# Package crc32

## Overview ▹

## Index ▹

## Constants

Predefined polynomials.

const ( // IEEE is by far and away the most common CRC-32 polynomial. // Used by ethernet (IEEE 802.3), v.42, fddi, gzip, zip, png, ... IEEE = 0xedb88320 // Castagnoli's polynomial, used in iSCSI. // Has better error detection characteristics than IEEE. // http://dx.doi.org/10.1109/26.231911 Castagnoli = 0x82f63b78 // Koopman's polynomial. // Also has better error detection characteristics than IEEE. // http://dx.doi.org/10.1109/DSN.2002.1028931 Koopman = 0xeb31d82e )

The size of a CRC-32 checksum in bytes.

const Size = 4

## Variables

IEEETable is the table for the IEEE polynomial.

var IEEETable = simpleMakeTable(IEEE)

## func Checksum ¶

func Checksum(data []byte, tab *Table) uint32

Checksum returns the CRC-32 checksum of data using the polynomial represented by the Table.

## func ChecksumIEEE ¶

func ChecksumIEEE(data []byte) uint32

ChecksumIEEE returns the CRC-32 checksum of data using the IEEE polynomial.

## func New ¶

func New(tab *Table) hash.Hash32

New creates a new hash.Hash32 computing the CRC-32 checksum using the polynomial represented by the Table. Its Sum method will lay the value out in big-endian byte order.

## func NewIEEE ¶

func NewIEEE() hash.Hash32

NewIEEE creates a new hash.Hash32 computing the CRC-32 checksum using the IEEE polynomial. Its Sum method will lay the value out in big-endian byte order.

## func Update ¶

func Update(crc uint32, tab *Table, p []byte) uint32

Update returns the result of adding the bytes in p to the crc.

## type Table ¶

Table is a 256-word table representing the polynomial for efficient processing.

type Table [256]uint32

### func MakeTable ¶

func MakeTable(poly uint32) *Table

MakeTable returns a Table constructed from the specified polynomial. The contents of this Table must not be modified.

▹ Example