Update

Author: River

src/com/hipipal/sl4alib/StreamGobbler.java

@@ -0,0 +1,308 @@
+package com.hipipal.sl4alib;
+
+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.
+ * 
+ * @author Christian Plattner, plattner@trilead.com
+ * @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;
+						Log.e("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;
+
+								Log.e("read_pos > 0:" + buffer);
+
+							}
+							else {
+								write_pos = 0;
+								saveBuffer = buffer;
+
+								Log.e("read_pos <=0 :" + buffer);
+
+							}
+						}
+
+						synchronizer.notifyAll();
+					}
+					writeToFile(saveBuffer);
+
+				}
+				catch (IOException e) {
+					synchronized (synchronizer) {
+						exception = e;
+						synchronizer.notifyAll();
+						break;
+					}
+				}
+			}
+		}*/
+
+		public void run() {
+			byte[] buff = new byte[8192];
+
+			while (true) {
+				try {
+					int avail = is.read(buff);
+
+					synchronized (synchronizer) {
+						if (avail <= 0) {
+							isEOF = true;
+							synchronizer.notifyAll();
+							break;
+						}
+
+						int space_available = buffer.length - write_pos;
+
+						if (space_available < avail) {
+
+							int unread_size = write_pos - read_pos;
+							int need_space = unread_size + avail;
+
+							byte[] new_buffer = buffer;
+
+							if (need_space > buffer.length) {
+								int inc = need_space / 3;
+								inc = (inc < 256) ? 256 : inc;
+								inc = (inc > 8192) ? 8192 : inc;
+								new_buffer = new byte[need_space + inc];
+							}
+
+							if (unread_size > 0)
+								System.arraycopy(buffer, read_pos, new_buffer, 0, unread_size);
+
+							buffer = new_buffer;
+
+							read_pos = 0;
+							write_pos = unread_size;
+						}
+
+						byte[] s_buffer = new byte[avail];
+						System.arraycopy(buff, 0, s_buffer, 0, avail);
+						System.arraycopy(buff, 0, buffer, write_pos, avail);
+						write_pos += avail;
+
+						synchronizer.notifyAll();
+						writeToFile(s_buffer);
+						// Log.e("OUTPUT:"+String.valueOf(s_buffer));
+					}
+
+				}
+				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;
+		}
+	}
+}