/
encoder.go
303 lines (259 loc) · 7.15 KB
/
encoder.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
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
package protocol
import (
"fmt"
"io"
"math"
"sort"
"strconv"
"time"
)
// ErrIsNaN is a field error for when a float field is NaN.
var ErrIsNaN = &FieldError{"is NaN"}
// ErrIsInf is a field error for when a float field is Inf.
var ErrIsInf = &FieldError{"is Inf"}
// Encoder marshals Metrics into influxdb line protocol.
// It is not safe for concurrent use, make a new one!
// The default behavior when encountering a field error is to ignore the field and move on.
// If you wish it to error out on field errors, use Encoder.FailOnFieldErr(true)
type Encoder struct {
w io.Writer
fieldSortOrder FieldSortOrder
fieldTypeSupport FieldTypeSupport
failOnFieldError bool
maxLineBytes int
fieldList []*Field
header []byte
footer []byte
pair []byte
precision time.Duration
}
// SetMaxLineBytes sets a maximum length for a line, Encode will error if the generated line is longer
func (e *Encoder) SetMaxLineBytes(i int) {
e.maxLineBytes = i
}
// SetFieldSortOrder sets a sort order for the data.
// The options are:
// NoSortFields (doesn't sort the fields)
// SortFields (sorts the keys in alphabetical order)
func (e *Encoder) SetFieldSortOrder(s FieldSortOrder) {
e.fieldSortOrder = s
}
// SetFieldTypeSupport sets flags for if the encoder supports certain optional field types such as uint64
func (e *Encoder) SetFieldTypeSupport(s FieldTypeSupport) {
e.fieldTypeSupport = s
}
// FailOnFieldErr whether or not to fail on a field error or just move on.
// The default behavior to move on
func (e *Encoder) FailOnFieldErr(s bool) {
e.failOnFieldError = s
}
// SetPrecision sets time precision for writes
// Default is nanoseconds precision
func (e *Encoder) SetPrecision(p time.Duration) {
e.precision = p
}
// NewEncoder gives us an encoder that marshals to a writer in influxdb line protocol
// as defined by:
// https://docs.influxdata.com/influxdb/v1.5/write_protocols/line_protocol_reference/
func NewEncoder(w io.Writer) *Encoder {
return &Encoder{
w: w,
header: make([]byte, 0, 128),
footer: make([]byte, 0, 128),
pair: make([]byte, 0, 128),
fieldList: make([]*Field, 0, 16),
precision: time.Nanosecond,
}
}
// This is here to significantly reduce allocations, wish that we had constant/immutable keyword that applied to
// more complex objects
var comma = []byte(",")
// Encode marshals a Metric to the io.Writer in the Encoder
func (e *Encoder) Encode(m Metric) (int, error) {
err := e.buildHeader(m)
if err != nil {
return 0, err
}
e.buildFooter(m.Time())
// here we make a copy of the *fields so we can do an in-place sort
e.fieldList = append(e.fieldList[:0], m.FieldList()...)
if e.fieldSortOrder == SortFields {
sort.Slice(e.fieldList, func(i, j int) bool {
return e.fieldList[i].Key < e.fieldList[j].Key
})
}
i := 0
totalWritten := 0
pairsLen := 0
firstField := true
for _, field := range e.fieldList {
err = e.buildFieldPair(field.Key, field.Value)
if err != nil {
if e.failOnFieldError {
return 0, err
}
continue
}
bytesNeeded := len(e.header) + pairsLen + len(e.pair) + len(e.footer)
// Additional length needed for field separator `,`
if !firstField {
bytesNeeded++
}
if e.maxLineBytes > 0 && bytesNeeded > e.maxLineBytes {
// Need at least one field per line
if firstField {
return 0, ErrNeedMoreSpace
}
i, err = e.w.Write(e.footer)
if err != nil {
return 0, err
}
pairsLen = 0
totalWritten += i
bytesNeeded = len(e.header) + len(e.pair) + len(e.footer)
if e.maxLineBytes > 0 && bytesNeeded > e.maxLineBytes {
return 0, ErrNeedMoreSpace
}
i, err = e.w.Write(e.header)
if err != nil {
return 0, err
}
totalWritten += i
i, err = e.w.Write(e.pair)
if err != nil {
return 0, err
}
totalWritten += i
pairsLen += len(e.pair)
firstField = false
continue
}
if firstField {
i, err = e.w.Write(e.header)
if err != nil {
return 0, err
}
totalWritten += i
} else {
i, err = e.w.Write(comma)
if err != nil {
return 0, err
}
totalWritten += i
}
i, err = e.w.Write(e.pair)
if err != nil {
return 0, err
}
totalWritten += i
pairsLen += len(e.pair)
firstField = false
}
if firstField {
return 0, ErrNoFields
}
i, err = e.w.Write(e.footer)
if err != nil {
return 0, err
}
totalWritten += i
return totalWritten, nil
}
func (e *Encoder) buildHeader(m Metric) error {
e.header = e.header[:0]
name := nameEscape(m.Name())
if name == "" {
return ErrInvalidName
}
e.header = append(e.header, name...)
for _, tag := range m.TagList() {
key := escape(tag.Key)
value := escape(tag.Value)
// Some keys and values are not encodeable as line protocol, such as
// those with a trailing '\' or empty strings.
if key == "" || value == "" {
continue
}
e.header = append(e.header, ',')
e.header = append(e.header, key...)
e.header = append(e.header, '=')
e.header = append(e.header, value...)
}
e.header = append(e.header, ' ')
return nil
}
func (e *Encoder) buildFieldVal(value interface{}) error {
switch v := value.(type) {
case uint64:
if e.fieldTypeSupport&UintSupport != 0 {
e.pair = append(strconv.AppendUint(e.pair, v, 10), 'u')
} else if v <= uint64(math.MaxInt64) {
e.pair = append(strconv.AppendInt(e.pair, int64(v), 10), 'i')
} else {
e.pair = append(strconv.AppendInt(e.pair, math.MaxInt64, 10), 'i')
}
case int64:
e.pair = append(strconv.AppendInt(e.pair, v, 10), 'i')
case int:
e.pair = append(strconv.AppendInt(e.pair, int64(v), 10), 'i')
case float64:
if math.IsNaN(v) {
return ErrIsNaN
}
if math.IsInf(v, 0) {
return ErrIsInf
}
e.pair = strconv.AppendFloat(e.pair, v, 'f', -1, 64)
case float32:
v32 := float64(v)
if math.IsNaN(v32) {
return ErrIsNaN
}
if math.IsInf(v32, 0) {
return ErrIsInf
}
e.pair = strconv.AppendFloat(e.pair, v32, 'f', -1, 64)
case string:
e.pair = append(e.pair, '"')
e.pair = append(e.pair, stringFieldEscape(v)...)
e.pair = append(e.pair, '"')
case []byte:
e.pair = append(e.pair, '"')
stringFieldEscapeBytes(&e.pair, v)
e.pair = append(e.pair, '"')
case bool:
e.pair = strconv.AppendBool(e.pair, v)
default:
return &FieldError{fmt.Sprintf("invalid value type: %T", v)}
}
return nil
}
func (e *Encoder) buildFieldPair(key string, value interface{}) error {
e.pair = e.pair[:0]
key = escape(key)
// Some keys are not encodeable as line protocol, such as those with a
// trailing '\' or empty strings.
if key == "" || key[:len(key)-1] == "\\" {
return &FieldError{"invalid field key"}
}
e.pair = append(e.pair, key...)
e.pair = append(e.pair, '=')
return e.buildFieldVal(value)
}
func (e *Encoder) buildFooter(t time.Time) {
e.footer = e.footer[:0]
if !t.IsZero() {
e.footer = append(e.footer, ' ')
switch e.precision {
case time.Microsecond:
e.footer = strconv.AppendInt(e.footer, t.UnixNano()/1000, 10)
case time.Millisecond:
e.footer = strconv.AppendInt(e.footer, t.UnixNano()/1000000, 10)
case time.Second:
e.footer = strconv.AppendInt(e.footer, t.Unix(), 10)
default:
e.footer = strconv.AppendInt(e.footer, t.UnixNano(), 10)
}
}
e.footer = append(e.footer, '\n')
}