Package nz.org.riskscape.engine.task

Interface WritePageBuffer

All Known Subinterfaces:
PageBuffer
All Known Implementing Classes:
LinkedListBuffer
public interface WritePageBuffer

Buffer that a WorkerTask writes output to. The Tuple output is split into chunks ('pages') to allow for parallelization (i.e. different threads can each work on their own page of output, which they then add to this shared output buffer.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    add(Page page)
    Adds a page of output Tuples to the buffer.
    int
    getTupleCapacity()
     
    boolean
    isFull()
     
    void
    markComplete()
    Signals to the downstream worker task that this process has now completed writing all its output to the buffer.
    Page
    newPage()
    Allocates a new page to write Tuples to.
    long
    numTuplesRead()
     
    long
    numTuplesWritten()
     

  • Method Details

    • add

      void add(Page page)

      Adds a page of output Tuples to the buffer.

    • isFull

      boolean isFull()
      Returns:
      true if the WritePageBuffer has reached capacity. If so, the downstream worker task needs to read pages from the buffer before more can be written. Note that due to supporting multi-threaded writers, this is a polite back-off that the writing worker task should honour, rather than a hard limit, i.e. newPage() and add(Page page) will not strictly enforce the capacity limit.

    • newPage

      Page newPage()

      Allocates a new page to write Tuples to. Note that add(Page page) actually adds the Tuples to the buffer.

    • markComplete

      void markComplete()

      Signals to the downstream worker task that this process has now completed writing all its output to the buffer.

    • numTuplesWritten

      long numTuplesWritten()
      Returns:
      the total number of Tuples written to this buffer (for diagnostics).

    • numTuplesRead

      long numTuplesRead()

    • getTupleCapacity

      int getTupleCapacity()