GZIP gin's middleware

Gin middleware to enable GZIP support.

Usage

Download and install it:

go get github.com/gin-contrib/gzip

Import it in your code:

import "github.com/gin-contrib/gzip"

Canonical example:

package main

import (
  "fmt"
  "net/http"
  "time"

  "github.com/gin-contrib/gzip"
  "github.com/gin-gonic/gin"
)

func main() {
  r := gin.Default()
  r.Use(gzip.Gzip(gzip.DefaultCompression))
  r.GET("/ping", func(c *gin.Context) {
    c.String(http.StatusOK, "pong "+fmt.Sprint(time.Now().Unix()))
  })

  // Listen and Server in 0.0.0.0:8080
  if err := r.Run(":8080"); err != nil {
    log.Fatal(err)
  }
}

Compress only when response meets minimum byte size

package main

import (
	"log"
	"net/http"
	"strconv"
	"strings"

	"github.com/gin-contrib/gzip"
	"github.com/gin-gonic/gin"
)

func main() {
	r := gin.Default()
	r.Use(gzip.Gzip(gzip.DefaultCompression, gzip.WithMinLength(2048)))
	r.GET("/ping", func(c *gin.Context) {
		sizeStr := c.Query("size")
		size, _ := strconv.Atoi(sizeStr)
		c.String(http.StatusOK, strings.Repeat("a", size))
	})

	// Listen and Server in 0.0.0.0:8080
	if err := r.Run(":8080"); err != nil {
		log.Fatal(err)
	}
}

Test with curl:

curl -i --compressed 'http://localhost:8080/ping?size=2047'
curl -i --compressed 'http://localhost:8080/ping?size=2048'

Notes:

• If a "Content-Length" header is set, that will be used to determine whether to compress based on the given min length.
• If no "Content-Length" header is set, a buffer is used to temporarily store writes until the min length is met or the request completes.
  • Setting a high min length will result in more buffering (2048 bytes is a recommended default for most cases)
  • The handler performs optimizations to avoid unnecessary operations, such as testing if len(data) exceeds min length before writing to the buffer, and reusing buffers between requests.

Customized Excluded Extensions

package main

import (
  "fmt"
  "net/http"
  "time"

  "github.com/gin-contrib/gzip"
  "github.com/gin-gonic/gin"
)

func main() {
  r := gin.Default()
  r.Use(gzip.Gzip(gzip.DefaultCompression, gzip.WithExcludedExtensions([]string{".pdf", ".mp4"})))
  r.GET("/ping", func(c *gin.Context) {
    c.String(http.StatusOK, "pong "+fmt.Sprint(time.Now().Unix()))
  })

  // Listen and Server in 0.0.0.0:8080
  if err := r.Run(":8080"); err != nil {
    log.Fatal(err)
  }
}

Customized Excluded Paths

package main

import (
  "fmt"
  "net/http"
  "time"

  "github.com/gin-contrib/gzip"
  "github.com/gin-gonic/gin"
)

func main() {
  r := gin.Default()
  r.Use(gzip.Gzip(gzip.DefaultCompression, gzip.WithExcludedPaths([]string{"/api/"})))
  r.GET("/ping", func(c *gin.Context) {
    c.String(http.StatusOK, "pong "+fmt.Sprint(time.Now().Unix()))
  })

  // Listen and Server in 0.0.0.0:8080
  if err := r.Run(":8080"); err != nil {
    log.Fatal(err)
  }
}

Customized Excluded Paths with Regex

package main

import (
  "fmt"
  "net/http"
  "time"

  "github.com/gin-contrib/gzip"
  "github.com/gin-gonic/gin"
)

func main() {
  r := gin.Default()
  r.Use(gzip.Gzip(gzip.DefaultCompression, gzip.WithExcludedPathsRegexs([]string{".*"})))
  r.GET("/ping", func(c *gin.Context) {
    c.String(http.StatusOK, "pong "+fmt.Sprint(time.Now().Unix()))
  })

  // Listen and Server in 0.0.0.0:8080
  if err := r.Run(":8080"); err != nil {
    log.Fatal(err)
  }
}

Server Push

package main

import (
  "fmt"
  "log"
  "net/http"
  "time"

  "github.com/gin-contrib/gzip"
  "github.com/gin-gonic/gin"
)

func main() {
  r := gin.Default()
  r.Use(gzip.Gzip(gzip.DefaultCompression))
  r.GET("/stream", func(c *gin.Context) {
    c.Header("Content-Type", "text/event-stream")
    c.Header("Connection", "keep-alive")
    for i := 0; i < 10; i++ {
      fmt.Fprintf(c.Writer, "id: %d\ndata: tick %d\n\n", i, time.Now().Unix())
      c.Writer.Flush()
      time.Sleep(1 * time.Second)
    }
  })

  // Listen and Server in 0.0.0.0:8080
  if err := r.Run(":8080"); err != nil {
    log.Fatal(err)
  }
}