org.apache.druid.segment

Class DimensionDictionary<T extends Comparable<T>>

java.lang.Object

org.apache.druid.segment.DimensionDictionary<T>

Direct Known Subclasses:

StringDimensionDictionary

public abstract class DimensionDictionary<T extends Comparable<T>>
extends Object

Buildable dictionary for some comparable type. Values are unsorted, or rather sorted in the order which they are added. A SortedDimensionDictionary can be constructed with a mapping of ids from this dictionary to the sorted dictionary with the sort() method.

Concrete implementations of this dictionary must be thread-safe.

Field Summary

Fields

Modifier and Type	Field and Description
static int	ABSENT_VALUE_ID

Constructor Summary

Constructors

Constructor and Description
DimensionDictionary(Class<T> cls)

Method Summary

Modifier and Type	Method and Description
int	add(T originalValue)
abstract boolean	computeOnHeapSize() Whether on-heap size of this dictionary should be computed.
abstract long	estimateSizeOfValue(T value) Estimates the size of the dimension value in bytes.
int	getId(T value)
int	getIdForNull()
T	getMaxValue()
T	getMinValue()
T	getValue(int id)
T[]	getValues(int[] ids)
int	size()
long	sizeInBytes() Gets the current size of this dictionary in bytes.
SortedDimensionDictionary<T>	sort()

Methods inherited from class java.lang.Object

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

Field Detail

ABSENT_VALUE_ID

public static final int ABSENT_VALUE_ID

See Also:

Constant Field Values

Constructor Detail

DimensionDictionary

public DimensionDictionary(Class<T> cls)

Method Detail

getId

public int getId(@Nullable
                 T value)

getValue

@Nullable
public T getValue(int id)

getValues

public T[] getValues(int[] ids)

size

public int size()

sizeInBytes

public long sizeInBytes()

Gets the current size of this dictionary in bytes.

Throws:

IllegalStateException - if size computation is disabled.

add

public int add(@Nullable
               T originalValue)

getMinValue

public T getMinValue()

getMaxValue

public T getMaxValue()

getIdForNull

public int getIdForNull()

sort

public SortedDimensionDictionary<T> sort()

estimateSizeOfValue

public abstract long estimateSizeOfValue(T value)

Estimates the size of the dimension value in bytes.

This method is called when adding a new dimension value to the lookup only if computeOnHeapSize() returns true.

computeOnHeapSize

public abstract boolean computeOnHeapSize()

Whether on-heap size of this dictionary should be computed.