All Superinterfaces:

AutoCloseable

All Known Subinterfaces:

SourceOperator

All Known Implementing Classes:

AggregationOperator, DeleteOperator, DevNullOperator, DistinctLimitOperator, DynamicFilterSourceOperator, EnforceSingleRowOperator, ExchangeOperator, ExplainAnalyzeOperator, FinishedOperator, GroupIdOperator, HashAggregationOperator, HashBuilderOperator, IndexSourceOperator, LimitOperator, LocalExchangeSinkOperator, LocalExchangeSourceOperator, LocalMergeSourceOperator, LookupOuterOperator, MarkDistinctOperator, MergeOperator, NestedLoopBuildOperator, NestedLoopJoinOperator, NullOutputOperator, OrderByOperator, PageBufferOperator, PageConsumerOperator, PagesIndexBuilderOperator, PageSourceOperator, PartitionedOutputOperator, RowNumberOperator, SetBuilderOperator, SpatialIndexBuilderOperator, SpatialJoinOperator, StatisticsWriterOperator, TableDeleteOperator, TableFinishOperator, TableScanOperator, TableWriterOperator, TaskOutputOperator, TopNRowNumberOperator, UnnestOperator, ValuesOperator, WindowOperator, WorkProcessorOperatorAdapter, WorkProcessorPipelineSourceOperator, WorkProcessorSourceOperatorAdapter
```
public interface Operator
extends AutoCloseable
```

Field Summary

Fields
Modifier and Type Field Description

static com.google.common.util.concurrent.ListenableFuture<?> NOT_BLOCKED

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
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<?>`	`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<?>`	`startMemoryRevoke()`	After calling this method operator should revoke all reserved revocable memory.

- Field Detail
  - NOT_BLOCKED
```
static final com.google.common.util.concurrent.ListenableFuture<?> NOT_BLOCKED
```
- Method Detail
  - getOperatorContext
```
OperatorContext getOperatorContext()
```
  - isBlocked
```
default com.google.common.util.concurrent.ListenableFuture<?> 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<?> 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 any processing methods on it (isBlocked/needsInput/addInput/getOutput) until finishMemoryRevoke() is called.
  - 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

Interface Operator

Field Summary

Method Summary

Field Detail

NOT_BLOCKED

Method Detail

getOperatorContext

isBlocked

needsInput

addInput

getOutput

startMemoryRevoke

finishMemoryRevoke

finish

isFinished

close