Package org.jgroups.util

Class Headers

java.lang.Object

org.jgroups.util.Headers

public final class Headers
extends Object

Helper class providing functions to manipulate the headers array in BaseMessage. The headers are stored in the array as follows:

 Headers:  hdr-1 | hdr-2 | hdr-3 | ... | hdr-n |
 

The arrays are populated from left to right, and any empty slot in 'headers' can terminate an interation (e.g. a getHeader())

It is assumed that we only have a few headers, 3-4 on average. Note that getting a header for a given key and putting a new key/header are operations with O(n) cost, so this implementation is not recommended for a large number of elements.

This class is unsynchronized.

Field Summary

Fields

Modifier and Type	Field	Description
private static final int	RESIZE_INCR

Constructor Summary

Constructors

Modifier	Constructor	Description
private	Headers()

Method Summary

Modifier and Type	Method	Description
static Header[]	copy(Header[] headers)
static <T extends Header> T	getHeader(Header[] hdrs, short id)	Returns the header associated with an ID
static <T extends Header> T	getHeader(Header[] hdrs, short... ids)	Returns the header associated with a set of IDs
static Map<Short,Header>	getHeaders(Header[] hdrs)
static int	marshalledSize(Header[] hdrs)
static String	printHeaders(Header[] hdrs)
static Header[]	putHeader(Header[] headers, short id, Header hdr, boolean replace_if_present)	Adds hdr at the next available slot.
private static Header	readHeader(DataInput in)
static Header[]	readHeaders(DataInput in)
static Header[]	resize(Header[] headers)	Increases the capacity of the array and copies the contents of the old into the new array
static int	size(Header[] hdrs)
private static void	writeHeader(Header hdr, DataOutput out)
static void	writeHeaders(Header[] hdrs, DataOutput out)

Methods inherited from class java.lang.Object

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

Field Details

RESIZE_INCR

private static final int RESIZE_INCR

See Also:

• Constant Field Values

Constructor Details

Headers

private Headers()

Method Details

getHeader

public static <T extends Header> T getHeader(Header[] hdrs,
 short id)

Returns the header associated with an ID

Parameters:

id - The ID

Returns:

getHeader

public static <T extends Header> T getHeader(Header[] hdrs,
 short... ids)

Returns the header associated with a set of IDs

Type Parameters:

T -

Parameters:

hdrs -

ids - The IDs

Returns:

getHeaders

public static Map<Short,Header> getHeaders(Header[] hdrs)

printHeaders

public static String printHeaders(Header[] hdrs)

putHeader

public static Header[] putHeader(Header[] headers,
 short id,
 Header hdr,
 boolean replace_if_present)

Adds hdr at the next available slot. If none is available, the headers array passed in will be copied and the copy returned

Parameters:

headers - The headers array

id - The protocol ID of the header

hdr - The header

replace_if_present - Whether to overwrite an existing header

Returns:

A new copy of headers if the array needed to be expanded, or null otherwise

writeHeaders

public static void writeHeaders(Header[] hdrs,
 DataOutput out)
                         throws IOException

Throws:

IOException

readHeaders

public static Header[] readHeaders(DataInput in)
                            throws IOException,
ClassNotFoundException

Throws:

IOException

ClassNotFoundException

resize

public static Header[] resize(Header[] headers)

Increases the capacity of the array and copies the contents of the old into the new array

copy

public static Header[] copy(Header[] headers)

marshalledSize

public static int marshalledSize(Header[] hdrs)

size

public static int size(Header[] hdrs)

writeHeader

private static void writeHeader(Header hdr,
 DataOutput out)
                         throws IOException

Throws:

IOException

readHeader

private static Header readHeader(DataInput in)
                          throws IOException,
ClassNotFoundException

Throws:

IOException

ClassNotFoundException