Imports #
"unsafe"
"internal/cpu"
"errors"
"hash"
"internal/byteorder"
"sync"
"sync/atomic"
"internal/byteorder"
"internal/cpu"
"unsafe"
"internal/cpu"
"internal/cpu"
crc32
Imports
Constants & Variables
Castagnoli const #
Castagnoli's polynomial, used in iSCSI. Has better error detection characteristics than IEEE. https://dx.doi.org/10.1109/26.231911
const Castagnoli = 0x82f63b78IEEE 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, ...
const IEEE = 0xedb88320IEEETable var #
IEEETable is the table for the [IEEE] polynomial.
var IEEETable = *ast.CallExprKoopman const #
Koopman's polynomial. Also has better error detection characteristics than IEEE. https://dx.doi.org/10.1109/DSN.2002.1028931
const Koopman = 0xeb31d82eSize const #
The size of a CRC-32 checksum in bytes.
const Size = 4archCastagnoliTable8 var #
var archCastagnoliTable8 *slicing8TablearchCastagnoliTable8 var #
var archCastagnoliTable8 *slicing8TablearchIeeeTable8 var #
var archIeeeTable8 *slicing8TablearchIeeeTable8 var #
var archIeeeTable8 *slicing8TablearchIeeeTable8 var #
var archIeeeTable8 *slicing8TablecastagnoliInitOnce var #
var castagnoliInitOnce = *ast.CallExprcastagnoliK1 const #
const castagnoliK1 = 168castagnoliK2 const #
const castagnoliK2 = 1344castagnoliSSE42TableK1 var #
var castagnoliSSE42TableK1 *sse42TablecastagnoliSSE42TableK2 var #
var castagnoliSSE42TableK2 *sse42TablecastagnoliTable var #
castagnoliTable points to a lazily initialized Table for the Castagnoli polynomial. MakeTable will always return this value when asked to make a Castagnoli table so we can compare against it to find when the caller is using this polynomial.
var castagnoliTable *TablecastagnoliTable8 var #
var castagnoliTable8 *slicing8TablecrcCast const #
const crcCast = 2crcIEEE const #
const crcIEEE = 1hasVX var #
hasVX reports whether the machine has the z/Architecture vector facility installed and enabled.
var hasVX = cpu.S390X.HasVXhaveCastagnoli var #
var haveCastagnoli atomic.BoolieeeInitOnce var #
var ieeeInitOnce = *ast.CallExprieeeTable8 var #
ieeeTable8 is the slicing8Table for IEEE
var ieeeTable8 *slicing8Tablemagic const #
const magic = "crc\x01"marshaledSize const #
const marshaledSize = *ast.BinaryExprslicing8Cutoff const #
Use slicing-by-8 when payload >= this value.
const slicing8Cutoff = 16updateCastagnoli var #
var updateCastagnoli func(crc uint32, p []byte) uint32updateIEEE var #
var updateIEEE func(crc uint32, p []byte) uint32vecAlignMask const #
const vecAlignMask = 15vecMinLen const #
const vecMinLen = 16vxAlignMask const #
const vxAlignMask = 15vxMinLen const #
const vxMinLen = 64Type Aliases
Table type #
Table is a 256-word table representing the polynomial for efficient processing.
type Table [256]uint32slicing8Table type #
slicing8Table is array of 8 Tables, used by the slicing-by-8 algorithm.
type slicing8Table [8]Tablesse42Table type #
type sse42Table [4]TableStructs
digest struct #
digest represents the partial evaluation of a checksum.
type digest struct {
crc uint32
tab *Table
}Functions
AppendBinary method #
func (d *digest) AppendBinary(b []byte) ([]byte, error)BlockSize method #
func (d *digest) BlockSize() intChecksum function #
Checksum returns the CRC-32 checksum of data using the polynomial represented by the [Table].
func Checksum(data []byte, tab *Table) uint32ChecksumIEEE function #
ChecksumIEEE returns the CRC-32 checksum of data using the [IEEE] polynomial.
func ChecksumIEEE(data []byte) uint32MakeTable function #
MakeTable returns a [Table] constructed from the specified polynomial. The contents of this [Table] must not be modified.
func MakeTable(poly uint32) *TableMarshalBinary method #
func (d *digest) MarshalBinary() ([]byte, error)New function #
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. The returned Hash32 also implements [encoding.BinaryMarshaler] and [encoding.BinaryUnmarshaler] to marshal and unmarshal the internal state of the hash.
func New(tab *Table) hash.Hash32NewIEEE function #
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. The returned Hash32 also implements [encoding.BinaryMarshaler] and [encoding.BinaryUnmarshaler] to marshal and unmarshal the internal state of the hash.
func NewIEEE() hash.Hash32Reset method #
func (d *digest) Reset()Size method #
func (d *digest) Size() intSum method #
func (d *digest) Sum(in []byte) []byteSum32 method #
func (d *digest) Sum32() uint32UnmarshalBinary method #
func (d *digest) UnmarshalBinary(b []byte) errorUpdate function #
Update returns the result of adding the bytes in p to the crc.
func Update(crc uint32, tab *Table, p []byte) uint32Write method #
func (d *digest) Write(p []byte) (n int, err error)archAvailableCastagnoli function #
func archAvailableCastagnoli() boolarchAvailableCastagnoli function #
func archAvailableCastagnoli() boolarchAvailableCastagnoli function #
func archAvailableCastagnoli() boolarchAvailableCastagnoli function #
func archAvailableCastagnoli() boolarchAvailableCastagnoli function #
func archAvailableCastagnoli() boolarchAvailableCastagnoli function #
func archAvailableCastagnoli() boolarchAvailableIEEE function #
func archAvailableIEEE() boolarchAvailableIEEE function #
func archAvailableIEEE() boolarchAvailableIEEE function #
func archAvailableIEEE() boolarchAvailableIEEE function #
func archAvailableIEEE() boolarchAvailableIEEE function #
func archAvailableIEEE() boolarchAvailableIEEE function #
func archAvailableIEEE() boolarchInitCastagnoli function #
func archInitCastagnoli()archInitCastagnoli function #
func archInitCastagnoli()archInitCastagnoli function #
func archInitCastagnoli()archInitCastagnoli function #
func archInitCastagnoli()archInitCastagnoli function #
func archInitCastagnoli()archInitCastagnoli function #
func archInitCastagnoli()archInitIEEE function #
func archInitIEEE()archInitIEEE function #
func archInitIEEE()archInitIEEE function #
func archInitIEEE()archInitIEEE function #
func archInitIEEE()archInitIEEE function #
func archInitIEEE()archInitIEEE function #
func archInitIEEE()archUpdateCastagnoli function #
func archUpdateCastagnoli(crc uint32, p []byte) uint32archUpdateCastagnoli function #
func archUpdateCastagnoli(crc uint32, p []byte) uint32archUpdateCastagnoli function #
func archUpdateCastagnoli(crc uint32, p []byte) uint32archUpdateCastagnoli function #
archUpdateCastagnoli calculates the checksum of p using vectorizedCastagnoli.
func archUpdateCastagnoli(crc uint32, p []byte) uint32archUpdateCastagnoli function #
func archUpdateCastagnoli(crc uint32, p []byte) uint32archUpdateCastagnoli function #
func archUpdateCastagnoli(crc uint32, p []byte) uint32archUpdateIEEE function #
func archUpdateIEEE(crc uint32, p []byte) uint32archUpdateIEEE function #
archUpdateIEEE calculates the checksum of p using vectorizedIEEE.
func archUpdateIEEE(crc uint32, p []byte) uint32archUpdateIEEE function #
func archUpdateIEEE(crc uint32, p []byte) uint32archUpdateIEEE function #
archUpdateIEEE calculates the checksum of p using vectorizedIEEE.
func archUpdateIEEE(crc uint32, p []byte) uint32archUpdateIEEE function #
func archUpdateIEEE(crc uint32, p []byte) uint32archUpdateIEEE function #
func archUpdateIEEE(crc uint32, p []byte) uint32castagnoliSSE42 function #
castagnoliSSE42 is defined in crc32_amd64.s and uses the SSE 4.2 CRC32 instruction. go:noescape
func castagnoliSSE42(crc uint32, p []byte) uint32castagnoliSSE42Triple function #
castagnoliSSE42Triple is defined in crc32_amd64.s and uses the SSE 4.2 CRC32 instruction. go:noescape
func castagnoliSSE42Triple(crcA uint32, crcB uint32, crcC uint32, a []byte, b []byte, c []byte, rounds uint32) (retA uint32, retB uint32, retC uint32)castagnoliShift function #
castagnoliShift computes the CRC32-C of K1 or K2 zeroes (depending on the table given) with the given initial crc value. This corresponds to CRC(crc, O) in the description in updateCastagnoli.
func castagnoliShift(table *sse42Table, crc uint32) uint32castagnoliUpdate function #
func castagnoliUpdate(crc uint32, p []byte) uint32castagnoliUpdate function #
func castagnoliUpdate(crc uint32, p []byte) uint32ieeeCLMUL function #
ieeeCLMUL is defined in crc_amd64.s and uses the PCLMULQDQ instruction as well as SSE 4.1. go:noescape
func ieeeCLMUL(crc uint32, p []byte) uint32ieeeUpdate function #
func ieeeUpdate(crc uint32, p []byte) uint32ieeeUpdate function #
func ieeeUpdate(crc uint32, p []byte) uint32ppc64SlicingUpdateBy8 function #
go:noescape
func ppc64SlicingUpdateBy8(crc uint32, table8 *slicing8Table, p []byte) uint32simpleMakeTable function #
simpleMakeTable allocates and constructs a Table for the specified polynomial. The table is suitable for use with the simple algorithm (simpleUpdate).
func simpleMakeTable(poly uint32) *TablesimplePopulateTable function #
simplePopulateTable constructs a Table for the specified polynomial, suitable for use with simpleUpdate.
func simplePopulateTable(poly uint32, t *Table)simpleUpdate function #
simpleUpdate uses the simple algorithm to update the CRC, given a table that was previously computed using simpleMakeTable.
func simpleUpdate(crc uint32, tab *Table, p []byte) uint32slicingMakeTable function #
slicingMakeTable constructs a slicing8Table for the specified polynomial. The table is suitable for use with the slicing-by-8 algorithm (slicingUpdate).
func slicingMakeTable(poly uint32) *slicing8TableslicingUpdate function #
slicingUpdate uses the slicing-by-8 algorithm to update the CRC, given a table that was previously computed using slicingMakeTable.
func slicingUpdate(crc uint32, tab *slicing8Table, p []byte) uint32tableSum function #
tableSum returns the IEEE checksum of table t.
func tableSum(t *Table) uint32update function #
func update(crc uint32, tab *Table, p []byte, checkInitIEEE bool) uint32vectorCrc32 function #
this function requires the buffer to be 16 byte aligned and > 16 bytes long. go:noescape
func vectorCrc32(crc uint32, poly uint32, p []byte) uint32vectorizedCastagnoli function #
vectorizedCastagnoli implements CRC32 using vector instructions. It is defined in crc32_s390x.s. go:noescape
func vectorizedCastagnoli(crc uint32, p []byte) uint32vectorizedIEEE function #
vectorizedIEEE implements CRC32 using vector instructions. It is defined in crc32_s390x.s. go:noescape
func vectorizedIEEE(crc uint32, p []byte) uint32Generated with Arrow