Package net.i2p.kademlia

Class KBucketImpl<T extends SimpleDataStructure>

java.lang.Object

net.i2p.kademlia.KBucketImpl<T>

All Implemented Interfaces:

KBucket<T>

class KBucketImpl<T extends SimpleDataStructure>
extends Object
implements KBucket<T>

A concurrent implementation using ConcurrentHashSet. The max size (K) may be temporarily exceeded due to concurrency, a pending split, or the behavior of the supplied trimmer, as explained below. The creator is responsible for splits. This class has no knowledge of the DHT base used for XORing, and thus there are no validity checks in add/remove. The begin and end values are immutable. All entries in this bucket will have at least one bit different from us in the range [begin, end] inclusive. Splits must be implemented by creating two new buckets and discarding this one. The keys are kept in a Set and are NOT sorted by last-seen. Per-key last-seen-time, failures, etc. must be tracked elsewhere. If this bucket is full (i.e. begin == end && size == max) then add() will call KBucketTrimmer.trim() do (possibly) remove older entries, and indicate whether to add the new entry. If the trimmer returns true without removing entries, this KBucket will exceed the max size. Refactored from net.i2p.router.networkdb.kademlia

Since:

0.9.2 in i2psnark, moved to core in 0.9.10

Constructor Summary

Constructors

Constructor	Description
KBucketImpl(I2PAppContext context, int begin, int end, int max, KBucketTrimmer<T> trimmer)	All entries in this bucket will have at least one bit different from us in the range [begin, end] inclusive.

Method Summary

Modifier and Type	Method	Description
boolean	add(T peer)	Sets last-changed if rv is true OR if the peer is already present.
void	clear()
Set<T>	getEntries()	Retrieve all routing table entries stored in the bucket
void	getEntries(SelectionCollector<T> collector)
int	getKeyCount()	Number of keys already contained in this kbucket
long	getLastChanged()	The last-changed timestamp, which actually indicates last-added or last-seen.
int	getRangeBegin()	Lowest order high bit for difference keys.
int	getRangeEnd()	Highest high bit for the difference keys.
boolean	remove(T peer)	Remove the key from the bucket
void	setLastChanged()	Update the last-changed timestamp to now.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

KBucketImpl

public KBucketImpl(I2PAppContext context,
                   int begin,
                   int end,
                   int max,
                   KBucketTrimmer<T> trimmer)

All entries in this bucket will have at least one bit different from us in the range [begin, end] inclusive.

Method Detail

getRangeBegin

public int getRangeBegin()

Description copied from interface: KBucket

Lowest order high bit for difference keys. The lower-bounds distance of this bucket is 2**begin. If begin == 0, this is the closest bucket.

Specified by:

getRangeBegin in interface KBucket<T extends SimpleDataStructure>

getRangeEnd

public int getRangeEnd()

Description copied from interface: KBucket

Highest high bit for the difference keys. The upper-bounds distance of this bucket is (2**(end+1)) - 1. If begin == end, the bucket cannot be split further. If end == (numbits - 1), this is the furthest bucket.

Specified by:

getRangeEnd in interface KBucket<T extends SimpleDataStructure>

getKeyCount

public int getKeyCount()

Description copied from interface: KBucket

Number of keys already contained in this kbucket

Specified by:

getKeyCount in interface KBucket<T extends SimpleDataStructure>

getEntries

public Set<T> getEntries()

Description copied from interface: KBucket

Retrieve all routing table entries stored in the bucket

Specified by:

getEntries in interface KBucket<T extends SimpleDataStructure>

Returns:

an unmodifiable view; not a copy

getEntries

public void getEntries(SelectionCollector<T> collector)

Specified by:

getEntries in interface KBucket<T extends SimpleDataStructure>

clear

public void clear()

Specified by:

clear in interface KBucket<T extends SimpleDataStructure>

add

public boolean add(T peer)

Sets last-changed if rv is true OR if the peer is already present. Calls the trimmer if begin == end and we are full. If begin != end then add it and caller must do bucket splitting.

Specified by:

add in interface KBucket<T extends SimpleDataStructure>

Returns:

true if added

remove

public boolean remove(T peer)

Description copied from interface: KBucket

Remove the key from the bucket

Specified by:

remove in interface KBucket<T extends SimpleDataStructure>

Returns:

if removed. Does NOT set lastChanged.

setLastChanged

public void setLastChanged()

Update the last-changed timestamp to now.

Specified by:

setLastChanged in interface KBucket<T extends SimpleDataStructure>

getLastChanged

public long getLastChanged()

The last-changed timestamp, which actually indicates last-added or last-seen.

Specified by:

getLastChanged in interface KBucket<T extends SimpleDataStructure>

toString

public String toString()

Overrides:

toString in class Object