use encode replace json marshal increase json encoder speed

[itcloudy]

func WriteJSON(w http.ResponseWriter, obj interface{}) error {
	writeContentType(w, jsonContentType)
	jsonBytes, err := json.Marshal(obj)
	if err != nil {
		return err
	}
	w.Write(jsonBytes)
	return nil
}

func WriteJSON(w http.ResponseWriter, obj interface{}) error {
	writeContentType(w, jsonContentType)
	encoder := json.NewEncoder(w)
	err := encoder.Encode(&obj)
	if err != nil {
		return err
	}
	return nil
}

[thinkerou]

@itcloudy please fix unit test error, and can you give one link or doc about compare encode with marshal? thanks!

[chainhelen]

Marshal => String
Encode => Stream

go doc Encoder.Encode

[appleboy]

@itcloudy build fail

[codecov]

Codecov Report

Merging #1546 into master will decrease coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #1546      +/-   ##
==========================================
- Coverage   98.74%   98.74%   -0.01%     
==========================================
  Files          38       38              
  Lines        2145     2143       -2     
==========================================
- Hits         2118     2116       -2     
  Misses         15       15              
  Partials       12       12

Impacted Files	Coverage Δ
render/json.go	87.34% <100%> (-0.32%)	⬇️

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[lpa]

Hello, I'm sticking to Gin master revision since last week (to benefit from a dependency issue fix in master using gin + zerolog) and I agree more speed is good, but ... am I the only one shocked to have to cope with the additionnal "\n" that the use of Encode introduce or did I miss a way to remove it ? I mean it's the first time I see a framework forcing additional "\n" at the end of any JSON body data in responses (not that I've used many though ;) ) if we follow the documentation examples. I could use c.indentedJSON of c.asciiJSON but I don't want extra features, just plain JSON as I had before with c.JSON

[ghost]

This felt like an early Xmas present. Between the disappearance of the gin/json package and a surprise newline character in my JSON payloads I really don't know which is more exciting.

But seriously breaking changes on this project need to be much better controlled especially in minor revisions.

[jpninanjohn]

How does using encoder increase speed? If I follow the code of encode, it calls marshal() which is the same as what Marshal calls. Am I missing something here?
The only difference is that encode converts from/to a stream where as marshal converts from/to a string.

[AlexanderYastrebov]

How does using encoder increase speed? If I follow the code of encode, it calls marshal() which is the same as what Marshal calls. Am I missing something here?

Marshal creates a copy https://cs.opensource.google/go/go/+/refs/tags/go1.22.0:src/encoding/json/encode.go;l=167
while Encode writes internal buffer Bytes() https://cs.opensource.google/go/go/+/refs/tags/go1.22.0:src/encoding/json/stream.go;l=222 to the writer