mirror of https://github.com/minio/minio.git
135 lines
4.4 KiB
Markdown
135 lines
4.4 KiB
Markdown
# XHandler
|
|
|
|
[](https://godoc.org/github.com/rs/xhandler) [](https://raw.githubusercontent.com/rs/xhandler/master/LICENSE) [](https://travis-ci.org/rs/xhandler) [](http://gocover.io/github.com/rs/xhandler)
|
|
|
|
XHandler is a bridge between [net/context](https://godoc.org/golang.org/x/net/context) and `http.Handler`.
|
|
|
|
It lets you enforce `net/context` in your handlers without sacrificing compatibility with existing `http.Handlers` nor imposing a specific router.
|
|
|
|
Thanks to `net/context` deadline management, `xhandler` is able to enforce a per request deadline and will cancel the context when the client closes the connection unexpectedly.
|
|
|
|
You may create your own `net/context` aware handler pretty much the same way as you would do with http.Handler.
|
|
|
|
Read more about xhandler on [Dailymotion engineering blog](http://engineering.dailymotion.com/our-way-to-go/).
|
|
|
|
## Installing
|
|
|
|
go get -u github.com/rs/xhandler
|
|
|
|
## Usage
|
|
|
|
```go
|
|
package main
|
|
|
|
import (
|
|
"log"
|
|
"net/http"
|
|
"time"
|
|
|
|
"github.com/rs/cors"
|
|
"github.com/rs/xhandler"
|
|
"golang.org/x/net/context"
|
|
)
|
|
|
|
type myMiddleware struct {
|
|
next xhandler.HandlerC
|
|
}
|
|
|
|
func (h myMiddleware) ServeHTTPC(ctx context.Context, w http.ResponseWriter, r *http.Request) {
|
|
ctx = context.WithValue(ctx, "test", "World")
|
|
h.next.ServeHTTPC(ctx, w, r)
|
|
}
|
|
|
|
func main() {
|
|
c := xhandler.Chain{}
|
|
|
|
// Add close notifier handler so context is cancelled when the client closes
|
|
// the connection
|
|
c.UseC(xhandler.CloseHandler)
|
|
|
|
// Add timeout handler
|
|
c.UseC(xhandler.TimeoutHandler(2 * time.Second))
|
|
|
|
// Middleware putting something in the context
|
|
c.UseC(func(next xhandler.HandlerC) xhandler.HandlerC {
|
|
return myMiddleware{next: next}
|
|
})
|
|
|
|
// Mix it with a non-context-aware middleware handler
|
|
c.Use(cors.Default().Handler)
|
|
|
|
// Final handler (using handlerFuncC), reading from the context
|
|
xh := xhandler.HandlerFuncC(func(ctx context.Context, w http.ResponseWriter, r *http.Request) {
|
|
value := ctx.Value("test").(string)
|
|
w.Write([]byte("Hello " + value))
|
|
})
|
|
|
|
// Bridge context aware handlers with http.Handler using xhandler.Handle()
|
|
http.Handle("/test", c.Handler(xh))
|
|
|
|
if err := http.ListenAndServe(":8080", nil); err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
}
|
|
```
|
|
|
|
### Using xmux
|
|
|
|
Xhandler comes with an optional context aware [muxer](https://github.com/rs/xmux) forked from [httprouter](https://github.com/julienschmidt/httprouter):
|
|
|
|
```go
|
|
package main
|
|
|
|
import (
|
|
"fmt"
|
|
"log"
|
|
"net/http"
|
|
"time"
|
|
|
|
"github.com/rs/xhandler"
|
|
"github.com/rs/xmux"
|
|
"golang.org/x/net/context"
|
|
)
|
|
|
|
func main() {
|
|
c := xhandler.Chain{}
|
|
|
|
// Append a context-aware middleware handler
|
|
c.UseC(xhandler.CloseHandler)
|
|
|
|
// Another context-aware middleware handler
|
|
c.UseC(xhandler.TimeoutHandler(2 * time.Second))
|
|
|
|
mux := xmux.New()
|
|
|
|
// Use c.Handler to terminate the chain with your final handler
|
|
mux.GET("/welcome/:name", xhandler.HandlerFuncC(func(ctx context.Context, w http.ResponseWriter, req *http.Request) {
|
|
fmt.Fprintf(w, "Welcome %s!", xmux.Params(ctx).Get("name"))
|
|
}))
|
|
|
|
if err := http.ListenAndServe(":8080", c.Handler(mux)); err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
}
|
|
```
|
|
|
|
See [xmux](https://github.com/rs/xmux) for more examples.
|
|
|
|
## Context Aware Middleware
|
|
|
|
Here is a list of `net/context` aware middleware handlers implementing `xhandler.HandlerC` interface.
|
|
|
|
Feel free to put up a PR linking your middleware if you have built one:
|
|
|
|
| Middleware | Author | Description |
|
|
| ---------- | ------ | ----------- |
|
|
| [xmux](https://github.com/rs/xmux) | [Olivier Poitrey](https://github.com/rs) | HTTP request muxer |
|
|
| [xlog](https://github.com/rs/xlog) | [Olivier Poitrey](https://github.com/rs) | HTTP handler logger |
|
|
| [xstats](https://github.com/rs/xstats) | [Olivier Poitrey](https://github.com/rs) | A generic client for service instrumentation |
|
|
| [xaccess](https://github.com/rs/xaccess) | [Olivier Poitrey](https://github.com/rs) | HTTP handler access logger with [xlog](https://github.com/rs/xlog) and [xstats](https://github.com/rs/xstats) |
|
|
| [cors](https://github.com/rs/cors) | [Olivier Poitrey](https://github.com/rs) | [Cross Origin Resource Sharing](http://www.w3.org/TR/cors/) (CORS) support |
|
|
|
|
## Licenses
|
|
|
|
All source code is licensed under the [MIT License](https://raw.github.com/rs/xhandler/master/LICENSE).
|