Package org.jgroups.util

Class Headers

java.lang.Object

org.jgroups.util.Headers

public final class Headers
extends java.lang.Object

Helper class providing functions to manipulate the Message.headers array. 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 synchronized for writes (put(), resize()), but not for reads (size(), get())

Author:

Bela Ban

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 java.util.Map<java.lang.Short,Header>	getHeaders(Header[] hdrs)
static int	marshalledSize(Header[] hdrs)
static java.lang.String	printHeaders(Header[] hdrs)
static java.lang.String	printObjectHeaders(Header[] hdrs)
static Header[]	putHeader(Header[] headers, short id, Header hdr, boolean replace_if_present)	Adds hdr at the next available slot.
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)
static int	size(Header[] hdrs, short... excluded_ids)

Methods inherited from class java.lang.Object

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

Method Detail

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 java.util.Map<java.lang.Short,Header> getHeaders(Header[] hdrs)

printHeaders

public static java.lang.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 or not to overwrite an existing header

Returns:

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

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)

printObjectHeaders

public static java.lang.String printObjectHeaders(Header[] hdrs)

marshalledSize

public static int marshalledSize(Header[] hdrs)

size

public static int size(Header[] hdrs)

size

public static int size(Header[] hdrs,
                       short... excluded_ids)