org.apache.catalina.tribes.io

Class XByteBuffer

java.lang.Object

org.apache.catalina.tribes.io.XByteBuffer

public class XByteBuffer
extends Object

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

Field Summary

Fields

Modifier and Type	Field and Description
protected byte[]	buf Variable to hold the data
protected int	bufSize Current length of data in the buffer
protected boolean	discard 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 static StringManager	sm

Constructor Summary

Constructors

Constructor and Description
XByteBuffer(byte[] data, boolean discard)
XByteBuffer(byte[] data, int size, boolean discard)
XByteBuffer(int size, boolean discard) Constructs a new XByteBuffer.

Method Summary

Modifier and Type	Method and Description
boolean	append(boolean i)
boolean	append(byte i)
boolean	append(byte[] b, int off, int len)
boolean	append(ByteBuffer b, int len) Appends the data to the buffer.
boolean	append(int i)
boolean	append(long i)
void	clear() Resets the buffer
int	countPackages() Internal mechanism to make a check if a complete package exists within the buffer
int	countPackages(boolean first)
static byte[]	createDataPackage(byte[] data)
static byte[]	createDataPackage(byte[] data, int doff, int dlength, byte[] buffer, int bufoff)
static byte[]	createDataPackage(ChannelData cdata) Creates a complete data package
static Serializable	deserialize(byte[] data)
static Serializable	deserialize(byte[] data, int offset, int length)
static Serializable	deserialize(byte[] data, int offset, int length, ClassLoader[] cls)
boolean	doesPackageExist() Method to check if a package exists in this byte buffer.
void	expand(int newcount)
XByteBuffer	extractDataPackage(boolean clearFromBuffer) Extracts the message bytes from a package.
ChannelData	extractPackage(boolean clearFromBuffer)
static int	firstIndexOf(byte[] src, int srcOff, byte[] find) Similar to a String.IndexOf, but uses pure bytes.
byte[]	getBytes()
byte[]	getBytesDirect()
int	getCapacity()
static int	getDataPackageLength(int datalength)
boolean	getDiscard()
int	getLength()
void	reset()
static byte[]	serialize(Serializable msg) Serializes a message into cluster data
void	setDiscard(boolean discard)
void	setLength(int size)
static boolean	toBoolean(byte[] b, int offset) Converts a byte array entry to boolean.
static byte[]	toBytes(boolean bool, byte[] data, int offset) Converts a boolean and put it in a byte array.
static byte[]	toBytes(int n, byte[] b, int offset) Converts an integer to four bytes.
static byte[]	toBytes(long n, byte[] b, int offset) Converts an long to eight bytes.
static int	toInt(byte[] b, int off) Convert four bytes to an int
static long	toLong(byte[] b, int off) Convert eight bytes to a long
void	trim(int length)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

sm

protected static final StringManager sm

buf

protected byte[] buf

Variable to hold the data

bufSize

protected int bufSize

Current length of data in the buffer

discard

protected boolean discard

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.

Constructor Detail

XByteBuffer

public XByteBuffer(int size,
                   boolean discard)

Constructs a new XByteBuffer.
TODO use a pool of byte[] for performance

Parameters:

size - the initial size of the byte buffer

discard - Flag for discarding invalid packages

XByteBuffer

public XByteBuffer(byte[] data,
                   boolean discard)

XByteBuffer

public XByteBuffer(byte[] data,
                   int size,
                   boolean discard)

Method Detail

getLength

public int getLength()

setLength

public void setLength(int size)

trim

public void trim(int length)

reset

public void reset()

getBytesDirect

public byte[] getBytesDirect()

getBytes

public byte[] getBytes()

Returns:

the bytes in the buffer, in its exact length

clear

public void clear()

Resets the buffer

append

public boolean append(ByteBuffer b,
                      int len)

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.

Parameters:

b - - bytes to be appended

len - - the number of bytes to append.

Returns:

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

append

public boolean append(byte i)

append

public boolean append(boolean i)

append

public boolean append(long i)

append

public boolean append(int i)

append

public boolean append(byte[] b,
                      int off,
                      int len)

expand

public void expand(int newcount)

getCapacity

public int getCapacity()

countPackages

public int countPackages()

Internal mechanism to make a check if a complete package exists within the buffer

Returns:

- true if a complete package (header,compress,size,data,footer) exists within the buffer

countPackages

public int countPackages(boolean first)

doesPackageExist

public boolean doesPackageExist()

Method to check if a package exists in this byte buffer.

Returns:

- true if a complete package (header,options,size,data,footer) exists within the buffer

extractDataPackage

public XByteBuffer extractDataPackage(boolean clearFromBuffer)

Extracts the message bytes from a package. If no package exists, a IllegalStateException will be thrown.

Parameters:

clearFromBuffer - - if true, the package will be removed from the byte buffer

Returns:

- returns the actual message bytes (header, compress,size and footer not included).

extractPackage

public ChannelData extractPackage(boolean clearFromBuffer)

createDataPackage

public static byte[] createDataPackage(ChannelData cdata)

Creates a complete data package

Parameters:

cdata - - the message data to be contained within the package

Returns:

- a full package (header,size,data,footer)

createDataPackage

public static byte[] createDataPackage(byte[] data,
                                       int doff,
                                       int dlength,
                                       byte[] buffer,
                                       int bufoff)

getDataPackageLength

public static int getDataPackageLength(int datalength)

createDataPackage

public static byte[] createDataPackage(byte[] data)

toInt

public static int toInt(byte[] b,
                        int off)

Convert four bytes to an int

Parameters:

b - - the byte array containing the four bytes

off - - the offset

Returns:

the integer value constructed from the four bytes

toLong

public static long toLong(byte[] b,
                          int off)

Convert eight bytes to a long

Parameters:

b - - the byte array containing the four bytes

off - - the offset

Returns:

the long value constructed from the eight bytes

toBytes

public static byte[] toBytes(boolean bool,
                             byte[] data,
                             int offset)

Converts a boolean and put it in a byte array.

Parameters:

bool - the integer

data - the byte buffer in which the boolean will be placed

offset - the offset in the byte array

Returns:

the byte array

toBoolean

public static boolean toBoolean(byte[] b,
                                int offset)

Converts a byte array entry to boolean.

Parameters:

b - byte array

offset - within byte array

Returns:

true if byte array entry is non-zero, false otherwise

toBytes

public static byte[] toBytes(int n,
                             byte[] b,
                             int offset)

Converts an integer to four bytes.

Parameters:

n - the integer

b - the byte buffer in which the integer will be placed

offset - the offset in the byte array

Returns:

four bytes in an array

toBytes

public static byte[] toBytes(long n,
                             byte[] b,
                             int offset)

Converts an long to eight bytes.

Parameters:

n - the long

b - the byte buffer in which the integer will be placed

offset - the offset in the byte array

Returns:

eight bytes in an array

firstIndexOf

public static int firstIndexOf(byte[] src,
                               int srcOff,
                               byte[] find)

Similar to a String.IndexOf, but uses pure bytes.

Parameters:

src - - the source bytes to be searched

srcOff - - offset on the source buffer

find - - the string to be found within src

Returns:

- the index of the first matching byte. -1 if the find array is not found

deserialize

public static Serializable deserialize(byte[] data)
                                throws IOException,
                                       ClassNotFoundException,
                                       ClassCastException

Throws:

IOException

ClassNotFoundException

ClassCastException

deserialize

public static Serializable deserialize(byte[] data,
                                       int offset,
                                       int length)
                                throws IOException,
                                       ClassNotFoundException,
                                       ClassCastException

Throws:

IOException

ClassNotFoundException

ClassCastException

deserialize

public static Serializable deserialize(byte[] data,
                                       int offset,
                                       int length,
                                       ClassLoader[] cls)
                                throws IOException,
                                       ClassNotFoundException,
                                       ClassCastException

Throws:

IOException

ClassNotFoundException

ClassCastException

serialize

public static byte[] serialize(Serializable msg)
                        throws IOException

Serializes a message into cluster data

Parameters:

msg - ClusterMessage

Returns:

serialized content as byte[] array

Throws:

IOException - Serialization error

setDiscard

public void setDiscard(boolean discard)

getDiscard

public boolean getDiscard()