kmgQrcode

README

Description

a golang qrcode writer

A QR Code is a matrix (two-dimensional) barcode. Arbitrary content may be encoded.

A QR Code contains error recovery information to aid reading damaged or obscured codes. There are four levels of error recovery: qrcode.{Low, Medium, High, Highest}. QR Codes with a higher recovery level are more robust to damage, at the cost of being physically larger.

The maximum capacity of a QR Code varies according to the content encoded and the error recovery level. The maximum capacity is 2,953 bytes, 4,296 alphanumeric characters, 7,089 numeric digits, or a combination of these.

This package implements a subset of QR Code 2005, as defined in ISO/IEC 18004:2006.

Example

package main

import (
	"github.com/bronze1man/kmgQrcode"
	"io/ioutil"
)

func main(){
	resp:= kmgQrcode.MustEncode(kmgQrcode.EncodeReq{
		Content: "https://www.google.com/",
	})
	err:=ioutil.WriteFile("tmp.png",resp.PngContent,0777)
	if err!=nil{
		panic(err)
	}
}

Notice

• It can not read qrcode into text, it can only translate qrcode text into png byte slice.
• fork from https://github.com/skip2/go-qrcode , with following change:
  • Make the package name easy to remember and import.
  • Simplify the caller interface, leave only one function kmgQrcode.MustEncode .
  • Delete surrounding blank, make the qrcode part as large as possible.(use float64 instead of int to generate image.)

Documentation

Index

• type EncodeReq
• type EncodeResp
  • func MustEncode(req EncodeReq) (resp EncodeResp)
• type EncodeV2Cacher
  • func (c *EncodeV2Cacher) GetByKey(key string) (resp EncodeResp, ok bool)
  • func (c *EncodeV2Cacher) SetByKey(key string, resp EncodeResp)
• type RecoveryLevel

Types

type EncodeReq

type EncodeReq struct {
	Content string        `json:",omitempty"`
	Level   RecoveryLevel `json:",omitempty"` // 冗余比例，默认 Highest
	PngSize int           `json:",omitempty"` // 输出的png的长宽，会输出一个正方形的图形，所以长宽都一样。 默认 256

	IsOutputDataUrl bool `json:",omitempty"` // 输出Data url,(就不输出 png了）

	MemoryCacher *EncodeV2Cacher `json:"-"` // 在进程内存中缓存生成qrcode的请求和结果。以便下次可以快速使用。
	CacheKey     string          `json:",omitempty"`

	PngUseBufferPool    bool                 `json:",omitempty"` // 是否使用 UsePngBufferPool,这个东西可以减少alloc，但是会产生一个一直不释放的内存占用
	PngCompressionLevel png.CompressionLevel `json:",omitempty"`
}

type EncodeResp

type EncodeResp struct {
	PngContent []byte
	DataUrl    string
}

func MustEncode

func MustEncode(req EncodeReq) (resp EncodeResp)

type EncodeV2Cacher

type EncodeV2Cacher struct {
	MaxCacheSize int // 默认 1000,创建之后不要修改。
	// contains filtered or unexported fields
}

func (*EncodeV2Cacher) GetByKey

func (c *EncodeV2Cacher) GetByKey(key string) (resp EncodeResp, ok bool)

func (*EncodeV2Cacher) SetByKey

func (c *EncodeV2Cacher) SetByKey(key string, resp EncodeResp)

type RecoveryLevel

type RecoveryLevel int

Error detection/recovery capacity.

There are several levels of error detection/recovery capacity. Higher levels of error recovery are able to correct more errors, with the trade-off of increased symbol size.

const (
	// Level L: 7% error recovery.
	Low RecoveryLevel = 1

	// Level M: 15% error recovery. Good default choice.
	Medium RecoveryLevel = 2

	// Level Q: 25% error recovery.
	High RecoveryLevel = 3

	// Level H: 30% error recovery.
	Highest RecoveryLevel = 4
)