| /* |
| * 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.druid.query; |
| |
| import com.fasterxml.jackson.core.JsonGenerator; |
| import com.fasterxml.jackson.databind.SerializerProvider; |
| import com.fasterxml.jackson.databind.jsontype.TypeSerializer; |
| import com.fasterxml.jackson.databind.ser.std.StdSerializer; |
| import org.apache.druid.java.util.common.RE; |
| import org.apache.druid.java.util.common.jackson.JacksonUtils; |
| import org.apache.druid.segment.column.ColumnType; |
| import org.apache.druid.segment.column.RowSignature; |
| |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.stream.Collectors; |
| import java.util.stream.IntStream; |
| |
| /** |
| * Serializes {@link FrameBasedInlineDataSource} to the representation of {@link InlineDataSource} |
| * so that the servers' on wire transfer data doesn't change. {@link FrameBasedInlineDataSource} is currently limited |
| * to the brokers only and therefore this aids in conversion of the object to a representation that the data servers |
| * can recognize |
| */ |
| public class FrameBasedInlineDataSourceSerializer extends StdSerializer<FrameBasedInlineDataSource> |
| { |
| public FrameBasedInlineDataSourceSerializer() |
| { |
| super(FrameBasedInlineDataSource.class); |
| } |
| |
| @Override |
| public void serialize(FrameBasedInlineDataSource value, JsonGenerator jg, SerializerProvider serializers) |
| throws IOException |
| { |
| jg.writeStartObject(); |
| jg.writeStringField("type", "inline"); |
| |
| RowSignature rowSignature = value.getRowSignature(); |
| jg.writeObjectField("columnNames", rowSignature.getColumnNames()); |
| List<ColumnType> columnTypes = IntStream.range(0, rowSignature.size()) |
| .mapToObj(i -> rowSignature.getColumnType(i).orElse(null)) |
| .collect(Collectors.toList()); |
| jg.writeObjectField("columnTypes", columnTypes); |
| |
| jg.writeArrayFieldStart("rows"); |
| |
| value.getRowsAsSequence().forEach(row -> { |
| try { |
| JacksonUtils.writeObjectUsingSerializerProvider(jg, serializers, row); |
| } |
| catch (IOException e) { |
| // Ideally, this shouldn't be reachable. |
| // Wrap the IO exception in the runtime exception and propogate it forward |
| List<String> elements = new ArrayList<>(); |
| for (Object o : row) { |
| elements.add(o.toString()); |
| } |
| throw new RE( |
| e, |
| "Exception encountered while serializing [%s] in [%s]", |
| String.join(", ", elements), |
| FrameBasedInlineDataSource.class |
| ); |
| } |
| }); |
| |
| jg.writeEndArray(); |
| jg.writeEndObject(); |
| } |
| |
| /** |
| * Required because {@link DataSource} is polymorphic |
| */ |
| @Override |
| public void serializeWithType( |
| FrameBasedInlineDataSource value, |
| JsonGenerator jg, |
| SerializerProvider serializers, |
| TypeSerializer typeSer |
| ) throws IOException |
| { |
| serialize(value, jg, serializers); |
| } |
| } |