/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.catalina.tribes.io;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.nio.ByteBuffer;
/**
* The XByteBuffer provides a dual functionality.
* One, it stores message bytes and automatically extends the byte buffer if needed.<BR>
* Two, it can encode and decode packages so that they can be defined and identified
* as they come in on a socket.
* <br>
* <b>THIS CLASS IS NOT THREAD SAFE</B><BR>
* <br/>
* Transfer package:
* <ul>
* <li><b>START_DATA/b> - 7 bytes - <i>FLT2002</i></li>
* <li><b>SIZE</b> - 4 bytes - size of the data package</li>
* <li><b>DATA</b> - should be as many bytes as the prev SIZE</li>
* <li><b>END_DATA</b> - 7 bytes - <i>TLF2003</i></lI>
* </ul>
* @author Filip Hanik
* @version $Revision: 467173 $, $Date: 2006-10-24 01:12:17 +0200 (mar., 24 oct. 2006) $
*/
public class XByteBuffer
{
public static org.apache.juli.logging.Log log =
org.apache.juli.logging.LogFactory.getLog( XByteBuffer.class );
/**
* This is a package header, 7 bytes (FLT2002)
*/
public static final byte[] START_DATA = {70,76,84,50,48,48,50};
/**
* This is the package footer, 7 bytes (TLF2003)
*/
public static final byte[] END_DATA = {84,76,70,50,48,48,51};
/**
* Default size on the initial byte buffer
*/
private static final int DEF_SIZE = 2048;
/**
* Default size to extend the buffer with
*/
private static final int DEF_EXT = 1024;
/**
* Variable to hold the data
*/
protected byte[] buf = null;
/**
* Current length of data in the buffer
*/
protected int bufSize = 0;
/**
* Flag for discarding invalid packages
* If this flag is set to true, and append(byte[],...) is called,
* the data added will be inspected, and if it doesn't start with
* <code>START_DATA</code> it will be thrown away.
*
*/
protected boolean discard = true;
/**
* Constructs a new XByteBuffer
* @param size - the initial size of the byte buffer
* @todo use a pool of byte[] for performance
*/
public XByteBuffer(int size, boolean discard) {
buf = new byte[size];
this.discard = discard;
}
public XByteBuffer(byte[] data,boolean discard) {
this(data,data.length+128,discard);
}
public XByteBuffer(byte[] data, int size,boolean discard) {
int length = Math.max(data.length,size);
buf = new byte[length];
System.arraycopy(data,0,buf,0,data.length);
bufSize = data.length;
this.discard = discard;
}
public int getLength() {
return bufSize;
}
public void setLength(int size) {
if ( size > buf.length ) throw new ArrayIndexOutOfBoundsException("Size is larger than existing buffer.");
bufSize = size;
}
public void trim(int length) {
if ( (bufSize - length) < 0 )
throw new ArrayIndexOutOfBoundsException("Can't trim more bytes than are available. length:"+bufSize+" trim:"+length);
bufSize -= length;
}
public void reset() {
bufSize = 0;
}
public byte[] getBytesDirect() {
return this.buf;
}
/**
* Returns the bytes in the buffer, in its exact length
*/
public byte[] getBytes() {
byte[] b = new byte[bufSize];
System.arraycopy(buf,0,b,0,bufSize);
return b;
}
/**
* Resets the buffer
*/
public void clear() {
bufSize = 0;
}
/**
* Appends the data to the buffer. If the data is incorrectly formatted, ie, the data should always start with the
* header, false will be returned and the data will be discarded.
* @param b - bytes to be appended
* @param off - the offset to extract data from
* @param len - the number of bytes to append.
* @return true if the data was appended correctly. Returns false if the package is incorrect, ie missing header or something, or the length of data is 0
*/
public boolean append(ByteBuffer b, int len) {
int newcount = bufSize + len;
if (newcount > buf.length) {
expand(newcount);
}
b.get(buf,bufSize,len);
bufSize = newcount;
if ( discard ) {
if (bufSize > START_DATA.length && (firstIndexOf(buf, 0, START_DATA) == -1)) {
bufSize = 0;
log.error("Discarded the package, invalid header");
return false;
}
}
return true;
}
public boolean append(byte i) {
int newcount = bufSize + 1;
if (newcount > buf.length) {
expand(newcount);
}
buf[bufSize] = i;
bufSize = newcount;
return true;
}
public boolean append(boolean i) {
int newcount = bufSize + 1;
if (newcount > buf.length) {
expand(newcount);
}
XByteBuffer.toBytes(i,buf,bufSize);
bufSize = newcount;
return true;
}
public boolean append(long i) {
int newcount = bufSize + 8;
if (newcount > buf.length) {
expand(newcount);
}
XByteBuffer.toBytes(i,buf,bufSize);
bufSize = newcount;
return true;
}
public boolean append(int i) {
int newcount = bufSize + 4;
if (newcount > buf.length) {
expand(newcount);
}
XByteBuffer.toBytes(i,buf,bufSize);
bufSize = newcount;
return true;
}
public boolean append(byte[] b, int off, int len) {
if ((off < 0) || (off > b.length) || (len < 0) ||
((off + len) > b.length) || ((off + len) < 0)) {
throw new IndexOutOfBoundsException();
} else if (len == 0) {
return false;
}
int newcount = bufSize + len;
if (newcount > buf.length) {
expand(newcount);
}
System.arraycopy(b, off, buf, bufSize, len);
bufSize = newcount;
if ( discard ) {
if (bufSize > START_DATA.length && (firstIndexOf(buf, 0, START_DATA) == -1)) {
bufSize = 0;
log.error("Discarded the package, invalid header");
return false;
}
}
return true;
}
public void expand(int newcount) {
//don't change the allocation strategy
byte newbuf[] = new byte[Math.max(buf.length << 1, newcount)];
System.arraycopy(buf, 0, newbuf, 0, bufSize);
buf = newbuf;
}
public int getCapacity() {
return buf.length;
}
/**
* Internal mechanism to make a check if a complete package exists
* within the buffer
* @return - true if a complete package (header,compress,size,data,footer) exists within the buffer
*/
public int countPackages() {
return countPackages(false);
}
public int countPackages(boolean first)
{
int cnt = 0;
int pos = START_DATA.length;
int start = 0;
while ( start < bufSize ) {
//first check start header
int index = XByteBuffer.firstIndexOf(buf,start,START_DATA);
//if the header (START_DATA) isn't the first thing or
//the buffer isn't even 14 bytes
if ( index != start || ((bufSize-start)<14) ) break;
//next 4 bytes are compress flag not needed for count packages
//then get the size 4 bytes
int size = toInt(buf, pos);
//now the total buffer has to be long enough to hold
//START_DATA.length+4+size+END_DATA.length
pos = start + START_DATA.length + 4 + size;
if ( (pos + END_DATA.length) > bufSize) break;
//and finally check the footer of the package END_DATA
int newpos = firstIndexOf(buf, pos, END_DATA);
//mismatch, there is no package
if (newpos != pos) break;
//increase the packet count
cnt++;
//reset the values
start = pos + END_DATA.length;
pos = start + START_DATA.length;
//we only want to verify that we have at least one package
if ( first ) break;
}
return cnt;
}
/**
* Method to check if a package exists in this byte buffer.
* @return - true if a complete package (header,options,size,data,footer) exists within the buffer
*/
public boolean doesPackageExist() {
return (countPackages(true)>0);
}
/**
* Extracts the message bytes from a package.
* If no package exists, a IllegalStateException will be thrown.
* @param clearFromBuffer - if true, the package will be removed from the byte buffer
* @return - returns the actual message bytes (header, compress,size and footer not included).
*/
public XByteBuffer extractDataPackage(boolean clearFromBuffer) {
int psize = countPackages(true);
if (psize == 0) {
throw new java.lang.IllegalStateException("No package exists in XByteBuffer");
}
int size = toInt(buf, START_DATA.length);
XByteBuffer xbuf = BufferPool.getBufferPool().getBuffer(size,false);
xbuf.setLength(size);
System.arraycopy(buf, START_DATA.length + 4, xbuf.getBytesDirect(), 0, size);
if (clearFromBuffer) {
int totalsize = START_DATA.length + 4 + size + END_DATA.length;
bufSize = bufSize - totalsize;
System.arraycopy(buf, totalsize, buf, 0, bufSize);
}
return xbuf;
}
public ChannelData extractPackage(boolean clearFromBuffer) throws java.io.IOException {
XByteBuffer xbuf = extractDataPackage(clearFromBuffer);
ChannelData cdata = ChannelData.getDataFromPackage(xbuf);
return cdata;
}
/**
* Creates a complete data package
* @param indata - the message data to be contained within the package
* @param compressed - compression flag for the indata buffer
* @return - a full package (header,size,data,footer)
*
*/
public static byte[] createDataPackage(ChannelData cdata) {
// return createDataPackage(cdata.getDataPackage());
//avoid one extra byte array creation
int dlength = cdata.getDataPackageLength();
int length = getDataPackageLength(dlength);
byte[] data = new byte[length];
int offset = 0;
System.arraycopy(START_DATA, 0, data, offset, START_DATA.length);
offset += START_DATA.length;
toBytes(dlength,data, START_DATA.length);
offset += 4;
cdata.getDataPackage(data,offset);
offset += dlength;
System.arraycopy(END_DATA, 0, data, offset, END_DATA.length);
offset += END_DATA.length;
return data;
}
public static byte[] createDataPackage(byte[] data, int doff, int dlength, byte[] buffer, int bufoff) {
if ( (buffer.length-bufoff) > getDataPackageLength(dlength) ) {
throw new ArrayIndexOutOfBoundsException("Unable to create data package, buffer is too small.");
}
System.arraycopy(START_DATA, 0, buffer, bufoff, START_DATA.length);
toBytes(data.length,buffer, bufoff+START_DATA.length);
System.arraycopy(data, doff, buffer, bufoff+START_DATA.length + 4, dlength);
System.arraycopy(END_DATA, 0, buffer, bufoff+START_DATA.length + 4 + data.length, END_DATA.length);
return buffer;
}
public static int getDataPackageLength(int datalength) {
int length =
START_DATA.length + //header length
4 + //data length indicator
datalength + //actual data length
END_DATA.length; //footer length
return length;
}
public static byte[] createDataPackage(byte[] data) {
int length = getDataPackageLength(data.length);
byte[] result = new byte[length];
return createDataPackage(data,0,data.length,result,0);
}
// public static void fillDataPackage(byte[] data, int doff, int dlength, XByteBuffer buf) {
// int pkglen = getDataPackageLength(dlength);
// if ( buf.getCapacity() < pkglen ) buf.expand(pkglen);
// createDataPackage(data,doff,dlength,buf.getBytesDirect(),buf.getLength());
// }
/**
* Convert four bytes to an int
* @param b - the byte array containing the four bytes
* @param off - the offset
* @return the integer value constructed from the four bytes
* @exception java.lang.ArrayIndexOutOfBoundsException
*/
public static int toInt(byte[] b,int off){
return ( ( (int) b[off+3]) & 0xFF) +
( ( ( (int) b[off+2]) & 0xFF) << 8) +
( ( ( (int) b[off+1]) & 0xFF) << 16) +
( ( ( (int) b[off+0]) & 0xFF) << 24);
}
/**
* Convert eight bytes to a long
* @param b - the byte array containing the four bytes
* @param off - the offset
* @return the long value constructed from the eight bytes
* @exception java.lang.ArrayIndexOutOfBoundsException
*/
public static long toLong(byte[] b,int off){
return ( ( (long) b[off+7]) & 0xFF) +
( ( ( (long) b[off+6]) & 0xFF) << 8) +
( ( ( (long) b[off+5]) & 0xFF) << 16) +
( ( ( (long) b[off+4]) & 0xFF) << 24) +
( ( ( (long) b[off+3]) & 0xFF) << 32) +
( ( ( (long) b[off+2]) & 0xFF) << 40) +
( ( ( (long) b[off+1]) & 0xFF) << 48) +
( ( ( (long) b[off+0]) & 0xFF) << 56);
}
/**
* Converts an integer to four bytes
* @param n - the integer
* @return - four bytes in an array
* @deprecated use toBytes(boolean,byte[],int)
*/
public static byte[] toBytes(boolean bool) {
byte[] b = new byte[1] ;
return toBytes(bool,b,0);
}
public static byte[] toBytes(boolean bool, byte[] data, int offset) {
data[offset] = (byte)(bool?1:0);
return data;
}
/**
*
* @param <any> long
* @return use
*/
public static boolean toBoolean(byte[] b, int offset) {
return b[offset] != 0;
}
/**
* Converts an integer to four bytes
* @param n - the integer
* @return - four bytes in an array
* @deprecated use toBytes(int,byte[],int)
*/
public static byte[] toBytes(int n) {
return toBytes(n,new byte[4],0);
}
public static byte[] toBytes(int n,byte[] b, int offset) {
b[offset+3] = (byte) (n);
n >>>= 8;
b[offset+2] = (byte) (n);
n >>>= 8;
b[offset+1] = (byte) (n);
n >>>= 8;
b[offset+0] = (byte) (n);
return b;
}
/**
* Converts an long to eight bytes
* @param n - the long
* @return - eight bytes in an array
* @deprecated use toBytes(long,byte[],int)
*/
public static byte[] toBytes(long n) {
return toBytes(n,new byte[8],0);
}
public static byte[] toBytes(long n, byte[] b, int offset) {
b[offset+7] = (byte) (n);
n >>>= 8;
b[offset+6] = (byte) (n);
n >>>= 8;
b[offset+5] = (byte) (n);
n >>>= 8;
b[offset+4] = (byte) (n);
n >>>= 8;
b[offset+3] = (byte) (n);
n >>>= 8;
b[offset+2] = (byte) (n);
n >>>= 8;
b[offset+1] = (byte) (n);
n >>>= 8;
b[offset+0] = (byte) (n);
return b;
}
/**
* Similar to a String.IndexOf, but uses pure bytes
* @param src - the source bytes to be searched
* @param srcOff - offset on the source buffer
* @param find - the string to be found within src
* @return - the index of the first matching byte. -1 if the find array is not found
*/
public static int firstIndexOf(byte[] src, int srcOff, byte[] find){
int result = -1;
if (find.length > src.length) return result;
if (find.length == 0 || src.length == 0) return result;
if (srcOff >= src.length ) throw new java.lang.ArrayIndexOutOfBoundsException();
boolean found = false;
int srclen = src.length;
int findlen = find.length;
byte first = find[0];
int pos = srcOff;
while (!found) {
//find the first byte
while (pos < srclen){
if (first == src[pos])
break;
pos++;
}
if (pos >= srclen)
return -1;
//we found the first character
//match the rest of the bytes - they have to match
if ( (srclen - pos) < findlen)
return -1;
//assume it does exist
found = true;
for (int i = 1; ( (i < findlen) && found); i++)
found = found && (find[i] == src[pos + i]);
if (found)
result = pos;
else if ( (srclen - pos) < findlen)
return -1; //no more matches possible
else
pos++;
}
return result;
}
public static Serializable deserialize(byte[] data)
throws IOException, ClassNotFoundException, ClassCastException {
return deserialize(data,0,data.length);
}
public static Serializable deserialize(byte[] data, int offset, int length)
throws IOException, ClassNotFoundException, ClassCastException {
return deserialize(data,offset,length,null);
}
public static int invokecount = 0;
public static Serializable deserialize(byte[] data, int offset, int length, ClassLoader[] cls)
throws IOException, ClassNotFoundException, ClassCastException {
synchronized (XByteBuffer.class) { invokecount++;}
Object message = null;
if ( cls == null ) cls = new ClassLoader[0];
if (data != null) {
InputStream instream = new ByteArrayInputStream(data,offset,length);
ObjectInputStream stream = null;
stream = (cls.length>0)? new ReplicationStream(instream,cls):new ObjectInputStream(instream);
message = stream.readObject();
instream.close();
stream.close();
}
if ( message == null ) {
return null;
} else if (message instanceof Serializable)
return (Serializable) message;
else {
throw new ClassCastException("Message has the wrong class. It should implement Serializable, instead it is:"+message.getClass().getName());
}
}
/**
* Serializes a message into cluster data
* @param msg ClusterMessage
* @param compress boolean
* @return
* @throws IOException
*/
public static byte[] serialize(Serializable msg) throws IOException {
ByteArrayOutputStream outs = new ByteArrayOutputStream();
ObjectOutputStream out = new ObjectOutputStream(outs);
out.writeObject(msg);
out.flush();
byte[] data = outs.toByteArray();
return data;
}
public void setDiscard(boolean discard) {
this.discard = discard;
}
public boolean getDiscard() {
return discard;
}
}
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