org.jgroups.util
Class Headers

java.lang.Object
  org.jgroups.util.Headers

public class Headers
extends java.lang.Object

Open addressing based implementation of a hashmap (not supporting the Map interface though) for message headers. The keys are shorts (IDs) and the values Headers, and they're stored in 2 arrays: an ID array and a headers array. The indices of the IDs array corespond with the headers array, e.g.

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

The arrays are populated from left to right, and any 0 slots in 'ids' can terminate an interation, or signal empty slots.
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 not synchronized

Author:

Bela Ban

Constructor Summary

Headers(Headers other)

Headers(int capacity)

Method Summary

int	capacity()
Headers	copy()
Header	getHeader(short id) Returns the header associated with an ID
java.util.Map<java.lang.Short,Header>	getHeaders()
Header[]	getRawHeaders()
short[]	getRawIDs()
int	marshalledSize()
java.lang.String	printHeaders()
java.lang.String	printObjectHeaders()
void	putHeader(short id, Header hdr) Puts a header given a key into the hashmap.
Header	putHeaderIfAbsent(short id, Header hdr) Puts a header given a key into the map, only if the key doesn't exist yet
int	size()
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

Headers

public Headers(int capacity)

Headers

public Headers(Headers other)

Method Detail

getRawIDs

public short[] getRawIDs()

getRawHeaders

public Header[] getRawHeaders()

getHeader

public Header getHeader(short id)

Returns the header associated with an ID

Parameters:

id - The ID

Returns:

getHeaders

public java.util.Map<java.lang.Short,Header> getHeaders()

printHeaders

public java.lang.String printHeaders()

putHeader

public void putHeader(short id,
                      Header hdr)

Puts a header given a key into the hashmap. Overwrites potential existing entry.

putHeaderIfAbsent

public Header putHeaderIfAbsent(short id,
                                Header hdr)

Puts a header given a key into the map, only if the key doesn't exist yet

Parameters:

id -

hdr -

Returns:

the previous value associated with the specified id, or null if there was no mapping for the id. (A null return can also indicate that the map previously associated null with the id, if the implementation supports null values.)

copy

public Headers copy()

marshalledSize

public int marshalledSize()

size

public int size()

capacity

public int capacity()

printObjectHeaders

public java.lang.String printObjectHeaders()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object