Package org.apache.iotdb.db.query.reader.universal

Class AlignedPriorityMergeReader

java.lang.Object

org.apache.iotdb.db.query.reader.universal.PriorityMergeReader

org.apache.iotdb.db.query.reader.universal.AlignedPriorityMergeReader

All Implemented Interfaces:

org.apache.iotdb.tsfile.read.reader.IPointReader

public class AlignedPriorityMergeReader
extends PriorityMergeReader

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.iotdb.db.query.reader.universal.PriorityMergeReader

PriorityMergeReader.MergeReaderPriority

Field Summary

Fields inherited from class org.apache.iotdb.db.query.reader.universal.PriorityMergeReader

currentReadStopTime, heap

Constructor Summary

Constructors

Constructor	Description
AlignedPriorityMergeReader()

Method Summary

Modifier and Type	Method	Description
protected void	fillNullValue(org.apache.iotdb.tsfile.read.TimeValuePair v, org.apache.iotdb.tsfile.read.TimeValuePair c)	In the case of aligned time seres, like d1.s1, d1.s2, d1.s3, we may first only write d1.s2, d1.s3 (2, 3)and then flush it into one tsfile, and then an unseq record come, it contains only d1.s1 and d1.s3 -> (10,30).

Methods inherited from class org.apache.iotdb.db.query.reader.universal.PriorityMergeReader

addReader, addReader, close, currentTimeValuePair, getCurrentReadStopTime, hasNextTimeValuePair, nextTimeValuePair, updateHeap

Methods inherited from class java.lang.Object

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

Constructor Detail

AlignedPriorityMergeReader

public AlignedPriorityMergeReader()

Method Detail

fillNullValue

protected void fillNullValue(org.apache.iotdb.tsfile.read.TimeValuePair v,
                             org.apache.iotdb.tsfile.read.TimeValuePair c)

In the case of aligned time seres, like d1.s1, d1.s2, d1.s3, we may first only write d1.s2, d1.s3 (2, 3)and then flush it into one tsfile, and then an unseq record come, it contains only d1.s1 and d1.s3 -> (10,30). So now we have [null, 2, 3] with low priority and [10, null, 30] with high priority. we use [null, 2, 3] to fill null value in [10, null, 30], so we get [10, 2, 30], we won't use 3 to replace 30, because [10, null, 30] has higher priority

Overrides:

fillNullValue in class PriorityMergeReader

Parameters:

v - TimeValuePair with high priority needs to be filled

c - TimeValuePair with low priority is used to fill the v