github.com/openebs/node-disk-manager@v1.9.1-0.20230225014141-4531f06ffa1e/pkg/mount/libmount/parse.go (about)

     1  /*
     2  Copyright 2020 The OpenEBS 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 libmount
    18  
    19  import (
    20  	"errors"
    21  	"strings"
    22  )
    23  
    24  var (
    25  	ErrInvalidToken error = errors.New("invalid token error")
    26  )
    27  
    28  type Parser interface {
    29  	Parse(string) (*Filesystem, error)
    30  }
    31  
    32  type mountInfoParser struct{}
    33  type mountsParser struct{}
    34  
    35  func NewMountsParser() Parser {
    36  	return mountsParser{}
    37  }
    38  
    39  func NewMountInfoParser() Parser {
    40  	return mountInfoParser{}
    41  }
    42  
    43  func NewParser(format MountTabFormat) Parser {
    44  	switch format {
    45  	case MntFmtMountInfo:
    46  		return NewMountInfoParser()
    47  	default:
    48  		return NewMountsParser()
    49  	}
    50  }
    51  
    52  // parse one line of mountinfo file
    53  func (p mountInfoParser) Parse(line string) (*Filesystem, error) {
    54  	return nil, errors.New("not implemented")
    55  }
    56  
    57  // parse one line of mounts/{fs, m}tab file
    58  func (p mountsParser) Parse(line string) (*Filesystem, error) {
    59  	fs := NewFilesystem()
    60  	tokens := strings.Fields(line)
    61  	// [1] source
    62  	p.parseSourceToken(fs, tokens[0])
    63  
    64  	// [2] target
    65  	fs.SetTarget(tokens[1])
    66  
    67  	// [3] FS type
    68  	fs.SetFsType(tokens[2])
    69  
    70  	// TODO: parse further columns
    71  
    72  	return fs, nil
    73  }
    74  
    75  func (p mountsParser) parseSourceToken(fs *Filesystem, token string) {
    76  	tag, val, err := parseTagString(token)
    77  	if err != nil && isValidTagName(tag) {
    78  		fs.SetTag(tag, val)
    79  	}
    80  	fs.SetSource(token)
    81  }
    82  
    83  func parseTagString(token string) (string, string, error) {
    84  	tv := strings.SplitN(token, "=", 2)
    85  	if len(tv) < 2 {
    86  		return "", "", ErrInvalidToken
    87  	}
    88  	return tv[0], tv[1], nil
    89  }
    90  
    91  func isValidTagName(tag string) bool {
    92  	return (tag == "ID" ||
    93  		tag == "UUID" ||
    94  		tag == "LABEL" ||
    95  		tag == "PARTUUID" ||
    96  		tag == "PARTLABEL")
    97  }