vitess.io/vitess@v0.16.2/go/vt/topo/etcd2topo/directory.go (about)

     1  /*
     2  Copyright 2019 The Vitess Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package etcd2topo
    18  
    19  import (
    20  	"path"
    21  	"strings"
    22  
    23  	"context"
    24  
    25  	clientv3 "go.etcd.io/etcd/client/v3"
    26  
    27  	"vitess.io/vitess/go/vt/topo"
    28  )
    29  
    30  // ListDir is part of the topo.Conn interface.
    31  func (s *Server) ListDir(ctx context.Context, dirPath string, full bool) ([]topo.DirEntry, error) {
    32  	nodePath := path.Join(s.root, dirPath) + "/"
    33  	if nodePath == "//" {
    34  		// Special case where s.root is "/", dirPath is empty,
    35  		// we would end up with "//". in that case, we want "/".
    36  		nodePath = "/"
    37  	}
    38  	resp, err := s.cli.Get(ctx, nodePath,
    39  		clientv3.WithPrefix(),
    40  		clientv3.WithSort(clientv3.SortByKey, clientv3.SortAscend),
    41  		clientv3.WithKeysOnly())
    42  	if err != nil {
    43  		return nil, convertError(err, dirPath)
    44  	}
    45  	if len(resp.Kvs) == 0 {
    46  		// No key starts with this prefix, means the directory
    47  		// doesn't exist.
    48  		return nil, topo.NewError(topo.NoNode, nodePath)
    49  	}
    50  
    51  	prefixLen := len(nodePath)
    52  	var result []topo.DirEntry
    53  	for _, ev := range resp.Kvs {
    54  		p := string(ev.Key)
    55  
    56  		// Remove the prefix, base path.
    57  		if !strings.HasPrefix(p, nodePath) {
    58  			return nil, ErrBadResponse
    59  		}
    60  		p = p[prefixLen:]
    61  
    62  		// Keep only the part until the first '/'.
    63  		t := topo.TypeFile
    64  		if i := strings.Index(p, "/"); i >= 0 {
    65  			p = p[:i]
    66  			t = topo.TypeDirectory
    67  		}
    68  
    69  		// Remove duplicates, add to list.
    70  		if len(result) == 0 || result[len(result)-1].Name != p {
    71  			e := topo.DirEntry{
    72  				Name: p,
    73  			}
    74  			if full {
    75  				e.Type = t
    76  				if ev.Lease != 0 {
    77  					// Only locks have a lease associated with them.
    78  					e.Ephemeral = true
    79  				}
    80  			}
    81  			result = append(result, e)
    82  		}
    83  	}
    84  
    85  	return result, nil
    86  }