| /* |
| * Copyright (C) 2017 The Android Open Source Project |
| * |
| * Licensed 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 com.trilead.ssh2; |
| |
| import com.googlecode.android_scripting.Log; |
| |
| import java.io.File; |
| import java.io.FileOutputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| |
| /** |
| * A <code>StreamGobbler</code> is an InputStream that uses an internal worker thread to constantly |
| * consume input from another InputStream. It uses a buffer to store the consumed data. The buffer |
| * size is automatically adjusted, if needed. |
| * <p> |
| * This class is sometimes very convenient - if you wrap a session's STDOUT and STDERR InputStreams |
| * with instances of this class, then you don't have to bother about the shared window of STDOUT and |
| * STDERR in the low level SSH-2 protocol, since all arriving data will be immediatelly consumed by |
| * the worker threads. Also, as a side effect, the streams will be buffered (e.g., single byte |
| * read() operations are faster). |
| * <p> |
| * Other SSH for Java libraries include this functionality by default in their STDOUT and STDERR |
| * InputStream implementations, however, please be aware that this approach has also a downside: |
| * <p> |
| * If you do not call the StreamGobbler's <code>read()</code> method often enough and the peer is |
| * constantly sending huge amounts of data, then you will sooner or later encounter a low memory |
| * situation due to the aggregated data (well, it also depends on the Java heap size). Joe Average |
| * will like this class anyway - a paranoid programmer would never use such an approach. |
| * <p> |
| * The term "StreamGobbler" was taken from an article called "When Runtime.exec() won't", see |
| * http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps.html. |
| * |
| * @version $Id: StreamGobbler.java,v 1.1 2007/10/15 12:49:56 cplattne Exp $ |
| */ |
| |
| public class StreamGobbler extends InputStream { |
| class GobblerThread extends Thread { |
| @Override |
| public void run() { |
| |
| while (true) { |
| try { |
| byte[] saveBuffer = null; |
| |
| int avail = is.read(buffer, write_pos, buffer.length - write_pos); |
| |
| synchronized (synchronizer) { |
| if (avail <= 0) { |
| isEOF = true; |
| synchronizer.notifyAll(); |
| break; |
| } |
| write_pos += avail; |
| |
| int space_available = buffer.length - write_pos; |
| |
| if (space_available == 0) { |
| if (read_pos > 0) { |
| saveBuffer = new byte[read_pos]; |
| System.arraycopy(buffer, 0, saveBuffer, 0, read_pos); |
| System.arraycopy(buffer, read_pos, buffer, 0, buffer.length - read_pos); |
| write_pos -= read_pos; |
| read_pos = 0; |
| } else { |
| write_pos = 0; |
| saveBuffer = buffer; |
| } |
| } |
| |
| synchronizer.notifyAll(); |
| } |
| |
| writeToFile(saveBuffer); |
| |
| } catch (IOException e) { |
| synchronized (synchronizer) { |
| exception = e; |
| synchronizer.notifyAll(); |
| break; |
| } |
| } |
| } |
| } |
| } |
| |
| private InputStream is; |
| private GobblerThread t; |
| |
| private Object synchronizer = new Object(); |
| |
| private boolean isEOF = false; |
| private boolean isClosed = false; |
| private IOException exception = null; |
| |
| private byte[] buffer; |
| private int read_pos = 0; |
| private int write_pos = 0; |
| private final FileOutputStream mLogStream; |
| private final int mBufferSize; |
| |
| public StreamGobbler(InputStream is, File log, int buffer_size) { |
| this.is = is; |
| mBufferSize = buffer_size; |
| FileOutputStream out = null; |
| try { |
| out = new FileOutputStream(log, false); |
| } catch (IOException e) { |
| Log.e(e); |
| } |
| mLogStream = out; |
| buffer = new byte[mBufferSize]; |
| t = new GobblerThread(); |
| t.setDaemon(true); |
| t.start(); |
| } |
| |
| public void writeToFile(byte[] buffer) { |
| if (mLogStream != null && buffer != null) { |
| try { |
| mLogStream.write(buffer); |
| } catch (IOException e) { |
| Log.e(e); |
| } |
| } |
| } |
| |
| @Override |
| public int read() throws IOException { |
| synchronized (synchronizer) { |
| if (isClosed) { |
| throw new IOException("This StreamGobbler is closed."); |
| } |
| |
| while (read_pos == write_pos) { |
| if (exception != null) { |
| throw exception; |
| } |
| |
| if (isEOF) { |
| return -1; |
| } |
| |
| try { |
| synchronizer.wait(); |
| } catch (InterruptedException e) { |
| } |
| } |
| |
| int b = buffer[read_pos++] & 0xff; |
| |
| return b; |
| } |
| } |
| |
| @Override |
| public int available() throws IOException { |
| synchronized (synchronizer) { |
| if (isClosed) { |
| throw new IOException("This StreamGobbler is closed."); |
| } |
| |
| return write_pos - read_pos; |
| } |
| } |
| |
| @Override |
| public int read(byte[] b) throws IOException { |
| return read(b, 0, b.length); |
| } |
| |
| @Override |
| public void close() throws IOException { |
| synchronized (synchronizer) { |
| if (isClosed) { |
| return; |
| } |
| isClosed = true; |
| isEOF = true; |
| synchronizer.notifyAll(); |
| is.close(); |
| } |
| } |
| |
| @Override |
| public int read(byte[] b, int off, int len) throws IOException { |
| if (b == null) { |
| throw new NullPointerException(); |
| } |
| |
| if ((off < 0) || (len < 0) || ((off + len) > b.length) || ((off + len) < 0) || (off > b.length)) { |
| throw new IndexOutOfBoundsException(); |
| } |
| |
| if (len == 0) { |
| return 0; |
| } |
| |
| synchronized (synchronizer) { |
| if (isClosed) { |
| throw new IOException("This StreamGobbler is closed."); |
| } |
| |
| while (read_pos == write_pos) { |
| if (exception != null) { |
| throw exception; |
| } |
| |
| if (isEOF) { |
| return -1; |
| } |
| |
| try { |
| synchronizer.wait(); |
| } catch (InterruptedException e) { |
| } |
| } |
| |
| int avail = write_pos - read_pos; |
| |
| avail = (avail > len) ? len : avail; |
| |
| System.arraycopy(buffer, read_pos, b, off, avail); |
| |
| read_pos += avail; |
| |
| return avail; |
| } |
| } |
| } |