| /* |
| * 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.geode.internal.process; |
| |
| import java.io.BufferedReader; |
| import java.io.IOException; |
| import java.io.InputStreamReader; |
| |
| import org.apache.logging.log4j.Logger; |
| |
| import org.apache.geode.internal.util.StopWatch; |
| import org.apache.geode.logging.internal.log4j.api.LogService; |
| |
| /** |
| * Reads the InputStream per-byte instead of per-line. Uses BufferedReader.ready() to ensure that |
| * calls to read() will not block. Uses continueReadingMillis to continue reading after the Process |
| * terminates in order to fully read the last of that Process' output (such as a stack trace). |
| * |
| * @since GemFire 8.2 |
| */ |
| class NonBlockingProcessStreamReader extends ProcessStreamReader { |
| private static final Logger logger = LogService.getLogger(); |
| |
| /** |
| * millis to continue reading after Process terminates in order to fully read the last of its |
| * output |
| */ |
| private final long continueReadingMillis; |
| |
| private final StopWatch continueReading; |
| |
| private StringBuilder stringBuilder; |
| private int character; |
| |
| NonBlockingProcessStreamReader(final Builder builder) { |
| super(builder); |
| |
| continueReadingMillis = builder.getContinueReadingMillis(); |
| continueReading = new StopWatch(); |
| stringBuilder = new StringBuilder(); |
| character = 0; |
| } |
| |
| @Override |
| public void run() { |
| try (BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream))) { |
| while (character != -1) { |
| readWhileReady(reader); |
| if (shouldTerminate()) { |
| break; |
| } |
| } |
| } catch (IOException e) { |
| if (logger.isDebugEnabled()) { |
| logger.debug("Failure reading from buffered input stream: {}", e.getMessage(), e); |
| } |
| } catch (InterruptedException e) { |
| if (logger.isDebugEnabled()) { |
| logger.debug("Interrupted reading from buffered input stream: {}", e.getMessage(), e); |
| } |
| } |
| } |
| |
| private boolean shouldTerminate() throws InterruptedException { |
| if (!ProcessUtils.isProcessAlive(process)) { |
| if (!continueReading.isRunning()) { |
| continueReading.start(); |
| } else if (continueReading.elapsedTimeMillis() > continueReadingMillis) { |
| return true; |
| } |
| } |
| Thread.sleep(10); |
| return false; |
| } |
| |
| /** |
| * This is a hot reader while there are characters ready to read. As soon as there are no more |
| * characters to read, it returns and the loop invokes shouldTerminate which has a 10 millisecond |
| * sleep until there are more characters ready to read. |
| */ |
| private void readWhileReady(BufferedReader reader) throws IOException { |
| while (reader.ready() && (character = reader.read()) != -1) { |
| stringBuilder.append((char) character); |
| if ((char) character == '\n') { |
| inputListener.notifyInputLine(stringBuilder.toString()); |
| stringBuilder = new StringBuilder(); |
| } |
| } |
| } |
| } |