diff options
Diffstat (limited to 'vendor/github.com/go-chi/chi/v5/context.go')
-rw-r--r-- | vendor/github.com/go-chi/chi/v5/context.go | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/vendor/github.com/go-chi/chi/v5/context.go b/vendor/github.com/go-chi/chi/v5/context.go new file mode 100644 index 0000000000..814c263012 --- /dev/null +++ b/vendor/github.com/go-chi/chi/v5/context.go @@ -0,0 +1,157 @@ +package chi + +import ( + "context" + "net/http" + "strings" +) + +// URLParam returns the url parameter from a http.Request object. +func URLParam(r *http.Request, key string) string { + if rctx := RouteContext(r.Context()); rctx != nil { + return rctx.URLParam(key) + } + return "" +} + +// URLParamFromCtx returns the url parameter from a http.Request Context. +func URLParamFromCtx(ctx context.Context, key string) string { + if rctx := RouteContext(ctx); rctx != nil { + return rctx.URLParam(key) + } + return "" +} + +// RouteContext returns chi's routing Context object from a +// http.Request Context. +func RouteContext(ctx context.Context) *Context { + val, _ := ctx.Value(RouteCtxKey).(*Context) + return val +} + +// NewRouteContext returns a new routing Context object. +func NewRouteContext() *Context { + return &Context{} +} + +var ( + // RouteCtxKey is the context.Context key to store the request context. + RouteCtxKey = &contextKey{"RouteContext"} +) + +// Context is the default routing context set on the root node of a +// request context to track route patterns, URL parameters and +// an optional routing path. +type Context struct { + Routes Routes + + // parentCtx is the parent of this one, for using Context as a + // context.Context directly. This is an optimization that saves + // 1 allocation. + parentCtx context.Context + + // Routing path/method override used during the route search. + // See Mux#routeHTTP method. + RoutePath string + RouteMethod string + + // URLParams are the stack of routeParams captured during the + // routing lifecycle across a stack of sub-routers. + URLParams RouteParams + + // Route parameters matched for the current sub-router. It is + // intentionally unexported so it cant be tampered. + routeParams RouteParams + + // The endpoint routing pattern that matched the request URI path + // or `RoutePath` of the current sub-router. This value will update + // during the lifecycle of a request passing through a stack of + // sub-routers. + routePattern string + + // Routing pattern stack throughout the lifecycle of the request, + // across all connected routers. It is a record of all matching + // patterns across a stack of sub-routers. + RoutePatterns []string + + // methodNotAllowed hint + methodNotAllowed bool +} + +// Reset a routing context to its initial state. +func (x *Context) Reset() { + x.Routes = nil + x.RoutePath = "" + x.RouteMethod = "" + x.RoutePatterns = x.RoutePatterns[:0] + x.URLParams.Keys = x.URLParams.Keys[:0] + x.URLParams.Values = x.URLParams.Values[:0] + + x.routePattern = "" + x.routeParams.Keys = x.routeParams.Keys[:0] + x.routeParams.Values = x.routeParams.Values[:0] + x.methodNotAllowed = false + x.parentCtx = nil +} + +// URLParam returns the corresponding URL parameter value from the request +// routing context. +func (x *Context) URLParam(key string) string { + for k := len(x.URLParams.Keys) - 1; k >= 0; k-- { + if x.URLParams.Keys[k] == key { + return x.URLParams.Values[k] + } + } + return "" +} + +// RoutePattern builds the routing pattern string for the particular +// request, at the particular point during routing. This means, the value +// will change throughout the execution of a request in a router. That is +// why its advised to only use this value after calling the next handler. +// +// For example, +// +// func Instrument(next http.Handler) http.Handler { +// return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { +// next.ServeHTTP(w, r) +// routePattern := chi.RouteContext(r.Context()).RoutePattern() +// measure(w, r, routePattern) +// }) +// } +func (x *Context) RoutePattern() string { + routePattern := strings.Join(x.RoutePatterns, "") + return replaceWildcards(routePattern) +} + +// replaceWildcards takes a route pattern and recursively replaces all +// occurrences of "/*/" to "/". +func replaceWildcards(p string) string { + if strings.Contains(p, "/*/") { + return replaceWildcards(strings.Replace(p, "/*/", "/", -1)) + } + + return p +} + +// RouteParams is a structure to track URL routing parameters efficiently. +type RouteParams struct { + Keys, Values []string +} + +// Add will append a URL parameter to the end of the route param +func (s *RouteParams) Add(key, value string) { + s.Keys = append(s.Keys, key) + s.Values = append(s.Values, value) +} + +// contextKey is a value for use with context.WithValue. It's used as +// a pointer so it fits in an interface{} without allocation. This technique +// for defining context keys was copied from Go 1.7's new use of context in net/http. +type contextKey struct { + name string +} + +func (k *contextKey) String() string { + return "chi context value " + k.name +} |