io.druid.segment

Class StringDimensionHandler

java.lang.Object

io.druid.segment.StringDimensionHandler

All Implemented Interfaces:

DimensionHandler<Integer,int[],String>

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

Field Summary

Fields

Modifier and Type	Field and Description
static Comparator<Integer>	ENCODED_COMPARATOR
static com.google.common.base.Function<Object,String>	STRING_TRANSFORMER
static Comparator<String>	UNENCODED_COMPARATOR

Constructor Summary

Constructors

Constructor and Description
StringDimensionHandler(String dimensionName)

Method Summary

Modifier and Type	Method and Description
int	compareSortedEncodedArrays(int[] lhs, int[] rhs) Given two arrays representing sorted encoded row value(s), return the result of their comparison.
String	getDimensionName() Get the name of the column associated with this handler.
int	getLengthFromEncodedArray(int[] dimVals) Given an array representing a single set of row value(s) for this dimension as an Object, return the length of the array after appropriate type-casting.
Object	getRowValueArrayFromColumn(Closeable column, int currRow) Given a subcolumn from getSubColumn, and the index of the current row, retrieve a row as an array of values.
Closeable	getSubColumn(Column column) Given a Column, return a type-specific object that can be used to retrieve row values.
DimensionIndexer<Integer,int[],String>	makeIndexer() Creates a new DimensionIndexer, a per-dimension object responsible for processing ingested rows in-memory, used by the IncrementalIndex.
DimensionMergerLegacy	makeLegacyMerger(IndexSpec indexSpec, File outDir, IOPeon ioPeon, ColumnCapabilities capabilities, ProgressIndicator progress) Creates a new DimensionMergerLegacy, a per-dimension object responsible for merging indexes/row data across segments and building the on-disk representation of a dimension.
DimensionMergerV9	makeMerger(IndexSpec indexSpec, File outDir, IOPeon ioPeon, ColumnCapabilities capabilities, ProgressIndicator progress) 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.
void	validateSortedEncodedArrays(int[] lhs, int[] rhs, Indexed<String> lhsEncodings, Indexed<String> rhsEncodings) Given two arrays representing sorted encoded row value(s), check that the two arrays have the same encoded values, or if the encoded values differ, that they translate into the same actual values, using the mappings provided by lhsEncodings and rhsEncodings (if applicable).

Methods inherited from class java.lang.Object

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

Field Detail

STRING_TRANSFORMER

public static final com.google.common.base.Function<Object,String> STRING_TRANSFORMER

ENCODED_COMPARATOR

public static final Comparator<Integer> ENCODED_COMPARATOR

UNENCODED_COMPARATOR

public static final Comparator<String> UNENCODED_COMPARATOR

Constructor Detail

StringDimensionHandler

public StringDimensionHandler(String dimensionName)

Method Detail

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

getLengthFromEncodedArray

public int getLengthFromEncodedArray(int[] dimVals)

Description copied from interface: DimensionHandler

Given an array representing a single set of row value(s) for this dimension as an Object, return the length of the array after appropriate type-casting. For example, a dictionary encoded String dimension would receive an int[] as an Object.

Specified by:

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

Parameters:

dimVals - Array of row values

Returns:

Size of dimVals

compareSortedEncodedArrays

public int compareSortedEncodedArrays(int[] lhs,
                                      int[] rhs)

Description copied from interface: DimensionHandler

Given two arrays representing sorted encoded row value(s), return the result of their comparison. If the two arrays have different lengths, the shorter array should be ordered first in the comparison. Otherwise, this function should iterate through the array values and return the comparison of the first difference.

Specified by:

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

Parameters:

lhs - array of row values

rhs - array of row values

Returns:

integer indicating comparison result of arrays

validateSortedEncodedArrays

public void validateSortedEncodedArrays(int[] lhs,
                                        int[] rhs,
                                        Indexed<String> lhsEncodings,
                                        Indexed<String> rhsEncodings)
                                 throws SegmentValidationException

Description copied from interface: DimensionHandler

Given two arrays representing sorted encoded row value(s), check that the two arrays have the same encoded values, or if the encoded values differ, that they translate into the same actual values, using the mappings provided by lhsEncodings and rhsEncodings (if applicable). If validation fails, this method should throw a SegmentValidationException. Used by IndexIO for validating segments. See StringDimensionHandler.validateSortedEncodedArrays() for a reference implementation.

Specified by:

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

Parameters:

lhs - array of row values

rhs - array of row values

lhsEncodings - encoding lookup from lhs's segment, null if not applicable for this dimension's type

rhsEncodings - encoding lookup from rhs's segment, null if not applicable for this dimension's type

Throws:

SegmentValidationException

getSubColumn

public Closeable getSubColumn(Column column)

Description copied from interface: DimensionHandler

Given a Column, return a type-specific object that can be used to retrieve row values. For example: - A String-typed implementation would return the result of column.getDictionaryEncoding() - A long-typed implemention would return the result of column.getGenericColumn().

Specified by:

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

Parameters:

column - Column for this dimension from a QueryableIndex

Returns:

The type-specific column subobject for this dimension.

getRowValueArrayFromColumn

public Object getRowValueArrayFromColumn(Closeable column,
                                         int currRow)

Description copied from interface: DimensionHandler

Given a subcolumn from getSubColumn, and the index of the current row, retrieve a row as an array of values. For example: - A String-typed implementation would read the current row from a DictionaryEncodedColumn as an int[]. - A long-typed implemention would read the current row from a GenericColumn return the current row as a long[].

Specified by:

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

Parameters:

column - Column for this dimension from a QueryableIndex

currRow - The index of the row to retrieve

Returns:

The row from "column" specified by "currRow", as an array of values

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(IndexSpec indexSpec,
                                    File outDir,
                                    IOPeon ioPeon,
                                    ColumnCapabilities capabilities,
                                    ProgressIndicator progress)

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:

indexSpec - Specification object for the index merge

outDir - Location to store files generated by the merging process

ioPeon - ioPeon object passed in by IndexMerger, manages files created by the merging process

capabilities - The ColumnCapabilities of the dimension represented by this DimensionHandler

progress - ProgressIndicator used by the merging process

Returns:

A new DimensionMergerV9 object.

makeLegacyMerger

public DimensionMergerLegacy makeLegacyMerger(IndexSpec indexSpec,
                                              File outDir,
                                              IOPeon ioPeon,
                                              ColumnCapabilities capabilities,
                                              ProgressIndicator progress)

Description copied from interface: DimensionHandler

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

Specified by:

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

Parameters:

indexSpec - Specification object for the index merge

outDir - Location to store files generated by the merging process

ioPeon - ioPeon object passed in by IndexMerger, manages files created by the merging process

capabilities - The ColumnCapabilities of the dimension represented by this DimensionHandler

progress - ProgressIndicator used by the merging process

Returns:

A new DimensionMergerLegacy object.