-
Notifications
You must be signed in to change notification settings - Fork 2.1k
/
matcher.go
201 lines (176 loc) · 4.5 KB
/
matcher.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
// Copyright 2017 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package labels
import (
"bytes"
"encoding/json"
"fmt"
"regexp"
"strings"
"github.com/prometheus/common/model"
)
// MatchType is an enum for label matching types.
type MatchType int
// Possible MatchTypes.
const (
MatchEqual MatchType = iota
MatchNotEqual
MatchRegexp
MatchNotRegexp
)
func (m MatchType) String() string {
typeToStr := map[MatchType]string{
MatchEqual: "=",
MatchNotEqual: "!=",
MatchRegexp: "=~",
MatchNotRegexp: "!~",
}
if str, ok := typeToStr[m]; ok {
return str
}
panic("unknown match type")
}
// Matcher models the matching of a label.
type Matcher struct {
Type MatchType
Name string
Value string
re *regexp.Regexp
}
// NewMatcher returns a matcher object.
func NewMatcher(t MatchType, n, v string) (*Matcher, error) {
m := &Matcher{
Type: t,
Name: n,
Value: v,
}
if t == MatchRegexp || t == MatchNotRegexp {
re, err := regexp.Compile("^(?:" + v + ")$")
if err != nil {
return nil, err
}
m.re = re
}
return m, nil
}
func (m *Matcher) String() string {
return fmt.Sprintf(`%s%s"%s"`, m.Name, m.Type, openMetricsEscape(m.Value))
}
// Matches returns whether the matcher matches the given string value.
func (m *Matcher) Matches(s string) bool {
switch m.Type {
case MatchEqual:
return s == m.Value
case MatchNotEqual:
return s != m.Value
case MatchRegexp:
return m.re.MatchString(s)
case MatchNotRegexp:
return !m.re.MatchString(s)
}
panic("labels.Matcher.Matches: invalid match type")
}
type apiV1Matcher struct {
Name string `json:"name"`
Value string `json:"value"`
IsRegex bool `json:"isRegex"`
IsEqual bool `json:"isEqual"`
}
// MarshalJSON retains backwards compatibility with types.Matcher for the v1 API.
func (m Matcher) MarshalJSON() ([]byte, error) {
return json.Marshal(apiV1Matcher{
Name: m.Name,
Value: m.Value,
IsRegex: m.Type == MatchRegexp || m.Type == MatchNotRegexp,
IsEqual: m.Type == MatchRegexp || m.Type == MatchEqual,
})
}
func (m *Matcher) UnmarshalJSON(data []byte) error {
v1m := apiV1Matcher{
IsEqual: true,
}
if err := json.Unmarshal(data, &v1m); err != nil {
return err
}
var t MatchType
switch {
case v1m.IsEqual && !v1m.IsRegex:
t = MatchEqual
case !v1m.IsEqual && !v1m.IsRegex:
t = MatchNotEqual
case v1m.IsEqual && v1m.IsRegex:
t = MatchRegexp
case !v1m.IsEqual && v1m.IsRegex:
t = MatchNotRegexp
}
matcher, err := NewMatcher(t, v1m.Name, v1m.Value)
if err != nil {
return err
}
*m = *matcher
return nil
}
// openMetricsEscape is similar to the usual string escaping, but more
// restricted. It merely replaces a new-line character with '\n', a double-quote
// character with '\"', and a backslash with '\\', which is the escaping used by
// OpenMetrics.
func openMetricsEscape(s string) string {
r := strings.NewReplacer(
`\`, `\\`,
"\n", `\n`,
`"`, `\"`,
)
return r.Replace(s)
}
// Matchers is a slice of Matchers that is sortable, implements Stringer, and
// provides a Matches method to match a LabelSet against all Matchers in the
// slice. Note that some users of Matchers might require it to be sorted.
type Matchers []*Matcher
func (ms Matchers) Len() int { return len(ms) }
func (ms Matchers) Swap(i, j int) { ms[i], ms[j] = ms[j], ms[i] }
func (ms Matchers) Less(i, j int) bool {
if ms[i].Name > ms[j].Name {
return false
}
if ms[i].Name < ms[j].Name {
return true
}
if ms[i].Value > ms[j].Value {
return false
}
if ms[i].Value < ms[j].Value {
return true
}
return ms[i].Type < ms[j].Type
}
// Matches checks whether all matchers are fulfilled against the given label set.
func (ms Matchers) Matches(lset model.LabelSet) bool {
for _, m := range ms {
if !m.Matches(string(lset[model.LabelName(m.Name)])) {
return false
}
}
return true
}
func (ms Matchers) String() string {
var buf bytes.Buffer
buf.WriteByte('{')
for i, m := range ms {
if i > 0 {
buf.WriteByte(',')
}
buf.WriteString(m.String())
}
buf.WriteByte('}')
return buf.String()
}