github.com/cs3org/reva/v2@v2.27.7/pkg/rhttp/router/router.go (about)

     1  // Copyright 2018-2021 CERN
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  //
    15  // In applying this license, CERN does not waive the privileges and immunities
    16  // granted to it by virtue of its status as an Intergovernmental Organization
    17  // or submit itself to any jurisdiction.
    18  
    19  package router
    20  
    21  import (
    22  	"path"
    23  	"strings"
    24  )
    25  
    26  // ShiftPath splits off the first component of p, which will be cleaned of
    27  // relative components before processing. head will never contain a slash and
    28  // tail will always be a rooted path without trailing slash.
    29  // see https://blog.merovius.de/2017/06/18/how-not-to-use-an-http-router.html
    30  // and https://gist.github.com/weatherglass/62bd8a704d4dfdc608fe5c5cb5a6980c#gistcomment-2161690 for the zero alloc code below
    31  func ShiftPath(p string) (head, tail string) {
    32  	if p == "" {
    33  		return "", "/"
    34  	}
    35  	p = strings.TrimPrefix(path.Clean(p), "/")
    36  	i := strings.Index(p, "/")
    37  	if i < 0 {
    38  		return p, "/"
    39  	}
    40  	return p[:i], p[i:]
    41  }