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

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

public class PersistentList
extends java.lang.Object

This class provides a mechanism for persistent linked list. One persistent file is capable of storing multiple linked lists. However, the store procedure (adding nodes) need to be done at one time consequencially for one linked list.

The file format is:
header + node1 + node2 + ...
where header is:

• 0~3 : int : numbers of nodes
• 4~11: long: next address (address will be used for next node).

node:

• 0~x: specific data (length varies)
• x+1~x+8: long: next

History:

Version:

V-2006p

Author:

NLM NLS Development Team

See Also:

Design Document

Field Summary

static int

HEADER_OFFSET the size of header used in binary file

Constructor Summary

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

Method Summary

void	Add(PersistentListNode node) Add a persistent node to the current persistent list.
void	Close() Close the random access file of current persistent list.
long	GetAddress() Get the beginning address of current persistent list.
java.io.RandomAccessFile	GetRaf() Get the random access file of the current persistent list.
static void	main(java.lang.String[] args) A test driver for this class.

Methods inherited from class java.lang.Object

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

Field Detail

HEADER_OFFSET

public static final int HEADER_OFFSET

the size of header used in binary file

See Also:

Constant Field Values

Constructor Detail

PersistentList

public PersistentList(java.lang.String path)

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

Method Detail

Add

public void Add(PersistentListNode node)
         throws java.io.IOException

Add a persistent node to the current persistent list.

Parameters:

node - the persistent node to be added

Throws:

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

GetAddress

public long GetAddress()

Get the beginning address of current persistent list.

Returns:

the beginning address of current persistent list

GetRaf

public java.io.RandomAccessFile GetRaf()

Get the random access file of the current persistent list.

Returns:

the random access file of the current persistent list

Close

public void Close()
           throws java.io.IOException

Close the random access file of current persistent list.

Throws:

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

main

public static void main(java.lang.String[] args)

A test driver for this class.