Package com.semedy.reasoner.edb.persistentstore.bplustree

Class FreeSlotsDynamicLength

java.lang.Object

com.semedy.reasoner.edb.persistentstore.bplustree.FreeSlotsDynamicLength

All Implemented Interfaces:

FreeSlotsHandler

public class FreeSlotsDynamicLength
extends Object
implements FreeSlotsHandler

Handles file pieces with dynamic length

Author:

angele

Constructor Summary

Constructors

Constructor	Description
FreeSlotsDynamicLength(RandomAccessToFile file, long pagesPosition, long freePosition, long validPosition)

Method Summary

Modifier and Type	Method	Description
int	allocate(int length)	allocate a new address and get index of it
void	allocate(int index, int length)	search for a new address for index
int	append(int length)	append a slot of length len at end of file
void	clear()	clear all used slots
void	copy(FreeSlotsHandler freeSlots)	copy all pages and free slots from freeSlots to this
void	free(int index)	free address at index
void	free(long address)	free address
long	getAddress(int index)	get the file address of slot index
boolean	isValid()	is it valid?
void	load()	load slot table from file
void	save()	save slot table to file
void	setFile(RandomAccessToFile file)	set basic file
void	setValid(boolean b)	set valid flag
int	size()	number of slots
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Details

FreeSlotsDynamicLength

public FreeSlotsDynamicLength(RandomAccessToFile file,
 long pagesPosition,
 long freePosition,
 long validPosition)

Method Details

clear

public void clear()

Description copied from interface: FreeSlotsHandler

clear all used slots

Specified by:

clear in interface FreeSlotsHandler

setFile

public void setFile(RandomAccessToFile file)

Description copied from interface: FreeSlotsHandler

set basic file

Specified by:

setFile in interface FreeSlotsHandler

setValid

public void setValid(boolean b)
              throws IOException

Description copied from interface: FreeSlotsHandler

set valid flag

Specified by:

setValid in interface FreeSlotsHandler

Throws:

IOException

isValid

public boolean isValid()
                throws IOException

Description copied from interface: FreeSlotsHandler

is it valid?

Specified by:

isValid in interface FreeSlotsHandler

Returns:

Throws:

IOException

load

public void load()
          throws IOException

Description copied from interface: FreeSlotsHandler

load slot table from file

Specified by:

load in interface FreeSlotsHandler

Throws:

IOException

save

public void save()
          throws IOException

Description copied from interface: FreeSlotsHandler

save slot table to file

Specified by:

save in interface FreeSlotsHandler

Throws:

IOException

allocate

public void allocate(int index,
 int length)
              throws IOException

Description copied from interface: FreeSlotsHandler

search for a new address for index

Specified by:

allocate in interface FreeSlotsHandler

Parameters:

index - , index

length - TODO

Throws:

IOException

allocate

public int allocate(int length)
             throws IOException

Description copied from interface: FreeSlotsHandler

allocate a new address and get index of it

Specified by:

allocate in interface FreeSlotsHandler

Parameters:

length - TODO

Returns:

slot index

Throws:

IOException

free

public void free(int index)
          throws IOException

Description copied from interface: FreeSlotsHandler

free address at index

Specified by:

free in interface FreeSlotsHandler

Throws:

IOException

getAddress

public long getAddress(int index)

Description copied from interface: FreeSlotsHandler

get the file address of slot index

Specified by:

getAddress in interface FreeSlotsHandler

Returns:

append

public int append(int length)
           throws IOException

Description copied from interface: FreeSlotsHandler

append a slot of length len at end of file

Specified by:

append in interface FreeSlotsHandler

Parameters:

length - , length of slot

Returns:

Throws:

IOException

size

public int size()

Description copied from interface: FreeSlotsHandler

number of slots

Specified by:

size in interface FreeSlotsHandler

Returns:

free

public void free(long address)
          throws IOException

Description copied from interface: FreeSlotsHandler

free address

Specified by:

free in interface FreeSlotsHandler

Throws:

IOException

copy

public void copy(FreeSlotsHandler freeSlots)

Description copied from interface: FreeSlotsHandler

copy all pages and free slots from freeSlots to this

Specified by:

copy in interface FreeSlotsHandler

toString

public String toString()

Overrides:

toString in class Object