Golang高性能json包:easyjson

原创
2017/08/04 20:59
阅读数 2.9W

简介

easyjson是什么呢? 根据官网介绍,easyjson是提供高效快速且易用的结构体structs<-->json转换包。easyjson并没有使用反射方式实现,所以性能比其他的json包该4-5倍,比golang 自带的json包快2-3倍。 easyjson目标是维持生成去代码简单,以致于它可以轻松地进行优化或固定。

安装


go get -u github.com/mailru/easyjson/
go install  github.com/mailru/easyjson/easyjson
or
go build -o easyjson github.com/mailru/easyjson/easyjson

验证是否安装成功。

$ easyjson
Usage of D:\Code\go\bin\easyjson.exe:
  -all
        generate marshaler/unmarshalers for all structs in a file
  -build_tags string
        build tags to add to generated file
  -leave_temps
        do not delete temporary files
  -lower_camel_case
        use lowerCamelCase names instead of CamelCase by default
  -no_std_marshalers
        don't generate MarshalJSON/UnmarshalJSON funcs
  -noformat
        do not run 'gofmt -w' on output file
  -omit_empty
        omit empty fields by default
  
   string
        specify the filename of the output
  -pkg
        process the whole package instead of just the given file
  -snake_case
        use snake_case names instead of CamelCase by default
  -stubs
        only generate stubs for marshaler/unmarshaler funcs

其中有几个选项需要注意:

-lower_camel_case:将结构体字段field首字母改为小写。如Name=>name。  
-build_tags string:将指定的string生成到生成的go文件头部。  
-no_std_marshalers:不为结构体生成MarshalJSON/UnmarshalJSON函数。  
-omit_empty:没有赋值的field可以不生成到json,否则field为该字段类型的默认值。
-output_filename:定义生成的文件名称。
-pkg:对包内指定有`//easyjson:json`结构体生成对应的easyjson配置。
-snke_case:可以下划线的field如`Name_Student`改为`name_student`。

使用

记得在需要使用easyjson的结构体上加上//easyjson:json。 如下:

//easyjson:json
type School struct {
	Name string		`json:"name"`
	Addr string		`json:"addr"`
}

//easyjson:json
type Student struct {
	Id       int       `json:"id"`
	Name     string    `json:"s_name"`
	School   School    `json:"s_chool"`
	Birthday time.Time `json:"birthday"`
}

在结构体包下执行

easyjson  -all student.go

此时在该目录下出现一个新的文件。

// Code generated by easyjson for marshaling/unmarshaling. DO NOT EDIT.

package easyjson

import (
	json "encoding/json"
	easyjson "github.com/mailru/easyjson"
	jlexer "github.com/mailru/easyjson/jlexer"
	jwriter "github.com/mailru/easyjson/jwriter"
)

// suppress unused package warning
var (
	_ *json.RawMessage
	_ *jlexer.Lexer
	_ *jwriter.Writer
	_ easyjson.Marshaler
)

func easyjsonB83d7b77DecodeStudygoEasyjson(in *jlexer.Lexer, out *Student) {
	isTopLevel := in.IsStart()
	if in.IsNull() {
		if isTopLevel {
			in.Consumed()
		}
		in.Skip()
		return
	}
	in.Delim('{')
	for !in.IsDelim('}') {
		key := in.UnsafeString()
		in.WantColon()
		if in.IsNull() {
			in.Skip()
			in.WantComma()
			continue
		}
		switch key {
		case "id":
			out.Id = int(in.Int())
		case "s_name":
			out.Name = string(in.String())
		case "s_chool":
			easyjsonB83d7b77DecodeStudygoEasyjson1(in, &out.School)
		case "birthday":
			if data := in.Raw(); in.Ok() {
				in.AddError((out.Birthday).UnmarshalJSON(data))
			}
		default:
			in.SkipRecursive()
		}
		in.WantComma()
	}
	in.Delim('}')
	if isTopLevel {
		in.Consumed()
	}
}
func easyjsonB83d7b77EncodeStudygoEasyjson(out *jwriter.Writer, in Student) {
	out.RawByte('{')
	first := true
	_ = first
	if !first {
		out.RawByte(',')
	}
	first = false
	out.RawString("\"id\":")
	out.Int(int(in.Id))
	if !first {
		out.RawByte(',')
	}
	first = false
	out.RawString("\"s_name\":")
	out.String(string(in.Name))
	if !first {
		out.RawByte(',')
	}
	first = false
	out.RawString("\"s_chool\":")
	easyjsonB83d7b77EncodeStudygoEasyjson1(out, in.School)
	if !first {
		out.RawByte(',')
	}
	first = false
	out.RawString("\"birthday\":")
	out.Raw((in.Birthday).MarshalJSON())
	out.RawByte('}')
}

// MarshalJSON supports json.Marshaler interface
func (v Student) MarshalJSON() ([]byte, error) {
	w := jwriter.Writer{}
	easyjsonB83d7b77EncodeStudygoEasyjson(&w, v)
	return w.Buffer.BuildBytes(), w.Error
}

// MarshalEasyJSON supports easyjson.Marshaler interface
func (v Student) MarshalEasyJSON(w *jwriter.Writer) {
	easyjsonB83d7b77EncodeStudygoEasyjson(w, v)
}

// UnmarshalJSON supports json.Unmarshaler interface
func (v *Student) UnmarshalJSON(data []byte) error {
	r := jlexer.Lexer{Data: data}
	easyjsonB83d7b77DecodeStudygoEasyjson(&r, v)
	return r.Error()
}

// UnmarshalEasyJSON supports easyjson.Unmarshaler interface
func (v *Student) UnmarshalEasyJSON(l *jlexer.Lexer) {
	easyjsonB83d7b77DecodeStudygoEasyjson(l, v)
}
func easyjsonB83d7b77DecodeStudygoEasyjson1(in *jlexer.Lexer, out *School) {
	isTopLevel := in.IsStart()
	if in.IsNull() {
		if isTopLevel {
			in.Consumed()
		}
		in.Skip()
		return
	}
	in.Delim('{')
	for !in.IsDelim('}') {
		key := in.UnsafeString()
		in.WantColon()
		if in.IsNull() {
			in.Skip()
			in.WantComma()
			continue
		}
		switch key {
		case "name":
			out.Name = string(in.String())
		case "addr":
			out.Addr = string(in.String())
		default:
			in.SkipRecursive()
		}
		in.WantComma()
	}
	in.Delim('}')
	if isTopLevel {
		in.Consumed()
	}
}
func easyjsonB83d7b77EncodeStudygoEasyjson1(out *jwriter.Writer, in School) {
	out.RawByte('{')
	first := true
	_ = first
	if !first {
		out.RawByte(',')
	}
	first = false
	out.RawString("\"name\":")
	out.String(string(in.Name))
	if !first {
		out.RawByte(',')
	}
	first = false
	out.RawString("\"addr\":")
	out.String(string(in.Addr))
	out.RawByte('}')
}

现在可以写一个测试类啦。


package main

import (
    "studygo/easyjson"
    "time"
    "fmt"
)

func main(){
    s:=easyjson.Student{
        Id: 11,
        Name:"qq",
        School:easyjson.School{
            Name:"CUMT",
            Addr:"xz",
        },
        Birthday:time.Now(),
    }
    bt,err:=s.MarshalJSON()
    fmt.Println(string(bt),err)
    json:=`{"id":11,"s_name":"qq","s_chool":{"name":"CUMT","addr":"xz"},"birthday":"2017-08-04T20:58:07.9894603+08:00"}`
    ss:=easyjson.Student{}
    ss.UnmarshalJSON([]byte(json))
    fmt.Println(ss)
}

运行结果:

{"id":11,"s_name":"qq","s_chool":{"name":"CUMT","addr":"xz"},"birthday":"2017-08-04T20:58:07.9894603+08:00"} <nil>
{121  {CwwwwwwwUMT xzwwwww} 2017-08-04 20:52:03.4066002 +0800 CST}

性能测试对比

Benchmark Results

ffjson results are from February 4th, 2016, using the latest ffjson and go1.6. go/codec results are from March 4th, 2016, using the latest go/codec and go1.6.

Unmarshaling

lib json size MB/s allocs/op B/op
standard regular 22 218 10229
standard small 9.7 14 720
easyjson regular 125 128 9794
easyjson small 67 3 128
ffjson regular 66 141 9985
ffjson small 17.6 10 488
codec regular 55 434 19299
codec small 29 7 336
ujson regular 103 N/A N/A

Marshaling, one goroutine.

lib json size MB/s allocs/op B/op
standard regular 75 9 23256
standard small 32 3 328
standard large 80 17 1.2M
easyjson regular 213 9 10260
easyjson* regular 263 8 742
easyjson small 125 1 128
easyjson large 212 33 490k
easyjson* large 262 25 2879
ffjson regular 122 153 21340
ffjson** regular 146 152 4897
ffjson small 36 5 384
ffjson** small 64 4 128
ffjson large 134 7317 818k
ffjson** large 125 7320 827k
codec regular 80 17 33601
codec*** regular 108 9 1153
codec small 42 3 304
codec*** small 56 1 48
codec large 73 483 2.5M
codec*** large 103 451 66007
ujson regular 92 N/A N/A

* marshaling to a writer, ** using ffjson.Pool(), *** reusing output slice instead of resetting it to nil

Marshaling, concurrent.

lib json size MB/s allocs/op B/op
standard regular 252 9 23257
standard small 124 3 328
standard large 289 17 1.2M
easyjson regular 792 9 10597
easyjson* regular 1748 8 779
easyjson small 333 1 128
easyjson large 718 36 548k
easyjson* large 2134 25 4957
ffjson regular 301 153 21629
ffjson** regular 707 152 5148
ffjson small 62 5 384
ffjson** small 282 4 128
ffjson large 438 7330 1.0M
ffjson** large 131 7319 820k
codec regular 183 17 33603
codec*** regular 671 9 1157
codec small 147 3 304
codec*** small 299 1 48
codec large 190 483 2.5M
codec*** large 752 451 77574

* marshaling to a writer, ** using ffjson.Pool(), *** reusing output slice instead of resetting it to nil

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与其说是个包,不如说是一个工具
2017/08/06 19:25
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梦朝思夕博主
进入官网查看呀
2017/08/05 00:10
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性能对比数据呢?
2017/08/05 00:06
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