Denco

The fast and flexible HTTP request router for Go.

Denco is based on Double-Array implementation of Kocha-urlrouter. However, Denco is optimized and some features added.

Features

• Fast (See go-http-routing-benchmark)
• URL patterns (

  /foo/:bar

  and

  /foo/*wildcard

  )
• Small (but enough) URL router API
• HTTP request multiplexer like

  http.ServeMux

Installation

go get -u github.com/naoina/denco

Using as HTTP request multiplexer

package main

import (
    "fmt"
    "log"
    "net/http"
"github.com/naoina/denco"
)
func Index(w http.ResponseWriter, r *http.Request, params denco.Params) {
    fmt.Fprintf(w, "Welcome to Denco!\n")
}
func User(w http.ResponseWriter, r *http.Request, params denco.Params) {
    fmt.Fprintf(w, "Hello %s!\n", params.Get("name"))
}
func main() {
    mux := denco.NewMux()
    handler, err := mux.Build([]denco.Handler{
        mux.GET("/", Index),
        mux.GET("/user/:name", User),
        mux.POST("/user/:name", User),
    })
    if err != nil {
        panic(err)
    }
    log.Fatal(http.ListenAndServe(":8080", handler))
}

Using as URL router

package main

import (
    "fmt"
"github.com/naoina/denco"
)
type route struct {
    name string
}
func main() {
    router := denco.New()
    router.Build([]denco.Record{
        {"/", &route{"root"}},
        {"/user/:id", &route{"user"}},
        {"/user/:name/:id", &route{"username"}},
        {"/static/*filepath", &route{"static"}},
    })
data, params, found := router.Lookup("/")
// print `&main.route{name:"root"}, denco.Params(nil), true`.
fmt.Printf("%#v, %#v, %#v\n", data, params, found)

data, params, found = router.Lookup("/user/hoge")
// print `&main.route{name:"user"}, denco.Params{denco.Param{Name:"id", Value:"hoge"}}, true`.
fmt.Printf("%#v, %#v, %#v\n", data, params, found)

data, params, found = router.Lookup("/user/hoge/7")
// print `&main.route{name:"username"}, denco.Params{denco.Param{Name:"name", Value:"hoge"}, denco.Param{Name:"id", Value:"7"}}, true`.
fmt.Printf("%#v, %#v, %#v\n", data, params, found)

data, params, found = router.Lookup("/static/path/to/file")
// print `&main.route{name:"static"}, denco.Params{denco.Param{Name:"filepath", Value:"path/to/file"}}, true`.
fmt.Printf("%#v, %#v, %#v\n", data, params, found)
}

See Godoc for more details.

Getting the value of path parameter

You can get the value of path parameter by 2 ways.

1. Using

   denco.Params.Get

   method
2. Find by loop

package main

import (
    "fmt"
"github.com/naoina/denco"
)
func main() {
    router := denco.New()
    if err := router.Build([]denco.Record{
        {"/user/:name/:id", "route1"},
    }); err != nil {
        panic(err)
    }
// 1. Using denco.Params.Get method.
_, params, _ := router.Lookup("/user/alice/1")
name := params.Get("name")
if name != "" {
    fmt.Printf("Hello %s.\n", name) // prints "Hello alice.".
}

// 2. Find by loop.
for _, param := range params {
    if param.Name == "name" {
        fmt.Printf("Hello %s.\n", name) // prints "Hello alice.".
    }
}
}

URL patterns

Denco's route matching strategy is "most nearly matching".

When routes

/:name

/alice

/alice

/alice

/:name

/alice

/alice

/:name

For more example, when routes below have been built:

/user/alice
/user/:name
/user/:name/:id
/user/alice/:id
/user/:id/bob

Routes matching are:

/user/alice      => "/user/alice" (no match with "/user/:name")
/user/bob        => "/user/:name"
/user/naoina/1   => "/user/:name/1"
/user/alice/1    => "/user/alice/:id" (no match with "/user/:name/:id")
/user/1/bob      => "/user/:id/bob"   (no match with "/user/:name/:id")
/user/alice/bob  => "/user/alice/:id" (no match with "/user/:name/:id" and "/user/:id/bob")

Limitation

Denco has some limitations below.

• Number of param records (such as

  /:name

  ) must be less than 2^22
• Number of elements of internal slice must be less than 2^22

Benchmarks

cd $GOPATH/github.com/naoina/denco
go test -bench . -benchmem

License

Denco is licensed under the MIT License.