wrap_generated_lt_1.8.go raw
1 // +build !go1.8
2 // Code generated by "httpsnoop/codegen"; DO NOT EDIT.
3
4 package httpsnoop
5
6 import (
7 "bufio"
8 "io"
9 "net"
10 "net/http"
11 )
12
13 // HeaderFunc is part of the http.ResponseWriter interface.
14 type HeaderFunc func() http.Header
15
16 // WriteHeaderFunc is part of the http.ResponseWriter interface.
17 type WriteHeaderFunc func(code int)
18
19 // WriteFunc is part of the http.ResponseWriter interface.
20 type WriteFunc func(b []byte) (int, error)
21
22 // FlushFunc is part of the http.Flusher interface.
23 type FlushFunc func()
24
25 // CloseNotifyFunc is part of the http.CloseNotifier interface.
26 type CloseNotifyFunc func() <-chan bool
27
28 // HijackFunc is part of the http.Hijacker interface.
29 type HijackFunc func() (net.Conn, *bufio.ReadWriter, error)
30
31 // ReadFromFunc is part of the io.ReaderFrom interface.
32 type ReadFromFunc func(src io.Reader) (int64, error)
33
34 // Hooks defines a set of method interceptors for methods included in
35 // http.ResponseWriter as well as some others. You can think of them as
36 // middleware for the function calls they target. See Wrap for more details.
37 type Hooks struct {
38 Header func(HeaderFunc) HeaderFunc
39 WriteHeader func(WriteHeaderFunc) WriteHeaderFunc
40 Write func(WriteFunc) WriteFunc
41 Flush func(FlushFunc) FlushFunc
42 CloseNotify func(CloseNotifyFunc) CloseNotifyFunc
43 Hijack func(HijackFunc) HijackFunc
44 ReadFrom func(ReadFromFunc) ReadFromFunc
45 }
46
47 // Wrap returns a wrapped version of w that provides the exact same interface
48 // as w. Specifically if w implements any combination of:
49 //
50 // - http.Flusher
51 // - http.CloseNotifier
52 // - http.Hijacker
53 // - io.ReaderFrom
54 //
55 // The wrapped version will implement the exact same combination. If no hooks
56 // are set, the wrapped version also behaves exactly as w. Hooks targeting
57 // methods not supported by w are ignored. Any other hooks will intercept the
58 // method they target and may modify the call's arguments and/or return values.
59 // The CaptureMetrics implementation serves as a working example for how the
60 // hooks can be used.
61 func Wrap(w http.ResponseWriter, hooks Hooks) http.ResponseWriter {
62 rw := &rw{w: w, h: hooks}
63 _, i0 := w.(http.Flusher)
64 _, i1 := w.(http.CloseNotifier)
65 _, i2 := w.(http.Hijacker)
66 _, i3 := w.(io.ReaderFrom)
67 switch {
68 // combination 1/16
69 case !i0 && !i1 && !i2 && !i3:
70 return struct {
71 Unwrapper
72 http.ResponseWriter
73 }{rw, rw}
74 // combination 2/16
75 case !i0 && !i1 && !i2 && i3:
76 return struct {
77 Unwrapper
78 http.ResponseWriter
79 io.ReaderFrom
80 }{rw, rw, rw}
81 // combination 3/16
82 case !i0 && !i1 && i2 && !i3:
83 return struct {
84 Unwrapper
85 http.ResponseWriter
86 http.Hijacker
87 }{rw, rw, rw}
88 // combination 4/16
89 case !i0 && !i1 && i2 && i3:
90 return struct {
91 Unwrapper
92 http.ResponseWriter
93 http.Hijacker
94 io.ReaderFrom
95 }{rw, rw, rw, rw}
96 // combination 5/16
97 case !i0 && i1 && !i2 && !i3:
98 return struct {
99 Unwrapper
100 http.ResponseWriter
101 http.CloseNotifier
102 }{rw, rw, rw}
103 // combination 6/16
104 case !i0 && i1 && !i2 && i3:
105 return struct {
106 Unwrapper
107 http.ResponseWriter
108 http.CloseNotifier
109 io.ReaderFrom
110 }{rw, rw, rw, rw}
111 // combination 7/16
112 case !i0 && i1 && i2 && !i3:
113 return struct {
114 Unwrapper
115 http.ResponseWriter
116 http.CloseNotifier
117 http.Hijacker
118 }{rw, rw, rw, rw}
119 // combination 8/16
120 case !i0 && i1 && i2 && i3:
121 return struct {
122 Unwrapper
123 http.ResponseWriter
124 http.CloseNotifier
125 http.Hijacker
126 io.ReaderFrom
127 }{rw, rw, rw, rw, rw}
128 // combination 9/16
129 case i0 && !i1 && !i2 && !i3:
130 return struct {
131 Unwrapper
132 http.ResponseWriter
133 http.Flusher
134 }{rw, rw, rw}
135 // combination 10/16
136 case i0 && !i1 && !i2 && i3:
137 return struct {
138 Unwrapper
139 http.ResponseWriter
140 http.Flusher
141 io.ReaderFrom
142 }{rw, rw, rw, rw}
143 // combination 11/16
144 case i0 && !i1 && i2 && !i3:
145 return struct {
146 Unwrapper
147 http.ResponseWriter
148 http.Flusher
149 http.Hijacker
150 }{rw, rw, rw, rw}
151 // combination 12/16
152 case i0 && !i1 && i2 && i3:
153 return struct {
154 Unwrapper
155 http.ResponseWriter
156 http.Flusher
157 http.Hijacker
158 io.ReaderFrom
159 }{rw, rw, rw, rw, rw}
160 // combination 13/16
161 case i0 && i1 && !i2 && !i3:
162 return struct {
163 Unwrapper
164 http.ResponseWriter
165 http.Flusher
166 http.CloseNotifier
167 }{rw, rw, rw, rw}
168 // combination 14/16
169 case i0 && i1 && !i2 && i3:
170 return struct {
171 Unwrapper
172 http.ResponseWriter
173 http.Flusher
174 http.CloseNotifier
175 io.ReaderFrom
176 }{rw, rw, rw, rw, rw}
177 // combination 15/16
178 case i0 && i1 && i2 && !i3:
179 return struct {
180 Unwrapper
181 http.ResponseWriter
182 http.Flusher
183 http.CloseNotifier
184 http.Hijacker
185 }{rw, rw, rw, rw, rw}
186 // combination 16/16
187 case i0 && i1 && i2 && i3:
188 return struct {
189 Unwrapper
190 http.ResponseWriter
191 http.Flusher
192 http.CloseNotifier
193 http.Hijacker
194 io.ReaderFrom
195 }{rw, rw, rw, rw, rw, rw}
196 }
197 panic("unreachable")
198 }
199
200 type rw struct {
201 w http.ResponseWriter
202 h Hooks
203 }
204
205 func (w *rw) Unwrap() http.ResponseWriter {
206 return w.w
207 }
208
209 func (w *rw) Header() http.Header {
210 f := w.w.(http.ResponseWriter).Header
211 if w.h.Header != nil {
212 f = w.h.Header(f)
213 }
214 return f()
215 }
216
217 func (w *rw) WriteHeader(code int) {
218 f := w.w.(http.ResponseWriter).WriteHeader
219 if w.h.WriteHeader != nil {
220 f = w.h.WriteHeader(f)
221 }
222 f(code)
223 }
224
225 func (w *rw) Write(b []byte) (int, error) {
226 f := w.w.(http.ResponseWriter).Write
227 if w.h.Write != nil {
228 f = w.h.Write(f)
229 }
230 return f(b)
231 }
232
233 func (w *rw) Flush() {
234 f := w.w.(http.Flusher).Flush
235 if w.h.Flush != nil {
236 f = w.h.Flush(f)
237 }
238 f()
239 }
240
241 func (w *rw) CloseNotify() <-chan bool {
242 f := w.w.(http.CloseNotifier).CloseNotify
243 if w.h.CloseNotify != nil {
244 f = w.h.CloseNotify(f)
245 }
246 return f()
247 }
248
249 func (w *rw) Hijack() (net.Conn, *bufio.ReadWriter, error) {
250 f := w.w.(http.Hijacker).Hijack
251 if w.h.Hijack != nil {
252 f = w.h.Hijack(f)
253 }
254 return f()
255 }
256
257 func (w *rw) ReadFrom(src io.Reader) (int64, error) {
258 f := w.w.(io.ReaderFrom).ReadFrom
259 if w.h.ReadFrom != nil {
260 f = w.h.ReadFrom(f)
261 }
262 return f(src)
263 }
264
265 type Unwrapper interface {
266 Unwrap() http.ResponseWriter
267 }
268
269 // Unwrap returns the underlying http.ResponseWriter from within zero or more
270 // layers of httpsnoop wrappers.
271 func Unwrap(w http.ResponseWriter) http.ResponseWriter {
272 if rw, ok := w.(Unwrapper); ok {
273 // recurse until rw.Unwrap() returns a non-Unwrapper
274 return Unwrap(rw.Unwrap())
275 } else {
276 return w
277 }
278 }
279