Package org.apache.iotdb.db.query.aggregation.impl

Class FirstValueAggrResult

java.lang.Object

org.apache.iotdb.db.query.aggregation.AggregateResult

org.apache.iotdb.db.query.aggregation.impl.FirstValueAggrResult

All Implemented Interfaces:

java.lang.Cloneable

Direct Known Subclasses:

FirstValueDescAggrResult

public class FirstValueAggrResult
extends AggregateResult

Field Summary

Fields inherited from class org.apache.iotdb.db.query.aggregation.AggregateResult

hasCandidateResult, resultDataType, TIME_LENGTH_FOR_FIRST_VALUE, timestamp

Constructor Summary

Constructors

Constructor	Description
FirstValueAggrResult(org.apache.iotdb.tsfile.file.metadata.enums.TSDataType dataType)

Method Summary

Modifier and Type	Method	Description
protected void	deserializeSpecificFields(java.nio.ByteBuffer buffer)
java.lang.Object	getResult()
boolean	hasFinalResult()	Judge if aggregation results have been calculated.
void	merge(AggregateResult another)	Merge another aggregateResult into this
void	reset()
protected void	serializeSpecificFields(java.io.OutputStream outputStream)
void	updateResultFromPageData(org.apache.iotdb.tsfile.read.common.IBatchDataIterator batchIterator)	Aggregate results cannot be calculated using Statistics directly, using the data in each page.
void	updateResultFromPageData(org.apache.iotdb.tsfile.read.common.IBatchDataIterator batchIterator, long minBound, long maxBound)	Aggregate results cannot be calculated using Statistics directly, using the data in each page.
void	updateResultFromStatistics(org.apache.iotdb.tsfile.file.metadata.statistics.Statistics statistics)	Calculate the aggregation using Statistics
void	updateResultUsingTimestamps(long[] timestamps, int length, IReaderByTimestamp dataReader)	This method calculates the aggregation using common timestamps of the cross series filter.
void	updateResultUsingValues(long[] timestamps, int length, ValueIterator valueIterator)	This method calculates the aggregation using values that have been calculated

Methods inherited from class org.apache.iotdb.db.query.aggregation.AggregateResult

clone, deserializeFrom, getAggregationType, getBinaryValue, getBooleanValue, getDoubleAbsValue, getDoubleValue, getFloatAbsValue, getFloatValue, getIntAbsValue, getIntValue, getLongAbsValue, getLongValue, getResultDataType, getTime, getValue, hasCandidateResult, isAscending, serialize, serializeTo, setBinaryValue, setBooleanValue, setDoubleValue, setFloatValue, setIntValue, setLongValue, setTime, setValue, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

FirstValueAggrResult

public FirstValueAggrResult(org.apache.iotdb.tsfile.file.metadata.enums.TSDataType dataType)

Method Detail

reset

public void reset()

Overrides:

reset in class AggregateResult

getResult

public java.lang.Object getResult()

Specified by:

getResult in class AggregateResult

updateResultFromStatistics

public void updateResultFromStatistics(org.apache.iotdb.tsfile.file.metadata.statistics.Statistics statistics)

Description copied from class: AggregateResult

Calculate the aggregation using Statistics

Specified by:

updateResultFromStatistics in class AggregateResult

Parameters:

statistics - chunkStatistics or pageStatistics

updateResultFromPageData

public void updateResultFromPageData(org.apache.iotdb.tsfile.read.common.IBatchDataIterator batchIterator)

Description copied from class: AggregateResult

Aggregate results cannot be calculated using Statistics directly, using the data in each page. This method is used in global aggregation query.

Specified by:

updateResultFromPageData in class AggregateResult

Parameters:

batchIterator - the data in Page

updateResultFromPageData

public void updateResultFromPageData(org.apache.iotdb.tsfile.read.common.IBatchDataIterator batchIterator,
                                     long minBound,
                                     long maxBound)

Description copied from class: AggregateResult

Aggregate results cannot be calculated using Statistics directly, using the data in each page. This method is used in GROUP BY aggregation query.

Specified by:

updateResultFromPageData in class AggregateResult

Parameters:

batchIterator - the data in Page

minBound - calculate points whose time >= bound

maxBound - calculate points whose time < bound

updateResultUsingTimestamps

public void updateResultUsingTimestamps(long[] timestamps,
                                        int length,
                                        IReaderByTimestamp dataReader)
                                 throws java.io.IOException

Description copied from class: AggregateResult

This method calculates the aggregation using common timestamps of the cross series filter.

Specified by:

updateResultUsingTimestamps in class AggregateResult

Throws:

java.io.IOException - TsFile data read error

updateResultUsingValues

public void updateResultUsingValues(long[] timestamps,
                                    int length,
                                    ValueIterator valueIterator)

Description copied from class: AggregateResult

This method calculates the aggregation using values that have been calculated

Specified by:

updateResultUsingValues in class AggregateResult

hasFinalResult

public boolean hasFinalResult()

Description copied from class: AggregateResult

Judge if aggregation results have been calculated. In other words, if the aggregated result does not need to compute the remaining data, it returns true.

Specified by:

hasFinalResult in class AggregateResult

Returns:

If the aggregation result has been calculated return true, else return false.

merge

public void merge(AggregateResult another)

Description copied from class: AggregateResult

Merge another aggregateResult into this

Specified by:

merge in class AggregateResult

deserializeSpecificFields

protected void deserializeSpecificFields(java.nio.ByteBuffer buffer)

Specified by:

deserializeSpecificFields in class AggregateResult

serializeSpecificFields

protected void serializeSpecificFields(java.io.OutputStream outputStream)
                                throws java.io.IOException

Specified by:

serializeSpecificFields in class AggregateResult

Throws:

java.io.IOException