org.kth.dks
Class JDHT

java.lang.Object
  org.kth.dks.JDHT

All Implemented Interfaces:

java.util.Map

public class JDHT
extends java.lang.Object
implements java.util.Map

Nested Class Summary

Nested classes/interfaces inherited from interface java.util.Map

java.util.Map.Entry<K,V>

Constructor Summary

JDHT()
Creates an empty local Distributed Hash Table (DHT), listening on default port 4440 Other nodes can connect to this DHT using a reference to this instance An IMPORTANT invariant is to call close() upon exit to disconnect.

JDHT(int port)
Creates an empty local Distributed Hash Table (DHT), listening on default port 4440 Other nodes can connect to this DHT using a reference to this instance An IMPORTANT invariant is to call close() upon exit to disconnect.

JDHT(int port, java.lang.String url)
Joins an existing Distributed Hash Table (DHT) running on some machines, will bind to the supplied local port number An IMPORTANT invariant is to call close() upon exit to disconnect.

JDHT(java.lang.String url)
Joins an existing Distributed Hash Table (DHT) running on some machines, will bind to local port 4444 An IMPORTANT invariant is to call close() upon exit to disconnect.

Method Summary

void	clear() Currently unimplemented, will throw UnsupportedOperationException
void	close() Unbinds from the local port and disconnects from the DHT.
boolean	containsKey(java.lang.Object key) Returns whether the key exists in the DHT Makes use of hashCode() in key
boolean	containsValue(java.lang.Object value) Currently unimplemented, will throw UnsupportedOperationException
java.util.Set	entrySet() Currently unimplemented, will throw UnsupportedOperationException
boolean	equals(java.lang.Object o) Currently unimplemented, will throw UnsupportedOperationException
java.lang.Object	get(java.lang.Object key) Gets the value associated with key in the DHT Makes use of hashCode() in key
java.lang.String	getReference() Returns a stringified reference to the current DHT instance.
boolean	isEmpty() Currently unimplemented, will throw UnsupportedOperationException
java.util.Set	keySet() Currently unimplemented, will throw UnsupportedOperationException
java.lang.Object	put(java.lang.Object key, java.lang.Object value) Inserts an item (key/value pair) into the DHT It requires the value to be serializable, and depends on the hashCode() implementation of key
void	putAll(java.util.Map t) Currently unimplemented, will throw UnsupportedOperationException
java.lang.Object	remove(java.lang.Object key) Currently unimplemented, will throw UnsupportedOperationException
int	size() Currently unimplemented, will throw UnsupportedOperationException
java.util.Collection	values() Currently unimplemented, will throw UnsupportedOperationException

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Map

hashCode

Constructor Detail

JDHT

public JDHT()
     throws java.io.IOException

Creates an empty local Distributed Hash Table (DHT), listening on default port 4440 Other nodes can connect to this DHT using a reference to this instance An IMPORTANT invariant is to call close() upon exit to disconnect.

Throws:

java.io.IOException - thrown if it cannot bind to the local port

See Also:

close(), getReference()

JDHT

public JDHT(int port)
     throws java.io.IOException

Creates an empty local Distributed Hash Table (DHT), listening on default port 4440 Other nodes can connect to this DHT using a reference to this instance An IMPORTANT invariant is to call close() upon exit to disconnect.

Parameters:

port - int port number to bind to

Throws:

java.io.IOException - thrown if it cannot bind to the local port

See Also:

close(), getReference()

JDHT

public JDHT(java.lang.String url)
     throws java.io.IOException,
            DKSTooManyRestartJoins,
            DKSIdentifierAlreadyTaken,
            DKSRefNoResponse

Joins an existing Distributed Hash Table (DHT) running on some machines, will bind to local port 4444 An IMPORTANT invariant is to call close() upon exit to disconnect.

Parameters:

url - String reference to an existing node running a DHT

Throws:

java.io.IOException - thrown if there is a problem binding to the local port

DKSTooManyRestartJoins - if it cannot join (see DKS documentation)

DKSIdentifierAlreadyTaken - if the internal DKS identifier is already taken

DKSRefNoResponse - if the existing node (url) does not respond

See Also:

getReference(), close()

JDHT

public JDHT(int port,
            java.lang.String url)
     throws java.io.IOException,
            DKSTooManyRestartJoins,
            DKSIdentifierAlreadyTaken,
            DKSRefNoResponse

Joins an existing Distributed Hash Table (DHT) running on some machines, will bind to the supplied local port number An IMPORTANT invariant is to call close() upon exit to disconnect.

Parameters:

port - int local port number to bind to

url - String reference to an existing node running a DHT

Throws:

java.io.IOException - thrown if there is a problem binding to the local port

DKSTooManyRestartJoins - if it cannot join (see DKS documentation)

DKSIdentifierAlreadyTaken - if the internal DKS identifier is already taken

DKSRefNoResponse - if the existing node (url) does not respond

See Also:

close(), getReference()

Method Detail

put

public java.lang.Object put(java.lang.Object key,
                            java.lang.Object value)

Inserts an item (key/value pair) into the DHT It requires the value to be serializable, and depends on the hashCode() implementation of key

Specified by:

put in interface java.util.Map

Parameters:

key - Object key of the item

value - Object value of the item

Returns:

Object always null

get

public java.lang.Object get(java.lang.Object key)

Gets the value associated with key in the DHT Makes use of hashCode() in key

Specified by:

get in interface java.util.Map

Parameters:

key - Object key of the item

Returns:

Object value associated with key in the DHT, null if none found

getReference

public java.lang.String getReference()

Returns a stringified reference to the current DHT instance. This is used to supply other nodes with a reference, such that they can connect to the running DHT

Returns:

String a string representing this DHT instance (dksref://hostname:port/gid/id/guid/nonce)

close

public void close()

Unbinds from the local port and disconnects from the DHT. Has to be called before exit.

containsKey

public boolean containsKey(java.lang.Object key)

Returns whether the key exists in the DHT Makes use of hashCode() in key

Specified by:

containsKey in interface java.util.Map

Parameters:

key - Object key of the item

Returns:

boolean is true if key exists in DHT, fales otherwise

remove

public java.lang.Object remove(java.lang.Object key)
                        throws java.lang.UnsupportedOperationException

Currently unimplemented, will throw UnsupportedOperationException

Specified by:

remove in interface java.util.Map

Parameters:

key - Object

Returns:

Object

Throws:

java.lang.UnsupportedOperationException

clear

public void clear()
           throws java.lang.UnsupportedOperationException

Currently unimplemented, will throw UnsupportedOperationException

Specified by:

clear in interface java.util.Map

Throws:

java.lang.UnsupportedOperationException

containsValue

public boolean containsValue(java.lang.Object value)
                      throws java.lang.UnsupportedOperationException

Currently unimplemented, will throw UnsupportedOperationException

Specified by:

containsValue in interface java.util.Map

Parameters:

value - Object

Returns:

boolean

Throws:

java.lang.UnsupportedOperationException

entrySet

public java.util.Set entrySet()
                       throws java.lang.UnsupportedOperationException

Currently unimplemented, will throw UnsupportedOperationException

Specified by:

entrySet in interface java.util.Map

Returns:

Set

Throws:

java.lang.UnsupportedOperationException

equals

public boolean equals(java.lang.Object o)
               throws java.lang.UnsupportedOperationException

Currently unimplemented, will throw UnsupportedOperationException

Specified by:

equals in interface java.util.Map

Overrides:

equals in class java.lang.Object

Parameters:

o - Object

Returns:

boolean

Throws:

java.lang.UnsupportedOperationException

isEmpty

public boolean isEmpty()
                throws java.lang.UnsupportedOperationException

Currently unimplemented, will throw UnsupportedOperationException

Specified by:

isEmpty in interface java.util.Map

Returns:

boolean

Throws:

java.lang.UnsupportedOperationException

keySet

public java.util.Set keySet()
                     throws java.lang.UnsupportedOperationException

Currently unimplemented, will throw UnsupportedOperationException

Specified by:

keySet in interface java.util.Map

Returns:

Set

Throws:

java.lang.UnsupportedOperationException

putAll

public void putAll(java.util.Map t)
            throws java.lang.UnsupportedOperationException

Currently unimplemented, will throw UnsupportedOperationException

Specified by:

putAll in interface java.util.Map

Parameters:

t - Map

Throws:

java.lang.UnsupportedOperationException

size

public int size()
         throws java.lang.UnsupportedOperationException

Currently unimplemented, will throw UnsupportedOperationException

Specified by:

size in interface java.util.Map

Returns:

int

Throws:

java.lang.UnsupportedOperationException

values

public java.util.Collection values()
                            throws java.lang.UnsupportedOperationException

Currently unimplemented, will throw UnsupportedOperationException

Specified by:

values in interface java.util.Map

Returns:

Collection

Throws:

java.lang.UnsupportedOperationException