69 lines
1.2 KiB
Go
69 lines
1.2 KiB
Go
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package gzip
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import (
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"compress/gzip"
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"net/http"
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"path/filepath"
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"strings"
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"github.com/gin-gonic/gin"
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)
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const (
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BestCompression = gzip.BestCompression
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BestSpeed = gzip.BestSpeed
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DefaultCompression = gzip.DefaultCompression
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NoCompression = gzip.NoCompression
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)
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func Gzip(level int) gin.HandlerFunc {
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return func(c *gin.Context) {
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if !shouldCompress(c.Request) {
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return
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}
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gz, err := gzip.NewWriterLevel(c.Writer, level)
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if err != nil {
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return
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}
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c.Header("Content-Encoding", "gzip")
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c.Header("Vary", "Accept-Encoding")
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c.Writer = &gzipWriter{c.Writer, gz}
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defer func() {
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c.Header("Content-Length", "0")
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gz.Close()
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}()
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c.Next()
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}
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}
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type gzipWriter struct {
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gin.ResponseWriter
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writer *gzip.Writer
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}
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func (g *gzipWriter) WriteString(s string) (int, error) {
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return g.writer.Write([]byte(s))
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}
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func (g *gzipWriter) Write(data []byte) (int, error) {
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return g.writer.Write(data)
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}
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func shouldCompress(req *http.Request) bool {
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if !strings.Contains(req.Header.Get("Accept-Encoding"), "gzip") {
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return false
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}
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extension := filepath.Ext(req.URL.Path)
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if len(extension) < 4 { // fast path
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return true
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}
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switch extension {
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case ".png", ".gif", ".jpeg", ".jpg":
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return false
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default:
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return true
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}
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}
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