iitb.con.util
Class ArrayFreeSpaceList

java.lang.Object
  iitb.con.util.ArrayFreeSpaceList

All Implemented Interfaces:

FreeSpaceList

public class ArrayFreeSpaceList
extends java.lang.Object
implements FreeSpaceList

ArrayFreeSpaceList is the list which maintains the information about the free blocks in a file.

The format of the list is : {[Start Location], [End Location]}
where the start location and end location indicates the block start and end in the file.

Constructor Summary

ArrayFreeSpaceList(java.lang.String fileName, java.lang.String mode)
Reads and initializes the information about the free blocks space

Method Summary

void	close() Closes the free space list file
void	commit() Commits the changes to the free space list file
void	dumpFreeSpaceList() Dumps the free space list contents
boolean	freeTheBlock(long location, long size) Frees the specified block in the file
long	getFreeBlock(long size) Returns the free block location

Methods inherited from class java.lang.Object

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

Constructor Detail

ArrayFreeSpaceList

public ArrayFreeSpaceList(java.lang.String fileName,
                          java.lang.String mode)
                   throws java.io.FileNotFoundException,
                          java.io.IOException

Reads and initializes the information about the free blocks space

Parameters:

fileName - free space list file name

mode - opening mode (r, rw)

Throws:

java.io.FileNotFoundException - if file not found

java.io.IOException - if file operation fails

Method Detail

close

public void close()
           throws java.io.IOException

Closes the free space list file

Specified by:

close in interface FreeSpaceList

Throws:

java.io.IOException - if file operation fails

commit

public void commit()
            throws java.io.IOException

Commits the changes to the free space list file

Specified by:

commit in interface FreeSpaceList

Throws:

java.io.IOException - if file operation fails

dumpFreeSpaceList

public void dumpFreeSpaceList()

Dumps the free space list contents

freeTheBlock

public boolean freeTheBlock(long location,
                            long size)

Frees the specified block in the file

Specified by:

freeTheBlock in interface FreeSpaceList

Parameters:

location - block location

size - block size

Returns:

true on success

getFreeBlock

public long getFreeBlock(long size)

Returns the free block location

Specified by:

getFreeBlock in interface FreeSpaceList

Parameters:

size - request block size

Returns:

free block location