Package com.scurrilous.circe.crc

Class AbstractIntCrc

java.lang.Object

com.scurrilous.circe.impl.AbstractIncrementalIntHash

com.scurrilous.circe.crc.AbstractIntCrc

All Implemented Interfaces:

Hash, IncrementalIntHash, StatelessHash, StatelessIntHash

Direct Known Subclasses:

NormalByteCrc, NormalIntCrc, ReflectedIntCrc

abstract class AbstractIntCrc
extends AbstractIncrementalIntHash

Base implementation of int-width CRC functions.

Field Summary

Fields

Modifier and Type	Field	Description
protected int	bitWidth

Constructor Summary

Constructors

Constructor	Description
AbstractIntCrc(java.lang.String algorithm, int bitWidth, int initial, int xorOut)

Method Summary

Modifier and Type	Method	Description
java.lang.String	algorithm()	Returns the canonical name of this hash algorithm.
protected int	initial()	The initial state of the hash function, which is the same as the output value for an empty input sequence.
int	length()	Returns the length in bytes of the output of this hash function.
protected int	reflect(int value)
protected abstract int	resumeRaw(int crc, byte[] input, int index, int length)
protected int	resumeUnchecked(int current, byte[] input, int index, int length)	Evaluates this hash function as if the given range of the given input array were appended to the previously hashed input.

Methods inherited from class com.scurrilous.circe.impl.AbstractIncrementalIntHash

calculate, calculate, calculate, calculate, createStateful, resume, resume, resume, resume, supportsUnsafe

Methods inherited from class java.lang.Object

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

Field Detail

bitWidth

protected final int bitWidth

Constructor Detail

AbstractIntCrc

AbstractIntCrc(java.lang.String algorithm,
               int bitWidth,
               int initial,
               int xorOut)

Method Detail

algorithm

public java.lang.String algorithm()

Description copied from interface: Hash

Returns the canonical name of this hash algorithm.

Returns:

the name of this hash algorithm

length

public int length()

Description copied from interface: Hash

Returns the length in bytes of the output of this hash function.

Returns:

the hash length in bytes

initial

protected int initial()

Description copied from class: AbstractIncrementalIntHash

The initial state of the hash function, which is the same as the output value for an empty input sequence.

Specified by:

initial in class AbstractIncrementalIntHash

Returns:

the initial hash state/output

resumeUnchecked

protected int resumeUnchecked(int current,
                              byte[] input,
                              int index,
                              int length)

Description copied from class: AbstractIncrementalIntHash

Evaluates this hash function as if the given range of the given input array were appended to the previously hashed input. The index and length parameters have already been validated.

Specified by:

resumeUnchecked in class AbstractIncrementalIntHash

Parameters:

current - the hash output for input hashed so far

input - the input array

index - the starting index of the first input byte

length - the length of the input range

Returns:

the output of the hash function for the concatenated input

resumeRaw

protected abstract int resumeRaw(int crc,
                                 byte[] input,
                                 int index,
                                 int length)

reflect

protected final int reflect(int value)