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

Class AggregationOperator

java.lang.Object

org.apache.iotdb.db.mpp.execution.operator.process.AggregationOperator

All Implemented Interfaces:

java.lang.AutoCloseable, Operator, ProcessOperator

public class AggregationOperator
extends java.lang.Object
implements ProcessOperator

AggregationOperator can process the situation: aggregation of intermediate aggregate result, it will output one tsBlock contain many results on aggregation time intervals. One intermediate tsBlock input will contain the result of many time intervals.

Field Summary

Fields inherited from interface org.apache.iotdb.db.mpp.execution.operator.Operator

NOT_BLOCKED

Constructor Summary

Constructors

Constructor	Description
AggregationOperator(OperatorContext operatorContext, java.util.List<Aggregator> aggregators, ITimeRangeIterator timeRangeIterator, java.util.List<Operator> children, long maxReturnSize)

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()
void	close()	This method will always be called before releasing the Operator reference.
OperatorContext	getOperatorContext()
boolean	hasNext()
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.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AggregationOperator

public AggregationOperator(OperatorContext operatorContext,
                           java.util.List<Aggregator> aggregators,
                           ITimeRangeIterator timeRangeIterator,
                           java.util.List<Operator> children,
                           long maxReturnSize)

Method Detail

getOperatorContext

public OperatorContext getOperatorContext()

Specified by:

getOperatorContext in interface Operator

calculateMaxPeekMemory

public long calculateMaxPeekMemory()

Description copied from interface: Operator

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.

Specified by:

calculateMaxPeekMemory in interface Operator

Returns:

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

calculateMaxReturnSize

public long calculateMaxReturnSize()

Specified by:

calculateMaxReturnSize in interface Operator

Returns:

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

calculateRetainedSizeAfterCallingNext

public long calculateRetainedSizeAfterCallingNext()

Specified by:

calculateRetainedSizeAfterCallingNext in interface Operator

Returns:

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

isBlocked

public com.google.common.util.concurrent.ListenableFuture<?> isBlocked()

Description copied from interface: Operator

Returns a future that will be completed when the operator becomes unblocked. If the operator is not blocked, this method should return NOT_BLOCKED.

Specified by:

isBlocked in interface Operator

hasNext

public boolean hasNext()

Specified by:

hasNext in interface Operator

Returns:

true if the operator has more data, otherwise false

next

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

Description copied from interface: Operator

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

Specified by:

next in interface Operator

isFinished

public boolean isFinished()

Description copied from interface: Operator

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

Specified by:

isFinished in interface Operator

close

public void close()
           throws java.lang.Exception

Description copied from interface: Operator

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

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface Operator

Throws:

java.lang.Exception