Package crc32
import "hash/crc32"
This package implements the 32-bit cyclic redundancy check, or CRC-32, checksum. See http://en.wikipedia.org/wiki/Cyclic_redundancy_check for information.
Package files
crc32.goConstants
Predefined polynomials.
const (
// Far and away the most common CRC-32 polynomial.
// Used by ethernet (IEEE 802.3), v.42, fddi, gzip, zip, png, mpeg-2, ...
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 = MakeTable(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.
func NewIEEE
func NewIEEE() hash.Hash32
NewIEEE creates a new hash.Hash32 computing the CRC-32 checksum using the IEEE polynomial.
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 the Table constructed from the specified polynomial.