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router.go
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router.go
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package slim
import (
"bytes"
"errors"
"fmt"
"io/fs"
"net/http"
"net/url"
"path/filepath"
"slices"
"sort"
"strings"
"sync/atomic"
)
// Router is interface for routing requests to registered routes.
type Router interface {
// Add 注册请求处理器,返回对应的路由接口实例
Add([]string, string, HandlerFunc) (Route, error)
// Remove 移除路由
Remove(methods []string, path string) error
// Routes 返回注册的路由
Routes() []Route
// Match 匹配路由
Match(req *http.Request, params *PathParams) RouteMatch
MiddlewareRegistrar
MiddlewareComposer
RouteRegistrar
}
// RouteCollector 路由收集器接口
type RouteCollector interface {
// Prefix 返回路由共用前缀
Prefix() string
// Parent 返回上级路由收集器
Parent() RouteCollector
// Router 返回所属路由器
Router() Router
MiddlewareRegistrar
MiddlewareComposer
RouteRegistrar
}
type RouteRegistrar interface {
// Group 实现路由分组注册,实际调用 `RouteCollector.Route` 实现
Group(fn func(sub RouteCollector))
// Route 以指定前缀实现路由分组注册
Route(prefix string, fn func(sub RouteCollector))
// Some registers a new route for multiple HTTP methods and path with matching
// handler in the router. Panics on error.
Some(methods []string, pattern string, h HandlerFunc) Route
// Any registers a new route for all supported HTTP methods and path with matching
// handler in the router. Panics on error.
Any(pattern string, h HandlerFunc) Route
// CONNECT registers a new CONNECT route for a path with matching handler in
// the router. Panics on error.
CONNECT(pattern string, h HandlerFunc) Route
// DELETE registers a new DELETE route for a path with matching handler in
// the router. Panics on error.
DELETE(pattern string, h HandlerFunc) Route
// GET registers a new GET route for a path with matching handler in
// the router. Panics on error.
GET(pattern string, h HandlerFunc) Route
// HEAD registers a new HEAD route for a path with matching handler in
// the router. Panics on error.
HEAD(pattern string, h HandlerFunc) Route
// OPTIONS registers a new OPTIONS route for a path with matching handler
// in the router. Panics on error.
OPTIONS(pattern string, h HandlerFunc) Route
// PATCH registers a new PATCH route for a path with matching handler in
// the router. Panics on error.
PATCH(pattern string, h HandlerFunc) Route
// POST registers a new POST route for a path with matching handler in
// the router. Panics on error.
POST(pattern string, h HandlerFunc) Route
// PUT registers a new PUT route for a path with matching handler in
// the router. Panics on error.
PUT(pattern string, h HandlerFunc) Route
// TRACE registers a new TRACE route for a path with matching handler in
// the router. Panics on error.
TRACE(pattern string, h HandlerFunc) Route
// Static registers a new route with path prefix to serve static files
// from the provided root directory. Panics on error.
Static(prefix, root string) Route
// File registers a new route with a path to serve a static file.
// Panics on error.
File(pattern, file string) Route
}
// Route 路由接口
type Route interface {
// Router 返回所属路由器
Router() Router
// Collector 返回所属收集器
Collector() RouteCollector
// Name 返回路由名称
Name() string
// SetName 设置路由名称,返回 Route 方便链式操作。
SetName(name string) Route
// Pattern 路由路径表达式
Pattern() string
// Methods 返回支持的 HTTP 请求方法
Methods() []string
// Handler 返回注册的请求处理器函数
Handler() HandlerFunc
// Params 返回支持的路由参数列表
Params() []string
// ToRouteInfo 返回路由描述接口实例
ToRouteInfo() RouteInfo
// Use 注册中间件,返回 Route 方便链式操作。
Use(middleware ...MiddlewareFunc) Route
// Middleware 返回注册的中间件
Middleware() []MiddlewareFunc
MiddlewareComposer
}
// RouteInfo 路由描述接口
type RouteInfo interface {
// Router 返回所属路由器
Router() Router
// Collector 返回所属收集器
Collector() RouteCollector
// Name 返回路由名称
Name() string
// Methods 返回支持的请求方法列表
Methods() []string
// Pattern 路由路径表达式
Pattern() string
// Params 返回支持的路由参数列表
Params() []string
// Reverse 通过提供的参数来反转路由表达式,返回为真实请求路径。
// 如果参数为空或 nil 时则尝试使用用默认值,若无法解决参数
// 则会 panic 错误
Reverse(params ...any) string
}
// RouteMatchType describes possible states that request could be in perspective of routing
type RouteMatchType uint8
const (
// RouteMatchUnknown is state before routing is done. Default state for fresh context.
RouteMatchUnknown RouteMatchType = iota
// RouteMatchNotFound is state when router did not find matching route for current request
RouteMatchNotFound
// RouteMatchMethodNotAllowed is state when router did not find route with matching path + method for current request.
// Although router had a matching route with that path but different method.
RouteMatchMethodNotAllowed
// RouteMatchFound is state when router found exact match for path + method combination
RouteMatchFound
)
// RouteMatch is result object for Router.Match. Its main purpose is to avoid allocating memory for PathParams inside router.
type RouteMatch struct {
// Type contains a result as enumeration of Router.Match and helps to understand did Router actually matched Route or
// what kind of error case (404/405) we have at the end of the handler chain.
Type RouteMatchType
// AllowMethods 能够接受处理的请求方法列表,主要
// 在 Type 值为 RouteMatchMethodNotAllowed 时被使用。
AllowMethods []string
// Handler is function(chain) that was matched by router. In case of no match could result to ErrNotFound or ErrMethodNotAllowed.
Handler HandlerFunc
// RouteInfo is information about the route we just matched
RouteInfo RouteInfo
}
type RouterConfig struct {
AllowOverwritingRoute bool
UnescapePathParamValues bool
UseEscapedPathForRouting bool
RoutingTrailingSlash bool
RouteCollector RouteCollector
ErrorHandler ErrorHandlerFunc
}
func NewRouter(config RouterConfig) Router {
r := &defaultRouter{
collector: config.RouteCollector,
tree: &node{},
routes: make([]Route, 0),
middleware: make([]MiddlewareFunc, 0),
errorHandler: config.ErrorHandler,
allowOverwritingRoute: config.AllowOverwritingRoute,
unescapePathParamValues: config.UnescapePathParamValues,
useEscapedPathForRouting: config.UseEscapedPathForRouting,
routingTrailingSlash: config.RoutingTrailingSlash,
}
if r.collector == nil {
r.collector = NewRouteCollector("", nil, r)
}
return r
}
func NewRouteCollector(prefix string, parent RouteCollector, router Router) RouteCollector {
if router == nil {
if parent != nil {
router = parent.Router()
}
} else if parent != nil {
if parent.Router() != router {
panic("invalid router for the given parent")
}
}
if router == nil {
panic("no router")
}
return &defaultRouteCollector{
prefix: prefix,
parent: parent,
router: router,
}
}
var nextRouteId uint32
type defaultRouter struct {
collector RouteCollector // 路由收集器
tree *node // 路由节点树,与根节点的节点树相同
routes []Route // 实际类型是 `[]*defaultRoute`
middleware []MiddlewareFunc // 中间件列表
errorHandler ErrorHandlerFunc // 路由级别的错误处理器
slim *Slim
allowOverwritingRoute bool
unescapePathParamValues bool
useEscapedPathForRouting bool
routingTrailingSlash bool
}
func (r *defaultRouter) Use(middleware ...MiddlewareFunc) {
r.middleware = append(r.middleware, middleware...)
}
func (r *defaultRouter) Middleware() []MiddlewareFunc {
return r.middleware
}
func (r *defaultRouter) Compose() MiddlewareFunc {
return Compose(r.middleware...)
}
func (r *defaultRouter) Add(methods []string, pattern string, h HandlerFunc) (Route, error) {
segments, trailingSlash := split(pattern)
params := make([]string, 0)
tail, _ := r.tree.insert(segments, ¶ms, 0)
route := &defaultRoute{
id: atomic.AddUint32(&nextRouteId, 1),
pattern: strings.Join(segments, ""),
methods: methods,
params: params,
handler: h,
}
for _, method := range methods {
if e := tail.leaf.endpoint(method); e != nil {
if !r.allowOverwritingRoute {
panic(errors.New("slim: adding duplicate route (same method+path) is not allowed"))
}
r.routes = slices.DeleteFunc(r.routes, func(route Route) bool {
return route.(*defaultRoute).id == e.routeId
})
e.trailingSlash = trailingSlash
e.routeId = route.id
} else {
tail.leaf.endpoints = append(tail.leaf.endpoints, &endpoint{
method: method,
pattern: route.pattern,
trailingSlash: trailingSlash,
routeId: route.id,
})
}
}
sort.Sort(tail.leaf.endpoints) // 对端点排序
r.routes = append(r.routes, route)
// TODO(hupeh): 如何针对 remove 处理
if r.slim.contextPathParamAllocSize < tail.leaf.paramsCount {
r.slim.contextPathParamAllocSize = tail.leaf.paramsCount
}
return route, nil
}
func (r *defaultRouter) Group(fn func(sub RouteCollector)) {
r.collector.Group(fn)
}
func (r *defaultRouter) Route(prefix string, fn func(sub RouteCollector)) {
r.collector.Route(prefix, fn)
}
func (r *defaultRouter) Some(methods []string, pattern string, h HandlerFunc) Route {
return r.collector.Some(methods, pattern, h)
}
func (r *defaultRouter) Any(pattern string, h HandlerFunc) Route {
return r.collector.Any(pattern, h)
}
func (r *defaultRouter) CONNECT(pattern string, h HandlerFunc) Route {
return r.collector.CONNECT(pattern, h)
}
func (r *defaultRouter) DELETE(pattern string, h HandlerFunc) Route {
return r.collector.DELETE(pattern, h)
}
func (r *defaultRouter) GET(pattern string, h HandlerFunc) Route {
return r.collector.GET(pattern, h)
}
func (r *defaultRouter) HEAD(pattern string, h HandlerFunc) Route {
return r.collector.HEAD(pattern, h)
}
func (r *defaultRouter) OPTIONS(pattern string, h HandlerFunc) Route {
return r.collector.OPTIONS(pattern, h)
}
func (r *defaultRouter) PATCH(pattern string, h HandlerFunc) Route {
return r.collector.PATCH(pattern, h)
}
func (r *defaultRouter) POST(pattern string, h HandlerFunc) Route {
return r.collector.POST(pattern, h)
}
func (r *defaultRouter) PUT(pattern string, h HandlerFunc) Route {
return r.collector.PUT(pattern, h)
}
func (r *defaultRouter) TRACE(pattern string, h HandlerFunc) Route {
return r.collector.TRACE(pattern, h)
}
func (r *defaultRouter) Static(prefix, root string) Route {
return r.collector.Static(prefix, root)
}
func (r *defaultRouter) File(pattern, file string) Route {
return r.collector.File(pattern, file)
}
// Remove 通过 `method+pattern` 的组合移除服务端点
func (r *defaultRouter) Remove(methods []string, pattern string) error {
segments, trailingSlash := split(pattern)
routes, ok := r.tree.remove(methods, trailingSlash, r.routingTrailingSlash, segments, 0)
if !ok {
return nil
}
for _, route := range routes {
i := slices.IndexFunc(r.routes, func(x Route) bool {
return x.(*defaultRoute).id == route
})
if i == -1 {
return errors.New("route not found")
}
r.routes[i].(*defaultRoute).Remove()
}
return nil
}
func (r *defaultRouter) Routes() []Route {
return r.routes
}
func (r *defaultRouter) Match(req *http.Request, pathParams *PathParams) RouteMatch {
*pathParams = (*pathParams)[0:cap(*pathParams)]
path := req.URL.Path
if r.useEscapedPathForRouting && req.URL.RawPath != "" {
path = req.URL.RawPath
}
segments, tailingSlash := split(path)
tail := r.tree.match(segments, 0)
result := RouteMatch{Type: RouteMatchNotFound, Handler: NotFoundHandler}
if tail == nil {
*pathParams = (*pathParams)[0:0]
return result
}
// 安装叶子参数数量重新分配长度
*pathParams = (*pathParams)[0:tail.leaf.paramsCount]
var ep *endpoint
result.AllowMethods, ep = tail.leaf.match(req.Method)
if ep == nil || (ep.trailingSlash != tailingSlash && !r.routingTrailingSlash) {
// TODO(hupeh): 在使用 OPTIONS 方法的情况下,可以使用该节点拥有的方法列表进行响应。
// FIXME: See https://httpwg.org/specs/rfc7231.html#OPTIONS
result.Type = RouteMatchMethodNotAllowed
result.Handler = MethodNotAllowedHandler
return result
}
// 查找路由
var route *defaultRoute
for _, rr := range r.routes {
dr := rr.(*defaultRoute)
if dr.id == ep.routeId {
route = dr
break
}
}
// 找不到直接内部错误
if route == nil {
panic(fmt.Errorf(
"slim: route %s@%s#%d not found",
req.Method, ep.pattern, ep.routeId,
))
}
pattern := route.Pattern()
var valueIndex int
var paramIndex int
for i, l := 0, len(pattern); i < l; i++ {
if pattern[i] == paramLabel || pattern[i] == anyLabel {
j := i
for ; j < l && pattern[j] != pathSeparator; j++ {
}
if paramIndex >= tail.leaf.paramsCount {
panic(fmt.Errorf(
"slim: invalid param count for routing %s@%s#%d",
req.Method, ep.pattern, ep.routeId,
))
}
key := pattern[i+1 : j]
value := segments[valueIndex][1:]
if pattern[i] == anyLabel {
if key == "" {
key = string(anyLabel)
}
value = strings.Join(segments[valueIndex:], "/")[1:]
if tailingSlash {
value += "/"
}
i = l
} else {
i = j
}
// there are cases when path parameter needs to be unescaped
tmpVal, err := url.PathUnescape(value)
if err == nil { // handle problems by ignoring them.
value = tmpVal
}
(*pathParams)[paramIndex].Name = key
(*pathParams)[paramIndex].Value = value
paramIndex++
valueIndex++
} else if pattern[i] == pathSeparator && i > 0 {
valueIndex++
}
}
result.Type = RouteMatchFound
result.Handler = ComposeChainHandler(route)
result.RouteInfo = route.ToRouteInfo()
return result
}
// ComposeChainHandler 组合路由收集器的中间件和路由的中间件
func ComposeChainHandler(route Route) HandlerFunc {
return func(c Context) error {
stack := make([]MiddlewareFunc, 0)
collector := route.Collector()
for collector != nil {
if mw := collector.Compose(); mw != nil {
stack = append(stack, mw)
}
collector = collector.Parent()
}
// 上面是逆向的,所以这里要反转
slices.Reverse(stack)
mw := Compose(stack...)
h := HandlerFunc(func(c Context) error {
h2 := route.Handler()
mw2 := Compose(route.Middleware()...)
if mw2 != nil {
return mw2(c, h2)
}
return h2(c)
})
if mw == nil {
return h(c)
}
return mw(c, h)
}
}
type defaultRouteCollector struct {
prefix string // 路由前缀
parent RouteCollector // 上级路由收集器
router Router // 上级路由器
middleware []MiddlewareFunc // 中间件列表
}
func (c *defaultRouteCollector) Prefix() string {
return c.prefix
}
func (c *defaultRouteCollector) Parent() RouteCollector {
return c.parent
}
func (c *defaultRouteCollector) Router() Router {
return c.router
}
func (c *defaultRouteCollector) Use(middleware ...MiddlewareFunc) {
c.middleware = append(c.middleware, middleware...)
}
func (c *defaultRouteCollector) Middleware() []MiddlewareFunc {
return c.middleware
}
func (c *defaultRouteCollector) Compose() MiddlewareFunc {
return Compose(c.middleware...)
}
func (c *defaultRouteCollector) Group(fn func(sub RouteCollector)) {
if fn != nil {
fn(NewRouteCollector("", c, nil))
}
}
func (c *defaultRouteCollector) Route(prefix string, fn func(sub RouteCollector)) {
if fn != nil {
fn(NewRouteCollector(prefix, c, nil))
}
}
func (c *defaultRouteCollector) Some(methods []string, pattern string, h HandlerFunc) Route {
var collector RouteCollector
collector = c
for collector != nil {
pattern = collector.Prefix() + pattern
collector = collector.Parent()
}
route, err := c.Router().Add(methods, pattern, h)
if err != nil {
panic(err)
}
// TODO(hupeh): 需要更加合理的方式设置路由收集器
if dr, ok := route.(*defaultRoute); ok {
dr.collector = c
}
return route
}
func (c *defaultRouteCollector) Any(pattern string, h HandlerFunc) Route {
return c.Some([]string{"*"}, pattern, h)
}
func (c *defaultRouteCollector) method(method string, pattern string, h HandlerFunc) Route {
return c.Some([]string{method}, pattern, h)
}
func (c *defaultRouteCollector) CONNECT(pattern string, h HandlerFunc) Route {
return c.method(http.MethodConnect, pattern, h)
}
func (c *defaultRouteCollector) DELETE(pattern string, h HandlerFunc) Route {
return c.method(http.MethodDelete, pattern, h)
}
func (c *defaultRouteCollector) GET(pattern string, h HandlerFunc) Route {
return c.method(http.MethodGet, pattern, h)
}
func (c *defaultRouteCollector) HEAD(pattern string, h HandlerFunc) Route {
return c.method(http.MethodHead, pattern, h)
}
func (c *defaultRouteCollector) OPTIONS(pattern string, h HandlerFunc) Route {
return c.method(http.MethodOptions, pattern, h)
}
func (c *defaultRouteCollector) PATCH(pattern string, h HandlerFunc) Route {
return c.method(http.MethodPatch, pattern, h)
}
func (c *defaultRouteCollector) POST(pattern string, h HandlerFunc) Route {
return c.method(http.MethodPost, pattern, h)
}
func (c *defaultRouteCollector) PUT(pattern string, h HandlerFunc) Route {
return c.method(http.MethodPut, pattern, h)
}
func (c *defaultRouteCollector) TRACE(pattern string, h HandlerFunc) Route {
return c.method(http.MethodTrace, pattern, h)
}
func (c *defaultRouteCollector) Static(prefix, root string) Route {
return c.GET(prefix+"*", StaticDirectoryHandler(root, false))
}
func (c *defaultRouteCollector) File(pattern, file string) Route {
return c.GET(pattern, func(c Context) error { return c.File(file) })
}
// StaticDirectoryHandler creates handler function to serve files from given a root path
func StaticDirectoryHandler(root string, disablePathUnescaping bool) HandlerFunc {
if root == "" {
root = "." // For security, we want to restrict to CWD.
}
return func(c Context) error {
p := c.PathParam("*")
if !disablePathUnescaping { // when router is already unescaping, we do not want to do is twice
tmpPath, err := url.PathUnescape(p)
if err != nil {
return fmt.Errorf("failed to unescape path variable: %w", err)
}
p = tmpPath
}
name := filepath.Join(root, filepath.Clean("/"+p)) // "/"+ for security
fi, err := fs.Stat(c.Filesystem(), name)
if err != nil {
// The access path does not exist
return ErrNotFound
}
// If the request is for a directory and does not end with "/"
p = c.Request().URL.Path // the path must not be empty.
if fi.IsDir() && p[len(p)-1] != '/' {
// Redirect to end with "/"
return c.Redirect(http.StatusMovedPermanently, p+"/")
}
return c.File(name)
}
}
type defaultRoute struct {
id uint32
name string
collector RouteCollector
pattern string
methods []string
params []string
handler HandlerFunc
middleware []MiddlewareFunc
}
func (r *defaultRoute) SetName(name string) Route {
r.name = name
return r
}
func (r *defaultRoute) Use(middleware ...MiddlewareFunc) Route {
r.middleware = append(r.middleware, middleware...)
return r
}
func (r *defaultRoute) ID() uint32 { return r.id }
func (r *defaultRoute) Router() Router { return r.collector.Router() }
func (r *defaultRoute) Collector() RouteCollector { return r.collector }
func (r *defaultRoute) Name() string { return r.name }
func (r *defaultRoute) Pattern() string { return r.pattern }
func (r *defaultRoute) Methods() []string { return r.methods[:] }
func (r *defaultRoute) Handler() HandlerFunc { return r.handler }
func (r *defaultRoute) Params() []string { return r.params[:] }
func (r *defaultRoute) Middleware() []MiddlewareFunc { return r.middleware[:] }
func (r *defaultRoute) Compose() MiddlewareFunc { return Compose(r.middleware...) }
func (r *defaultRoute) ToRouteInfo() RouteInfo { return r }
func (r *defaultRoute) Remove() {
router := r.Router()
if x, ok := router.(*defaultRouter); ok {
x.routes = slices.DeleteFunc(x.routes, func(route Route) bool {
return route.(*defaultRoute).id == r.id
})
} else {
// 为自定义路由器提供移除子路由的预留接口
if i, yes := router.(interface{ RemoveRoute(Route) }); yes {
i.RemoveRoute(r)
}
}
}
func (r *defaultRoute) Reverse(params ...any) string {
uri := new(bytes.Buffer)
ln := len(params)
n := 0
for i, l := 0, len(r.pattern); i < l; i++ {
if (r.pattern[i] == paramLabel || r.pattern[i] == anyLabel) && n < ln {
for ; i < l && r.pattern[i] != pathSeparator; i++ {
}
if n < ln {
uri.WriteString(fmt.Sprintf("%v", params[n]))
}
n++
}
if i < l {
uri.WriteByte(r.pattern[i])
}
}
return uri.String()
}