org.apache.jena.dboe.base.block

Class BlockMgrFileAccess

java.lang.Object

org.apache.jena.dboe.base.block.BlockMgrBase

org.apache.jena.dboe.base.block.BlockMgrFileAccess

All Implemented Interfaces:

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

public final class BlockMgrFileAccess
extends BlockMgrBase

Block manager that maps from the FileAccess layer to a BlockMgr. Add free block management (but we should layer with BlockMgrFreeChain)

Method Summary

Modifier and Type	Method and Description
long	allocLimit() The fixed allocated blocks are in the range [0,allocLimit).
void	close() Close the block manager
void	free(Block block) Announce a block is no longer in use (i.e it's now freed)
Block	getRead(long id) Fetch a block, use for read only
Block	getWrite(long id) Fetch a block, use for write and read - only inside "update"
boolean	isClosed() Is this block manager still usable? Closed block managers can not perform any operations except this one.
boolean	isEmpty() Answer whether there are any blocks in the collection being managed
void	overwrite(Block block) Replace the contents of a block slot with new contents.
Block	promote(Block block) Promote to writable : it's OK to promote an already writable block
void	release(Block block) Release a block, unmodified or already written.
void	resetAlloc(long boundary) Reset the allocation limit, should be a number previously obtained from allocLimit
void	sync() Sync the block manager
void	syncForce() Sync the block manager : system operation to ensure sync() is passed down
String	toString()
boolean	valid(int id) Is this a valid block id? (may be a free block)
void	write(Block block) Write a block back - it still needs releasing.

Methods inherited from class org.apache.jena.dboe.base.block.BlockMgrBase

allocate, beginRead, beginUpdate, endRead, endUpdate, getLabel

Methods inherited from class java.lang.Object

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

Method Detail

promote

public Block promote(Block block)

Description copied from interface: BlockMgr

Promote to writable : it's OK to promote an already writable block

getRead

public Block getRead(long id)

Description copied from interface: BlockMgr

Fetch a block, use for read only

getWrite

public Block getWrite(long id)

Description copied from interface: BlockMgr

Fetch a block, use for write and read - only inside "update"

release

public void release(Block block)

Description copied from interface: BlockMgr

Release a block, unmodified or already written.

write

public void write(Block block)

Description copied from interface: BlockMgr

Write a block back - it still needs releasing.

overwrite

public void overwrite(Block block)

Description copied from interface: BlockMgr

Replace the contents of a block slot with new contents. Block does not need releasing. The write() operation may not do real work if the block is mapped - this operation really does replace the contents with the new contents.

free

public void free(Block block)

Description copied from interface: BlockMgr

Announce a block is no longer in use (i.e it's now freed)

valid

public boolean valid(int id)

Description copied from interface: BlockMgr

Is this a valid block id? (may be a free block)

sync

public void sync()

Description copied from interface: BlockMgr

Sync the block manager

syncForce

public void syncForce()

Description copied from interface: BlockMgr

Sync the block manager : system operation to ensure sync() is passed down

isClosed

public boolean isClosed()

Description copied from interface: BlockMgr

Is this block manager still usable? Closed block managers can not perform any operations except this one.

close

public void close()

Description copied from interface: BlockMgr

Close the block manager

isEmpty

public boolean isEmpty()

Description copied from interface: BlockMgr

Answer whether there are any blocks in the collection being managed

allocLimit

public long allocLimit()

Description copied from interface: BlockMgr

The fixed allocated blocks are in the range [0,allocLimit). Allocation units need not be +1 increments

resetAlloc

public void resetAlloc(long boundary)

Description copied from interface: BlockMgr

Reset the allocation limit, should be a number previously obtained from allocLimit

toString

public String toString()

Overrides:

toString in class Object