Package 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:

  • Method Summary

    Modifier and Type
    Method
    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.Closeable

    close

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

    sync

  • Method Details

    • 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()