enrinal/mux

A method based HTTP router.

mux

Mux is an HTTP request multiplexer (HTTP Router). It matches the URL of each incoming request against a list of registered patterns and calls the handler for the pattern that matches the URL.

In contrast to the default mux of Go's net/http package, this Mux supports variables in the routing pattern and matches against the request method. It also scales better and compatible with Go's http.Handler.

This Mux is very simple, basically this Mux only aims to store and search for handlers based on method and path patterns.

Quick Start

go get github.com/josestg/mux

Usages

package main

import (
	"fmt"
	"io"
	"log"
	"net/http"

	"github.com/josestg/mux"
)

func main() {
	m := mux.New()

	m.HandleFunc(http.MethodGet, "/hello", hello)
	m.HandleFunc(http.MethodGet, "/hello/:name", helloWithVars)

	log.Fatal(http.ListenAndServe("0.0.0.0:8080", m))
}

func hello(w http.ResponseWriter, _ *http.Request) {
	io.WriteString(w, "Hello, World\n")
}

func helloWithVars(w http.ResponseWriter, r *http.Request) {
	vars := mux.GetVars(r.Context())
	msg := fmt.Sprintf("Hello, %s\n", vars.Get("name"))
	io.WriteString(w, msg)
}

How does it work?

The router relies on a Trie (Prefix Tree) data structure. Each handler is stored in a specific location which can be reached using path and method pairs.

Unlike Trie in general, each child of Trie contains one character from a word. In this Trie, each child stores one segment of a path. For example the path /ab/cd/e has three segments namely /ab, /cd, /e.

Example

Suppose we have a list of method pairs, urls, and handlers as in the following table.

Method	Path	Handler
GET	/products	getProducts()
GET	/products/:id	getProductInfo()
POST	/products	addProduct()
PATCH	/products/:id	updateProduct()
GET	/products/:id/stars	getProductStars()
GET	/products/:id/comments	getProductComments()
GET	/products/carts	getProductCarts()
DELETE	/products/carts/:id	removeProductCart()
GET	/profiles/:id	getUserProfile()
GET	/profiles/settings	getUserSettings()

When the handler is registered into Mux, it will logically form a Trie data structure as shown in the image below.

Notes:

:<var-name> (ex. :id) indicates that the segment is a variable. That means, /products/123/stars and /products/abc/stars will match with /products/:id/stars where the id values are "123" and "abc".