org.apache.jena.dboe.base.block

Interface BlockMgr

All Superinterfaces:

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

All Known Implementing Classes:

BlockMgrBase, BlockMgrCache, BlockMgrFileAccess, BlockMgrFreeChain, BlockMgrLogger, BlockMgrReadonly, BlockMgrSwitcher, BlockMgrSync, BlockMgrTracker, BlockMgrWrapper

public interface BlockMgr
extends org.apache.jena.atlas.lib.Sync, org.apache.jena.atlas.lib.Closeable

Method Summary

Modifier and Type	Method and Description
Block	allocate(int blockSize) Allocate an uninitialized block - writable - call only inside a update sequence.
long	allocLimit() The fixed allocated blocks are in the range [0,allocLimit).
void	beginRead() Start of read
void	beginUpdate() Start of update
void	close() Close the block manager
void	endRead() Completion of read
void	endUpdate() Completion of update
void	free(Block block) Announce a block is no longer in use (i.e it's now freed)
String	getLabel()
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 blk) 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
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.

Method Detail

allocate

Block allocate(int blockSize)

Allocate an uninitialized block - writable - call only inside a update sequence. If blockSize is -1, means "default/fixed size" for this BlockMgr

isEmpty

boolean isEmpty()

Answer whether there are any blocks in the collection being managed

allocLimit

long allocLimit()

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

resetAlloc

void resetAlloc(long boundary)

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

getRead

Block getRead(long id)

Fetch a block, use for read only

getWrite

Block getWrite(long id)

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

release

void release(Block block)

Release a block, unmodified or already written.

promote

Block promote(Block block)

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

write

void write(Block block)

Write a block back - it still needs releasing.

overwrite

void overwrite(Block blk)

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

void free(Block block)

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

valid

boolean valid(int id)

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

close

void close()

Close the block manager

Specified by:

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

isClosed

boolean isClosed()

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

sync

void sync()

Sync the block manager

Specified by:

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

syncForce

void syncForce()

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

beginUpdate

void beginUpdate()

Start of update

endUpdate

void endUpdate()

Completion of update

beginRead

void beginRead()

Start of read

endRead

void endRead()

Completion of read

getLabel

String getLabel()