org.apache.jena.dboe.base.file

Class BlockAccessMem

java.lang.Object

org.apache.jena.dboe.base.file.BlockAccessMem

All Implemented Interfaces:

org.apache.jena.atlas.lib.Closeable, org.apache.jena.atlas.lib.Sync, BlockAccess

public class BlockAccessMem
extends Object
implements BlockAccess

File access layer that simulates a disk in-memory - for testing, not written for efficiency. There is a safe mode, whereby blocks are copied in and out to guarantee no writing to an unallocated block. This is very inefficient but a better simulation of a disk.

See Also:

BlockAccessByteArray

Field Summary

Fields

Modifier and Type	Field and Description
static boolean	SafeMode

Constructor Summary

Constructors

Constructor and Description
BlockAccessMem(String label, int blockSize)

Method Summary

Modifier and Type	Method and Description
Block	allocate(int blkSize)
long	allocBoundary()
void	close()
String	getLabel()
boolean	isEmpty()
void	overwrite(Block block)
Block	read(long id)
void	resetAllocBoundary(long boundary) Reset the allocation space (i.e.
void	sync()
String	toString()
boolean	valid(long id)
void	write(Block block)

Methods inherited from class java.lang.Object

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

Field Detail

SafeMode

public static boolean SafeMode

Constructor Detail

BlockAccessMem

public BlockAccessMem(String label,
                      int blockSize)

Method Detail

allocate

public Block allocate(int blkSize)

Specified by:

allocate in interface BlockAccess

read

public Block read(long id)

Specified by:

read in interface BlockAccess

write

public void write(Block block)

Specified by:

write in interface BlockAccess

overwrite

public void overwrite(Block block)

Specified by:

overwrite in interface BlockAccess

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface BlockAccess

allocBoundary

public long allocBoundary()

Specified by:

allocBoundary in interface BlockAccess

resetAllocBoundary

public void resetAllocBoundary(long boundary)

Description copied from interface: BlockAccess

Reset the allocation space (i.e. truncate). The boundary should be a number obtained from a previous call of allocLimit. It can not be greater than the current allocation boundary.

Specified by:

resetAllocBoundary in interface BlockAccess

valid

public boolean valid(long id)

Specified by:

valid in interface BlockAccess

close

public void close()

Specified by:

close in interface org.apache.jena.atlas.lib.Closeable

sync

public void sync()

Specified by:

sync in interface org.apache.jena.atlas.lib.Sync

getLabel

public String getLabel()

Specified by:

getLabel in interface BlockAccess

toString

public String toString()

Overrides:

toString in class Object