aboutsummaryrefslogtreecommitdiff
path: root/fasthttpadaptor/adaptor.go
blob: dcd43e4431231a0ca7b801d24cba4ffe20c51064 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
// Package fasthttpadaptor provides helper functions for converting net/http
// request handlers to fasthttp request handlers.
package fasthttpadaptor

import (
	"io"
	"net/http"

	"github.com/valyala/fasthttp"
)

// NewFastHTTPHandlerFunc wraps net/http handler func to fasthttp
// request handler, so it can be passed to fasthttp server.
//
// While this function may be used for easy switching from net/http to fasthttp,
// it has the following drawbacks comparing to using manually written fasthttp
// request handler:
//
//   - A lot of useful functionality provided by fasthttp is missing
//     from net/http handler.
//   - net/http -> fasthttp handler conversion has some overhead,
//     so the returned handler will be always slower than manually written
//     fasthttp handler.
//
// So it is advisable using this function only for quick net/http -> fasthttp
// switching. Then manually convert net/http handlers to fasthttp handlers
// according to https://github.com/valyala/fasthttp#switching-from-nethttp-to-fasthttp .
func NewFastHTTPHandlerFunc(h http.HandlerFunc) fasthttp.RequestHandler {
	return NewFastHTTPHandler(h)
}

// NewFastHTTPHandler wraps net/http handler to fasthttp request handler,
// so it can be passed to fasthttp server.
//
// While this function may be used for easy switching from net/http to fasthttp,
// it has the following drawbacks comparing to using manually written fasthttp
// request handler:
//
//   - A lot of useful functionality provided by fasthttp is missing
//     from net/http handler.
//   - net/http -> fasthttp handler conversion has some overhead,
//     so the returned handler will be always slower than manually written
//     fasthttp handler.
//
// So it is advisable using this function only for quick net/http -> fasthttp
// switching. Then manually convert net/http handlers to fasthttp handlers
// according to https://github.com/valyala/fasthttp#switching-from-nethttp-to-fasthttp .
func NewFastHTTPHandler(h http.Handler) fasthttp.RequestHandler {
	return func(ctx *fasthttp.RequestCtx) {
		var r http.Request
		if err := ConvertRequest(ctx, &r, true); err != nil {
			ctx.Logger().Printf("cannot parse requestURI %q: %v", r.RequestURI, err)
			ctx.Error("Internal Server Error", fasthttp.StatusInternalServerError)
			return
		}

		w := netHTTPResponseWriter{w: ctx.Response.BodyWriter()}
		h.ServeHTTP(&w, r.WithContext(ctx))

		ctx.SetStatusCode(w.StatusCode())
		haveContentType := false
		for k, vv := range w.Header() {
			if k == fasthttp.HeaderContentType {
				haveContentType = true
			}

			for _, v := range vv {
				ctx.Response.Header.Add(k, v)
			}
		}
		if !haveContentType {
			// From net/http.ResponseWriter.Write:
			// If the Header does not contain a Content-Type line, Write adds a Content-Type set
			// to the result of passing the initial 512 bytes of written data to DetectContentType.
			l := 512
			b := ctx.Response.Body()
			if len(b) < 512 {
				l = len(b)
			}
			ctx.Response.Header.Set(fasthttp.HeaderContentType, http.DetectContentType(b[:l]))
		}
	}
}

type netHTTPResponseWriter struct {
	statusCode int
	h          http.Header
	w          io.Writer
}

func (w *netHTTPResponseWriter) StatusCode() int {
	if w.statusCode == 0 {
		return http.StatusOK
	}
	return w.statusCode
}

func (w *netHTTPResponseWriter) Header() http.Header {
	if w.h == nil {
		w.h = make(http.Header)
	}
	return w.h
}

func (w *netHTTPResponseWriter) WriteHeader(statusCode int) {
	w.statusCode = statusCode
}

func (w *netHTTPResponseWriter) Write(p []byte) (int, error) {
	return w.w.Write(p)
}

func (w *netHTTPResponseWriter) Flush() {}