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mirror of https://github.com/labstack/echo.git synced 2024-12-22 20:06:21 +02:00
echo/middleware/compress.go
Alex Ungur 6d9e043284 Introduced Go module support as v4, removed obsolete CloseNotifier() mechanism
This reintroduces support for Go modules, as v4.

CloseNotifier() is removed as it has been obsoleted, see https://golang.org/doc/go1.11#net/http

It was already NOT working (not sending signals) as of 1.11 the functionality was gone, we merely
deleted the functions that exposed it. If anyone still relies on it they should migrate to using
`c.Request().Context().Done()` instead.

Closes #1268, #1255
2019-01-30 16:11:42 +02:00

119 lines
2.7 KiB
Go

package middleware
import (
"bufio"
"compress/gzip"
"io"
"io/ioutil"
"net"
"net/http"
"strings"
"github.com/labstack/echo/v4"
)
type (
// GzipConfig defines the config for Gzip middleware.
GzipConfig struct {
// Skipper defines a function to skip middleware.
Skipper Skipper
// Gzip compression level.
// Optional. Default value -1.
Level int `yaml:"level"`
}
gzipResponseWriter struct {
io.Writer
http.ResponseWriter
}
)
const (
gzipScheme = "gzip"
)
var (
// DefaultGzipConfig is the default Gzip middleware config.
DefaultGzipConfig = GzipConfig{
Skipper: DefaultSkipper,
Level: -1,
}
)
// Gzip returns a middleware which compresses HTTP response using gzip compression
// scheme.
func Gzip() echo.MiddlewareFunc {
return GzipWithConfig(DefaultGzipConfig)
}
// GzipWithConfig return Gzip middleware with config.
// See: `Gzip()`.
func GzipWithConfig(config GzipConfig) echo.MiddlewareFunc {
// Defaults
if config.Skipper == nil {
config.Skipper = DefaultGzipConfig.Skipper
}
if config.Level == 0 {
config.Level = DefaultGzipConfig.Level
}
return func(next echo.HandlerFunc) echo.HandlerFunc {
return func(c echo.Context) error {
if config.Skipper(c) {
return next(c)
}
res := c.Response()
res.Header().Add(echo.HeaderVary, echo.HeaderAcceptEncoding)
if strings.Contains(c.Request().Header.Get(echo.HeaderAcceptEncoding), gzipScheme) {
res.Header().Set(echo.HeaderContentEncoding, gzipScheme) // Issue #806
rw := res.Writer
w, err := gzip.NewWriterLevel(rw, config.Level)
if err != nil {
return err
}
defer func() {
if res.Size == 0 {
if res.Header().Get(echo.HeaderContentEncoding) == gzipScheme {
res.Header().Del(echo.HeaderContentEncoding)
}
// We have to reset response to it's pristine state when
// nothing is written to body or error is returned.
// See issue #424, #407.
res.Writer = rw
w.Reset(ioutil.Discard)
}
w.Close()
}()
grw := &gzipResponseWriter{Writer: w, ResponseWriter: rw}
res.Writer = grw
}
return next(c)
}
}
}
func (w *gzipResponseWriter) WriteHeader(code int) {
if code == http.StatusNoContent { // Issue #489
w.ResponseWriter.Header().Del(echo.HeaderContentEncoding)
}
w.Header().Del(echo.HeaderContentLength) // Issue #444
w.ResponseWriter.WriteHeader(code)
}
func (w *gzipResponseWriter) Write(b []byte) (int, error) {
if w.Header().Get(echo.HeaderContentType) == "" {
w.Header().Set(echo.HeaderContentType, http.DetectContentType(b))
}
return w.Writer.Write(b)
}
func (w *gzipResponseWriter) Flush() {
w.Writer.(*gzip.Writer).Flush()
}
func (w *gzipResponseWriter) Hijack() (net.Conn, *bufio.ReadWriter, error) {
return w.ResponseWriter.(http.Hijacker).Hijack()
}