xbytebuffer.java

业界著名的tomcat服务器的最新6.0的源代码。

    }

    /**
     * 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;
    }

}