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/*
 * 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;
import java.util.concurrent.atomic.AtomicInteger;

import org.apache.catalina.tribes.util.StringManager;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;

/**
 * The XByteBuffer provides a dual functionality.
 * One, it stores message bytes and automatically extends the byte buffer if needed.
* Two, it can encode and decode packages so that they can be defined and identified * as they come in on a socket. *
* THIS CLASS IS NOT THREAD SAFE
*
* Transfer package: *
    *
  • START_DATA- 7 bytes - FLT2002
  • *
  • SIZE - 4 bytes - size of the data package
  • *
  • DATA - should be as many bytes as the prev SIZE
  • *
  • END_DATA - 7 bytes - TLF2003
  • *
*/ public class XByteBuffer implements Serializable { private static final long serialVersionUID = 1L; private static final Log log = LogFactory.getLog(XByteBuffer.class); protected static final StringManager sm = StringManager.getManager(XByteBuffer.class); /** * This is a package header, 7 bytes (FLT2002) */ private static final byte[] START_DATA = {70,76,84,50,48,48,50}; /** * This is the package footer, 7 bytes (TLF2003) */ private static final byte[] END_DATA = {84,76,70,50,48,48,51}; /** * 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 * START_DATA it will be thrown away. * */ protected boolean discard = true; /** * Constructs a new XByteBuffer.
* TODO use a pool of byte[] for performance * @param size the initial size of the byte buffer * @param discard Flag for discarding invalid packages */ 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(sm.getString("xByteBuffer.size.larger.buffer")); } bufSize = size; } public void trim(int length) { if ( (bufSize - length) < 0 ) { throw new ArrayIndexOutOfBoundsException(sm.getString("xByteBuffer.unableTrim", Integer.toString(bufSize), Integer.toString(length))); } bufSize -= length; } public void reset() { bufSize = 0; } public byte[] getBytesDirect() { return this.buf; } /** * @return 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 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(sm.getString("xByteBuffer.discarded.invalidHeader")); 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); } toBytes(i,buf,bufSize); bufSize = newcount; return true; } public boolean append(long i) { int newcount = bufSize + 8; if (newcount > buf.length) { expand(newcount); } toBytes(i,buf,bufSize); bufSize = newcount; return true; } public boolean append(int i) { int newcount = bufSize + 4; if (newcount > buf.length) { expand(newcount); } 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(sm.getString("xByteBuffer.discarded.invalidHeader")); 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 = 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 IllegalStateException(sm.getString("xByteBuffer.no.package")); } 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) { XByteBuffer xbuf = extractDataPackage(clearFromBuffer); ChannelData cdata = ChannelData.getDataFromPackage(xbuf); return cdata; } /** * Creates a complete data package * @param cdata - the message data to be contained within the package * @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(sm.getString("xByteBuffer.unableCreate")); } 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 */ public static int toInt(byte[] b,int off){ return ( ( b[off+3]) & 0xFF) + ( ( ( b[off+2]) & 0xFF) << 8) + ( ( ( b[off+1]) & 0xFF) << 16) + ( ( ( 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 */ 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 a boolean and put it in a byte array. * @param bool the integer * @param data the byte buffer in which the boolean will be placed * @param offset the offset in the byte array * @return the byte array */ public static byte[] toBytes(boolean bool, byte[] data, int offset) { data[offset] = (byte)(bool?1:0); return data; } /** * Converts a byte array entry to boolean. * @param b byte array * @param offset within byte array * @return true if byte array entry is non-zero, false otherwise */ public static boolean toBoolean(byte[] b, int offset) { return b[offset] != 0; } /** * Converts an integer to four bytes. * @param n the integer * @param b the byte buffer in which the integer will be placed * @param offset the offset in the byte array * @return four bytes in an array */ 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 a long to eight bytes. * @param n the long * @param b the byte buffer in which the integer will be placed * @param offset the offset in the byte array * @return eight bytes in an array */ 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 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 = (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); } private static final AtomicInteger invokecount = new AtomicInteger(0); public static Serializable deserialize(byte[] data, int offset, int length, ClassLoader[] cls) throws IOException, ClassNotFoundException, ClassCastException { invokecount.addAndGet(1); Object message = null; if ( cls == null ) { cls = new ClassLoader[0]; } if (data != null && length > 0) { 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(sm.getString("xByteBuffer.wrong.class", message.getClass().getName())); } } /** * Serializes a message into cluster data * @param msg ClusterMessage * @return serialized content as byte[] array * @throws IOException Serialization error */ 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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