/**
* Helios, OpenSource Monitoring
* Brought to you by the Helios Development Group
*
* Copyright 2007, Helios Development Group and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*
*/
package org.helios.apmrouter.util;
import org.snmp4j.PDU;
import org.snmp4j.asn1.BERInputStream;
import org.snmp4j.asn1.BEROutputStream;
import java.io.*;
import java.nio.ByteBuffer;
import java.nio.channels.Channels;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.WritableByteChannel;
import java.util.concurrent.atomic.AtomicLong;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;
/**
* <p>Title: IO</p>
* <p>Description: IO utility methods</p>
* <p>Company: Helios Development Group LLC</p>
* @author Whitehead (nwhitehead AT heliosdev DOT org)
* <p><code>org.helios.apmrouter.util.IO</code></p>
*/
public class IO {
/** A null output stream */
public static final OutputStream NULL_OUTPUTSTREAM = newNullOutputStream();
/** A null print stream */
public static final PrintStream NULL_PRINTSTREAM = newNullPrintStream();
/**
* Creates a NoOp OutputStream
* @return a NoOp OutputStream
*/
public static OutputStream newNullOutputStream() {
return new OutputStream() {
@Override
public void write(int b) throws IOException {
}
};
}
/**
* Creates a NoOp print stream
* @return a NoOp print stream
*/
public static PrintStream newNullPrintStream() {
return new PrintStream(NULL_OUTPUTSTREAM);
}
/**
* Reads an object from a byte buffer
* @param buff The byte buffer to read from
* @return The read object, or null if the buffer was null or zero size
*/
public static Object readFromByteBuffer(final ByteBuffer buff) {
if(buff==null) return null;
if(buff.capacity()<1) return null;
ObjectInputStream ois = null;
InputStream channelInputStream = null;
GZIPInputStream zipInputStream = null;
buff.rewind();
try {
if(buff.hasArray()) {
channelInputStream = new ByteArrayInputStream(buff.array());
} else {
channelInputStream = Channels.newInputStream(new ReadableByteChannel(){
protected boolean open = true;
@Override
public boolean isOpen() {
return open;
}
@Override
public void close() throws IOException {
open = false;
}
@Override
public int read(ByteBuffer dst) throws IOException {
try {
if(buff.remaining()<1) return -1;
int bytes = 0;
while(buff.remaining()>0 && dst.position()<dst.limit()) {
dst.put(
buff.get()
);
bytes++;
}
return bytes;
} catch (Exception e) {
e.printStackTrace(System.err);
throw new IOException(e);
}
}
});
}
byte c = buff.get();
boolean compressed = c==1;
if(compressed) {
zipInputStream = new GZIPInputStream(channelInputStream);
ois = new ObjectInputStream(zipInputStream);
} else {
ois = new ObjectInputStream(channelInputStream);
}
return ois.readObject();
} catch (Exception e) {
throw new RuntimeException("Failed to Deserialize from ByteBuffer", e);
} finally {
try { ois.close(); } catch (Exception ex) {};
if(zipInputStream!=null) try { zipInputStream.close(); } catch (Exception ex) {};
}
}
private static String logb(ByteBuffer b) {
StringBuilder sb = new StringBuilder(" ByteBuffer:");
sb.append("\n\tCapacity:").append(b.capacity());
sb.append("\n\tPosition:").append(b.position());
sb.append("\n\tLimit:").append(b.limit());
return sb.toString();
}
/**
* Serializes an object to a byte buffer using a default buffer size of 8192
* @param value The object to serialize
* @param direct true to return a direct buffer, false for a heap buffer
* @param compress Indicates if the byte array should be compressed
* @return The buffer containing the serialized object which may be empty if the value was null
*/
public static ByteBuffer writeToByteBuffer(Object value, boolean direct, boolean compress) {
return writeToByteBuffer(value, direct, 8192, compress);
}
/**
* Returns an input stream for the passed ByteBuffer
* @param buff the ByteBuffer to read from
* @return an InputStream that reads from the passed ByteBuffer
* FIXME: Needs to support testing the compression byte and adding a decompressor if required.
*/
public static InputStream read(final ByteBuffer buff) {
return Channels.newInputStream(new ReadableByteChannel(){
protected boolean open = true;
@Override
public boolean isOpen() {
return open;
}
@Override
public void close() throws IOException {
open = false;
}
@Override
public int read(ByteBuffer dst) throws IOException {
try {
if(buff.remaining()<1) return -1;
int bytes = 0;
while(buff.remaining()>0 && dst.position()<dst.limit()) {
dst.put(
buff.get()
);
bytes++;
}
return bytes;
} catch (Exception e) {
e.printStackTrace(System.err);
throw new IOException(e);
}
}
});
}
/**
* Serializes an object to a byte buffer
* @param value The object to serialize
* @param direct true to return a direct buffer, false for a heap buffer
* @param bufferSize The incremental size of the buffers to create while streaming
* @param compress Indicates if the byte array should be compressed
* @return The buffer containing the serialized object which may be empty if the value was null
*/
public static ByteBuffer writeToByteBufferX(final Object value, final boolean direct, final int bufferSize, final boolean compress) {
if(value==null) return direct ? ByteBuffer.allocateDirect(0) : ByteBuffer.allocate(0);
ObjectOutputStream ois = null;
OutputStream channelOutputStream = null;
GZIPOutputStream zipOutputStream = null;
final AtomicLong cntr = new AtomicLong();
final ByteBuffer[] buff = new ByteBuffer[]{direct ? ByteBuffer.allocateDirect(bufferSize) : ByteBuffer.allocate(bufferSize)};
try {
channelOutputStream = Channels.newOutputStream(new WritableByteChannel() {
protected boolean open = true;
@Override
public boolean isOpen() {
return open;
}
@Override
public void close() throws IOException {
open = false;
}
@Override
public int write(ByteBuffer src) throws IOException {
int bytesRead = 0;
while(src.remaining()>0) {
if(buff[0].position()==buff[0].limit()-1) {
ByteBuffer newBuff = direct ? ByteBuffer.allocateDirect(buff[0].capacity()+bufferSize) : ByteBuffer.allocate(buff[0].capacity()+bufferSize);
newBuff.put(buff[0]);
buff[0] = newBuff;
}
buff[0].put(src.get());
bytesRead++;
}
cntr.addAndGet(bytesRead);
return bytesRead;
}
});
buff[0].position(0);
if(compress) {
buff[0].put((byte)1);
zipOutputStream = new GZIPOutputStream(channelOutputStream);
ois = new ObjectOutputStream(zipOutputStream);
} else {
buff[0].put((byte)0);
ois = new ObjectOutputStream(channelOutputStream);
}
ois.writeObject(value);
ois.flush();
if(compress) zipOutputStream.finish();
//log("Total Bytes:" + cntr.get());
buff[0].flip();
return buff[0];
} catch (Throwable e) {
e.printStackTrace(System.err);
throw new RuntimeException("Failed to write instance of [" + value.getClass().getName() + "]", e);
} finally {
if(ois!=null) try { ois.close(); } catch (Exception ex) {}
if(zipOutputStream!=null) try { zipOutputStream.close(); } catch (Exception ex) {}
}
}
/**
* Serializes an object to a byte buffer
* @param value The object to serialize
* @param direct true to return a direct buffer, false for a heap buffer
* @param bufferSize The incremental size of the buffers to create while streaming
* @param compress Indicates if the byte array should be compressed
* @return The buffer containing the serialized object which may be empty if the value was null
*/
public static ByteBuffer writeToByteBuffer(final Object value, final boolean direct, final int bufferSize, final boolean compress) {
if(value==null) return direct ? ByteBuffer.allocateDirect(0) : ByteBuffer.allocate(0);
ObjectOutputStream ois = null;
ByteArrayOutputStream channelOutputStream = new ByteArrayOutputStream(bufferSize);
GZIPOutputStream zipOutputStream = null;
try {
if(compress) {
zipOutputStream = new GZIPOutputStream(channelOutputStream);
ois = new ObjectOutputStream(zipOutputStream);
// channelOutputStream.write(1);
} else {
ois = new ObjectOutputStream(channelOutputStream);
// channelOutputStream.write(0);
}
// channelOutputStream.flush();
ois.writeObject(value);
ois.flush();
if(compress) zipOutputStream.finish();
channelOutputStream.flush();
ByteBuffer bb = null;
byte[] bytes = channelOutputStream.toByteArray();
if(direct) {
bb = ByteBuffer.allocateDirect(bytes.length+1);
} else {
bb = ByteBuffer.allocate(bytes.length+1);
}
bb.put((byte) (compress ? 1 : 0));
bb.put(bytes);
//bb.flip();
return bb;
} catch (Throwable e) {
e.printStackTrace(System.err);
throw new RuntimeException("Failed to write instance of [" + value.getClass().getName() + "]", e);
} finally {
if(ois!=null) try { ois.close(); } catch (Exception ex) {}
if(zipOutputStream!=null) try { zipOutputStream.close(); } catch (Exception ex) {}
}
}
public static void log(Object msg) {
System.out.println(msg);
}
/**
* Writes out an SNMP PDU to a byte buffer
* @param pdu The PDU to write
* @param direct true for a direct buffer, false for a heap buffer
* @return the ByteBuffer the PDU was written to
*/
public static ByteBuffer writePDUToByteBuffer(PDU pdu, boolean direct) {
try {
ByteBuffer bb = direct ? ByteBuffer.allocateDirect(pdu.getBERLength()) : ByteBuffer.allocate(pdu.getBERLength());
BEROutputStream bos = new BEROutputStream(bb);
pdu.encodeBER(bos);
bos.flush();
return bb;
} catch (Exception e) {
e.printStackTrace(System.err);
throw new RuntimeException("Failed to write PDU", e);
}
}
/**
* Reads an SNMP PDU from the passed ByteBuffer
* @param bb The ByteBuffer to read the PDU from
* @return The read PDU
*/
public static PDU readPDUFromByteBuffer(ByteBuffer bb) {
try {
PDU pdu = new PDU();
BERInputStream bis = new BERInputStream(bb);
pdu.decodeBER(bis);
return pdu;
} catch (Exception e) {
e.printStackTrace(System.err);
throw new RuntimeException("Failed to read PDU", e);
}
}
}