1// Copyright 2018 Prometheus Team 2// Licensed under the Apache License, Version 2.0 (the "License"); 3// you may not use this file except in compliance with the License. 4// You may obtain a copy of the License at 5// 6// http://www.apache.org/licenses/LICENSE-2.0 7// 8// Unless required by applicable law or agreed to in writing, software 9// distributed under the License is distributed on an "AS IS" BASIS, 10// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 11// See the License for the specific language governing permissions and 12// limitations under the License. 13 14package labels 15 16import ( 17 "fmt" 18 "regexp" 19 "strings" 20) 21 22var ( 23 re = regexp.MustCompile(`(?:\s?)(\w+)(=|=~|!=|!~)(?:\"([^"=~!]+)\"|([^"=~!]+)|\"\")`) 24 typeMap = map[string]MatchType{ 25 "=": MatchEqual, 26 "!=": MatchNotEqual, 27 "=~": MatchRegexp, 28 "!~": MatchNotRegexp, 29 } 30) 31 32func ParseMatchers(s string) ([]*Matcher, error) { 33 matchers := []*Matcher{} 34 s = strings.TrimPrefix(s, "{") 35 s = strings.TrimSuffix(s, "}") 36 37 var insideQuotes bool 38 var token string 39 var tokens []string 40 for _, r := range s { 41 if !insideQuotes && r == ',' { 42 tokens = append(tokens, token) 43 token = "" 44 continue 45 } 46 token += string(r) 47 if r == '"' { 48 insideQuotes = !insideQuotes 49 } 50 } 51 if token != "" { 52 tokens = append(tokens, token) 53 } 54 for _, token := range tokens { 55 m, err := ParseMatcher(token) 56 if err != nil { 57 return nil, err 58 } 59 matchers = append(matchers, m) 60 } 61 62 return matchers, nil 63} 64 65func ParseMatcher(s string) (*Matcher, error) { 66 var ( 67 name, value string 68 matchType MatchType 69 ) 70 71 ms := re.FindStringSubmatch(s) 72 if len(ms) < 4 { 73 return nil, fmt.Errorf("bad matcher format: %s", s) 74 } 75 76 name = ms[1] 77 if name == "" { 78 return nil, fmt.Errorf("failed to parse label name") 79 } 80 81 matchType, found := typeMap[ms[2]] 82 if !found { 83 return nil, fmt.Errorf("failed to find match operator") 84 } 85 86 if ms[3] != "" { 87 value = ms[3] 88 } else { 89 value = ms[4] 90 } 91 92 return NewMatcher(matchType, name, value) 93} 94