https://github.com/boguslaw-wojcik/crc32a

A pure Go implementation of CRC32A (ITU I.363.5) checksum missing from Golang standard library.
https://github.com/boguslaw-wojcik/crc32a

crc32 crc32a go golang

Last synced: about 2 months ago
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A pure Go implementation of CRC32A (ITU I.363.5) checksum missing from Golang standard library.

• Host: GitHub
• URL: https://github.com/boguslaw-wojcik/crc32a
• Owner: boguslaw-wojcik
• License: mit
• Created: 2019-02-02T21:18:40.000Z (almost 6 years ago)
• Default Branch: master
• Last Pushed: 2020-01-14T08:18:18.000Z (almost 5 years ago)
• Last Synced: 2024-08-03T23:29:30.595Z (5 months ago)
• Topics: crc32, crc32a, go, golang
• Language: Go
• Size: 3.91 KB
• Stars: 8
• Watchers: 0
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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• awesome-golang-repositories - crc32a

README

        
# CRC32A

A pure Go implementation of CRC32A (ITU I.363.5) checksum missing from Golang standard library. Largely based on C implementation found in PHP source files.

## Usage

```go

package main

import (

	"fmt"

	

	"github.com/boguslaw-wojcik/crc32a"

)

func main() {

	b := []byte("123456789")

	sum := crc32a.Checksum(b)

	sumHex := crc32a.ChecksumHex(b)

	fmt.Println(sum)    // 404326908

	fmt.Println(sumHex) // 181989fc

}

```

## Background

There are four popular implementations of CRC32 of which three are included in Golang standard library. This package provides missing implementation of CRC32A (ITU I.363.5) popularized by bzip2 and PHP. If you're unsure what CRC32 algorithm you're using, calculate checksum for string `123456789` and compare results with the table below.

| Variant | Performance | Standard Library | Data | Hex | Sum |

| :--- | :---: | :---: | :---: | :---: | ---: |

| **CRC32A (ITU I.363.5)** | **31.4 ns/op** | **no** | **123456789** | **181989fc** | **404326908** |

| CRC32B (ITU V.42 / IEEE 802.3) | 24.0 ns/op | yes | 123456789 | cbf43926 | 3421780262 |

| CRC32C (Castagnoli) | 15.2 ns/op | yes | 123456789 | e3069283 | 3808858755 |

| CRC32K (Koopman) | 4534 ns/op | yes | 123456789 | 2d3dd0ae | 759025838 |

_Note: Unless you're required to use CRC32A for legacy reasons, in general you should choose CRC32B as the most popular and widely implemented CRC32 variation._

## References

* [CRC32 Demystified](https://github.com/Michaelangel007/crc32) by Michael Pohoreski

* [PHP CRC32 source](https://github.com/php/php-src/blob/php-7.3.1/ext/hash/hash_crc32.c) by PHP Group