Repository navigation
Expand file tree
/
Copy pathcontext.go
More file actions
568 lines (498 loc) · 16.2 KB
/
Copy pathcontext.go
File metadata and controls
568 lines (498 loc) · 16.2 KB
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
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
// Copyright 2014 Manu Martinez-Almeida. All rights reserved.
// Use of this source code is governed by a MIT style
// license that can be found in the LICENSE file.
package gin
import (
"errors"
"io"
"math"
"net"
"net/http"
"net/url"
"strings"
"time"
"github.com/gin-gonic/gin/binding"
"github.com/gin-gonic/gin/render"
"github.com/manucorporat/sse"
"golang.org/x/net/context"
)
// Content-Type MIME of the most common data formats
const (
MIMEJSON = binding.MIMEJSON
MIMEHTML = binding.MIMEHTML
MIMEXML = binding.MIMEXML
MIMEXML2 = binding.MIMEXML2
MIMEPlain = binding.MIMEPlain
MIMEPOSTForm = binding.MIMEPOSTForm
MIMEMultipartPOSTForm = binding.MIMEMultipartPOSTForm
)
const abortIndex int8 = math.MaxInt8 / 2
// Context is the most important part of gin. It allows us to pass variables between middleware,
// manage the flow, validate the JSON of a request and render a JSON response for example.
type Context struct {
writermem responseWriter
Request *http.Request
Writer ResponseWriter
Params Params
handlers HandlersChain
index int8
engine *Engine
Keys map[string]interface{}
Errors errorMsgs
Accepted []string
}
var _ context.Context = &Context{}
/************************************/
/********** CONTEXT CREATION ********/
/************************************/
func (c *Context) reset() {
c.Writer = &c.writermem
c.Params = c.Params[0:0]
c.handlers = nil
c.index = -1
c.Keys = nil
c.Errors = c.Errors[0:0]
c.Accepted = nil
}
// Copy returns a copy of the current context that can be safely used outside the request's scope.
// This have to be used then the context has to be passed to a goroutine.
func (c *Context) Copy() *Context {
var cp = *c
cp.writermem.ResponseWriter = nil
cp.Writer = &cp.writermem
cp.index = abortIndex
cp.handlers = nil
return &cp
}
// HandlerName returns the main handler's name. For example if the handler is "handleGetUsers()", this
// function will return "main.handleGetUsers"
func (c *Context) HandlerName() string {
return nameOfFunction(c.handlers.Last())
}
/************************************/
/*********** FLOW CONTROL ***********/
/************************************/
// Next should be used only inside middleware.
// It executes the pending handlers in the chain inside the calling handler.
// See example in github.
func (c *Context) Next() {
c.index++
s := int8(len(c.handlers))
for ; c.index < s; c.index++ {
c.handlers[c.index](c)
}
}
// IsAborted returns true if the current context was aborted.
func (c *Context) IsAborted() bool {
return c.index >= abortIndex
}
// Abort prevents pending handlers from being called. Note that this will not stop the current handler.
// Let's say you have an authorization middleware that validates that the current request is authorized. If the
// authorization fails (ex: the password does not match), call Abort to ensure the remaining handlers
// for this request are not called.
func (c *Context) Abort() {
c.index = abortIndex
}
// AbortWithStatus calls `Abort()` and writes the headers with the specified status code.
// For example, a failed attempt to authentificate a request could use: context.AbortWithStatus(401).
func (c *Context) AbortWithStatus(code int) {
c.Status(code)
c.Writer.WriteHeaderNow()
c.Abort()
}
// AbortWithError calls `AbortWithStatus()` and `Error()` internally. This method stops the chain, writes the status code and
// pushes the specified error to `c.Errors`.
// See Context.Error() for more details.
func (c *Context) AbortWithError(code int, err error) *Error {
c.AbortWithStatus(code)
return c.Error(err)
}
/************************************/
/********* ERROR MANAGEMENT *********/
/************************************/
// Attaches an error to the current context. The error is pushed to a list of errors.
// It's a good idea to call Error for each error that occurred during the resolution of a request.
// A middleware can be used to collect all the errors
// and push them to a database together, print a log, or append it in the HTTP response.
func (c *Context) Error(err error) *Error {
var parsedError *Error
switch err.(type) {
case *Error:
parsedError = err.(*Error)
default:
parsedError = &Error{
Err: err,
Type: ErrorTypePrivate,
}
}
c.Errors = append(c.Errors, parsedError)
return parsedError
}
/************************************/
/******** METADATA MANAGEMENT********/
/************************************/
// Set is used to store a new key/value pair exclusivelly for this context.
// It also lazy initializes c.Keys if it was not used previously.
func (c *Context) Set(key string, value interface{}) {
if c.Keys == nil {
c.Keys = make(map[string]interface{})
}
c.Keys[key] = value
}
// Get returns the value for the given key, ie: (value, true).
// If the value does not exists it returns (nil, false)
func (c *Context) Get(key string) (value interface{}, exists bool) {
if c.Keys != nil {
value, exists = c.Keys[key]
}
return
}
// MustGet returns the value for the given key if it exists, otherwise it panics.
func (c *Context) MustGet(key string) interface{} {
if value, exists := c.Get(key); exists {
return value
}
panic("Key \"" + key + "\" does not exist")
}
/************************************/
/************ INPUT DATA ************/
/************************************/
// Param returns the value of the URL param.
// It is a shortcut for c.Params.ByName(key)
// router.GET("/user/:id", func(c *gin.Context) {
// // a GET request to /user/john
// id := c.Param("id") // id == "john"
// })
func (c *Context) Param(key string) string {
return c.Params.ByName(key)
}
// Query returns the keyed url query value if it exists,
// othewise it returns an empty string `("")`.
// It is shortcut for `c.Request.URL.Query().Get(key)`
// GET /path?id=1234&name=Manu&value=
// c.Query("id") == "1234"
// c.Query("name") == "Manu"
// c.Query("value") == ""
// c.Query("wtf") == ""
func (c *Context) Query(key string) string {
value, _ := c.GetQuery(key)
return value
}
// DefaultQuery returns the keyed url query value if it exists,
// othewise it returns the specified defaultValue string.
// See: Query() and GetQuery() for further information.
// GET /?name=Manu&lastname=
// c.DefaultQuery("name", "unknown") == "Manu"
// c.DefaultQuery("id", "none") == "none"
// c.DefaultQuery("lastname", "none") == ""
func (c *Context) DefaultQuery(key, defaultValue string) string {
if value, ok := c.GetQuery(key); ok {
return value
}
return defaultValue
}
// GetQuery is like Query(), it returns the keyed url query value
// if it exists `(value, true)` (even when the value is an empty string),
// othewise it returns `("", false)`.
// It is shortcut for `c.Request.URL.Query().Get(key)`
// GET /?name=Manu&lastname=
// ("Manu", true) == c.GetQuery("name")
// ("", false) == c.GetQuery("id")
// ("", true) == c.GetQuery("lastname")
func (c *Context) GetQuery(key string) (string, bool) {
req := c.Request
if values, ok := req.URL.Query()[key]; ok &&
10BC8
; len(values) > 0 {
return values[0], true
}
return "", false
}
// PostForm returns the specified key from a POST urlencoded form or multipart form
// when it exists, otherwise it returns an empty string `("")`.
func (c *Context) PostForm(key string) string {
value, _ := c.GetPostForm(key)
return value
}
// DefaultPostForm returns the specified key from a POST urlencoded form or multipart form
// when it exists, otherwise it returns the specified defaultValue string.
// See: PostForm() and GetPostForm() for further information.
func (c *Context) DefaultPostForm(key, defaultValue string) string {
if value, ok := c.GetPostForm(key); ok {
return value
}
return defaultValue
}
// GetPostForm is like PostForm(key). It returns the specified key from a POST urlencoded
// form or multipart form when it exists `(value, true)` (even when the value is an empty string),
// otherwise it returns ("", false).
// For example, during a PATCH request to update the user's email:
// email=mail@example.com --> ("mail@example.com", true) := GetPostForm("email") // set email to "mail@example.com"
// email= --> ("", true) := GetPostForm("email") // set email to ""
// --> ("", false) := GetPostForm("email") // do nothing with email
func (c *Context) GetPostForm(key string) (string, bool) {
req := c.Request
req.ParseMultipartForm(32 << 20) // 32 MB
if values := req.PostForm[key]; len(values) > 0 {
return values[0], true
}
if req.MultipartForm != nil && req.MultipartForm.File != nil {
if values := req.MultipartForm.Value[key]; len(values) > 0 {
return values[0], true
}
}
return "", false
}
// Bind checks the Content-Type to select a binding engine automatically,
// Depending the "Content-Type" header different bindings are used:
// "application/json" --> JSON binding
// "application/xml" --> XML binding
// otherwise --> returns an error
// It parses the request's body as JSON if Content-Type == "application/json" using JSON or XML as a JSON input.
// It decodes the json payload into the struct specified as a pointer.
// Like ParseBody() but this method also writes a 400 error if the json is not valid.
func (c *Context) Bind(obj interface{}) error {
b := binding.Default(c.Request.Method, c.ContentType())
return c.BindWith(obj, b)
}
// BindJSON is a shortcut for c.BindWith(obj, binding.JSON)
func (c *Context) BindJSON(obj interface{}) error {
return c.BindWith(obj, binding.JSON)
}
// BindWith binds the passed struct pointer using the specified binding engine.
// See the binding package.
func (c *Context) BindWith(obj interface{}, b binding.Binding) error {
if err := b.Bind(c.Request, obj); err != nil {
c.AbortWithError(400, err).SetType(ErrorTypeBind)
return err
}
return nil
}
// ClientIP implements a best effort algorithm to return the real client IP, it parses
// X-Real-IP and X-Forwarded-For in order to work properly with reverse-proxies such us: nginx or haproxy.
func (c *Context) ClientIP() string {
if c.engine.ForwardedByClientIP {
clientIP := strings.TrimSpace(c.requestHeader("X-Real-Ip"))
if len(clientIP) > 0 {
return clientIP
}
clientIP = c.requestHeader("X-Forwarded-For")
if index := strings.IndexByte(clientIP, ','); index >= 0 {
clientIP = clientIP[0:index]
}
clientIP = strings.TrimSpace(clientIP)
if len(clientIP) > 0 {
return clientIP
}
}
if ip, _, err := net.SplitHostPort(strings.TrimSpace(c.Request.RemoteAddr)); err == nil {
return ip
}
return ""
}
// ContentType returns the Content-Type header of the request.
func (c *Context) ContentType() string {
return filterFlags(c.requestHeader("Content-Type"))
}
func (c *Context) requestHeader(key string) string {
if values, _ := c.Request.Header[key]; len(values) > 0 {
return values[0]
}
return ""
}
/************************************/
/******** RESPONSE RENDERING ********/
/************************************/
func (c *Context) Status(code int) {
c.writermem.WriteHeader(code)
}
// Header is a intelligent shortcut for c.Writer.Header().Set(key, value)
// It writes a header in the response.
// If value == "", this method removes the header `c.Writer.Header().Del(key)`
func (c *Context) Header(key, value string) {
if len(value) == 0 {
c.Writer.Header().Del(key)
} else {
c.Writer.Header().Set(key, value)
}
}
func (c *Context) SetCookie(
name string,
value string,
maxAge int,
path string,
domain string,
secure bool,
httpOnly bool,
) {
if path == "" {
path = "/"
}
http.SetCookie(c.Writer, &http.Cookie{
Name: name,
Value: url.QueryEscape(value),
MaxAge: maxAge,
Path: path,
Domain: domain,
Secure: secure,
HttpOnly: httpOnly,
})
}
func (c *Context) Cookie(name string) (string, error) {
cookie, err := c.Request.Cookie(name)
if err != nil {
return "", err
}
val, _ := url.QueryUnescape(cookie.Value)
return val, nil
}
func (c *Context) Render(code int, r render.Render) {
c.Status(code)
if err := r.Render(c.Writer); err != nil {
panic(err)
}
}
// HTML renders the HTTP template specified by its file name.
// It also updates the HTTP code and sets the Content-Type as "text/html".
// See http://golang.org/doc/articles/wiki/
func (c *Context) HTML(code int, name string, obj interface{}) {
instance := c.engine.HTMLRender.Instance(name, obj)
c.Render(code, instance)
}
// IndentedJSON serializes the given struct as pretty JSON (indented + endlines) into the response body.
// It also sets the Content-Type as "application/json".
// WARNING: we recommend to use this only for development propuses since printing pretty JSON is
// more CPU and bandwidth consuming. Use Context.JSON() instead.
func (c *Context) IndentedJSON(code int, obj interface{}) {
c.Render(code, render.IndentedJSON{Data: obj})
}
// JSON serializes the given struct as JSON into the response body.
// It also sets the Content-Type as "application/json".
func (c *Context) JSON(code int, obj interface{}) {
c.Status(code)
if err := render.WriteJSON(c.Writer, obj); err != nil {
panic(err)
}
}
// XML serializes the given struct as XML into the response body.
// It also sets the Content-Type as "application/xml".
func (c *Context) XML(code int, obj interface{}) {
c.Render(code, render.XML{Data: obj})
}
// YAML serializes the given struct as YAML into the response body.
func (c *Context) YAML(code int, obj interface{}) {
c.Render(code, render.YAML{Data: obj})
}
// String writes the given string into the response body.
func (c *Context) String(code int, format string, values ...interface{}) {
c.Status(code)
render.WriteString(c.Writer, format, values)
}
// Redirect returns a HTTP redirect to the specific location.
func (c *Context) Redirect(code int, location string) {
c.Render(-1, render.Redirect{
Code: code,
Location: location,
Request: c.Request,
})
}
// Data writes some data into the body stream and updates the HTTP code.
func (c *Context) Data(code int, contentType string, data []byte) {
c.Render(code, render.Data{
ContentType: contentType,
Data: data,
})
}
// File writes the specified file into the body stream in a efficient way.
func (c *Context) File(filepath string) {
http.ServeFile(c.Writer, c.Request, filepath)
}
// SSEvent writes a Server-Sent Event into the body stream.
func (c *Context) SSEvent(name string, message interface{}) {
c.Render(-1, sse.Event{
Event: name,
Data: message,
})
}
func (c *Context) Stream(step func(w io.Writer) bool) {
w := c.Writer
clientGone := w.CloseNotify()
for {
select {
case <-clientGone:
return
default:
keepOpen := step(w)
w.Flush()
if !keepOpen {
return
}
}
}
}
/************************************/
/******** CONTENT NEGOTIATION *******/
/************************************/
type Negotiate struct {
Offered []string
HTMLName string
HTMLData interface{}
JSONData interface{}
XMLData interface{}
Data interface{}
}
func (c *Context) Negotiate(code int, config Negotiate) {
switch c.NegotiateFormat(config.Offered...) {
case binding.MIMEJSON:
data := chooseData(config.JSONData, config.Data)
c.JSON(code, data)
case binding.MIMEHTML:
data := chooseData(config.HTMLData, config.Data)
c.HTML(code, config.HTMLName, data)
case binding.MIMEXML:
data := chooseData(config.XMLData, config.Data)
c.XML(code, data)
default:
c.AbortWithError(http.StatusNotAcceptable, errors.New("the accepted formats are not offered by the server"))
}
}
func (c *Context) NegotiateFormat(offered ...string) string {
assert1(len(offered) > 0, "you must provide at least one offer")
if c.Accepted == nil {
c.Accepted = parseAccept(c.requestHeader("Accept"))
}
if len(c.Accepted) == 0 {
return offered[0]
}
for _, accepted := range c.Accepted {
for _, offert := range offered {
if accepted == offert {
return offert
}
}
}
return ""
}
func (c *Context) SetAccepted(formats ...string) {
c.Accepted = formats
}
/************************************/
/***** GOLANG.ORG/X/NET/CONTEXT *****/
/************************************/
func (c *Context) Deadline() (deadline time.Time, ok bool) {
return
}
func (c *Context) Done() <-chan struct{} {
return nil
}
func (c *Context) Err() error {
return nil
}
func (c *Context) Value(key interface{}) interface{} {
if key == 0 {
return c.Request
}
if keyAsString, ok := key.(string); ok {
val, _ := c.Get(keyAsString)
return val
}
return nil
}