org.apache.jena.dboe.base.file

Interface BlockAccess

All Superinterfaces:

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

All Known Implementing Classes:

BlockAccessBase, BlockAccessByteArray, BlockAccessDirect, BlockAccessMapped, BlockAccessMem

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

Interface to concrete storage - read and write Blocks, addressed by id. Suitable for memory mapped I/O (returns internally allocated space for read, not provided from outside; write() can insist the block written comes from allocate()). This interface can also be backed by an in-memory implementation (BlockAccessMem, BlockAccessByteArray). This is wrapped in a BlockMgr to provide a higher level abstraction.

See Also:

BufferChannel

Method Summary

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

Methods inherited from interface org.apache.jena.atlas.lib.Sync

sync

Methods inherited from interface org.apache.jena.atlas.lib.Closeable

close

Method Detail

allocate

Block allocate(int size)

read

Block read(long id)

write

void write(Block block)

overwrite

void overwrite(Block block)

isEmpty

boolean isEmpty()

allocBoundary

long allocBoundary()

resetAllocBoundary

void resetAllocBoundary(long boundary)

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.

valid

boolean valid(long id)

getLabel

String getLabel()