crc32

原文：https://pkg.go.dev/hash/crc32@go1.23.0

Package crc32 implements the 32-bit cyclic redundancy check, or CRC-32, checksum. See https://en.wikipedia.org/wiki/Cyclic_redundancy_check for information.

​ crc32 包实现了 32 位循环冗余校验，或 CRC-32，校验和。有关信息，请参阅 https://en.wikipedia.org/wiki/Cyclic_redundancy_check。

Polynomials are represented in LSB-first form also known as reversed representation.

​ 多项式以 LSB 优先的形式表示，也称为反向表示。

See https://en.wikipedia.org/wiki/Mathematics_of_cyclic_redundancy_checks#Reversed_representations_and_reciprocal_polynomials for information.

​ 有关信息，请参阅 https://en.wikipedia.org/wiki/Mathematics_of_cyclic_redundancy_checks#Reversed_representations_and_reciprocal_polynomials。

常量

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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.
	// https://dx.doi.org/10.1109/26.231911
	Castagnoli = 0x82f63b78

	// Koopman's polynomial.
	// Also has better error detection characteristics than IEEE.
	// https://dx.doi.org/10.1109/DSN.2002.1028931
	Koopman = 0xeb31d82e
)

Predefined polynomials.

​ 预定义多项式。

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const Size = 4

The size of a CRC-32 checksum in bytes.

​ CRC-32 校验和以字节为单位的大小。

变量

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var IEEETable = simpleMakeTable(IEEE)

IEEETable is the table for the IEEE polynomial.

​ IEEETable 是 IEEE 多项式的表格。

函数

func Checksum

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

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

​ Checksum 返回使用由 Table 表示的多项式计算得出的数据的 CRC-32 校验和。

func ChecksumIEEE

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func ChecksumIEEE(data []byte) uint32

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

​ ChecksumIEEE 返回使用 IEEE 多项式计算得出的数据的 CRC-32 校验和。

func New

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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. The returned Hash32 also implements encoding.BinaryMarshaler and encoding.BinaryUnmarshaler to marshal and unmarshal the internal state of the hash.

​ New 创建一个新的 hash.Hash32，使用由 Table 表示的多项式计算 CRC-32 校验和。它的 Sum 方法将以大端字节顺序排列值。返回的 Hash32 还实现了 encoding.BinaryMarshaler 和 encoding.BinaryUnmarshaler 来编组和取消编组哈希的内部状态。

func NewIEEE

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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. The returned Hash32 also implements encoding.BinaryMarshaler and encoding.BinaryUnmarshaler to marshal and unmarshal the internal state of the hash.

​ NewIEEE 创建一个新的 hash.Hash32，使用 IEEE 多项式计算 CRC-32 校验和。它的 Sum 方法将以大端字节顺序排列值。返回的 Hash32 还实现了 encoding.BinaryMarshaler 和 encoding.BinaryUnmarshaler 来编组和取消编组哈希的内部状态。

func Update

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

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

​ Update 返回将 p 中的字节添加到 crc 的结果。

类型

type Table

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type Table [256]uint32

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

​ Table 是一个 256 字的表，表示用于高效处理的多项式。

func MakeTable

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func MakeTable(poly uint32) *Table

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

​ MakeTable 返回由指定多项式构建的 Table。此 Table 的内容不得修改。