Package io.trino.operator

Interface Operator

All Superinterfaces:
AutoCloseable
All Known Subinterfaces:
SourceOperator
All Known Implementing Classes:
AggregationOperator, DevNullOperator, DistinctLimitOperator, DynamicFilterSourceOperator, EnforceSingleRowOperator, ExchangeOperator, ExplainAnalyzeOperator, FinishedOperator, GroupIdOperator, HashAggregationOperator, HashBuilderOperator, HashBuilderOperator, IndexSourceOperator, LeafTableFunctionOperator, LimitOperator, LocalExchangeSinkOperator, LocalExchangeSourceOperator, LocalMergeSourceOperator, LookupOuterOperator, MarkDistinctOperator, MergeOperator, MergeWriterOperator, NestedLoopBuildOperator, NestedLoopJoinOperator, NullOutputOperator, OrderByOperator, PageBufferOperator, PageConsumerOperator, PagesIndexBuilderOperator, PageSourceOperator, PartitionedOutputOperator, RefreshMaterializedViewOperator, RowNumberOperator, SetBuilderOperator, SimpleTableExecuteOperator, SpatialIndexBuilderOperator, SpatialJoinOperator, StatisticsWriterOperator, TableFinishOperator, TableFunctionOperator, TableMutationOperator, TableScanOperator, TableWriterOperator, TaskOutputOperator, TopNRankingOperator, UnnestOperator, ValuesOperator, WindowOperator, WorkProcessorOperatorAdapter, WorkProcessorSourceOperatorAdapter
public interface Operator extends AutoCloseable

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final com.google.common.util.concurrent.ListenableFuture<Void>
    NOT_BLOCKED
     

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    addInput(Page page)
    Adds an input page to the operator.
    default void
    close()
    This method will always be called before releasing the Operator reference.
    void
    finish()
    Notifies the operator that no more pages will be added and the operator should finish processing and flush results.
    default void
    finishMemoryRevoke()
    Clean up and release resources after completed memory revoking.
    OperatorContext
    getOperatorContext()
     
    Page
    getOutput()
    Gets an output page from the operator.
    default com.google.common.util.concurrent.ListenableFuture<Void>
    isBlocked()
    Returns a future that will be completed when the operator becomes unblocked.
    boolean
    isFinished()
    Is this operator completely finished processing and no more output pages will be produced.
    boolean
    needsInput()
    Returns true if and only if this operator can accept an input page.
    default com.google.common.util.concurrent.ListenableFuture<Void>
    startMemoryRevoke()
    After calling this method operator should revoke all reserved revocable memory.

  • Field Details

    • NOT_BLOCKED

      static final com.google.common.util.concurrent.ListenableFuture<Void> NOT_BLOCKED

  • Method Details

    • getOperatorContext

      OperatorContext getOperatorContext()

    • isBlocked

      default com.google.common.util.concurrent.ListenableFuture<Void> isBlocked()
      Returns a future that will be completed when the operator becomes unblocked. If the operator is not blocked, this method should return NOT_BLOCKED.

    • needsInput

      boolean needsInput()
      Returns true if and only if this operator can accept an input page.

    • addInput

      void addInput(Page page)
      Adds an input page to the operator. This method will only be called if needsInput() returns true.

    • getOutput

      Page getOutput()
      Gets an output page from the operator. If no output data is currently available, return null.

    • startMemoryRevoke

      default com.google.common.util.concurrent.ListenableFuture<Void> startMemoryRevoke()
      After calling this method operator should revoke all reserved revocable memory. As soon as memory is revoked returned future should be marked as done.

      Spawned threads cannot modify OperatorContext because it's not thread safe. For this purpose implement finishMemoryRevoke()

      Since memory revoking signal is delivered asynchronously to the Operator, implementation must gracefully handle the case when there no longer is any revocable memory allocated.

      After this method is called on Operator the Driver is disallowed to call most of processing methods on it (isBlocked()/needsInput()/addInput(Page)/getOutput()) until finishMemoryRevoke() is called. finish() is the only processing method that can be called during that time and close() remains callable at any time.

    • finishMemoryRevoke

      default void finishMemoryRevoke()
      Clean up and release resources after completed memory revoking. Called by driver once future returned by startMemoryRevoke is completed.

    • finish

      void finish()
      Notifies the operator that no more pages will be added and the operator should finish processing and flush results. This method will not be called if the Task is already failed or canceled.

    • isFinished

      boolean isFinished()
      Is this operator completely finished processing and no more output pages will be produced.

    • close

      default void close() throws Exception
      This method will always be called before releasing the Operator reference.
      Specified by:
      close in interface AutoCloseable
      Throws:
      Exception