关于golang:聊聊dubbogoproxy的Route

序

本文次要钻研一下 dubbo-go-proxy 的 Route

Route

dubbo-go-proxy/pkg/router/route.go

// Route defines the tree of router APIs
type Route struct {
    lock         sync.RWMutex
    tree         *avltree.Tree
    wildcardTree *avltree.Tree
}

// NewRoute returns an empty router tree
func NewRoute() *Route {
    return &Route{tree:         avltree.NewWithStringComparator(),
        wildcardTree: avltree.NewWithStringComparator(),}
}

Route 定义了 lock、tree、wildcardTree 属性，其 NewRoute 办法用于创立 Route

PutAPI

dubbo-go-proxy/pkg/router/route.go

// PutAPI puts an api into the resource
func (rt *Route) PutAPI(api router.API) error {lowerCasePath := strings.ToLower(api.URLPattern)
    node, ok := rt.findNode(lowerCasePath)
    rt.lock.Lock()
    defer rt.lock.Unlock()
    if !ok {wildcard := strings.Contains(lowerCasePath, constant.PathParamIdentifier)
        rn := &Node{
            fullPath: lowerCasePath,
            methods:  map[config.HTTPVerb]*config.Method{api.Method.HTTPVerb: &api.Method},
            wildcard: wildcard,
            headers:  api.Headers,
        }
        if wildcard {rt.wildcardTree.Put(lowerCasePath, rn)
        }
        rt.tree.Put(lowerCasePath, rn)
        return nil
    }
    return node.putMethod(api.Method, api.Headers)
}

PutAPI 办法依据 lowerCasePath 去查找 node，若没有找到则加锁创立 Node，而后放到 tree 中，若是 path 是 wildcard 的则也会退出到 wildcardTree 中；如果有找到则执行 node.putMethod(api.Method, api.Headers)

UpdateAPI

dubbo-go-proxy/pkg/router/route.go

// UpdateAPI update the api method in the existing router node
func (rt *Route) UpdateAPI(api router.API) error {node, found := rt.findNode(api.URLPattern)
    if found {if _, ok := node.methods[api.Method.HTTPVerb]; ok {rt.lock.Lock()
            defer rt.lock.Unlock()
            node.methods[api.Method.HTTPVerb] = &api.Method
        }
    }
    return nil
}

UpdateAPI 办法先依据 api.URLPattern 查找 node，若找不到返回 nil，找到的话再去找 node.methods[api.Method.HTTPVerb]，若找到则将 api.Method 赋值给 node.methods[api.Method.HTTPVerb]

FindAPI

dubbo-go-proxy/pkg/router/route.go

// FindAPI returns the api that meets the
func (rt *Route) FindAPI(fullPath string, httpverb config.HTTPVerb) (*router.API, bool) {if n, found := rt.findNode(fullPath); found {rt.lock.RLock()
        defer rt.lock.RUnlock()
        if method, ok := n.methods[httpverb]; ok {
            return &router.API{
                URLPattern: n.fullPath,
                Method:     *method,
                Headers:    n.headers,
            }, ok
        }
    }
    return nil, false
}

FindAPI 办法先通过 findNode 找 node，再通过 node.methods[httpverb] 找 method

findNode

dubbo-go-proxy/pkg/router/route.go

func (rt *Route) findNode(fullPath string) (*Node, bool) {lowerPath := strings.ToLower(fullPath)
    var n interface{}
    var found bool
    if n, found = rt.searchWildcard(lowerPath); !found {rt.lock.RLock()
        defer rt.lock.RUnlock()
        if n, found = rt.tree.Get(lowerPath); !found {return nil, false}
    }
    return n.(*Node), found
}

findNode 办法通过 searchWildcard 来查找 node，找不到则从 node 的 tree.Get 办法查找

searchWildcard

dubbo-go-proxy/pkg/router/route.go

func (rt *Route) searchWildcard(fullPath string) (*Node, bool) {rt.lock.RLock()
    defer rt.lock.RUnlock()
    wildcardPaths := rt.wildcardTree.Keys()
    for _, p := range wildcardPaths {if wildcardMatch(p.(string), fullPath) != nil {n, ok := rt.wildcardTree.Get(p)
            return n.(*Node), ok
        }
    }
    return nil, false
}

searchWildcard 办法遍历 wildcardTree.Keys()，挨个执行 wildcardMatch，若匹配到则通过 wildcardTree.Get(p) 来获取 node

小结

Route 定义了 lock、tree、wildcardTree 属性，其 NewRoute 办法用于创立 Route；它提供了 PutAPI、UpdateAPI、FindAPI 等办法；外头实现应用的是 avltree.Tree。

doc

• dubbo-go-proxy