vendor dependencies with dep

vendor/github.com/go-chi/chi/middleware/closenotify17.go

@@ -0,0 +1,42 @@
+// +build go1.7,!go1.8
+
+package middleware
+
+import (
+	"context"
+	"net/http"
+)
+
+// CloseNotify is a middleware that cancels ctx when the underlying
+// connection has gone away. It can be used to cancel long operations
+// on the server when the client disconnects before the response is ready.
+//
+// Note: this behaviour is standard in Go 1.8+, so the middleware does nothing
+// on 1.8+ and exists just for backwards compatibility.
+func CloseNotify(next http.Handler) http.Handler {
+	fn := func(w http.ResponseWriter, r *http.Request) {
+		cn, ok := w.(http.CloseNotifier)
+		if !ok {
+			panic("chi/middleware: CloseNotify expects http.ResponseWriter to implement http.CloseNotifier interface")
+		}
+		closeNotifyCh := cn.CloseNotify()
+
+		ctx, cancel := context.WithCancel(r.Context())
+		defer cancel()
+
+		go func() {
+			select {
+			case <-ctx.Done():
+				return
+			case <-closeNotifyCh:
+				cancel()
+				return
+			}
+		}()
+
+		r = r.WithContext(ctx)
+		next.ServeHTTP(w, r)
+	}
+
+	return http.HandlerFunc(fn)
+}