srowen commented on a change in pull request #25583: [MINOR][SS] Reuse KafkaSourceInitialOffsetWriter to deduplicate URL: https://github.com/apache/spark/pull/25583#discussion_r317621165
########## File path: external/kafka-0-10-sql/src/main/scala/org/apache/spark/sql/kafka010/KafkaSourceInitialOffsetWriter.scala ########## @@ -0,0 +1,63 @@ +/* + * 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.spark.sql.kafka010 + +import java.io._ +import java.nio.charset.StandardCharsets + +import org.apache.commons.io.IOUtils + +import org.apache.spark.sql.SparkSession +import org.apache.spark.sql.execution.streaming.{HDFSMetadataLog, SerializedOffset} + +/** A version of [[HDFSMetadataLog]] specialized for saving the initial offsets. */ +private[kafka010] class KafkaSourceInitialOffsetWriter( + sparkSession: SparkSession, + metadataPath: String) + extends HDFSMetadataLog[KafkaSourceOffset](sparkSession, metadataPath) { + + val VERSION = 1 + + override def serialize(metadata: KafkaSourceOffset, out: OutputStream): Unit = { + out.write(0) // A zero byte is written to support Spark 2.1.0 (SPARK-19517) + val writer = new BufferedWriter(new OutputStreamWriter(out, StandardCharsets.UTF_8)) + writer.write("v" + VERSION + "\n") + writer.write(metadata.json) + writer.flush + } + + override def deserialize(in: InputStream): KafkaSourceOffset = { + in.read() // A zero byte is read to support Spark 2.1.0 (SPARK-19517) + val content = IOUtils.toString(new InputStreamReader(in, StandardCharsets.UTF_8)) + // HDFSMetadataLog guarantees that it never creates a partial file. + assert(content.length != 0) + if (content(0) == 'v') { + val indexOfNewLine = content.indexOf("\n") + if (indexOfNewLine > 0) { + validateVersion(content.substring(0, indexOfNewLine), VERSION) + KafkaSourceOffset(SerializedOffset(content.substring(indexOfNewLine + 1))) + } else { + throw new IllegalStateException( + s"Log file was malformed: failed to detect the log file version line.") Review comment: Nit: no need for interpolation ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org
