| /******************************************************************************* |
| * Copyright (c) 2000, 2020 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 |
| * Paul Pazderski - Bug 558463: add handling of raw stream content instead of strings |
| *******************************************************************************/ |
| package org.eclipse.debug.internal.core; |
| |
| import java.io.BufferedInputStream; |
| import java.io.ByteArrayOutputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| 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.IBinaryStreamListener; |
| import org.eclipse.debug.core.IStreamListener; |
| import org.eclipse.debug.core.model.IBinaryStreamMonitor; |
| |
| /** |
| * Monitors the output stream of a system process and notifies listeners of |
| * additions to the stream. |
| * <p> |
| * The output stream monitor reads system out (or err) via and input stream. |
| */ |
| public class OutputStreamMonitor implements IBinaryStreamMonitor { |
| /** |
| * The size of the read buffer. |
| */ |
| private static final int BUFFER_SIZE = 8192; |
| |
| /** |
| * The stream being monitored (connected system out or err). |
| */ |
| private InputStream fStream; |
| |
| /** |
| * A collection of listeners interested in decoded content. |
| */ |
| private ListenerList<IStreamListener> fListeners = new ListenerList<>(); |
| |
| /** |
| * A collection of listeners interested in the raw content. |
| */ |
| private ListenerList<IBinaryStreamListener> fBinaryListeners = new ListenerList<>(); |
| |
| /** |
| * The buffered stream content since last flush. Value of <code>null</code> |
| * indicates disabled buffering. |
| * |
| * @see #isBuffered() |
| */ |
| private ByteArrayOutputStream fContents; |
| |
| /** |
| * Decoder used for the buffered content. This is required to keep the state |
| * of an incomplete character. |
| */ |
| private StreamDecoder fBufferedDecoder; |
| private String fCachedDecodedContents; |
| |
| /** |
| * The thread which reads from the stream |
| */ |
| private Thread fThread; |
| |
| /** |
| * 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 Charset fCharset; |
| |
| private StreamDecoder fDecoder; |
| |
| 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; |
| * unused if only the binary interface is used |
| */ |
| public OutputStreamMonitor(InputStream stream, Charset charset) { |
| fStream = new BufferedInputStream(stream, 8192); |
| fCharset = charset; |
| fDecoder = new StreamDecoder(charset == null ? Charset.defaultCharset() : charset); |
| fDone = new AtomicBoolean(false); |
| setBuffered(true); |
| } |
| |
| /** |
| * 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); |
| } |
| |
| @Override |
| public synchronized void addBinaryListener(IBinaryStreamListener listener) { |
| fBinaryListeners.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<>(); |
| fBinaryListeners = new ListenerList<>(); |
| } |
| } |
| |
| /** |
| * Notifies the listeners that content has been appended to the stream. Will |
| * notify both, binary and text listeners. |
| * |
| * @param data that has been appended; not <code>null</code> |
| * @param offset start of valid data |
| * @param length number of valid bytes |
| */ |
| private void fireStreamAppended(final byte[] data, int offset, int length) { |
| if (!fListeners.isEmpty()) { |
| StringBuilder sb = new StringBuilder(); |
| fDecoder.decode(sb, data, offset, length); |
| final String text = sb.toString(); |
| for (final IStreamListener listener : fListeners) { |
| SafeRunner.run(new ISafeRunnable() { |
| @Override |
| public void run() throws Exception { |
| listener.streamAppended(text, OutputStreamMonitor.this); |
| } |
| |
| @Override |
| public void handleException(Throwable exception) { |
| DebugPlugin.log(exception); |
| } |
| }); |
| } |
| } |
| if (!fBinaryListeners.isEmpty()) { |
| final byte[] validData; |
| if (offset > 0 || length < data.length) { |
| validData = new byte[length]; |
| System.arraycopy(data, offset, validData, 0, length); |
| } else { |
| validData = data; |
| } |
| for (final IBinaryStreamListener listener : fBinaryListeners) { |
| SafeRunner.run(new ISafeRunnable() { |
| @Override |
| public void run() throws Exception { |
| listener.streamAppended(validData, OutputStreamMonitor.this); |
| } |
| |
| @Override |
| public void handleException(Throwable exception) { |
| DebugPlugin.log(exception); |
| } |
| }); |
| } |
| } |
| } |
| |
| @Override |
| public synchronized String getContents() { |
| if (!isBuffered()) { |
| return ""; //$NON-NLS-1$ |
| } |
| if (fCachedDecodedContents != null) { |
| return fCachedDecodedContents; |
| } |
| StringBuilder sb = new StringBuilder(); |
| byte[] data = getData(); |
| fBufferedDecoder.decode(sb, data, 0, data.length); |
| fCachedDecodedContents = sb.toString(); |
| return fCachedDecodedContents; |
| } |
| |
| @Override |
| public synchronized byte[] getData() { |
| return isBuffered() ? fContents.toByteArray() : new byte[0]; |
| } |
| |
| private void read() { |
| try { |
| internalRead(); |
| } finally { |
| fDone.set(true); |
| } |
| } |
| |
| /** |
| * Continually reads from the stream. |
| * <p> |
| * This method, along with the {@link #startMonitoring()} method is used to |
| * allow {@link OutputStreamMonitor} to implement {@link Runnable} without |
| * publicly exposing a {@link Runnable#run()} method. |
| */ |
| private void internalRead() { |
| long lastSleep = System.currentTimeMillis(); |
| long currentTime = lastSleep; |
| byte[] buffer = new byte[BUFFER_SIZE]; |
| int read = 0; |
| try { |
| while (read >= 0) { |
| try { |
| if (fKilled) { |
| break; |
| } |
| read = fStream.read(buffer); |
| if (read > 0) { |
| synchronized (this) { |
| if (isBuffered()) { |
| fCachedDecodedContents = null; |
| fContents.write(buffer, 0, read); |
| } |
| fireStreamAppended(buffer, 0, read); |
| } |
| } |
| } 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) { |
| } |
| } |
| } |
| } finally { |
| try { |
| fStream.close(); |
| } catch (IOException e) { |
| DebugPlugin.log(e); |
| } |
| } |
| } |
| |
| protected void kill() { |
| fKilled = true; |
| } |
| |
| @Override |
| public synchronized void removeListener(IStreamListener listener) { |
| fListeners.remove(listener); |
| } |
| |
| @Override |
| public synchronized void removeBinaryListener(IBinaryStreamListener listener) { |
| fBinaryListeners.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) { |
| if (isBuffered() != buffer) { |
| fCachedDecodedContents = null; |
| if (buffer) { |
| fContents = new ByteArrayOutputStream(); |
| fBufferedDecoder = new StreamDecoder(fCharset == null ? Charset.defaultCharset() : fCharset); |
| } else { |
| fContents = null; |
| fBufferedDecoder = null; |
| } |
| } |
| } |
| |
| @Override |
| public synchronized void flushContents() { |
| if (isBuffered()) { |
| fCachedDecodedContents = null; |
| fContents.reset(); |
| } |
| } |
| |
| @Override |
| public synchronized boolean isBuffered() { |
| return fContents != null; |
| } |
| |
| /** |
| * @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(); |
| } |
| } |