WeichenXu123 commented on code in PR #44294: URL: https://github.com/apache/spark/pull/44294#discussion_r1425410174
########## core/src/main/scala/org/apache/spark/api/python/CachedArrowBatchServer.scala: ########## @@ -0,0 +1,104 @@ +/* + * 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.api.python + +import java.io.{BufferedOutputStream, DataInputStream, DataOutputStream} +import java.net.{InetAddress, ServerSocket, Socket} +import java.nio.charset.StandardCharsets.UTF_8 + +import org.apache.spark.SparkEnv +import org.apache.spark.internal.Logging +import org.apache.spark.network.util.JavaUtils +import org.apache.spark.security.SocketAuthHelper +import org.apache.spark.storage.{ArrowBatchBlockId, BlockId} + + +class CachedArrowBatchServer extends Logging { + + val serverSocket = new ServerSocket( + 0, 1, InetAddress.getLoopbackAddress() + ) + + protected def readUtf8(s: Socket): String = { + val din = new DataInputStream(s.getInputStream()) + val len = din.readInt() + val bytes = new Array[Byte](len) + din.readFully(bytes) + new String(bytes, UTF_8) + } + + protected def writeUtf8(str: String, s: Socket): Unit = { + val bytes = str.getBytes(UTF_8) + val dout = new DataOutputStream(s.getOutputStream()) + dout.writeInt(bytes.length) + dout.write(bytes, 0, bytes.length) + dout.flush() + } + + def handleConnection(sock: Socket): Unit = { + val blockId = BlockId(readUtf8(sock)) + assert(blockId.isInstanceOf[ArrowBatchBlockId]) + + val blockManager = SparkEnv.get.blockManager + + val blockData = + blockManager.get[Array[Byte]](blockId).get.data.next().asInstanceOf[Array[Byte]] + val out = new BufferedOutputStream(sock.getOutputStream()) + out.write(blockData) + out.flush() + } + + def start(): (Int, String) = { + logTrace("Creating listening socket") + + val authHelper = new SocketAuthHelper(SparkEnv.get.conf) + + new Thread(s"CachedArrowBatchServer-listener") { + setDaemon(true) + + override def run(): Unit = { + var sock: Socket = null + + var connectionCount = 0 + try { + while (true) { + sock = serverSocket.accept() + connectionCount += 1 + new Thread(s"CachedArrowBatchServer-connection-$connectionCount") { Review Comment: The connection concurrency depends on `read_chunk` calls concurrency dispatched to the server, it's up to how 3rd-party datasource loader use it, but thread pool is a good idea. -- 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. To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org
