summaryrefslogtreecommitdiffstats
path: root/vendor/github.com/prometheus/common/model/value.go
blob: c9d8fb1a28313eeba3c79d3fcddb701572a1f1b6 (plain)
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
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
// Copyright 2013 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 model

import (
	"encoding/json"
	"fmt"
	"math"
	"sort"
	"strconv"
	"strings"
)

var (
	// ZeroSamplePair is the pseudo zero-value of SamplePair used to signal a
	// non-existing sample pair. It is a SamplePair with timestamp Earliest and
	// value 0.0. Note that the natural zero value of SamplePair has a timestamp
	// of 0, which is possible to appear in a real SamplePair and thus not
	// suitable to signal a non-existing SamplePair.
	ZeroSamplePair = SamplePair{Timestamp: Earliest}

	// ZeroSample is the pseudo zero-value of Sample used to signal a
	// non-existing sample. It is a Sample with timestamp Earliest, value 0.0,
	// and metric nil. Note that the natural zero value of Sample has a timestamp
	// of 0, which is possible to appear in a real Sample and thus not suitable
	// to signal a non-existing Sample.
	ZeroSample = Sample{Timestamp: Earliest}
)

// A SampleValue is a representation of a value for a given sample at a given
// time.
type SampleValue float64

// MarshalJSON implements json.Marshaler.
func (v SampleValue) MarshalJSON() ([]byte, error) {
	return json.Marshal(v.String())
}

// UnmarshalJSON implements json.Unmarshaler.
func (v *SampleValue) UnmarshalJSON(b []byte) error {
	if len(b) < 2 || b[0] != '"' || b[len(b)-1] != '"' {
		return fmt.Errorf("sample value must be a quoted string")
	}
	f, err := strconv.ParseFloat(string(b[1:len(b)-1]), 64)
	if err != nil {
		return err
	}
	*v = SampleValue(f)
	return nil
}

// Equal returns true if the value of v and o is equal or if both are NaN. Note
// that v==o is false if both are NaN. If you want the conventional float
// behavior, use == to compare two SampleValues.
func (v SampleValue) Equal(o SampleValue) bool {
	if v == o {
		return true
	}
	return math.IsNaN(float64(v)) && math.IsNaN(float64(o))
}

func (v SampleValue) String() string {
	return strconv.FormatFloat(float64(v), 'f', -1, 64)
}

// SamplePair pairs a SampleValue with a Timestamp.
type SamplePair struct {
	Timestamp Time
	Value     SampleValue
}

// MarshalJSON implements json.Marshaler.
func (s SamplePair) MarshalJSON() ([]byte, error) {
	t, err := json.Marshal(s.Timestamp)
	if err != nil {
		return nil, err
	}
	v, err := json.Marshal(s.Value)
	if err != nil {
		return nil, err
	}
	return []byte(fmt.Sprintf("[%s,%s]", t, v)), nil
}

// UnmarshalJSON implements json.Unmarshaler.
func (s *SamplePair) UnmarshalJSON(b []byte) error {
	v := [...]json.Unmarshaler{&s.Timestamp, &s.Value}
	return json.Unmarshal(b, &v)
}

// Equal returns true if this SamplePair and o have equal Values and equal
// Timestamps. The semantics of Value equality is defined by SampleValue.Equal.
func (s *SamplePair) Equal(o *SamplePair) bool {
	return s == o || (s.Value.Equal(o.Value) && s.Timestamp.Equal(o.Timestamp))
}

func (s SamplePair) String() string {
	return fmt.Sprintf("%s @[%s]", s.Value, s.Timestamp)
}

// Sample is a sample pair associated with a metric.
type Sample struct {
	Metric    Metric      `json:"metric"`
	Value     SampleValue `json:"value"`
	Timestamp Time        `json:"timestamp"`
}

// Equal compares first the metrics, then the timestamp, then the value. The
// semantics of value equality is defined by SampleValue.Equal.
func (s *Sample) Equal(o *Sample) bool {
	if s == o {
		return true
	}

	if !s.Metric.Equal(o.Metric) {
		return false
	}
	if !s.Timestamp.Equal(o.Timestamp) {
		return false
	}

	return s.Value.Equal(o.Value)
}

func (s Sample) String() string {
	return fmt.Sprintf("%s => %s", s.Metric, SamplePair{
		Timestamp: s.Timestamp,
		Value:     s.Value,
	})
}

// MarshalJSON implements json.Marshaler.
func (s Sample) MarshalJSON() ([]byte, error) {
	v := struct {
		Metric Metric     `json:"metric"`
		Value  SamplePair `json:"value"`
	}{
		Metric: s.Metric,
		Value: SamplePair{
			Timestamp: s.Timestamp,
			Value:     s.Value,
		},
	}

	return json.Marshal(&v)
}

// UnmarshalJSON implements json.Unmarshaler.
func (s *Sample) UnmarshalJSON(b []byte) error {
	v := struct {
		Metric Metric     `json:"metric"`
		Value  SamplePair `json:"value"`
	}{
		Metric: s.Metric,
		Value: SamplePair{
			Timestamp: s.Timestamp,
			Value:     s.Value,
		},
	}

	if err := json.Unmarshal(b, &v); err != nil {
		return err
	}

	s.Metric = v.Metric
	s.Timestamp = v.Value.Timestamp
	s.Value = v.Value.Value

	return nil
}

// Samples is a sortable Sample slice. It implements sort.Interface.
type Samples []*Sample

func (s Samples) Len() int {
	return len(s)
}

// Less compares first the metrics, then the timestamp.
func (s Samples) Less(i, j int) bool {
	switch {
	case s[i].Metric.Before(s[j].Metric):
		return true
	case s[j].Metric.Before(s[i].Metric):
		return false
	case s[i].Timestamp.Before(s[j].Timestamp):
		return true
	default:
		return false
	}
}

func (s Samples) Swap(i, j int) {
	s[i], s[j] = s[j], s[i]
}

// Equal compares two sets of samples and returns true if they are equal.
func (s Samples) Equal(o Samples) bool {
	if len(s) != len(o) {
		return false
	}

	for i, sample := range s {
		if !sample.Equal(o[i]) {
			return false
		}
	}
	return true
}

// SampleStream is a stream of Values belonging to an attached COWMetric.
type SampleStream struct {
	Metric Metric       `json:"metric"`
	Values []SamplePair `json:"values"`
}

func (ss SampleStream) String() string {
	vals := make([]string, len(ss.Values))
	for i, v := range ss.Values {
		vals[i] = v.String()
	}
	return fmt.Sprintf("%s =>\n%s", ss.Metric, strings.Join(vals, "\n"))
}

// Value is a generic interface for values resulting from a query evaluation.
type Value interface {
	Type() ValueType
	String() string
}

func (Matrix) Type() ValueType  { return ValMatrix }
func (Vector) Type() ValueType  { return ValVector }
func (*Scalar) Type() ValueType { return ValScalar }
func (*String) Type() ValueType { return ValString }

type ValueType int

const (
	ValNone ValueType = iota
	ValScalar
	ValVector
	ValMatrix
	ValString
)

// MarshalJSON implements json.Marshaler.
func (et ValueType) MarshalJSON() ([]byte, error) {
	return json.Marshal(et.String())
}

func (et *ValueType) UnmarshalJSON(b []byte) error {
	var s string
	if err := json.Unmarshal(b, &s); err != nil {
		return err
	}
	switch s {
	case "<ValNone>":
		*et = ValNone
	case "scalar":
		*et = ValScalar
	case "vector":
		*et = ValVector
	case "matrix":
		*et = ValMatrix
	case "string":
		*et = ValString
	default:
		return fmt.Errorf("unknown value type %q", s)
	}
	return nil
}

func (e ValueType) String() string {
	switch e {
	case ValNone:
		return "<ValNone>"
	case ValScalar:
		return "scalar"
	case ValVector:
		return "vector"
	case ValMatrix:
		return "matrix"
	case ValString:
		return "string"
	}
	panic("ValueType.String: unhandled value type")
}

// Scalar is a scalar value evaluated at the set timestamp.
type Scalar struct {
	Value     SampleValue `json:"value"`
	Timestamp Time        `json:"timestamp"`
}

func (s Scalar) String() string {
	return fmt.Sprintf("scalar: %v @[%v]", s.Value, s.Timestamp)
}

// MarshalJSON implements json.Marshaler.
func (s Scalar) MarshalJSON() ([]byte, error) {
	v := strconv.FormatFloat(float64(s.Value), 'f', -1, 64)
	return json.Marshal([...]interface{}{s.Timestamp, string(v)})
}

// UnmarshalJSON implements json.Unmarshaler.
func (s *Scalar) UnmarshalJSON(b []byte) error {
	var f string
	v := [...]interface{}{&s.Timestamp, &f}

	if err := json.Unmarshal(b, &v); err != nil {
		return err
	}

	value, err := strconv.ParseFloat(f, 64)
	if err != nil {
		return fmt.Errorf("error parsing sample value: %s", err)
	}
	s.Value = SampleValue(value)
	return nil
}

// String is a string value evaluated at the set timestamp.
type String struct {
	Value     string `json:"value"`
	Timestamp Time   `json:"timestamp"`
}

func (s *String) String() string {
	return s.Value
}

// MarshalJSON implements json.Marshaler.
func (s String) MarshalJSON() ([]byte, error) {
	return json.Marshal([]interface{}{s.Timestamp, s.Value})
}

// UnmarshalJSON implements json.Unmarshaler.
func (s *String) UnmarshalJSON(b []byte) error {
	v := [...]interface{}{&s.Timestamp, &s.Value}
	return json.Unmarshal(b, &v)
}

// Vector is basically only an alias for Samples, but the
// contract is that in a Vector, all Samples have the same timestamp.
type Vector []*Sample

func (vec Vector) String() string {
	entries := make([]string, len(vec))
	for i, s := range vec {
		entries[i] = s.String()
	}
	return strings.Join(entries, "\n")
}

func (vec Vector) Len() int      { return len(vec) }
func (vec Vector) Swap(i, j int) { vec[i], vec[j] = vec[j], vec[i] }

// Less compares first the metrics, then the timestamp.
func (vec Vector) Less(i, j int) bool {
	switch {
	case vec[i].Metric.Before(vec[j].Metric):
		return true
	case vec[j].Metric.Before(vec[i].Metric):
		return false
	case vec[i].Timestamp.Before(vec[j].Timestamp):
		return true
	default:
		return false
	}
}

// Equal compares two sets of samples and returns true if they are equal.
func (vec Vector) Equal(o Vector) bool {
	if len(vec) != len(o) {
		return false
	}

	for i, sample := range vec {
		if !sample.Equal(o[i]) {
			return false
		}
	}
	return true
}

// Matrix is a list of time series.
type Matrix []*SampleStream

func (m Matrix) Len() int           { return len(m) }
func (m Matrix) Less(i, j int) bool { return m[i].Metric.Before(m[j].Metric) }
func (m Matrix) Swap(i, j int)      { m[i], m[j] = m[j], m[i] }

func (mat Matrix) String() string {
	matCp := make(Matrix, len(mat))
	copy(matCp, mat)
	sort.Sort(matCp)

	strs := make([]string, len(matCp))

	for i, ss := range matCp {
		strs[i] = ss.String()
	}

	return strings.Join(strs, "\n")
}