com.oracle.graal.compiler.common.util

Class FrequencyEncoder<T>

java.lang.Object

com.oracle.graal.compiler.common.util.FrequencyEncoder<T>

public class FrequencyEncoder<T>
extends Object

Creates an array of T objects order by the occurrence frequency of each object. The most frequently used object is the first one, the least frequently used the last one. If null is added, it is always the first element. Either object identity or object equality can be used to build the array and count the frequency.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
(package private) static class	FrequencyEncoder.Entry<T>

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	containsNull
protected Map<T,FrequencyEncoder.Entry<T>>	map

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	FrequencyEncoder(Map<T,FrequencyEncoder.Entry<T>> map)

Method Summary

Modifier and Type	Method and Description
void	addObject(T object) Adds an object to the array.
static <T> FrequencyEncoder<T>	createEqualityEncoder() Creates an encoder that uses object equality.
static <T> FrequencyEncoder<T>	createIdentityEncoder() Creates an encoder that uses object identity.
T[]	encodeAll(T[] allObjects) Fills the provided array with the added objects.
int	getIndex(Object object) Returns the index of an object in the array.
int	getLength() Returns the number of distinct objects that have been added, i.e., the length of the array.

Methods inherited from class java.lang.Object

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

Field Detail

map

protected final Map<T,FrequencyEncoder.Entry<T>> map

containsNull

protected boolean containsNull

Constructor Detail

FrequencyEncoder

protected FrequencyEncoder(Map<T,FrequencyEncoder.Entry<T>> map)

Method Detail

createIdentityEncoder

public static <T> FrequencyEncoder<T> createIdentityEncoder()

Creates an encoder that uses object identity.

createEqualityEncoder

public static <T> FrequencyEncoder<T> createEqualityEncoder()

Creates an encoder that uses object equality.

addObject

public void addObject(T object)

Adds an object to the array.

getIndex

public int getIndex(Object object)

Returns the index of an object in the array. The object must have been added before.

getLength

public int getLength()

Returns the number of distinct objects that have been added, i.e., the length of the array.

encodeAll

public T[] encodeAll(T[] allObjects)

Fills the provided array with the added objects. The array must have the correct length.