requestMessage.getOp()); kryo.writeObject(output, requestMessage.getArgs()); final long size = output.total(); if (size > Integer.MAX_VALUE) throw new SerializationException( String.format("Message size of %s exceeds allocatable space", size)); output.flush(); encodedMessage = allocator.buffer((int) size); encodedMessage.writeBytes(baos.toByteArray()); } return encodedMessage; } catch (Exception ex) { if (encodedMessage != null) ReferenceCountUtil.release(encodedMessage); logger.warn("Request [{}] could not be serialized by {}.", requestMessage.toString(), GryoMessageSerializerV1d0.class.getName()); throw new SerializationException(ex); } } private Object serializeResultToString(final ResponseMessage msg) { if (msg.getResult() == null) return "null"; if (msg.getResult().getData() == null) return "null"; // the IteratorHandler should return a collection so keep it as such final Object o = msg.getResult().getData(); if (o instanceof Collection) { return ((Collection) o).stream().map(d -> null == d ? "null" : d.toString()) .collect(Collectors.toList()); } else { return o.toString(); } } }