By default, Echo uses Go's stdlib encoding/json, which have more performant alternatives such as jsoniter, go-json, and sonic. In almost all of the cases encoding/json is sufficient, and I never needed a faster JSON encoding for my backend. But while playing with Echo, I discovered that it has support for custom JSON serialization (JSONSerializer interface), and the idea of combining sonic and go-json seemed gorgeous to me, so I created this package.

Selection of JSON library is platform dependent. If the platform supports sonic (at the time of writing sonic supports AMD64 and Linux, macOS, & Windows), then sonic is used, otherwise go-json is used.

Also note that go-json's version is 0.10.0 at the time of writing. Please consider your backend's stability before using it.

go get -u github.com/tomruk/fj4echo

import (
    "fmt"
    "github.com/tomruk/fj4echo"
    "github.com/labstack/echo/v4"
)

func main() {
    e := echo.New()
    e.JSONSerializer = fj4echo.New()

    serializerType := fj4echo.Type()
    fmt.Printf("Serializer: %s\n", serializerType.Name())

    e.Start(":8000")
}

You can programmatically check which serializer is being used with SerializerType enum (see serializer_type.go):

serializerType := fj4echo.Type()
switch serializerType {
    case fj4echo.SerializerTypeSonic:
        fmt.Println("sonic is choosen. This means that the processor is amd64")
    case fj4echo.SerializerTypeGoJSON:
        fmt.Println("go-json is choosen")
}

Serializers can be customized. Keep in mind that you might jeopardize security or cause your backend to consume more memory. Please read and gain an understanding of the settings before you change them:

• sonic
• go-json

fj4echo uses a default configuration, and you can find it and explanations of the choices behind its settings inside the DefaultConfig function (in config.go).

The default configuration was written with the following things in mind:

• fj4echo was designed for backend, not for other cases. This means:
  • Do not compromise security.
  • Try not to compromise network latency.

To use a custom configuration, use NewWithConfig function:

import (
    "fmt"
    "github.com/tomruk/fj4echo"
    "github.com/labstack/echo/v4"
)

func main() {
    e := echo.New()
    config := fj4echo.Config{
        SonicConfig: sonic.Config{
            // I want to live in a dangerous world, so I enable this.
            EscapeHTML: true,
            // Redundant, and the last thing needed on this Earth.
            SortMapKeys: true,
        },
        GoJSON: GoJSONConfig{
            EncodeOptions: []json.EncodeOptionFunc{
                // I want to live in a dangerous world, so I disable HTML escape.
                json.DisableHTMLEscape(),
            },
        },
    }
    e.JSONSerializer = fj4echo.NewWithConfig(config)

    e.Start(":8000")
}