/* * 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.zeppelin.interpreter.remote; import java.util.HashMap; import java.util.LinkedList; import java.util.List; import java.util.Map; import java.util.concurrent.BlockingQueue; import java.util.concurrent.LinkedBlockingQueue; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * This thread sends paragraph's append-data * periodically, rather than continously, with * a period of BUFFER_TIME_MS. It handles append-data * for all paragraphs across all notebooks. */ public class AppendOutputRunner implements Runnable { private static final Logger logger = LoggerFactory.getLogger(AppendOutputRunner.class); public static final Long BUFFER_TIME_MS = new Long(100); private static final Long SAFE_PROCESSING_TIME = new Long(10); private static final Long SAFE_PROCESSING_STRING_SIZE = new Long(100000); private final BlockingQueue<AppendOutputBuffer> queue = new LinkedBlockingQueue<>(); private final RemoteInterpreterProcessListener listener; public AppendOutputRunner(RemoteInterpreterProcessListener listener) { this.listener = listener; } @Override public void run() { Map<String, StringBuilder> stringBufferMap = new HashMap<>(); List<AppendOutputBuffer> list = new LinkedList<>(); /* "drainTo" method does not wait for any element * to be present in the queue, and thus this loop would * continuosly run (with period of BUFFER_TIME_MS). "take()" method * waits for the queue to become non-empty and then removes * one element from it. Rest elements from queue (if present) are * removed using "drainTo" method. Thus we save on some un-necessary * cpu-cycles. */ try { list.add(queue.take()); } catch (InterruptedException e) { logger.error("Wait for OutputBuffer queue interrupted: " + e.getMessage()); } Long processingStartTime = System.currentTimeMillis(); queue.drainTo(list); for (AppendOutputBuffer buffer: list) { String noteId = buffer.getNoteId(); String paragraphId = buffer.getParagraphId(); int index = buffer.getIndex(); String stringBufferKey = noteId + ":" + paragraphId + ":" + index; StringBuilder builder = stringBufferMap.containsKey(stringBufferKey) ? stringBufferMap.get(stringBufferKey) : new StringBuilder(); builder.append(buffer.getData()); stringBufferMap.put(stringBufferKey, builder); } Long processingTime = System.currentTimeMillis() - processingStartTime; if (processingTime > SAFE_PROCESSING_TIME) { logger.warn("Processing time for buffered append-output is high: " + processingTime + " milliseconds."); } else { logger.debug("Processing time for append-output took " + processingTime + " milliseconds"); } Long sizeProcessed = new Long(0); for (String stringBufferKey : stringBufferMap.keySet()) { StringBuilder buffer = stringBufferMap.get(stringBufferKey); sizeProcessed += buffer.length(); String[] keys = stringBufferKey.split(":"); listener.onOutputAppend(keys[0], keys[1], Integer.parseInt(keys[2]), buffer.toString()); } if (sizeProcessed > SAFE_PROCESSING_STRING_SIZE) { logger.warn("Processing size for buffered append-output is high: " + sizeProcessed + " characters."); } else { logger.debug("Processing size for append-output is " + sizeProcessed + " characters"); } } public void appendBuffer(String noteId, String paragraphId, int index, String outputToAppend) { queue.offer(new AppendOutputBuffer(noteId, paragraphId, index, outputToAppend)); } }