Package com.horizen.librustsidechains

Class FieldElement

java.lang.Object

com.horizen.librustsidechains.FieldElement

All Implemented Interfaces:

AutoCloseable

public class FieldElement
extends Object
implements AutoCloseable

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	FieldElement(long fieldElementPointer)

Method Summary

Modifier and Type	Method	Description
void	close()
static FieldElement	createFromLong(long value)	Convert an integer value to a field element
static FieldElement	createRandom()
static FieldElement	createRandom(long seed)
static FieldElement	createRandom(Random r)
static FieldElement	deserialize(byte[] fieldElementBytes)	Deserialize a FieldElement from "fieldElementBytes"
boolean	equals(Object o)
void	freeFieldElement()
static FieldElement	joinAt(FieldElement fe1, int index1, FieldElement fe2, int index2)	The inverse of the splitAt() method: join fe1.bytes[0..index1) and fe2.bytes[0..index2) in a single byte array and deserialize a FieldElement out of it.
static FieldElement	joinAt(FieldElement fe1, int index1, FieldElement fe2, int index2, boolean checkZeroAfterIdx)	The inverse of the splitAt() method: join fe1.bytes[0..index1) and fe2.bytes[0..index2) in a single byte array and deserialize a FieldElement out of it.
protected void	nativePrintFieldElementBytes()
protected byte[]	nativeSerializeFieldElement()
void	printFieldElementBytes()
byte[]	serializeFieldElement()
List<FieldElement>	splitAt(int index)	Split this FieldElement into two FieldElements.

Methods inherited from class java.lang.Object

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

Constructor Detail

FieldElement

protected FieldElement(long fieldElementPointer)

Method Detail

createFromLong

public static FieldElement createFromLong(long value)

Convert an integer value to a field element

Parameters:

value - - A positive integer value to be converted to a field element

Returns:

The field element represented with the positive integer value provided as input

createRandom

public static FieldElement createRandom(long seed)

createRandom

public static FieldElement createRandom()

createRandom

public static FieldElement createRandom(Random r)

nativeSerializeFieldElement

protected byte[] nativeSerializeFieldElement()

serializeFieldElement

public byte[] serializeFieldElement()

deserialize

public static FieldElement deserialize(byte[] fieldElementBytes)
                                throws IllegalArgumentException

Deserialize a FieldElement from "fieldElementBytes"

Parameters:

fieldElementBytes - bytes of the FieldElement to be deserialized

Returns:

The deserialized FieldElement

Throws:

IllegalArgumentException - If fieldElementBytes.len() > FIELD_ELEMENT_LENGTH or if the bytes represent an invalid FieldElement

splitAt

public List<FieldElement> splitAt(int index)
                           throws IndexOutOfBoundsException

Split this FieldElement into two FieldElements. Split will happen at the specified index: one FieldElement will be read from the original bytes [0..index) and the other ones from the original bytes [index..FIELD_ELEMENT_LENGTH)

Parameters:

index - - a valid integer in the range (0, FIELD_ELEMENT_LENGTH)

Returns:

a List made up of two FieldElements, read from the original one split at index

Throws:

IndexOutOfBoundsException - in case of illegal index (i.e. index <= 0 OR index >= FIELD_ELEMENT_LENGTH)

joinAt

public static FieldElement joinAt(FieldElement fe1,
                                  int index1,
                                  FieldElement fe2,
                                  int index2,
                                  boolean checkZeroAfterIdx)
                           throws IllegalArgumentException

The inverse of the splitAt() method: join fe1.bytes[0..index1) and fe2.bytes[0..index2) in a single byte array and deserialize a FieldElement out of it.

Parameters:

fe1 - - the first FieldElement to join

index1 - - the number of bytes to consider from the first FieldElement

fe2 - - the second FieldElement to join

index2 - - the number of bytes to consider from the second FieldElement

checkZeroAfterIdx - - if enabled, check that fe1.bytes[index1..] and fe2.bytes[index2..] are all 0s.

Returns:

the FieldElement obtained from combining fe1.bytes[0..index1) with fe2.bytes[0..index2)

Throws:

IllegalArgumentException - if the combine operation would produce a byte array bigger than FIELD_ELEMENT_LENGTH

joinAt

public static FieldElement joinAt(FieldElement fe1,
                                  int index1,
                                  FieldElement fe2,
                                  int index2)
                           throws IllegalArgumentException

The inverse of the splitAt() method: join fe1.bytes[0..index1) and fe2.bytes[0..index2) in a single byte array and deserialize a FieldElement out of it.

Parameters:

fe1 - - the first FieldElement to join

index1 - - the number of bytes to consider from the first FieldElement

fe2 - - the second FieldElement to join

index2 - - the number of bytes to consider from the second FieldElement

Returns:

the FieldElement obtained from combining fe1.bytes[0..index1) with fe2.bytes[0..index2)

Throws:

IllegalArgumentException - if the combine operation would produce a byte array bigger than FIELD_ELEMENT_LENGTH

nativePrintFieldElementBytes

protected void nativePrintFieldElementBytes()

printFieldElementBytes

public void printFieldElementBytes()

freeFieldElement

public void freeFieldElement()

equals

public boolean equals(Object o)

Overrides:

equals in class Object

close

public void close()

Specified by:

close in interface AutoCloseable