近来无事，仿httprouter造一轮子gorouter
gorouter 是一个轻便的HTTP API 路由库。
项目创建背景
之前一直使用大名鼎鼎的 httprouter。但由于我写的RESTful API不规范，导致存在一些路由冲突。例如github上讨论的这个问题
r.GET("/teachers/list", func (c *gin.Context){})
r.GET("/teachers/:id/profile", func (c *gin.Context){})
Error:
[GIN-debug] GET /teachers/list --> main.func·001 (3 handlers)
[GIN-debug] GET /teachers/:id/profile --> main.func·002 (3 handlers)
panic: wildcard route ':id' conflicts with existing children in path '/teachers/:id/profile'
当然我们可以把 GET /teachers/list 改成 GET /teachers。或者把 GET /teachers/:id/profile 改成 GET /teacher/:id/profile。 按照restful风格应该采用第一种，但有时候接口太多或者没有严格按照restful风格风格就会导致路由冲突。所以我就偶尔我就会采用第二种，但第二种又会导致我没办法把两个接口归纳在同一个group。gorouter就是为了解决这个问题。
用法
func main() {
router := gorouter.New()
router.GET("/teachers/list", func(resp http.ResponseWriter, req *http.Request, params *gorouter.Param) {
resp.Write([]byte("/teachers/list"))
})
router.GET("/teachers/:id/profiles", func(resp http.ResponseWriter, req *http.Request, params *gorouter.Param) {
resp.Write([]byte(fmt.Sprintf("%s = %s", "id", params.GetValue("id"))))
})
router.GET("/teachers/:id/profiles/:id", func(resp http.ResponseWriter, req *http.Request, params *gorouter.Param) {
resp.Write([]byte(fmt.Sprintf("id1 = %s; id2 = %s", params.Values[0], params.Values[1])))
})
http.ListenAndServe(":3001", router)
}
路由规则
gorouter 借鉴了httprouter的基数树实现方法。但当存在通配符和静态路由都匹配url时，优先匹配静态路由，如果匹配失败则返回再去匹配通配符。
路由：
① GET /users/:id/name
② GET /users/id/name
请求：
/users/id/name 匹配②
/users/idd/name 匹配①
Benchmark
引用echo的测试用例编写了gorouter-example，跑了下基准测试，感觉性能还不错。因为功能简单可能占些便宜。
goos: darwin
goarch: amd64
Benchmark_Echo_Static-8 30000 42460 ns/op 2413 B/op 157 allocs/op
Benchmark_Echo_GitHubAPI-8 20000 61322 ns/op 2496 B/op 203 allocs/op
Benchmark_Echo_GplusAPI-8 500000 3255 ns/op 173 B/op 13 allocs/op
Benchmark_Echo_ParseAPI-8 300000 5634 ns/op 323 B/op 26 allocs/op
Benchmark_Gorouter_Static-8 50000 29292 ns/op 1007 B/op 157 allocs/op
Benchmark_Gorouter_GitHubAPI-8 30000 58802 ns/op 5666 B/op 275 allocs/op
Benchmark_Gorouter_GplusAPI-8 500000 3164 ns/op 437 B/op 22 allocs/op
Benchmark_Gorouter_ParseAPI-8 300000 4543 ns/op 615 B/op 37 allocs/op
Benchmark_Gin_Static-8 30000 52282 ns/op 8693 B/op 157 allocs/op
Benchmark_Gin_GitHubAPI-8 20000 79637 ns/op 10616 B/op 203 allocs/op
Benchmark_Gin_GplusAPI-8 300000 4409 ns/op 681 B/op 13 allocs/op
Benchmark_Gin_ParseAPI-8 200000 8040 ns/op 1421 B/op 26 allocs/op
Benchmark_Beego_Static-8 10000 198317 ns/op 76586 B/op 1099 allocs/op
Benchmark_Beego_GitHubAPI-8 5000 269359 ns/op 98868 B/op 1422 allocs/op
Benchmark_Beego_GplusAPI-8 100000 15628 ns/op 6356 B/op 91 allocs/op
Benchmark_Beego_ParseAPI-8 50000 29614 ns/op 12712 B/op 182 allocs/op
Benchmark_Httprouter_Static-8 100000 15696 ns/op 1006 B/op 157 allocs/op
Benchmark_Httprouter_GitHubAPI-8 50000 38157 ns/op 15583 B/op 370 allocs/op
Benchmark_Httprouter_GplusAPI-8 1000000 1874 ns/op 735 B/op 24 allocs/op
Benchmark_Httprouter_ParseAPI-8 500000 2866 ns/op 830 B/op 42 allocs/op
PASS
