gov.nih.nlm.nls.lvg.Trie
Class PersistentTree

java.lang.Object
  gov.nih.nlm.nls.lvg.Trie.PersistentTree

public class PersistentTree
extends java.lang.Object

This class provides a mechanism of persistent tree. One file is capable of storing multiple trie trees. However, we use one only tree in one file in our application for simplicity reason.

The file format is:

• 0~3: int: level
• 4~11: long: address for next node
• 12~19: long: address for parent node
• 20~27: long: address for child list
• 28~x: specific data (length varies)

History:

Version:

V-2006p

Author:

NLM NLS Development Team

See Also:

Design Document

Constructor Summary

PersistentTree(java.lang.String path)
Create an object of persistent tree, using a string for the path of the binary file to be strored.

Method Summary

void	Add(PersistentTreeNode node, long parentAddress) Add a persistent node to the current persistent tree at a specific address.
void	Close() Close the random access file of current persistent tree.
java.io.RandomAccessFile	GetRaf() Get the random access file of the current persistent tree.
long	GetRootAddress() Get the address of the root node of the current persistent tree.

Methods inherited from class java.lang.Object

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

Constructor Detail

PersistentTree

public PersistentTree(java.lang.String path)

Create an object of persistent tree, using a string for the path of the binary file to be strored.

Method Detail

GetRaf

public java.io.RandomAccessFile GetRaf()

Get the random access file of the current persistent tree.

Returns:

the random access file of the current persistent tree

GetRootAddress

public long GetRootAddress()

Get the address of the root node of the current persistent tree.

Returns:

the address of the root node of the current persistent tree

Add

public void Add(PersistentTreeNode node,
                long parentAddress)
         throws java.io.IOException

Add a persistent node to the current persistent tree at a specific address.

Parameters:

node - the persistent node to be added

parentAddress - the address that the persistent node to be added at

Throws:

java.io.IOException - if probelms happens when accessing random access file

Close

public void Close()
           throws java.io.IOException

Close the random access file of current persistent tree.

Throws:

java.io.IOException - if probelms happens when closing random access file