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

Class FreeSpaceManager

java.lang.Object

com.semedy.reasoner.edb.persistentstore.bplustree.FreeSpaceManager

public class FreeSpaceManager
extends Object

Manages space in file

Author:

angele

Constructor Summary

Constructors

Constructor	Description
FreeSpaceManager(long startInFile, long offsetValidByte)
FreeSpaceManager(RandomAccessToFile file, long startInFile, long offsetValidByte)

Method Summary

Modifier and Type	Method	Description
long	alloc(int length)	allocate space with length len
boolean	checkFileSanity()	compare internal free space list with file
boolean	checkSanity()	check sanity of free space list
void	clear()
FreeSpaceManager	clone()
void	copy(FreeSpaceManager p)
void	free(long offset, int len)	free up space at offset
void	freeAll()	free all pieces
boolean	isFreeAtPosition(long offset)	is space free at offset
boolean	isFreePiece(long offset, int len)	is piece at offset with len free?
boolean	isValid()	is it valid?
void	save()	store in file
void	setFile(RandomAccessToFile file)
void	setValid(boolean valid)	mark as valid
void	shrink(long offset, int length, int oldlength)	shrink already allocated space
int	size()	number of free pieces
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Details

FreeSpaceManager

public FreeSpaceManager(RandomAccessToFile file,
 long startInFile,
 long offsetValidByte)

FreeSpaceManager

public FreeSpaceManager(long startInFile,
 long offsetValidByte)

Method Details

clone

public FreeSpaceManager clone()

setFile

public void setFile(RandomAccessToFile file)

clear

public void clear()

copy

public void copy(FreeSpaceManager p)

setValid

public void setValid(boolean valid)
              throws IOException

mark as valid

Parameters:

valid -

Throws:

IOException

isValid

public boolean isValid()
                throws IOException

is it valid?

Returns:

Throws:

IOException

isFreeAtPosition

public boolean isFreeAtPosition(long offset)

is space free at offset

Parameters:

offset -

Returns:

free

public void free(long offset,
 int len)
          throws IOException

free up space at offset

Parameters:

offset - , offset of piece

len - , length of piece

Throws:

IOException

freeAll

public void freeAll()
             throws IOException

free all pieces

Throws:

IOException

alloc

public long alloc(int length)
           throws IOException

allocate space with length len

Parameters:

length - , length of needed space

Returns:

Throws:

IOException

shrink

public void shrink(long offset,
 int length,
 int oldlength)
            throws IOException

shrink already allocated space

Parameters:

offset -

length -

oldlength -

Throws:

IOException

save

public void save()
          throws IOException

store in file

Throws:

IOException

checkSanity

public boolean checkSanity()

check sanity of free space list

Returns:

checkFileSanity

public boolean checkFileSanity()
                        throws IOException

compare internal free space list with file

Returns:

Throws:

IOException

isFreePiece

public boolean isFreePiece(long offset,
 int len)

is piece at offset with len free?

Parameters:

offset -

len -

Returns:

size

public int size()

number of free pieces

Returns:

toString

public String toString()

Overrides:

toString in class Object