pkg/rest/roa.go

//Copyright 2017 Huawei Technologies Co., Ltd
//
//Licensed under the Apache License, Version 2.0 (the "License");
//you may not use this file except in compliance with the License.
//You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
//Unless required by applicable law or agreed to in writing, software
//distributed under the License is distributed on an "AS IS" BASIS,
//WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//See the License for the specific language governing permissions and
//limitations under the License.
package rest

import (
	"github.com/ServiceComb/service-center/pkg/util"
	"net/http"
	"reflect"
)

var (
	serverHandler *ROAServerHandler
)

func init() {
	initROAServerHandler()
}

type ROAServantService interface {
	URLPatterns() []Route
}

func initROAServerHandler() *ROAServerHandler {
	serverHandler = NewROAServerHander()
	return serverHandler
}

// servant must be an pointer to service object
func RegisterServent(servant interface{}) {
	val := reflect.ValueOf(servant)
	ind := reflect.Indirect(val)
	typ := ind.Type()
	name := typ.PkgPath() + "." + typ.Name()
	if val.Kind() != reflect.Ptr {
		util.Logger().Errorf(nil, "<rest.RegisterServent> cannot use non-ptr servant struct `%s`", name)
		return
	}

	urlPatternFunc := val.MethodByName("URLPatterns")
	if !urlPatternFunc.IsValid() {
		util.Logger().Errorf(nil, "<rest.RegisterServent> no 'URLPatterns' function in servant struct `%s`", name)
		return
	}

	vals := urlPatternFunc.Call([]reflect.Value{})
	if len(vals) <= 0 {
		util.Logger().Errorf(nil, "<rest.RegisterServent> call 'URLPatterns' function failed in servant struct `%s`", name)
		return
	}

	val0 := vals[0]
	if !val.CanInterface() {
		util.Logger().Errorf(nil, "<rest.RegisterServent> result of 'URLPatterns' function not interface type in servant struct `%s`", name)
		return
	}

	if routes, ok := val0.Interface().([]Route); ok {
		util.Logger().Infof("register servant %s", name)
		for _, route := range routes {
			err := serverHandler.addRoute(&route)
			if err != nil {
				util.Logger().Errorf(err, "register route failed.")
			}
		}
	} else {
		util.Logger().Errorf(nil, "<rest.RegisterServent> result of 'URLPatterns' function not []*Route type in servant struct `%s`", name)
	}
}

//GetRouter return the router fo REST service
func GetRouter() http.Handler {
	return serverHandler
}