| /******************************************************************************* |
| * Copyright (c) 2000, 2019 IBM Corporation and others. |
| * |
| * This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License 2.0 |
| * which accompanies this distribution, and is available at |
| * https://www.eclipse.org/legal/epl-2.0/ |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| * Paul Pazderski - Bug 545769: fixed rare UTF-8 character corruption bug |
| *******************************************************************************/ |
| package org.eclipse.debug.internal.core; |
| |
| import java.io.BufferedInputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.InputStreamReader; |
| import java.nio.charset.Charset; |
| import java.util.concurrent.atomic.AtomicBoolean; |
| |
| import org.eclipse.core.runtime.ISafeRunnable; |
| import org.eclipse.core.runtime.ListenerList; |
| import org.eclipse.core.runtime.SafeRunner; |
| import org.eclipse.debug.core.DebugPlugin; |
| import org.eclipse.debug.core.IStreamListener; |
| import org.eclipse.debug.core.model.IFlushableStreamMonitor; |
| |
| /** |
| * Monitors the output stream of a system process and notifies |
| * listeners of additions to the stream. |
| * |
| * The output stream monitor reads system out (or err) via |
| * and input stream. |
| */ |
| public class OutputStreamMonitor implements IFlushableStreamMonitor { |
| /** |
| * The stream being monitored (connected system out or err). |
| */ |
| private InputStream fStream; |
| |
| /** |
| * A collection of listeners |
| */ |
| private ListenerList<IStreamListener> fListeners = new ListenerList<>(); |
| |
| /** |
| * Whether content is being buffered |
| */ |
| private boolean fBuffered = true; |
| |
| /** |
| * The local copy of the stream contents |
| */ |
| private StringBuilder fContents; |
| |
| /** |
| * The thread which reads from the stream |
| */ |
| private Thread fThread; |
| |
| /** |
| * The size of the read buffer |
| */ |
| private static final int BUFFER_SIZE= 8192; |
| |
| /** |
| * Whether or not this monitor has been killed. |
| * When the monitor is killed, it stops reading |
| * from the stream immediately. |
| */ |
| private boolean fKilled= false; |
| |
| private long lastSleep; |
| |
| private Charset fCharset; |
| |
| private final AtomicBoolean fDone; |
| |
| /** |
| * Creates an output stream monitor on the given stream (connected to system |
| * out or err). |
| * |
| * @param stream input stream to read from |
| * @param charset stream charset or <code>null</code> for system default |
| */ |
| public OutputStreamMonitor(InputStream stream, Charset charset) { |
| fStream = new BufferedInputStream(stream, 8192); |
| fCharset = charset; |
| fContents= new StringBuilder(); |
| fDone = new AtomicBoolean(false); |
| } |
| |
| /** |
| * Creates an output stream monitor on the given stream (connected to system |
| * out or err). |
| * |
| * @param stream input stream to read from |
| * @param encoding stream encoding or <code>null</code> for system default |
| * @deprecated use {@link #OutputStreamMonitor(InputStream, Charset)} |
| * instead |
| */ |
| @Deprecated |
| public OutputStreamMonitor(InputStream stream, String encoding) { |
| this(stream, Charset.forName(encoding)); |
| } |
| |
| @Override |
| public synchronized void addListener(IStreamListener listener) { |
| fListeners.add(listener); |
| } |
| |
| /** |
| * Causes the monitor to close all |
| * communications between it and the |
| * underlying stream by waiting for the thread to terminate. |
| */ |
| protected void close() { |
| if (fThread != null) { |
| Thread thread= fThread; |
| fThread= null; |
| try { |
| thread.join(); |
| } catch (InterruptedException ie) { |
| } |
| fListeners = new ListenerList<>(); |
| } |
| } |
| |
| /** |
| * Notifies the listeners that text has |
| * been appended to the stream. |
| * @param text the text that was appended to the stream |
| */ |
| private void fireStreamAppended(String text) { |
| getNotifier().notifyAppend(text); |
| } |
| |
| @Override |
| public synchronized String getContents() { |
| return fContents.toString(); |
| } |
| |
| private void read() { |
| try { |
| internalRead(); |
| } finally { |
| fDone.set(true); |
| } |
| } |
| |
| /** |
| * Continually reads from the stream. |
| * <p> |
| * This method, along with the <code>startReading</code> |
| * method is used to allow <code>OutputStreamMonitor</code> |
| * to implement <code>Runnable</code> without publicly |
| * exposing a <code>run</code> method. |
| */ |
| private void internalRead() { |
| lastSleep = System.currentTimeMillis(); |
| long currentTime = lastSleep; |
| char[] chars = new char[BUFFER_SIZE]; |
| int read = 0; |
| try (InputStreamReader reader = (fCharset == null ? new InputStreamReader(fStream) : new InputStreamReader(fStream, fCharset))) { |
| while (read >= 0) { |
| try { |
| if (fKilled) { |
| break; |
| } |
| read = reader.read(chars); |
| if (read > 0) { |
| String text = new String(chars, 0, read); |
| synchronized (this) { |
| if (isBuffered()) { |
| fContents.append(text); |
| } |
| fireStreamAppended(text); |
| } |
| } |
| } catch (IOException ioe) { |
| if (!fKilled) { |
| DebugPlugin.log(ioe); |
| } |
| return; |
| } catch (NullPointerException e) { |
| // killing the stream monitor while reading can cause an NPE |
| // when reading from the stream |
| if (!fKilled && fThread != null) { |
| DebugPlugin.log(e); |
| } |
| return; |
| } |
| |
| currentTime = System.currentTimeMillis(); |
| if (currentTime - lastSleep > 1000) { |
| lastSleep = currentTime; |
| try { |
| // just give up CPU to maintain UI responsiveness. |
| Thread.sleep(1); |
| } catch (InterruptedException e) { |
| } |
| } |
| } |
| } catch (IOException e) { |
| DebugPlugin.log(e); |
| } |
| } |
| |
| protected void kill() { |
| fKilled= true; |
| } |
| |
| @Override |
| public synchronized void removeListener(IStreamListener listener) { |
| fListeners.remove(listener); |
| } |
| |
| /** |
| * Starts a thread which reads from the stream |
| */ |
| protected void startMonitoring() { |
| if (fThread == null) { |
| fDone.set(false); |
| fThread = new Thread((Runnable) this::read, DebugCoreMessages.OutputStreamMonitor_label); |
| fThread.setDaemon(true); |
| fThread.setPriority(Thread.MIN_PRIORITY); |
| fThread.start(); |
| } |
| } |
| |
| @Override |
| public synchronized void setBuffered(boolean buffer) { |
| fBuffered = buffer; |
| } |
| |
| @Override |
| public synchronized void flushContents() { |
| fContents.setLength(0); |
| } |
| |
| @Override |
| public synchronized boolean isBuffered() { |
| return fBuffered; |
| } |
| |
| private ContentNotifier getNotifier() { |
| return new ContentNotifier(); |
| } |
| |
| /** |
| * @return {@code true} if reading the underlying stream is done. |
| * {@code false} if reading the stream has not started or is not done. |
| */ |
| public boolean isReadingDone() { |
| return fDone.get(); |
| } |
| |
| class ContentNotifier implements ISafeRunnable { |
| |
| private IStreamListener fListener; |
| private String fText; |
| |
| @Override |
| public void handleException(Throwable exception) { |
| DebugPlugin.log(exception); |
| } |
| |
| @Override |
| public void run() throws Exception { |
| fListener.streamAppended(fText, OutputStreamMonitor.this); |
| } |
| |
| public void notifyAppend(String text) { |
| if (text == null) { |
| return; |
| } |
| fText = text; |
| for (IStreamListener iStreamListener : fListeners) { |
| fListener = iStreamListener; |
| SafeRunner.run(this); |
| } |
| fListener = null; |
| fText = null; |
| } |
| } |
| } |