Package org.apache.druid.segment

Class StringDimensionHandler

java.lang.Object

org.apache.druid.segment.StringDimensionHandler

All Implemented Interfaces:

DimensionHandler<Integer,int[],String>

public class StringDimensionHandler
extends Object
implements DimensionHandler<Integer,int[],String>

Constructor Summary

Constructors

Constructor	Description
StringDimensionHandler(String dimensionName, DimensionSchema.MultiValueHandling multiValueHandling, boolean hasBitmapIndexes, boolean hasSpatialIndexes)

Method Summary

Modifier and Type	Method	Description
String	getDimensionName()	Get the name of the column associated with this handler.
DimensionSchema	getDimensionSchema(ColumnCapabilities capabilities)
Comparator<ColumnValueSelector>	getEncodedValueSelectorComparator()	Returns a comparator that knows how to compare ColumnValueSelector of the assumed dimension type, corresponding to this DimensionHandler.
int	getLengthOfEncodedKeyComponent(int[] dimVals)	Given an key component representing a single set of row value(s) for this dimension as an Object, return the length of the key component after appropriate type-casting.
DimensionSchema.MultiValueHandling	getMultivalueHandling()	Get DimensionSchema.MultiValueHandling for the column associated with this handler.
DimensionIndexer<Integer,int[],String>	makeIndexer()	Creates a new DimensionIndexer, a per-dimension object responsible for processing ingested rows in-memory, used by the IncrementalIndex.
DimensionMergerV9	makeMerger(String outputName, IndexSpec indexSpec, SegmentWriteOutMedium segmentWriteOutMedium, ColumnCapabilities capabilities, ProgressIndicator progress, File segmentBaseDir, Closer closer)	Creates a new DimensionMergerV9, a per-dimension object responsible for merging indexes/row data across segments and building the on-disk representation of a dimension.
SettableColumnValueSelector	makeNewSettableEncodedValueSelector()	Creates and returns a new object of some implementation of SettableColumnValueSelector, that corresponds to the type of this DimensionHandler.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.druid.segment.DimensionHandler

getDimensionSpec, makeMerger

Constructor Details

StringDimensionHandler

public StringDimensionHandler(String dimensionName,
 DimensionSchema.MultiValueHandling multiValueHandling,
 boolean hasBitmapIndexes,
 boolean hasSpatialIndexes)

Method Details

getDimensionName

public String getDimensionName()

Description copied from interface: DimensionHandler

Get the name of the column associated with this handler. This string would be the output name of the column during ingestion, and the name of an input column when querying.

Specified by:

getDimensionName in interface DimensionHandler<Integer,int[],String>

Returns:

Dimension name

getDimensionSchema

public DimensionSchema getDimensionSchema(ColumnCapabilities capabilities)

Specified by:

getDimensionSchema in interface DimensionHandler<Integer,int[],String>

getMultivalueHandling

public DimensionSchema.MultiValueHandling getMultivalueHandling()

Description copied from interface: DimensionHandler

Get DimensionSchema.MultiValueHandling for the column associated with this handler. Only string columns can have DimensionSchema.MultiValueHandling currently.

Specified by:

getMultivalueHandling in interface DimensionHandler<Integer,int[],String>

getLengthOfEncodedKeyComponent

public int getLengthOfEncodedKeyComponent(int[] dimVals)

Description copied from interface: DimensionHandler

Given an key component representing a single set of row value(s) for this dimension as an Object, return the length of the key component after appropriate type-casting. For example, a dictionary encoded String dimension would receive an int[] as input to this method, while a Long numeric dimension would receive a single Long object (no multivalue support)

Specified by:

getLengthOfEncodedKeyComponent in interface DimensionHandler<Integer,int[],String>

Parameters:

dimVals - Values for this dimension from a row

Returns:

Size of dimVals

getEncodedValueSelectorComparator

public Comparator<ColumnValueSelector> getEncodedValueSelectorComparator()

Description copied from interface: DimensionHandler

Returns a comparator that knows how to compare ColumnValueSelector of the assumed dimension type, corresponding to this DimensionHandler. E. g. StringDimensionHandler returns a comparator, that compares ColumnValueSelectors as DimensionSelectors. The comparison rules used by this method should match the rules used by DimensionIndexer.compareUnsortedEncodedKeyComponents(EncodedKeyComponentType, EncodedKeyComponentType), otherwise incorrect ordering/merging of rows can occur during ingestion, causing issues such as imperfect rollup.

Specified by:

getEncodedValueSelectorComparator in interface DimensionHandler<Integer,int[],String>

makeNewSettableEncodedValueSelector

public SettableColumnValueSelector makeNewSettableEncodedValueSelector()

Description copied from interface: DimensionHandler

Creates and returns a new object of some implementation of SettableColumnValueSelector, that corresponds to the type of this DimensionHandler. E. g. LongDimensionHandler returns SettableLongColumnValueSelector, etc.

Specified by:

makeNewSettableEncodedValueSelector in interface DimensionHandler<Integer,int[],String>

makeIndexer

public DimensionIndexer<Integer,int[],String> makeIndexer()

Description copied from interface: DimensionHandler

Creates a new DimensionIndexer, a per-dimension object responsible for processing ingested rows in-memory, used by the IncrementalIndex. See DimensionIndexer interface for more information.

Specified by:

makeIndexer in interface DimensionHandler<Integer,int[],String>

Returns:

A new DimensionIndexer object.

makeMerger

public DimensionMergerV9 makeMerger(String outputName,
 IndexSpec indexSpec,
 SegmentWriteOutMedium segmentWriteOutMedium,
 ColumnCapabilities capabilities,
 ProgressIndicator progress,
 File segmentBaseDir,
 Closer closer)

Description copied from interface: DimensionHandler

Creates a new DimensionMergerV9, a per-dimension object responsible for merging indexes/row data across segments and building the on-disk representation of a dimension. For use with IndexMergerV9 only. See DimensionMergerV9 interface for more information.

Specified by:

makeMerger in interface DimensionHandler<Integer,int[],String>

Parameters:

outputName - Output "file" name for the column to use for serializers, to control where it is stored in the segments internal files

indexSpec - Specification object for the index merge

segmentWriteOutMedium - this SegmentWriteOutMedium object could be used internally in the created merger, if needed

capabilities - The ColumnCapabilities of the dimension represented by this DimensionHandler

progress - ProgressIndicator used by the merging process

segmentBaseDir - segment write out path; temporary files may be created here, though should delete after merge is finished OR be registered with the Closer parameter

closer - Closer tied to segment completion. Anything which is not cleaned up inside of the merger after merge is complete should be registered with this closer. For example, resources which are required for final serialization of the column

Returns:

A new DimensionMergerV9 object.