Package org.apache.iotdb.db.mpp.execution.operator

Interface Operator

All Superinterfaces:

java.lang.AutoCloseable

All Known Subinterfaces:

DataSourceOperator, ProcessOperator, SinkOperator, SourceOperator

All Known Implementing Classes:

AbstractSeriesAggregationScanOperator, AggregationOperator, AlignedSeriesAggregationScanOperator, AlignedSeriesScanOperator, CountMergeOperator, DeviceMergeOperator, DevicesCountOperator, DevicesSchemaScanOperator, DeviceViewOperator, ExchangeOperator, FillOperator, FilterAndProjectOperator, LastCacheScanOperator, LastQueryCollectOperator, LastQueryMergeOperator, LastQueryOperator, LastQuerySortOperator, LevelTimeSeriesCountOperator, LimitOperator, LinearFillOperator, NodeManageMemoryMergeOperator, NodePathsConvertOperator, NodePathsCountOperator, NodePathsSchemaScanOperator, OffsetOperator, PathsUsingTemplateScanOperator, RawDataAggregationOperator, RowBasedTimeJoinOperator, SchemaFetchMergeOperator, SchemaFetchScanOperator, SchemaQueryMergeOperator, SchemaQueryOrderByHeatOperator, SchemaQueryScanOperator, SeriesAggregationScanOperator, SeriesScanOperator, SingleInputAggregationOperator, SlidingWindowAggregationOperator, SortOperator, TimeJoinOperator, TimeSeriesCountOperator, TimeSeriesSchemaScanOperator, TransformOperator, UpdateLastCacheOperator

public interface Operator
extends java.lang.AutoCloseable

Field Summary

Fields

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

Method Summary

Modifier and Type	Method	Description
long	calculateMaxPeekMemory()	We should also consider the memory used by its children operator, so the calculation logic may be like: long estimatedOfCurrentOperator = XXXXX; return max(estimatedOfCurrentOperator, child1.calculateMaxPeekMemory(), child2.calculateMaxPeekMemory(), ....)
long	calculateMaxReturnSize()
long	calculateRetainedSizeAfterCallingNext()
default void	close()	This method will always be called before releasing the Operator reference.
OperatorContext	getOperatorContext()
boolean	hasNext()
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 TsBlock will be produced.
org.apache.iotdb.tsfile.read.common.block.TsBlock	next()	Gets next tsBlock from this operator.

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.

next

org.apache.iotdb.tsfile.read.common.block.TsBlock next()

Gets next tsBlock from this operator. If no data is currently available, return null.

hasNext

boolean hasNext()

Returns:

true if the operator has more data, otherwise false

close

default void close()
            throws java.lang.Exception

This method will always be called before releasing the Operator reference.

Specified by:

close in interface java.lang.AutoCloseable

Throws:

java.lang.Exception

isFinished

boolean isFinished()

Is this operator completely finished processing and no more output TsBlock will be produced.

calculateMaxPeekMemory

long calculateMaxPeekMemory()

We should also consider the memory used by its children operator, so the calculation logic may be like: long estimatedOfCurrentOperator = XXXXX; return max(estimatedOfCurrentOperator, child1.calculateMaxPeekMemory(), child2.calculateMaxPeekMemory(), ....)

Each operator's MaxPeekMemory should also take retained size of each child operator into account.

Returns:

estimated max memory footprint that the Operator Tree(rooted from this operator) will use while doing its own query processing

calculateMaxReturnSize

long calculateMaxReturnSize()

Returns:

estimated max memory footprint for returned TsBlock when calling operator.next()

calculateRetainedSizeAfterCallingNext

long calculateRetainedSizeAfterCallingNext()

Returns:

each operator's retained size(including all its children's retained size) after calling its next() method