org.limewire.collection
Class TreeStorage

java.lang.Object
  org.limewire.collection.TreeStorage

public class TreeStorage
extends Object

Structure that contains only the necessary nodes of a hash tree, automatically verifies new nodes against the root and compacts the tree as nodes are used. For the numbering of the nodes check http://www.limewire.org/wiki/index.php?title=HashTreeRangeEncoding

Method Summary

boolean	add(int id, byte[] data)
int	fileToNodeId(int fileId)
byte[]	get(int id)
Collection<Integer>	getUsedNodes()
Collection<Integer>	getVerifiedNodes()
static int	log2Ceil(long number)
int[]	nodeToFileId(int nodeId)
void	setAllowUnverifiedUse(boolean allow)
void	used(int id) notification that the node id has been used to verify data from the file.

Methods inherited from class java.lang.Object

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

Method Detail

setAllowUnverifiedUse

public void setAllowUnverifiedUse(boolean allow)

add

public boolean add(int id,
                   byte[] data)

Parameters:

id - the id of the tree node

data - the hash in the node

Returns:

true if the node was added and verified ok

get

public byte[] get(int id)

Returns:

the contents of the node with the given id

used

public void used(int id)

notification that the node id has been used to verify data from the file. This will compact the tree.

getUsedNodes

public Collection<Integer> getUsedNodes()

Returns:

the reprsentation as defined on the wiki page

getVerifiedNodes

public Collection<Integer> getVerifiedNodes()

log2Ceil

public static int log2Ceil(long number)

fileToNodeId

public int fileToNodeId(int fileId)

Parameters:

fileId - id of a chunk in a file starting from 0

Returns:

id of a node on the bottom row of the tree

nodeToFileId

public int[] nodeToFileId(int nodeId)

Parameters:

nodeId - node from the tree

Returns:

the start and end index of the chunks from the file the node maps to or null if id is invalid.