-
Notifications
You must be signed in to change notification settings - Fork 4
/
writer_proxy.go
83 lines (74 loc) · 1.72 KB
/
writer_proxy.go
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
package middleware
import (
"bufio"
"io"
"net"
"net/http"
)
func wrapWriter(w http.ResponseWriter) writerProxy {
_, cn := w.(http.CloseNotifier)
_, fl := w.(http.Flusher)
_, hj := w.(http.Hijacker)
_, rf := w.(io.ReaderFrom)
bw := basicWriter{ResponseWriter: w}
if cn && fl && hj && rf {
return &fancyWriter{bw}
}
return &bw
}
type writerProxy interface {
http.ResponseWriter
maybeWriteHeader()
status() int
}
type basicWriter struct {
http.ResponseWriter
wroteHeader bool
code int
}
func (b *basicWriter) WriteHeader(code int) {
if !b.wroteHeader {
b.code = code
b.wroteHeader = true
b.ResponseWriter.WriteHeader(code)
}
}
func (b *basicWriter) Write(buf []byte) (int, error) {
b.maybeWriteHeader()
return b.ResponseWriter.Write(buf)
}
func (b *basicWriter) maybeWriteHeader() {
if !b.wroteHeader {
b.WriteHeader(http.StatusOK)
}
}
func (b *basicWriter) status() int {
return b.code
}
func (b *basicWriter) Unwrap() http.ResponseWriter {
return b.ResponseWriter
}
type fancyWriter struct {
basicWriter
}
func (f *fancyWriter) CloseNotify() <-chan bool {
cn := f.basicWriter.ResponseWriter.(http.CloseNotifier)
return cn.CloseNotify()
}
func (f *fancyWriter) Flush() {
fl := f.basicWriter.ResponseWriter.(http.Flusher)
fl.Flush()
}
func (f *fancyWriter) Hijack() (net.Conn, *bufio.ReadWriter, error) {
hj := f.basicWriter.ResponseWriter.(http.Hijacker)
return hj.Hijack()
}
func (f *fancyWriter) ReadFrom(r io.Reader) (int64, error) {
rf := f.basicWriter.ResponseWriter.(io.ReaderFrom)
f.basicWriter.maybeWriteHeader()
return rf.ReadFrom(r)
}
var _ http.CloseNotifier = &fancyWriter{}
var _ http.Flusher = &fancyWriter{}
var _ http.Hijacker = &fancyWriter{}
var _ io.ReaderFrom = &fancyWriter{}